# China Quantum Communiations Technology: Cryptography, Radar, Satellite, Teleportation, Network



## cirr

Work has begun on the prototype development phase of China's&#65292; and the world's&#65292;first quantum communication satellite&#65306;

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The satellite is due for launch in 2015.

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## cirr

*Data teleportation: The quantum space race*

*Fierce rivals have joined forces in the race to teleport information to and from space.*

Zeeya Merali1 05 December 2012











Two photons are 'entangled' in the lab. Although their individual polarizations are not yet set, the entanglement ensures that any measurement will find both polarizations to be identical &#8212; no matter how widely the particles are separated.





One entangled photon is then beamed from Beijing to Vienna.





The stay-at-home photon is used to pick up information from another photon. The travelling photon is instantly affected by the comparison in China, and acquires information about the interrogated photon.





The photons in China are checked to see whether they match. This process destroys the information held by the interrogated photon. The test in China also destroys the link between the entangled photons.





The result of the test in China is communicated through conventional means. It tells the experimenters in Austria how to put their photon into a state identical to that of the interrogated photon &#8212; which has thus been 'teleported'.


*Three years ago*, Jian-Wei Pan brought a bit of Star Trek to the Great Wall of China. From a site near the base of the wall in the hills north of Beijing, he and his team of physicists from the University of Science and Technology of China (USTC) in Hefei aimed a laser at a detector on a rooftop 16 kilometres away, then used the quantum properties of the laser's photons to 'teleport' information across the intervening space1. At the time, it was a world distance record for quantum teleportation, and a major step towards the team's ultimate aim of teleporting photons to a satellite.

If that goal is achieved, it will establish the first links of a 'quantum Internet' that harnesses the powers of subatomic physics to create a super-secure global communication network. It will confirm China's ascent in the field, from a bit-player a little more than a decade ago to a global powerhouse: in 2016, ahead of Europe and North America, China plans to launch a satellite dedicated to quantum-science experiments. It will offer physicists a new arena in which to test the foundations of quantum theory, and explore how they fit together with the general theory of relativity &#8212; Einstein's very different theory of space, time and gravity.

It will also mark the culmination of Pan's long, yet fiercely competitive, friendship with Anton Zeilinger, a physicist at the University of Vienna. Zeilinger was Pan's PhD adviser, then for seven years his rival in the long-distance quantum-teleportation race, and now his collaborator. Once the satellite launches, the two physicists plan to create the first intercontinental quantum-secured network, connecting Asia to Europe by satellite. &#8220;There's an old Chinese saying, 'He who teaches me for one day is my father for life',&#8221; says Pan. &#8220;In scientific research, Zeilinger and I collaborate equally, but emotionally I always regard him as my respected elder.&#8221;

Fast mover

Pan was only in his early thirties when he set up China's first lab for manipulating the quantum properties of photons in 2001, and when he proposed the satellite mission in 2003. And he was 41 in 2011, when he became the youngest researcher ever to be inducted into the Chinese Academy of Sciences. &#8220;He almost single-handedly pushed this project through and put China on the quantum map,&#8221; says team member Yu-Ao Chen, also at the USTC.

Pan's drive dates back to his undergraduate years at the USTC in the late 1980s, when he first encountered the paradoxes at play in the atomic realm. Quantum objects can exist in a superposition of many states: a particle can spin both clockwise and anticlockwise at the same time, for instance, and it can simultaneously be both here and over there. This multiple personality is described mathematically by the particle's wavefunction, which gives the probability that it is in each of those states. Only when the particle's properties are measured does the wavefunction collapse, choosing a definite state in a single location. Crucially, there is no way, even in principle, to predict the result of a single experiment; the probabilities show up only as a statistical distribution and only when the experiment is repeated many times.

Things get even weirder when two or more particles are involved, thanks to the quantum property of entanglement. Multiple particles can be prepared in such a way that measurements on one are correlated with measurements made on the others, even if the particles are separated by huge distances &#8212; and even though the phenomenon of superposition demands that these properties cannot be fixed until the instant they are probed. It is as strange as a physicist in Beijing and another in Vienna flipping coins in unison, and finding that they always either both throw heads or both throw tails. &#8220;I was obsessed with these quantum paradoxes,&#8221; says Pan. &#8220;They distracted me so much that I couldn't even study other things.&#8221; He wanted to test the veracity of these almost inconceivable claims, but he could not find a suitable experimental quantum physics lab in China.

The natural progression for budding Chinese physicists in Pan's position was to study in the United States &#8212; so natural, in fact, that fellow students joked that their university's acronym, USTC, actually stood for 'United States Training Centre'. But Pan wanted to learn from a quantum experimental master. And for him, one physicist stood out: Zeilinger.

In 1989, Zeilinger had collaborated with physicists Daniel Greenberger, now at the City University of New York, and Michael Horne, now at Stonehill College in Easton, Massachusetts, on a key theorem governing the entanglement of three or more particles2. The work was a turning point for the field &#8212; and for Zeilinger. &#8220;At conferences, I realized that very important older physicists had started to regard me as the quantum expert,&#8221; he says. By the mid-1990s, Zeilinger had set up his own quantum lab at the University of Innsbruck in Austria and needed a student to test some of his ideas. Pan seemed the perfect fit. So, in a rare move for a Chinese student, Pan relocated to Austria, beginning a relationship with Zeilinger that would see their careers develop in tandem over the next two decades.

Even as a graduate student, Pan had big ambitions for his home country. At their first meeting, Zeilinger asked Pan what his dream was. &#8220;To build in China a world-leading lab like yours,&#8221; Pan replied. Zeilinger was impressed. &#8220;When he first came, he knew nothing about working in a lab, but he quickly picked up the rules of the game and was soon inventing his own experiments,&#8221; he says. &#8220;I always knew he would have a wonderful career &#8212; but the incredible success that he has had, I don't think anyone could have foreseen. I am very proud of him.&#8221;

While Pan was mastering his craft in Zeilinger's lab, physicists around the world were slowly embracing the notion that the esoteric quantum features that so enchanted Pan could be harnessed to create, say, ultra-powerful quantum computers. Standard computers chug slowly through information coded in binary digits &#8212; strings of zeros and ones. But as early as 1981, the physicist Richard Feynman had pointed out that quantum bits, known as 'qubits', need not be so encumbered. Because a qubit can simultaneously exist in superpositions of 0 and 1, it should be possible to build faster, more powerful quantum computers that would entangle multiple qubits together and perform certain calculations in parallel, and at breathtaking speed.

Another emerging idea was ultra-secure quantum encryption for applications such as bank transactions. The key idea is that measuring a quantum system irrevocably disrupts it. So two people, Alice and Bob, could generate and share a quantum key, safe in the knowledge that any meddling by an eavesdropper would leave a trace.

By the time Pan returned to China in 2001, the potential for quantum-based technologies was recognized enough to attract financial support from the Chinese Academy of Sciences and the National Natural Science Foundation of China. &#8220;The lucky thing was that in 2000 the economy of China started to grow, so the timing was suddenly right to do good science,&#8221; Pan says. He plunged into building his dream lab.

Back in Austria, meanwhile, Zeilinger had moved to the University of Vienna, where he continued to set quantum records thanks to his penchant for thinking big. One of his most celebrated experiments showed that buckyballs, fullerene molecules containing 60 carbon atoms, can exhibit both wave and particle behaviour3 &#8212; a peculiar quantum effect that many thought could not survive in such large molecules. &#8220;Everyone had been talking about maybe trying this experiment with small, diatomic molecules,&#8221; recalls Zeilinger. &#8220;I said, 'no guys, don't just think of the next one or two steps ahead, think about how to make a huge unexpected leap beyond everyone's thinking'.&#8221;

That was a lesson that Pan heeded well. Physicists around the world were beginning to imagine the futuristic quantum Internet, based on links between quantum computers that had yet to be built. At a time when most practitioners were still happy to get quantum information safely across a lab bench, Pan was already starting to think about how to teleport it across the planet.





Jian-Wei Pan is working on ways to teleport photons between Earth and space.


First proposed in 1993 by computer scientist Charles Bennett of IBM in New York and his colleagues4, quantum teleportation earned its sensational name because, &#8220;like something out of Star Trek&#8221;, says Chen, it allows all information about a quantum object to be scanned in one location and then recreated in a new place. The key is entanglement (see 'Quantum at a distance slideshow'): because operations carried out on one of the entangled particles affect the state of its partner, no matter how far away it is, the two objects can be manipulated to act like two ends of a quantum telephone line, transmitting quantum information between two widely separated locations.

The challenge arises when entangled particles, which must be produced together, are transmitted to their respective ends of the phone connection. Such a journey is fraught with noise, scattering interactions and all manner of other disruptions, any of which can destroy the delicate quantum correlations required to make teleportation work. Currently, for example, entangled photons are transported through optical fibres. But fibres absorb light, which keeps the photons from travelling more than a few hundred kilometres. Standard amplifiers can't help, because the amplification process will destroy the quantum information. &#8220;For teleporting to distances beyond the range of a city, we need to teleport through a satellite,&#8221; says Chen.

But would entanglement survive the upward trip through Earth's turbulent atmosphere to a satellite hundreds of kilometres overhead? To find out, Pan's team, including Chen, began in 2005 to carry out ground-based feasibility tests across ever-increasing expanses of clear air to find out whether photons lose their entanglement when they bump into air molecules. But they also needed to build a target detector that was both small enough to fit on a satellite and sensitive enough to pick out the teleported photons from background light. And then they had to show that they could focus their photon beam tightly enough to hit the detector.

The work aroused Zeilinger's competitive instincts. &#8220;The Chinese were doing it, so we thought, why not try it?&#8221; he says with a laugh. &#8220;Some friendly competition is always good.&#8221; The race began to push the distance record farther and farther (see 'Duelling records'). Over the next seven years, through a series of experiments carried out in Hefei, then by the Great Wall in Beijing and finally in Qinghai, the Chinese team teleported over ever-greater distances, until it passed 97 kilometres5. The researchers announced their results in May, posting a paper on the physics preprint server, arXiv &#8212; much to the chagrin of the Austrian team, which was writing up the results of its own effort to teleport photons between two of the Canary Islands. The Austrian group posted its paper on arXiv eight days later, reporting a new distance record of 143 kilometres6. The papers were eventually published, in quick succession, in Nature5, 6. &#8220;I think that was in recognition of the fact that each experiment has different and complementary merits,&#8221; says Xiao-song Ma, a physicist at the University of Vienna and a member of the Austrian team.






Both teams agree that any scientific concerns about teleporting to a satellite have been defused. Now they just need a satellite to host the tests and a functioning payload to put on board. Zeilinger's team had been discussing a possible quantum satellite mission with the European Space Agency (ESA), but those talks gradually fizzled out. &#8220;Its mechanisms are so slow that no decision was made,&#8221; says Zeilinger. ESA's hesitation opened up a gap for the China National Space Administration to swoop in. Pan has been instrumental in pushing through the mission, which should see a quantum-physics satellite launched in 2016. This places Pan ahead in the quantum space race, and his team will handle the bulk of the scientific tests.

Key to success

But there is no point in developing the first global quantum communication network if you do not have anybody to talk with. So Pan has invited his one-time rival to join him on the project. Their first joint goal will be to generate and share a secure quantum key between Beijing and Vienna. &#8220;Ultimately, teleporting to a satellite is too big a task for any single group to do alone,&#8221; says Ma.

Although the promise to push forward the technological frontier has been the main attraction for the Chinese government, many physicists find the satellite project tantalizing for other reasons. &#8220;As a scientist, what drives me is learning more about the foundational side of physics,&#8221; says Chen. So far, quantum theory's weirdness has been replicated time and again in labs, but it has never before been tested across distances that stretch into space &#8212; and there is reason to think that if it is going to break down anywhere, it will be there. At these larger scales, another fundamental theory of physics holds sway: general relativity. Relativity portrays time as another dimension interwoven with the three dimensions of space, thereby creating a four-dimensional space-time fabric that comprises the Universe. Gravity manifests because this malleable fabric bends around massive objects such as the Sun and it pulls less-massive objects, such as planets, towards them.

The challenge is that quantum theory and general relativity present fundamentally different conceptions of space and time, and physicists have struggled to meld them into one unifying framework of quantum gravity. In Einstein's picture, space-time is perfectly smooth, even when examined at infinitesimal scales. Quantum uncertainty, however, implies that it is impossible to examine space at such small distances. Somewhere along the line either quantum theory or general relativity, if not both, must give way, but it is not yet clear which. The satellite experiments could help by testing whether the rules of quantum theory still apply over scales across which gravity's pull cannot be ignored.

An obvious question is whether entanglement can stretch between Earth and a satellite. The team plans to answer it by producing a series of entangled particles on the satellite, firing one of each pair down to a ground station and then measuring its properties to verify that the pairs are correlated &#8212; and that the equipment is working properly. &#8220;If entanglement doesn't survive we'd have to look for an alternative theory to quantum mechanics,&#8221; says Nicolas Brunner, a theoretical physicist at the University of Geneva, Switzerland, who works on protocols for teleportation to a satellite.

The satellite could also go a step further and probe some of the predictions about the structure of space-time made by candidate quantum-gravity theories. For instance, all such theories predict that space-time would become grainy if scientists could somehow see it at scales of 10&#8722;35 metres, a characteristic distance known as the Planck length. If that is indeed the case, then photons travelling from the satellite along this grainy road would be very slightly slowed7 and their polarizations would undergo a tiny, random rotation8 &#8212; effects that could be large enough to be picked up at the ground station. &#8220;A satellite will open a truly novel window into a regime that experimenters haven't had access to before &#8212; and that is fantastic,&#8221; says Giovanni Amelino-Camelia, a physicist at the Sapienza University of Rome, Italy.

Pan, Zeilinger and their teams are currently scrutinizing the ideas generated in a recent series of workshops at the Perimeter Institute for Theoretical Physics in Waterloo, Canada, where physicists were asked to come up with other foundational questions that could be tested by satellites9. The questions that arose included: how does an entangled particle always know the result of a measurement made on its far-distant partner? Do the pairs somehow communicate though some still-unknown information channel? What causes the quantum wavefunction to collapse when it is measured? Is gravity somehow involved? And is time a precisely defined quantity, as described in general relativity &#8212; or is it fuzzy, as might be expected from quantum mechanics?

Answering such questions will require apparatus of extraordinary sensitivity, says Pan. But meeting the technical challenges they raise will be easier now that the teams have joined forces, he says. The Austrian group, too, is seizing the new collaboration with enthusiasm. As Zeilinger says, &#8220;One of my students has just started learning Chinese.&#8221;

http://www.nature.com/news/data-teleportation-the-quantum-space-race-1.11958

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## selvan33

congrats china.


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## cirr

By Nerea Rial | June 11, 2013






China might become the first space-faring nation with quantum communication capability, as it has announced plans to launch its Chinese Quantum Science Satellite" in 2016, *MIT Technology Review* reported.

Today, thanks to quantum cryptography, secure messages can be sent from one location on the planet to another. However, this is just possible over distances of 100 kilometres or so, through optical fibre or the atmosphere.

Back in 2012, Chinese physicists tried to set up a new record, but finally were the Europeans the ones that were able to send information through a quantum channel over 150 kilometres through the atmosphere.

Now, Chinese made a new step. Jian-Wei Pan at the *University of Science and Technology of China in Shanghai*(Why foreign reporters keep thinking that the USTC is in Shanghai is really beyond me!!!!!!!!) and his colleagues bounced single photons off an orbiting satellite and detected them back on our planet.

Chinese scientists achieved this by pointed at a satellite orbiting at an altitude of 400 km with two telescopes in a binocular formation. The satellite is covered with reflectors which bounce signals from Earth back from their original location.

Pan and his team say that they were able to detect the returning photons at a rate of about 600 per second. "These results are suf&#64257;cient to set up an unconditionally secure QKD link between satellite and earth, technically," they explained.

*Despite the team made the discovery in 2010, they decided to publish their paper now to also announce the launch of the Chinese Quantum Science Satellite, the first quantum science experiment into space, in three years.*

Pan and his colleagues aim to establish a quantum communication network between Beijing and Vienna, meaning that Europe, which is also planning to send these kind of communications to the International Space Station, might have to cooperate with its rivals.

China reveals first space-based quantum communications project | New Europe

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## Fsjal

What is the difference between basic comm and quantum comm?

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## Developereo

http://www.defence.pk/forums/chinese-defence/257563-china-surpasses-west-quantum-space-race.html

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## cirr

Basically Pan Jianwei and Team did it back in 2010 kept their &#8220;secret&#8221; for 3 long years&#12290;

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## MeshFree

If the quantum communication is intercepted, the information contained will be destroyed automatically. Meanwhile, communicators know that this communication is intercepted.

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## cirr

In the meantime&#65292;a project that will end up with a quantum communication network between Beijing and Shanghai is under way&#65306;

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It is expected to be brought into operation in 2-3 years&#12290;

It will be the world's 1st&#12290;

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## cirr

*Revelation that secret communications system was used at the party congress last autumn shows high level of security concern in Beijing*

Friday, 21 June, 2013, 5:37am

Stephen Chen





Secret quantum communications system was used at Party Congress in Beijing

Beijing was so worried about cyberspies during last autumn's party congress that it turned to a secret, state-of-the-art telecommunications network to handle sensitive information.

Use of the next-generation quantum encryption technology at the once-in-a-decade leadership transition was revealed in a passing remark reported last week in People's Daily.

Chinese scientists are well aware of how vulnerable data can be when it is being transmitted, describing it as the weakest link in their security.

Revelations by whistle-blower Edward Snowden that the US is targeting "network backbones" - through which huge amounts of data are transmitted - confirmed their fears.

Now all major countries are pouring resources into developing large-scale quantum networks. China came late into the game, but it is now the subject of a major national project.

And Beijing plans to launch the world's first quantum communications satellite in 2016, a top mainland researcher told the South China Morning Post.

In quantum mechanics, connections are made between two points when photons of light become entangled. This creates an encryption key that can be used to send the message through normal channels.

But if somebody tries to spy on that quantum communication, the connection is so fragile it disrupts the entanglement - letting both the sender and the receiver of the message know someone is snooping.

For years, Beijing has prohibited key government institutes and agencies from handling sensitive information by connection to the global internet. The enclosed systems include the China Golden Bridge Network, used by government institutes, and several military backbone networks.

They run on homegrown operating systems and on computers with core chips designed and developed by Chinese companies. Data is heavily encrypted to ensure security.

But even such measures may not go far enough. Data can be intercepted during transmission, while even the best encryption can be deciphered by talented mathematicians equipped with supercomputers.

Scientists involved in the quantum programme believe Snowden's revelations will "definitely speed up" China's move to quantum communications.

Even before the Snowden incident, Beijing leaders had used prototype quantum networks on critical occasions.

The latest example was during the party congress last year, which saw Xi Jinping succeed Hu Jintao as party chief. In the days leading up to the congress, intense horse-trading and negotiations among political leaders required an absolutely safe channel for communication.

But scientists still have one serious hurdle to overcome before they can apply the technology on a larger scale.

Professor Bao Xiaohui , a quantum information expert with the National Laboratory for Physical Sciences at the Microscale in Hefei , said most quantum communications networks in use today can operate over a maximum distance of only about 50 kilometres.

Bao's laboratory is leading the research of quantum communications on the mainland and now holds several records for the distance covered.

In traditional telecommunications, digital information is carried by electrons or photons in waves that can be amplified to achieve long-distance communication. But in quantum communication, the information is carried in the quantum state of each photon. The quantum state cannot be amplified once the photon has left the sender - much as a bullet cannot be given more spin after it has left the barrel of a gun.

After a certain distance, the quantum state might weaken or disappear. While existing fibre-optic cable networks are ideal for conventional, "wave-like" communications, they are inefficient for carrying individual photons over long distances.

To overcome this limitation, scientists have come up with the idea of quantum repeater. When a photon reaches the repeater it activates some sleeping atoms.

In a delicate operation, scientists can force these atoms back to sleep and in the process emit a new photon carrying the same quantum state.

But the operation is very difficult, Bao says. The energised atoms are quite unstable and can easily be affected by external elements such as the earth's magnetic field and lose their quantum state.

To achieve long-distance quantum communication, Bao's team is building what is expected to be the world's first quantum communications satellite.

Because photons can travel long distances in the open, especially in space, they could carry the quantum information between two locations thousands of kilometres apart with uplink and downlink to the satellite.

Detailed information on the satellite is classified, but Bao says it will look completely different from communications satellites today that rely on microwaves.

"It will not have a dish antenna to pick up or beam the signal because the communication would be purely optical," he said. "It will use a lot of mirrors, for sure. To some extent it may look like the Hubble Space Telescope - the difference is that its eyes would be pointing at the earth instead of the far universe."

Bao says the quantum satellite's signals cannot be intercepted. Unlike radio waves that would propagate as they travelled, the photons would aim precisely at a specific receiving station. Any attempted interception would be detected.

But it is difficult to judge when quantum communication will become available for use by ordinary people.

Existing encryption and protection methods are still good enough for the public, Bao says.

Tang Wei , cybersecurity engineer with mainland anti-virus company Rising, says that security technology, no matter how advanced it is, can only be as good as the person handling it.

"No technology is absolutely safe because all technology is used by humans," he said.

"With an insider, you can get into the most heavily guarded system without even touching a keyboard."

Quantum communications system was used at Party Congress in Beijing | South China Morning Post

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## cirr

The above ties in with the following Chinese report about *coming into service* of a quantum communication network between Beijing and Shanghai in the next 2-3 years&#65306;

http://news.ifeng.com/mil/4/detail_2013_06/14/26395900_0.shtml

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## Lightningbolt

Brazil should invest in Quantum Communication technology so that they can escape from Yankee tyranny.

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## tranquilium

Fsjal said:


> What is the difference between basic comm and quantum comm?



Quantum communication is faster and has significantly less signal degradation. On military application, it is also impossible to intercept.

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## applesauce

tranquilium said:


> Quantum communication is faster and has significantly less signal degradation. On military application, it is also impossible to intercept.



its not actually faster, at least right now, in fact right now its pretty slow compared to what we can do with regular communication technologies(keep in mind this is a relatively new field). the point of quantum communications is that it is secure, so long its done right, it is guaranteed by the laws of physics to be 100% secure against an enemy trying to snoop on your data, thus has obviously applications for everything from the military, to banking, to personal messages.


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## cirr

*Quantum communications leap out of the lab*

*China begins work on super-secure network as ‘real-world’ trial successfully sends quantum keys and data.*

Jane Qiu

23 April 2014

Cybersecurity is a step closer to the dream of sending data securely over long distances using quantum physics — spurred by two developments.

*This week, China will start installing the world’s longest quantum-communications network, which includes a 2,000-kilometre link between Beijing and Shanghai.* And a study jointly announced this week by the companies Toshiba, BT and ADVA, with the UK National Physical Laboratory in Teddington, reports “encouraging” results from a network field trial, suggesting that quantum communications could be feasible on existing fibre-optic infrastructure.

Conventional data-encryption systems rely on the exchange of a secret ‘key’ — in binary 0s and 1s — to encrypt and decrypt information. But the security of such a communication channel can be undermined if a hacker ‘eavesdrops’ on this key during transmission. Quantum communications use a technology called quantum key distribution (QKD), which harnesses the subatomic properties of photons to “remove this weakest link of the current system”, says Grégoire Ribordy, co-founder and chief executive of ID Quantique, a quantum-cryptography company in Geneva, Switzerland.

The method allows a user to send a pulse of photons that are placed in specific quantum states that characterize the cryptographic key. If anyone tries to intercept the key, the act of eavesdropping intrinsically alters its quantum state — alerting users to a security breach. Both the US$100-million Chinese initiative and the system tested in the latest study use QKD.

*The Chinese network “will not only provide the highest level of protection for government and financial data, but provide a test bed for quantum theories and new technologies”, says Jian-Wei Pan, a quantum physicist at the University of Science and Technology of China in Hefei, who is leading the Chinese project.*

*Pan hopes to test such ideas using the network, along with a quantum satellite that his team plans to launch next year *(see _Nature _*492,* 22–25; 2012). Together, he says, the technologies could perform further tests of fundamental quantum theories over large scales (around 2,000 kilometres), such as quantum non-locality, in which changing the quantum state of one particle can influence the state of another even if they are far apart, says Pan.

Sending single photons over long distances is one of the greatest problems in QKD because they tend to get absorbed by optical fibres, making the keys tricky to detect on the receiver’s end.

This is “a big challenge for conventional detectors”, says Hoi-Kwong Lo, a quantum physicist at the University of Toronto in Canada. But technological breakthroughs in recent years have significantly reduced the noise level of detectors while increasing their efficiency in detecting photons from just 15% to 50%.

Vast improvements have also been made in the rate at which detectors can ‘count’ photon pulses — crucial in determining the rate at which quantum keys can be sent, and thus the speed of the network. Counting rates have been raised 1,000-fold, to about 2 gigahertz, says Lo.

The breakthroughs are pushing the distance over which quantum signals can be sent. Trials using ‘dark fibres’ — optical fibres laid down by telecommunications companies but lying unused — have sent quantum signals up to 100 kilometres, says Don Hayford, a researcher at Battelle, a technology-development company headquartered in Columbus, Ohio.

To go farther than that, quantum signals must be relayed at ‘node points’ — the quantum networks between Beijing and Shanghai, for instance, will require 32 nodes. To transmit photons over longer distances without the use of nodes would require a satellite.

China is not alone in its quantum-communication efforts. A team led by Hayford, together with ID Quantique, has started installing a 650-kilometre link between Battelle’s headquarters and its offices in Washington DC. The partnership is also planning a network linking major US cities, which could exceed 10,000 kilometres, says Hayford, although it has yet to secure funding for that.

*The Chinese and US networks will both use dark fibres to send quantum keys. But these fibres “are not always available and can be prohibitively expensive”*, says Andrew Shields, a quantum physicist at Toshiba Research Europe in Cambridge, UK. One way to sidestep the problem is to piggyback the photon streams onto the ‘lit’ fibres that transmit conventional telecommunications data. However, those conventional data streams are usually about a million times stronger than quantum streams, so the quantum data tend to be drowned out.

“The breakthroughs are pushing the distance over which quantum signals can be sent.”

In the results announced this week, Shields and his colleagues were successful in achieving the stable and secure transmission of QKDs along a live lit fibre between two stations of the UK telecommunications company BT, 26 kilometres apart. The quantum keys were sent over several weeks at a high rate alongside four channels of strong conventional data on the same fibre.

The research builds on previous work in which Shields and his team developed a technique to detect quantum signals sent alongside noisy data in a 90-kilometre fibre, but in controlled laboratory conditions (K. A. Patel _et al. Phys. Rev. X_ *2, *041010; 2012).

“Implementing QKD in the ‘real world’ is much more challenging than in the controlled environment of the lab, due to environmental fluctuations and greater loss in the fibre,” says Shields.

The quantum keys in the latest study were sent alongside conventional data travelling at 40 gigabits per second. “As far as I am aware, this is the highest bandwidth of data that has been multiplexed with QKD to date,” add Shields.

He calculates that it would be possible to send QKD signals alongside 40 conventional data channels. Optical fibres usually carry between 40 and 160 telecommunications channels, meaning that quantum communication could be carried out with existing infrastructure.

“I find it an impressive piece of work that demonstrates the multiplexing of strong classical signals with quantum signals in the same fibre for the first time” in a field trial, says Lo. Removing the need for dark fibres, he says, is an important step in showing that QKD has the potential to be used in “real life”.

Quantum communications leap out of the lab : Nature News & Comment

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## indiatester

QKD is more relevant in an industrial control sort of scenario(remember Iran and the Siemens centrifuges) rather than securing communications over larger distances. The cases for security over larger distances are few. More over with the available encryption technology and reasonable tech savvy person can ensure secure communication.


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## cirr

*China to launch the world's first quantum communication satellite in 2016

China to build global quantum communication network in 2030
*
Editor: _zhangyerong _丨Xinhua

11-03-2014 09:15 BJT

HEFEI, Nov. 2 (Xinhua) -- China will build a global quantum communication network by 2030, said a leading Chinese quantum physicist on Sunday.

"*China's quantum information science and technology is developing very fast and China leads in some areas in this field*," said *Pan Jianwei*, a Chinese quantum scientist and professor at the University of Science and Technology of China.

The field of quantum communication, the science of transmitting quantum states from one place to another, grabbed global attention in recent years after the discovery of quantum cryptography, which is described as a way of creating "unbreakable" messages.

*China will achieve Asia-Europe intercontinental quantum key distribution in 2020 and build a global quantum communication network in 2030*, said Pan at the 2014 International Conference on Quantum Communication, Measurement and Computing,which opened Sunday in east China's Hefei city.

*In 2011, China initiated a program to launch a satellite for quantum information and technology experiments in 2016*, according to the Chinese Academy of Sciences.

*The program is going smoothly and major technological breakthroughs have been achieved*, according to Pan, who won the International Quantum Communication Award in 2012.

"*The technology of metropolitan quantum communication is basically mature, but if we want to achieve worldwide communication, we need the help of satellites*," he said.

This is the first time that China hosts the world's most influential biannual quantum conference, which will last until Thursday.

More than 400 experts from 28 countries and regions will discuss research, achievements and industrialization in the quantum information field during the meeting.

China to build global quantum communication network in 2030 - CCTV News - CCTV.com English

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## Kyusuibu Honbu

Congratulations!

This can significantly hamper SIGNIT capabilities of nations attempting spying on China


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## cirr

*Tests of China's first low-earth orbit comsat complete*


Staff Reporter
2014-10-28
16:30 (GMT+8)
*The Ling Qiao*, China's first low-earth-orbit communications satellite (comsat), designed by Beijing's Tsinghua University and Xinwei Telecom Enterprise Group, has completed its orbit test, marking a breakthrough for China, reports the website of China's Global Times.

Weighing 130 kilograms, the satellite runs at a Sun-synchronous orbit with an altitude of about 800 kilometers, covering an area 2,400 km in diameter. China launched the satellite with the Long March 2A rocket from the Jiuquan Satellite Launch Center Sept. 4, starting an in-orbit test communications task between mobile phones and hand-held GPS devices.

Two hundred and eight spacecraft were successfully launched in 2013 worldwide, exceeding the record high of 173 during the 1990s, due to the launch of a remarkably large amount of small satellites. Small satellites below 500 kg account for 63% of total spacecraft, and among them 44% weigh less than 10 kg.

Compared to big satellites, the functions of small satellites are limited when taken in isolation, but when several small satellites are deployed in multiple orbits, in what are called constellation networks, they provide greater resolution, an increase in coverage and decrease signal diminishing. The US recently updated their Iridium satellite constellation which was developed during the 1990s.

There was no effective or low-cost way for telecommunications technology to cover more than 80% of China's land mass and 95% of its claimed ocean territory until the development of the Ling Qiao satellite. It will provide an affordable mobile telecom service for fishermen and forestry workers, according to the project manager.

*It is possible that the satellite will be used for rescue work during natural disasters if the time between launch and operation can be reduced. The satellite could also enhance the positioning ability of Beidou, the Chinese satellite navigation system. It may also have military applications, according to the website.*

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## cirr

*Secure quantum communications go the distance*

Nov 13, 2014

Lockdown: quantum cryptography works across 200 km

*A quantum protocol designed to prevent hackers from stealing secret keys has been implemented across a 200 km fibre-optic link – which is four times further than previous incarnations of the scheme*. *This latest implementation of the "measurement-device-independent quantum-key distribution" (MDIQKD) protocol can also transmit keys more than 500 times faster than previous set-ups.*

Quantum cryptography involves two people – Alice and Bob – sharing a secret key that they can use to encode and decode messages. The key is encoded into a string of quantum particles, such as polarized photons, so that any eavesdropper – Eve – attempting to copy the key as it passes from Alice to Bob reveals her presence by virtue of the laws of quantum mechanics – which dictate that the act of measuring affects the system being measured.

While this quantum-key distribution (QKD) is completely secure in principle, imperfections in the equipment used to implement it make QKD vulnerable to hackers. In 2011, for example, physicists in Norway and Singapore showed that the single-photon detector used by Bob can be "blinded" with bright light so that it works as a classical rather than a quantum device. This allows Eve to intercept keys without Bob or Alice noticing.

*Bad patches*

While commercial QKD systems are now resilient to blinding – and all other weaknesses identified to date – this has involved a number of "patches", which leave the systems vulnerable to future, unknown attacks. In the latest work, a group from the University of Science and Technology of China in Hefei led by Jian-Wei Pan and Qiang Zhang has demonstrated a QKD protocol that aims for immunity against both known and unknown threats, by taking the detector out of Bob's hands.

Rather than Alice sending photons to Bob, both send streams of photons to an untrusted third party – who could even be Eve – to carry out a public measurement. Alice and Bob prepare their photons so that they are randomly polarized in one of four possible states – horizontally, vertically, or along one of two opposing diagonals – and Eve then measures the interference from each pair of incoming particles. If she hears a click she knows that Alice's photon is anti-correlated with Bob's, but she cannot know what specific states those photons are in, whereas the two senders can work out the state of their partner's photon simply by knowing the state of their own. Alice and Bob then publically compare a fraction of their bit strings to see how many errors Eve has made – if she has made too many they know that she has been lying.

*Splices and interconnectors*

The MDIQKD protocol was proposed by Hoi-Kwong Lo of the University of Toronto and colleagues in 2012, and has since been demonstrated by several groups including Lo's and Pan's. However, these previous tests involved low transmission rates – up to 0.1 bit/s – and were carried out across just a few tens of kilometres.

Now, Pan and colleagues have upped the bit rate by more than a factor of 500 along a lab-based spooled fibre-optic cable some 200 km long. They also field-tested using a 30 km underground cable-television fibre in Hefei. This only managed 17 bit/s because of losses at cable splices and interconnectors.

To get to higher bit rates, Pan's group increased the pulse rate of the two transmitting lasers. This was a major challenge because pulses from the two devices must remain indistinguishable, having the same pulse shape and frequency spectrum as well as arriving simultaneously. The group also increased the efficiency of its single-photon detector.

*Not all is lost for hackers* 
Vadim Makarov, University of Waterloo

One of the members of the Singapore/Norway hacking group,Vadim Makarov, now at the University of Waterloo in Canada, believes that *the latest demonstration represents an "important technological step" in the development of quantum cryptography*. But he says that "*not all is lost for hackers*", arguing that while eavesdroppers have been "defeated at the photon detector", they might still be able to exploit loopholes "lurking in the photon source".

Zhang agrees, explaining that complete security could be achieved by having Eve send pairs of entangled photons along a lossless channel to perfectly functioning detectors operated by Alice and Bob. However, he says, such high-performance devices would be very difficult to make, and argues that, in any case, photon detectors are far more vulnerable to attack than the sources are, because they must receive whatever a potential eavesdropper can throw at them. "Our scheme is less beautiful than the theoretically perfect one," he says, "but it is more practical."

*Lower-cost option*

Commercializing the scheme will involve further increasing the laser repetition rate and the detector efficiency. But Zhang argues that once a high-enough bit rate has been achieved, MDIQKD should prove ideal for building quantum networks. One important cost benefit of the scheme is that a network would only need one single-photon detector. This is the most expensive component in a QKD system, and existing commercial systems require one detector per receiving Bob.

For Makarov, however, it remains to be seen whether industry adopts the scheme. "It requires more sophisticated parts and finer engineering than today's commercial products," he says.

The research is published in _Physical Review Letters_.

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## Bussard Ramjet

*Data teleportation: The quantum space race*
Fierce rivals have joined forces in the race to teleport information to and from space.


Zeeya Merali
05 December 2012

Three years ago, Jian-Wei Pan brought a bit of _Star Trek_ to the Great Wall of China. From a site near the base of the wall in the hills north of Beijing, he and his team of physicists from the University of Science and Technology of China (USTC) in Hefei aimed a laser at a detector on a rooftop 16 kilometres away, then used the quantum properties of the laser's photons to 'teleport' information across the intervening space1. At the time, it was a world distance record for quantum teleportation, and a major step towards the team's ultimate aim of teleporting photons to a satellite.

If that goal is achieved, it will establish the first links of a 'quantum Internet' that harnesses the powers of subatomic physics to create a super-secure global communication network. It will confirm China's ascent in the field, from a bit-player a little more than a decade ago to a global powerhouse: in 2016, ahead of Europe and North America, China plans to launch a satellite dedicated to quantum-science experiments. It will offer physicists a new arena in which to test the foundations of quantum theory, and explore how they fit together with the general theory of relativity — Einstein's very different theory of space, time and gravity.

It will also mark the culmination of Pan's long, yet fiercely competitive, friendship with Anton Zeilinger, a physicist at the University of Vienna. Zeilinger was Pan's PhD adviser, then for seven years his rival in the long-distance quantum-teleportation race, and now his collaborator. Once the satellite launches, the two physicists plan to create the first intercontinental quantum-secured network, connecting Asia to Europe by satellite. “There's an old Chinese saying, 'He who teaches me for one day is my father for life',” says Pan. “In scientific research, Zeilinger and I collaborate equally, but emotionally I always regard him as my respected elder.”

*Fast mover*
Pan was only in his early thirties when he set up China's first lab for manipulating the quantum properties of photons in 2001, and when he proposed the satellite mission in 2003. And he was 41 in 2011, when he became the youngest researcher ever to be inducted into the Chinese Academy of Sciences. “He almost single-handedly pushed this project through and put China on the quantum map,” says team member Yu-Ao Chen, also at the USTC.

Pan's drive dates back to his undergraduate years at the USTC in the late 1980s, when he first encountered the paradoxes at play in the atomic realm. Quantum objects can exist in a superposition of many states: a particle can spin both clockwise and anticlockwise at the same time, for instance, and it can simultaneously be both here and over there. This multiple personality is described mathematically by the particle's wavefunction, which gives the probability that it is in each of those states. Only when the particle's properties are measured does the wavefunction collapse, choosing a definite state in a single location. Crucially, there is no way, even in principle, to predict the result of a single experiment; the probabilities show up only as a statistical distribution and only when the experiment is repeated many times.

Things get even weirder when two or more particles are involved, thanks to the quantum property of entanglement. Multiple particles can be prepared in such a way that measurements on one are correlated with measurements made on the others, even if the particles are separated by huge distances — and even though the phenomenon of superposition demands that these properties cannot be fixed until the instant they are probed. It is as strange as a physicist in Beijing and another in Vienna flipping coins in unison, and finding that they always either both throw heads or both throw tails. “I was obsessed with these quantum paradoxes,” says Pan. “They distracted me so much that I couldn't even study other things.” He wanted to test the veracity of these almost inconceivable claims, but he could not find a suitable experimental quantum physics lab in China.

The natural progression for budding Chinese physicists in Pan's position was to study in the United States — so natural, in fact, that fellow students joked that their university's acronym, USTC, actually stood for 'United States Training Centre'. But Pan wanted to learn from a quantum experimental master. And for him, one physicist stood out: Zeilinger.

In 1989, Zeilinger had collaborated with physicists Daniel Greenberger, now at the City University of New York, and Michael Horne, now at Stonehill College in Easton, Massachusetts, on a key theorem governing the entanglement of three or more particles2. The work was a turning point for the field — and for Zeilinger. “At conferences, I realized that very important older physicists had started to regard me as the quantum expert,” he says. By the mid-1990s, Zeilinger had set up his own quantum lab at the University of Innsbruck in Austria and needed a student to test some of his ideas. Pan seemed the perfect fit. So, in a rare move for a Chinese student, Pan relocated to Austria, beginning a relationship with Zeilinger that would see their careers develop in tandem over the next two decades.

Even as a graduate student, Pan had big ambitions for his home country. At their first meeting, Zeilinger asked Pan what his dream was. “To build in China a world-leading lab like yours,” Pan replied. Zeilinger was impressed. “When he first came, he knew nothing about working in a lab, but he quickly picked up the rules of the game and was soon inventing his own experiments,” he says. “I always knew he would have a wonderful career — but the incredible success that he has had, I don't think anyone could have foreseen. I am very proud of him.”

While Pan was mastering his craft in Zeilinger's lab, physicists around the world were slowly embracing the notion that the esoteric quantum features that so enchanted Pan could be harnessed to create, say, ultra-powerful quantum computers. Standard computers chug slowly through information coded in binary digits — strings of zeros and ones. But as early as 1981, the physicist Richard Feynman had pointed out that quantum bits, known as 'qubits', need not be so encumbered. Because a qubit can simultaneously exist in superpositions of 0 and 1, it should be possible to build faster, more powerful quantum computers that would entangle multiple qubits together and perform certain calculations in parallel, and at breathtaking speed.

Another emerging idea was ultra-secure quantum encryption for applications such as bank transactions. The key idea is that measuring a quantum system irrevocably disrupts it. So two people, Alice and Bob, could generate and share a quantum key, safe in the knowledge that any meddling by an eavesdropper would leave a trace.

By the time Pan returned to China in 2001, the potential for quantum-based technologies was recognized enough to attract financial support from the Chinese Academy of Sciences and the National Natural Science Foundation of China. “The lucky thing was that in 2000 the economy of China started to grow, so the timing was suddenly right to do good science,” Pan says. He plunged into building his dream lab.

Back in Austria, meanwhile, Zeilinger had moved to the University of Vienna, where he continued to set quantum records thanks to his penchant for thinking big. One of his most celebrated experiments showed that buckyballs, fullerene molecules containing 60 carbon atoms, can exhibit both wave and particle behaviour3 — a peculiar quantum effect that many thought could not survive in such large molecules. “Everyone had been talking about maybe trying this experiment with small, diatomic molecules,” recalls Zeilinger. “I said, 'no guys, don't just think of the next one or two steps ahead, think about how to make a huge unexpected leap beyond everyone's thinking'.”

That was a lesson that Pan heeded well. Physicists around the world were beginning to imagine the futuristic quantum Internet, based on links between quantum computers that had yet to be built. At a time when most practitioners were still happy to get quantum information safely across a lab bench, Pan was already starting to think about how to teleport it across the planet.






STEFANIE SCHRAMM

Jian-Wei Pan is working on ways to teleport photons between Earth and space.

First proposed in 1993 by computer scientist Charles Bennett of IBM in New York and his colleagues4, quantum teleportation earned its sensational name because, “like something out of_Star Trek_”, says Chen, it allows all information about a quantum object to be scanned in one location and then recreated in a new place. The key is entanglement (see 'Quantum at a distance slideshow'): because operations carried out on one of the entangled particles affect the state of its partner, no matter how far away it is, the two objects can be manipulated to act like two ends of a quantum telephone line, transmitting quantum information between two widely separated locations.

The challenge arises when entangled particles, which must be produced together, are transmitted to their respective ends of the phone connection. Such a journey is fraught with noise, scattering interactions and all manner of other disruptions, any of which can destroy the delicate quantum correlations required to make teleportation work. Currently, for example, entangled photons are transported through optical fibres. But fibres absorb light, which keeps the photons from travelling more than a few hundred kilometres. Standard amplifiers can't help, because the amplification process will destroy the quantum information. “For teleporting to distances beyond the range of a city, we need to teleport through a satellite,” says Chen.

But would entanglement survive the upward trip through Earth's turbulent atmosphere to a satellite hundreds of kilometres overhead? To find out, Pan's team, including Chen, began in 2005 to carry out ground-based feasibility tests across ever-increasing expanses of clear air to find out whether photons lose their entanglement when they bump into air molecules. But they also needed to build a target detector that was both small enough to fit on a satellite and sensitive enough to pick out the teleported photons from background light. And then they had to show that they could focus their photon beam tightly enough to hit the detector.

The work aroused Zeilinger's competitive instincts. “The Chinese were doing it, so we thought, why not try it?” he says with a laugh. “Some friendly competition is always good.” The race began to push the distance record farther and farther (see 'Duelling records'). Over the next seven years, through a series of experiments carried out in Hefei, then by the Great Wall in Beijing and finally in Qinghai, the Chinese team teleported over ever-greater distances, until it passed 97 kilometres5. The researchers announced their results in May, posting a paper on the physics preprint server, arXiv — much to the chagrin of the Austrian team, which was writing up the results of its own effort to teleport photons between two of the Canary Islands. The Austrian group posted its paper on arXiv eight days later, reporting a new distance record of 143 kilometres6. The papers were eventually published, in quick succession, in _Nature_5, 6. “I think that was in recognition of the fact that each experiment has different and complementary merits,” says Xiao-song Ma, a physicist at the University of Vienna and a member of the Austrian team.


7 and their polarizations would undergo a tiny, random rotation8 — effects that could be large enough to be picked up at the ground station. “A satellite will open a truly novel window into a regime that experimenters haven't had access to before — and that is fantastic,” says Giovanni Amelino-Camelia, a physicist at the Sapienza University of Rome, Italy.

Pan, Zeilinger and their teams are currently scrutinizing the ideas generated in a recent series of workshops at the Perimeter Institute for Theoretical Physics in Waterloo, Canada, where physicists were asked to come up with other foundational questions that could be tested by satellites9. The questions that arose included: how does an entangled particle always know the result of a measurement made on its far-distant partner? Do the pairs somehow communicate though some still-unknown information channel? What causes the quantum wavefunction to collapse when it is measured? Is gravity somehow involved? And is time a precisely defined quantity, as described in general relativity — or is it fuzzy, as might be expected from quantum mechanics?

Answering such questions will require apparatus of extraordinary sensitivity, says Pan. But meeting the technical challenges they raise will be easier now that the teams have joined forces, he says. The Austrian group, too, is seizing the new collaboration with enthusiasm. As Zeilinger says, “One of my students has just started learning Chinese.”

Nature

492,

22–25

(06 December 2012)

doi:10.1038/492022a


Data teleportation: The quantum space race : Nature News & Comment

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## Bussard Ramjet

This is a great story in Nature! 

Pan Jianwei, if he succeeds can win a Nobel for China! Also, China should work hard to bring the exceptional Chinese talent in foreign land, by giving them all kinds of benefits.


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## frequency

old news


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## cirr

The prototyping of the 1st quantum communication satellite，the launch of which is scheduled for 2016，is going smoothly and all according to the plan。

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## Aepsilons

Good Luck China! Keep up the Great Work !


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## my2cents

Three aspects of Quantum physics that could not be explained by classical physics...

1. observer effect on wave particles( wave collapse)
2. discontinuous quantum leaps(discrete quantum states)
3. Entanglement at a distance

Just imagine our view of this world if we could formulate physics at microscopic level. It is commendable that our neighbour is taking the lead in this understanding of mysteries of quantum physics.


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## cirr

*Quantum communication advances in China*

Staff Reporter

2015-02-04

*China will soon complete a quantum communication line linking Beijing and Shanghai*, as the country leads the way in technology that will offer a more secure delivery of information, the Chinese-language New Century magazine reports.

Pan Jianwei, a professor at the University of Science and Technology of China, is behind China's head position in the development of quantum communications technology, the magazine said.

A paper Pan co-wrote with Anton Zeilinger and other scientists in 1997, titled "Quantum Computing with Controlled-NOT and Few Qubits," was named by Nature as one of the 21 influential publications of the 20th century. Other publications chosen by the science journal include Roentgen's discovery of X-rays and Einstein's Theory of Relativity, according to the magazine.

Pan returned from Austria in 2001 and his team helped build the quantum communication hotlines used for China's military parade on Oct. 1, 2009, when his country celebrated its 60th anniversary.

According to Pan, his work in 2009 made China the first country in the world to adopt the technology for practical use.

Pan's team then designed a pilot quantum communication network in Hefei, Anhui province, where his university is located. The network at that time cost 60 million yuan (US$9.9 million) and was completed in February 2012 after 18 months of construction.

*The network in Hefei offers government agencies, financial institutions, medical facilities, weapon manufacturers and research institutes lines that can make secure phone calls or video calls. *

*Another network was inaugurated in March 2014 in Jinan, Shandong province*, the magazine added.

The two existing networks, along with a main communications line between Beijing and Shanghai, which is set to be completed this year, will begin providing transmission of information at the highest level of security between the two metropolises starting in 2016, according to the magazine.

Pan told the magazine that *China is now building satellites to be deployed for quantum communications. *

Jianyu Wang, deputy head of the Chinese Academy of Sciences' Shanghai branch, said during a forum late last year that China is set to launch the world's first quantum communication satellite in 2016.

Pan expects *China can achieve delivery of the distribution of quantum key*, which is used to decode encrypted information, *between Asia and Europe by 2020 and around the world by 2030. *

Zhao Yong, president of one of the two companies Pan's university set up to commercialize the technology, said quantum communication technology plays a supplementary role to offer more secure channels but will not replace existing methods.

Quantum communication advances in China｜Technology｜Business｜WantChinaTimes.com

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## TaiShang

*China Leads in Unhackable Quantum Communication, Completing 2000km Network by 2016*

China will complete and put into service the world’s longest quantum communication network stretching 2,000km from Beijing to Shanghai by 2016, say scientists leading the project.

International Daily News carries Xinhua Nov. 2 report that at the 12th International Conference on Quantum Communication, Measurement and Computing (QCMC), University of Science and Technology of China Prof. Pan Jianwei told the conference that as China has successfully carried out quite a few experiments at Qianhai Lake, it is now conducting a project to build a quantum communication satellite.

For over a decade, Chinese scientists have been world leaders in making major top breakthroughs to make quantum communication one of the not many sophisticated technologies China excels in the world.

At the beginning of 2012, Pan’s team successfully established in Hefei city world first large-scale quantum communication network covering the area of a city with 46 nodes, the largest in number of nodes compared to all similar networks in the world. It marked a key breakthrough in the technology of quantum communication network with large capacity.

Prof. Pan said that the technology in citywide quantum confidential communication network was in the main mature. SCMP says in its report on Nov. 4, “China will complete and put into service the world’s longest quantum communication network stretching 2,000km from Beijing to Shanghai by 2016, say scientists leading the project.”

However, Prof Pan says that satellites have to be used for a quantum communication network covering vast area.

According to Xinhua, China is carrying out smoothly its project of “Quantum Scientific Experimental Satellite”. After successful launch of a quantum communication satellite, China will continue its research in order to set up a global satellite quantum communication network by 2030.

Source: International Daily News “China to complete global quantum communication network by 2030” (summary by Chan Kai Yee based on the report in Chinese)

Source: SCMP “China to launch hack-proof quantum communication network in 2016”

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## xunzi

This will end NSA.

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## TaiShang

xunzi said:


> This will end NSA.



Indeed. US hacking and spying activity is worrisome for China.

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## Bussard Ramjet

Just one thing here, in the triumphalism of the whole thing lets not forget that nothing is "unhackable." Though yes the laws of physics say that superposition caused by observing photons destroy their quantum states, their are many ways to work around.

This is already an established field called Quantum Hacking. I will just give some details here.


*The Next Battleground In The War Against Quantum Hacking*

Ever since the first hack of a commercial quantum cryptography device, security specialists have been fighting back. Here’s an update on the battle.
*




*

Quantum hacking is the latest fear in the world of information security. Not so long ago, physicists were claiming that they could send information with perfect security using a technique known as quantum key distribution.

This uses the laws of quantum mechanics to guarantee perfectly secure communication. And perfectly secure communication is what you get, at least in theory.

The trouble is that in practice the equipment used to carry out quantum key distribution has a number of weaknesses that an eavesdropper can exploit to gain information about the messages being sent. Various groups have demonstrated how quantum hacking presents a real threat to “perfectly secure” communication.

So in the cat and mouse game of information security, physicists have been fighting back by designing equipment that is more secure. Today, Nitin Jain at the Max Planck Institute for the Science of Light in Erlangen, Germany, and a few pals show how the changes still leave the equipment open to attack but at the same time reveal how the next generation of quantum cryptography could be made better.

In quantum key distribution, Alice sends information to Bob encoded in the polarisation of single photons. So she might send a sequence of 0s and 1s as a series of photons polarised horizontally and vertically. Bob can then use this information as the key to a one-time pad for sending information with perfect security. Hence the name quantum key distribution.

An eavesdropper, Eve, can only see the information Alice sends if she knows the directions that correspond to vertical and horizontal. Physicists call this the base of the system.

Without knowing the base, the information the photons carry will seem random. So a key part of the security of quantum key distribution comes from keeping Alice’s base secret.

Just over 10 years ago, hackers found a way for Eve to discover Alice’s base. All Eve has to do is shine a light into Alice’s equipment and measure the polarisation of the reflected photons. These will have bounced off the optical components that determine Alice’s base and so will be polarised in the same way. That gives Eve the crucial information she needs to decode the transmissions without Alice being any the wiser.

Various teams have shown how this approach can hack commercially available quantum cryptography devices, revealing that the claim of perfect security is somewhat overblown.

But the physicists have fought back. One way to stop these kinds of attack is to include a device called an isolator that allows light to travel in one direction but not the other. So Alice can transmit her photons out of the equipment but Eve cannot send photons into it.

The work that Jain and co have done it to study the optical properties of these devices to see just how secure they are. These guys have tested the optical properties of a number of components used in quantum key distribution, including isolators.

The tests have been straightforward. They send a number of photons towards the device and measure the number that pass through. But crucially, they have done this at a number of different wavelengths between 1000 and 1700 nanometres.

The results are revealing. Telecommunication transmission use wavelengths of around 1550 nanometres. And the isolators Jain and co have measured work well at this wavelength.

But these devices are not so good at other wavelengths. “Even high performance isolators do not have high isolation in other wavelength regions, such as from 1300 to 1400 nanometres, where Eve can easily obtain both laser sources,” they say.

In other words, Eve can still discover Alice’s base using lasers of a different colour.

That will be a worrying discovery for organisations now using quantum key distribution to protect their data, not to mention the companies that sell commercial quantum key distribution equipment.

But all is not lost, say Jain and co. There are still more countermeasures that can protect quantum key distribution from Eve’s attacks at other wavelengths. Instead of using a passive device like an isolator, Alice could use an active device that measures incoming photons in the hope of spotting Eve in action. “If Alice contains a monitoring detector in addition to the isolator, then it would become fairly challenging for Eve to simultaneously circumvent both of these countermeasures,” say Jain and co.

Theorists can help here too. The laws of quantum mechanics guarantee the secrecy of a message provided that the amount of information that leaks out is below some threshold, determined by the specific details of the protocol being used..

In these kinds of attacks, Eve’s gains only a certain amount of information about the secret key. If she gets more than this threshold, she can begin to decrypt any secret messages encoded with it.

The theorists can help here by determining how much information Eve might get from her attacks and raising the threshold accordingly. That increases the security of the system but also makes it considerably slower to send data.

That is an interesting piece of work. Information security specialists have always indulged in a cat and mouse war against attackers. For a short time, these specialists had hoped that quantum key distribution would be the ultimate weapon to bring this war to an end. That hope now looks somewhat premature.

The Next Battleground In The War Against Quantum Hacking | MIT Technology Review


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## cirr

*Huawei, China Unicom commercially deploy tiny Atom Router*

February 3, 2015 | By Monica Alleven

Huawei and China Unicom Guangdong Branch (Guangdong Unicom) say they've deployed the world's first Atom Router for commercial use.




Atom Router (_Image source: Huawei_)

Unveiled last year at the Mobile World Congress (MWC) trade show in Barcelona, Spain, the finger-sized router is believed to be the world's tiniest, but it packs a punch.

For starters, it delivers smarter pipes to facilitate network operation and maintenance (O&M) and service innovation, according to the vendor. By providing visible service performance, real-time service level agreement (SLA) measuring and accurate SLA reporting, and quick fault location capabilities, the router enables service-aware network O&M.

The router also promises to allow smooth network evolution, such as an upgrade from GSM/UMTS to LTE/LTE-Advanced backhaul networks, from IPv4 to IPv6 networks and from traditional DCs to future-ready DCs. In addition, software-defined network-enabled Atom Routers allows operators to develop and provision service applications as required for on-demand network deployment.

Guangdong Unicom's deployment, which uses the Huawei Intelligent Perception solution, will help Guangdong Unicom build "industry-leading bearer networks" to deliver optimized mobile service experiences to users, according to the press release. 

Guangdong Unicom developed the concept of the "optimal user experience" with a focus on building bearer networks that streamline user services in an E2E manner and are critical to the user experience, but faced challenges related to a lack of basic data, network perception tools and evaluation systems.

To address those challenges, Huawei and Guangdong Unicom embarked on a joint project last June to deploy Huawei's SmartSense solution with the Atom Router. The E2E solution features benefits such as the ability to monitor service quality, including measuring packet loss rate and delay of end-to-end service packets transmitted on an IP network to determine network performance.

The "traffic snapshot" technology identifies and records instantaneous second-grade traffic peaks in real-time to assist in precise network planning, while anti-congestion technology is used to counter the congestion, packet loss and jitter caused by bursty traffic.

Huawei, China Unicom commercially deploy tiny Atom Router - FierceWirelessTech

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## esolve

China's bank ICBC Beijing Branch successfully used the quantum communication technology in the intra-city encryption transmission of its electronic archive. It is the first successful application of quantum technology in the Chinese banking industry, marking a new level of information security technology in China’s banking sector.

According to an official with ICBC, to further enhance information security, ICBC has implemented “Beijing-Shanghai Verification and Application Demonstration Project of Quantum Encrypted Communication Technology” together with the University of Science and Technology of China. Meanwhile, the Bank has launched financial application of the quantum technology in intra-city communication of Beijing and Shanghai as well as the thousand-km-level communication between the two cities.

Quantum is a status of microscopic particle. Data information composed of quantum dots is free from external interception or copying during transmission. Quantum communication is by far the only strictly testified technology that can guarantee the unconditional communication security from its principle. It has significant application value and prospect in various fields such as national defense and financial information security, and is regarded as an important technology foundation for safeguarding communication security in future information society. China has a leading position in the world in terms of quantum communication with a sizable experiment network of quantum communication. The “Beijing-Shanghai Verification and Application Demonstration Project of Quantum Encrypted Communication Technology” has been officially launched, with the aim to build a Beijing-Shanghai quantum communication route of over 2,000 km connecting Beijing, Jinan, Hefei and Shanghai as well as a metropolitan access network, which can serve the confidential transmission of governmental information and financial business information.

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## cirr

*Two quantum properties teleported together for first time*

Feb 27, 2015

Two quantum properties teleported together for first time - physicsworld.com





Twice the fun: teleporting two properties of a photon

*The values of two inherent properties of one photon – its spin and its orbital angular momentum – have been transferred via quantum teleportation onto another photon for the first time by physicists in China*. Previous experiments have managed to teleport a single property, but scaling that up to two properties proved to be a difficult task, which has only now been achieved. The team's work is a crucial step forward in improving our understanding of the fundamentals of quantum mechanics and the result could also play an important role in the development of quantum communications and quantum computers.

*Alice and Bob*

Quantum teleportation first appeared in the early 1990s after four researchers, including Charles Bennett of IBM in New York, developed a basic quantum teleportation protocol. To successfully teleport a quantum state, you must make a precise initial measurement of a system, transmit the measurement information to a receiving destination and then reconstruct a perfect copy of the original state. The "no-cloning" theorem of quantum mechanics dictates that it is impossible to make a perfect copy of a quantum particle. But researchers found a way around this via teleportation, which allows a flawless copy of a property of a particle to be made. This occurs thanks to what is ultimately a complete transfer (rather than an actual copy) of the property onto another particle such that the first particle loses all of the properties that are teleported.

The protocol has an observer, Alice, send information about an unknown quantum state (or property) to another observer, Bob, via the exchange of classical information. Both Alice and Bob are first given one half of an additional pair of entangled particles that act as the "quantum channel" via which the teleportation will ultimately take place. Alice would then interact the unknown quantum state with her half of the entangled particle, measure the combined quantum state and send the result through a classical channel to Bob. The act of the measurement itself alters the state of Bob's half of the entangled pair and this, combined with the result of Alice's measurement, allows Bob to reconstruct the unknown quantum state. The first experimentation teleportation of the spin (or polarization) of a photon took place in 1997. Since then, the states of atomic spins, coherent light fields, nuclear spins and trapped ions have all been teleported.

But any quantum particle has more than one given state or property – they possess various "degrees of freedom", many of which are related. Even the simple photon has various properties such as frequency, momentum, spin and orbital angular momentum (OAM), which are inherently linked.

*More than one*

*Teleporting more than one state simultaneously is essential to fully describe a quantum particle and achieving this would be a tentative step towards teleporting something larger than a quantum particle, which could be very useful in the exchange of quantum information*. Now, Chaoyang Lu and Jian-Wei Pan, along with colleagues at the University of Science and Technology of China in Hefei, have taken the first step in simultaneously teleporting multiple properties of a single photon.

In the experiment, the team teleports the composite quantum states of a single photon encoded in both its spin and OAM. To transfer the two properties requires not only an extra entangled set of particles (the quantum channel), but a "hyper-entangled" set – where the two particles are simultaneously entangled in both their spin _and_ their OAM. The researchers shine a strong ultraviolet pulsed laser on three nonlinear crystals to generate three entangled pairs of photons – one pair is hyper-entangled and is used as the "quantum channel", a second entangled pair is used to carry out an intermediate "non-destructive" measurement, while the third pair is used to prepare the two-property state of a single photon that will eventually be teleported.





Tricky protocol: comparative measurements and teleportation

The image above represents Pan's double-teleportation protocol – A is the single photon whose spin and OAM will eventually be teleported to C (one half of the hyper-entangled quantum channel). This occurs via the other particle in the channel – B. As B and C are hyper-entangled, we know that their spin and OAM are strongly correlated, but we do not actually know what their values are – i.e. whether they are horizontally, vertically or orthogonally polarized. So to actually transfer A's polarization and OAM onto C, the researchers make a "comparative measurements" (referred to as CM-P and CM-OAM in the image) with B. In other words, instead of revealing B's properties, they detect how A's polarization and OAM differ from B. If the difference is zero, we can tell that A and B have the same polarization or OAM, and since B and C are correlated, that C now has the same properties that A had before the comparison measurement.

On the other hand, if the comparative measurement showed that A's polarization as compared with B differed by 90° (i.e. A and B are orthogonally polarized), then we would rotate C's field by 90° with respect to that of A to make a perfect transfer once more. Simply put, making two comparative measurements, followed by a well-defined rotation of the still-unknown polarization or OAM, would allow us to teleport A's properties to C.

*Perfect protocol *

One of the most challenging steps for the researchers was to link together the two comparative measurements. Referring to the "joint measurements" box in the image above, we begin with the comparative measurement of A and B's polarization (CM-P). From here, either one of three scenarios can take place – one photon travels along path 1 to the middle box (labelled "non-destructive photon-number measurement"); no photons enter the middle box along path 1; or two single photons enter the middle box along path 1.

The middle box itself contains the second set of entangled photons mentioned previously (not shown in figure) and one of these two entangled photons is jointly measured with the incoming photons from path 1. But the researcher's condition is that if either no photons or two photons enter the middle box via path 1, then the measurement would fail. Indeed, what the middle box ultimately shows is that exactly one photon existed in path 1, and so exactly one photon existed in path 2, given that two photons (A and B) entered CM-P. To show that indeed one photon existed in path two required the third and final set of entangled photons in the CP-OAM box (not shown), where the OAM's of A and B undergo a comparative measurement.

The measurements ultimately result in the transfer or teleportation of A's properties onto C – although it may require rotating C's (as yet unknown) polarization and OAM depending on the outcomes of the comparative measurements, but the researchers did not actually implement the rotations in their current experiment. The team's work has been published in the journal _Nature_ this week. Pan tells _physicsworld.com_ that the team verified that "the teleportation works for both spin-orbit product state and hybrid entangled state, achieving an overall fidelity that well exceeds the classical limit". He says that these "methods can, in principle, be generalized to more [properties], for instance, involving the photon's momentum, time and frequency".

*Verification verdicts*

Physicist Wolfgang Tittel from the University of Calgary, who was not involved in the current work (but wrote an accompanying "News and Views" article in _Nature_) explains that the team verified that the teleportation had indeed occurred by measuring the properties of C after the teleportation. "Of course, the no-cloning theorem does not allow them to do this perfectly. But it is possible to repeat the teleportation of the properties of photon A, prepared every time in the same way, many times. Making measurements on photon C (one per repetition) allows reconstructing its properties." He points out that although the rotations were not ultimately implemented by the researchers, they found that "the properties of C differed from those of A almost exactly by the amount predicted by the outcomes of the comparative measurements. They repeated this large number of measurements for different preparations of A, always finding the properties of C close to those expected. This suffices to claim quantum teleportation".

While it is technically possible to extend Pan's method to teleport more than two properties simultaneously, this is increasingly difficult because the probability of a successful comparative measurement decreases with each added property. "I think with the scheme demonstrated by [the researchers], the limit is three properties. But this does not mean that other approaches, either other schemes based on photons, or approaches using other particles (e.g. trapped ions), can't do better," says Tittel.

*Pan says that to teleport three properties, their scheme "needs the experimental ability to control 10 photons. So far, our record is eight photon entanglement. We are currently working on two parallel lines to get more photon entanglement." Indeed, he says that the team's next goal is to experimentally create "the largest hyper-entangled state so far: a six-photon 18-qubit Schrödinger cat state, entangled in three degrees-of-freedom, polarization, orbital angular momentum, and spatial mode. To do this would provide us with an advanced platform for quantum communication and computation protocols"*.

*Say hello to scalable quantum computation and quantum network technology *

The work is published in _Nature_.

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## TaiShang

*The values of two inherent properties of one photon – its spin and its orbital angular momentum – have been transferred via quantum teleportation onto another photon for the first time by physicists in China. *Previous experiments have managed to teleport a single property, but scaling that up to two properties proved to be a difficult task, which has only now been achieved. The team’s work is a crucial step forward in improving our understanding of the fundamentals of quantum mechanics and the result could also play an important role in the development of quantum communications and quantum computers.

Quantum teleportation first appeared in the early 1990s after four researchers, including Charles Bennett of IBM in New York, developed a basic quantum teleportation protocol. To successfully teleport a quantum state, you must make a precise initial measurement of a system, transmit the measurement information to a receiving destination and then reconstruct a perfect copy of the original state. The “no-cloning” theorem of quantum mechanics dictates that it is impossible to make a perfect copy of a quantum particle. But researchers found a way around this via teleportation, which allows a flawless copy of a property of a particle to be made. This occurs thanks to what is ultimately a complete transfer (rather than an actual copy) of the property onto another particle such that the first particle loses all of the properties that are teleported.

The protocol has an observer, Alice, send information about an unknown quantum state (or property) to another observer, Bob, via the exchange of classical information. Both Alice and Bob are first given one half of an additional pair of entangled particles that act as the “quantum channel” via which the teleportation will ultimately take place. Alice would then interact the unknown quantum state with her half of the entangled particle, measure the combined quantum state and send the result through a classical channel to Bob. The act of the measurement itself alters the state of Bob’s half of the entangled pair and this, combined with the result of Alice’s measurement, allows Bob to reconstruct the unknown quantum state. The first experimentation teleportation of the spin (or polarization) of a photon took place in 1997. Since then, the states of atomic spins, coherent light fields, nuclear spins and trapped ions have all been teleported.

But any quantum particle has more than one given state or property – they possess various “degrees of freedom”, many of which are related. Even the simple photon has various properties such as frequency, momentum, spin and orbital angular momentum (OAM), which are inherently linked.

Teleporting more than one state simultaneously is essential to fully describe a quantum particle and achieving this would be a tentative step towards teleporting something larger than a quantum particle, which could be very useful in the exchange of quantum information. *Now, Chaoyang Lu and Jian-Wei Pan, along with colleagues at the University of Science and Technology of China in Hefei, have taken the first step in simultaneously teleporting multiple properties of a single photon.*

In the experiment, the team teleports the composite quantum states of a single photon encoded in both its spin and OAM. To transfer the two properties requires not only an extra entangled set of particles (the quantum channel), but a “hyper-entangled” set – where the two particles are simultaneously entangled in both their spin _and_ their OAM. The researchers shine a strong ultraviolet pulsed laser on three nonlinear crystals to generate three entangled pairs of photons – one pair is hyper-entangled and is used as the “quantum channel”, a second entangled pair is used to carry out an intermediate “non-destructive” measurement, while the third pair is used to prepare the two-property state of a single photon that will eventually be teleported.




This schematic shows exactly how the polarization and the OAM was teleported via the comparative measurements and an intermediate non-destructive step. (Courtesy: Nature 518 516/Wang et al.)

The image above represents Pan’s double-teleportation protocol – A is the single photon whose spin and OAM will eventually be teleported to C (one half of the hyper-entangled quantum channel). This occurs via the other particle in the channel B. As B and C are hyper-entangled, we know that their spin and OAM are strongly correlated, but we do not actually know what their values are – i.e. whether they are horizontally, vertically or orthogonally polarized. So to actually transfer A’s polarization and OAM onto C, the researchers make a “comparative measurements” (referred to as CM-P and CM-OAM in the image) with B. In other words, instead of revealing B’s properties, they detect how A’s polarization and OAM differ from B. If the difference is zero, we can tell that A and B have the same polarization or OAM, and since B and C are correlated, that C now has the same properties that A had before the comparison measurement.

On the other hand, if the comparative measurement showed that A’s polarization as compared with B differed by 90° (i.e. A and B are orthogonally polarized), then we would rotate C’s field by 90° with respect to that of A to make a perfect transfer once more. Simply put, making two comparative measurements, followed by a well-defined rotation of the still-unknown polarization or OAM, would allow us to teleport A’s properties to C.

One of the most challenging steps for the researchers was to link together the two comparative measurements. Referring to the “joint measurements” box in the image above, we begin with the comparative measurement of A and B’s polarization (CM-P). From here, either one of three scenarios can take place – one photon travels along path 1 to the middle box (labelled “non-destructive photon-number measurement”); no photons enter the middle box along path 1; or two single photons enter the middle box along path 1.

The middle box itself contains the second set of entangled photons mentioned previously (not shown in figure) and one of these two entangled photons is jointly measured with the incoming photons from path 1. But the researcher’s condition is that if either no photons or two photons enter the middle box via path 1, then the measurement would fail. Indeed, what the middle box ultimately shows is that exactly one photon existed in path 1, and so exactly one photon existed in path 2, given that two photons (A and B) entered CM-P. To show that indeed one photon existed in path two required the third and final set of entangled photons in the CP-OAM box (not shown), where the OAM’s of A and B undergo a comparative measurement.

The measurements ultimately result in the transfer or teleportation of A’s properties onto C – although it may require rotating C’s (as yet unknown) polarization and OAM depending on the outcomes of the comparative measurements, but the researchers did not actually implement the rotations in their current experiment. The team’s work has been published in the journal _Nature_ this week. Pan tells _physicsworld.com_ that the team verified that “the teleportation works for both spin-orbit product state and hybrid entangled state, achieving an overall fidelity that well exceeds the classical limit”. He says that these “methods can, in principle, be generalized to more [properties], for instance, involving the photon’s momentum, time and frequency”.

Physicist Wolfgang Tittel from the University of Calgary, who was not involved in the current work (but wrote an accompanying “News and Views” article in _Nature_) explains that the team verified that the teleportation had indeed occurred by measuring the properties of C after the teleportation. “Of course, the no-cloning theorem does not allow them to do this perfectly. But it is possible to repeat the teleportation of the properties of photon A, prepared every time in the same way, many times. Making measurements on photon C (one per repetition) allows reconstructing its properties.” He points out that although the rotations were not ultimately implemented by the researchers, they found that “the properties of C differed from those of A almost exactly by the amount predicted by the outcomes of the comparative measurements. They repeated this large number of measurements for different preparations of A, always finding the properties of C close to those expected. This suffices to claim quantum teleportation”.

While it is technically possible to extend Pan’s method to teleport more than two properties simultaneously, this is increasingly difficult because the probability of a successful comparative measurement decreases with each added property. “I think with the scheme demonstrated by [the researchers], the limit is three properties. But this does not mean that other approaches, either other schemes based on photons, or approaches using other particles (e.g. trapped ions), can’t do better,” says Tittel.

Pan says that to teleport three properties, their scheme “needs the experimental ability to control 10 photons. So far, our record is eight photon entanglement. We are currently working on two parallel lines to get more photon entanglement.” Indeed, he says that the team’s next goal is to experimentally create “the largest hyper-entangled state so far: a six-photon 18-qubit Schrödinger cat state, entangled in three degrees-of-freedom, polarization, orbital angular momentum, and spatial mode. To do this would provide us with an advanced platform for quantum communication and computation protocols”.

_The work is published in Nature. Reposted from PhysicsWorld.com_

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## Kiss_of_the_Dragon

When will i able to do this, hope I can get away in one piece

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## TimeTraveller

Nice and Amazing.........


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## cirr

@TaiShang Perhaps you would care to open up the following thread: 

*Reserachers in China make breakthroughs in space technology ...*

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## powastick

Kiss_of_the_Dragon said:


> When will i able to do this, hope I can get away in one piece


Doesn't work that way though. Quantum teleportation is a bad name and I'm quite confuse myself .


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## 55100864

The article that published in nature

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## SelfServeFive

We can teleport our photon torpedo directly on to the Gerald Ford's bridge.

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## AndrewJin

55100864 said:


> The article that published in nature





55100864 said:


> The article that published in nature


Too many terms in this paper. That's a problem with English, English terminology is a barrier between experts and the ordinary. They call Department of Cardiology rather than Department of Heart.

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## 55100864

AndrewJin said:


> Too many terms in this paper. That's a problem with English, English terminology is a barrier between experts and the ordinary. They call Department of Cardiology rather than Department of Heart.


That article is like "WTF" to me

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## AndrewJin

55100864 said:


> That article is like "WTF" to me


If it is translated into Chinese, I'll read. Terminology barrier in English makes the tendency of anti-intellectualism in the west even more popular. Every now and then they invent a new word from nowhere, but in Chinese we use existing characters to combine as a new word which makes sense to the ordinary people.

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## TaiShang

cirr said:


> @TaiShang Perhaps you would care to open up the following thread:
> 
> *Reserachers in China make breakthroughs in space technology ...*



But I cannot see the story. 

I am not sure this has been shared somewhere:

*Huawei Leads in Applications for Patents Globally*
2015-03-20 




File photo of Huawei [Photo: baidu]

China's leading telecom solutions provider Huawei has become the world's No. 1 applicant for global patents in 2014.

According to the United Nations agency, Huawei, with nearly 3500 published applications, overtook Panasonic of Japan as the largest applicant of last year.

U.S.-based Qualcomm was the second largest applicant with 2400 published applications, while China's ZTE took third place.

Insiders say the report is partially viewed as a rough barometer of a country's technological progress, and noted that China was the only country to see double-digit growth in its filings.

In recent years, China's top policy-makers have offered incentives to nudge Chinese companies to shift from low-value, low-cost manufacturing to fostering innovation.

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## AndrewJin

TaiShang said:


> But I cannot see the story.
> 
> I am not sure this has been shared somewhere:
> 
> *Huawei Leads in Applications for Patents Globally*
> 2015-03-20
> 
> 
> 
> 
> 
> File photo of Huawei [Photo: baidu]
> 
> China's leading telecom solutions provider Huawei has become the world's No. 1 applicant for global patents in 2014.
> 
> According to the United Nations agency, Huawei, with nearly 3500 published applications, overtook Panasonic of Japan as the largest applicant of last year.
> 
> U.S.-based Qualcomm was the second largest applicant with 2400 published applications, while China's ZTE took third place.
> 
> Insiders say the report is partially viewed as a rough barometer of a country's technological progress, and noted that China was the only country to see double-digit growth in its filings.
> 
> In recent years, China's top policy-makers have offered incentives to nudge Chinese companies to shift from low-value, low-cost manufacturing to fostering innovation.


Huawei is everywhere in the world.
When an airplane accident happens in Africa, the first person who is woken up will be the head of Huawei.
Can you find a single airplane crash without a Huawei technician or salesman in the plane?

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## TaiShang

*Huawei Launches Four New ICT Solutions at CeBIT 2015*

HANNOVER, Germany, March 17, 2015 /PRNewswire/ -- Huawei today shared its vision of "Innovative ICT, Building a Better Connected World" and introduced its latest innovative ICT solutions at CeBIT 2015 inHannover, Germany. Huawei believes that innovative ICT is the cornerstone for building a better connected world and strives to be the best ICT partner for enterprises by providing them with innovative, differentiated, cutting-edge, and easy-to-integrate ICT infrastructure products and solutions.

At the press conference, Huawei showcased its eLTE Broadband Trunking Solution, Agile Wide Area Network (WAN) Solution, OceanStor 9000, and Next Generation Anti-Distributed Denial-of-Service (DDoS) Solution. These solutions have been developed to address the impact of rapid ICT development, in particular changing business models within vertical industries such as the electric power, media, and finance sectors to drive the development of smart cities, smart-grids, omni-media and omni-financial services.

"The four major innovative ICT technologies, which include mobile broadband, software-defined networking (SDN), cloud computing and big data, are reshaping all traditional industries," said Mr. Ryan Ding, Executive Director and President of Products & Solutions, Huawei. "ICT infrastructure has transformed from being an enterprise's support system to a part of the value-adding production system. It has become a powerful engine that facilitates business transformations for enterprises across different industries. With our innovative approach and focus on ICT infrastructure, Huawei is openly collaborating with partners and customers to promote business transformation and the development of a better connected world," he added.

More information is provided below:

*eLTE Broadband Trunking: Enabling Interconnectivity Among Industries and in Smart Cities*

The Huawei eLTE Broadband Trunking Solution is based on 4G technology. It supports voice trunking, data, and video in one network, which enables dispatching visualization. To satisfy the vertical industry requirements, the Huawei eLTE Broadband Trunking Solution supports more frequency bands, offers greater flexibility in networking, and provides a number of terminal choices. Aside from the common frequencies of 400MHz, 800MHz, 1.4GHz, 1.8GHz and 2.3GHz, the solution also supports broadband trunking communications in the 3.5GHz frequency. In addition to EP820 Broadband Trunking Handset and the EM720 Industrial-Grade Mobile Hotspot, Huawei is also collaborating with partners to develop more devices to address industry-specific needs. The solution supports connections to intelligent video systems, Telepresence, IP call centers and third-party applications, which helps to improve the efficiency of inter-department collaboration and emergency response of governments overall.

*Agile WAN: WAN 3.0, Creating The Best Experience*

As the bridge connecting the world, Wide Area Networks are gradually becoming bottlenecks for enterprises that are trying to provide good end-user experience, and improving WAN capabilities is a current trend. The Huawei Agile WAN Solution, through integrating WAN SDN, Internet protocol (IP) hard-pipe technology, atom routers, high throughput, eSight mobile and other leading technologies, helps enterprises stay competitive by providing reliable network connections to ensure a high quality experience.

*OceanStor 9000: Fastest Scale-Out Storage, Opening 4K Age*

With the rise of 4K ultra-high-definition (UHD) era, Huawei launched its OceanStor 9000 – the world's fastest storage system with large-scale horizontal scalability – to meet the growing needs of the media industry. With its unique eTurbo communications protocol, OceanStor 9000 is the first network attached storage (NAS) system that addresses production and editing requirements with six-layer 4K UHD programs. With a high-density and energy-saving system design, OceanStor 9000 enables media organizations to save operating costs by reducing machine room space by 200 percent and energy consumption by 32 percent. It also helps improve overall efficiency by enabling the management of the entire program production including reporting, editing, broadcasting, managing and storing, in a single storage system.

*Next Generation Anti-DDoS: Protect Business Operations in a Better Way*

Huawei's Next Generation Anti-DDoS Solution uses big data technology to build traffic models in over 60 dimensions to prevent hundreds of DDoS attacks without unintentionally interrupting legitimate requests. Huawei's powerful and most current IP reputation technologies can accurately identify zombie hosts while improving the Internet access experience of legitimate users.

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## bobsm

*Breakthrough by Chinese scientists brings 'unhackable' quantum broadband closer to reality*

PUBLISHED : Thursday, 09 April, 2015, 8:00am
UPDATED : Thursday, 09 April, 2015, 8:53am
Stephen Chen

A breakthrough by Chinese scientists has brought high speed, quantum broadband communication closer than ever.

For the first time, scientists at the University of Science and Technology in Hefei, Anhui province, were able to demonstrate that quantum information could be stored and distributed under a broadband communication protocol.

Writing in the British journal Nature Photonics the researchers said the technology "shows great promise for the establishment of quantum networks in high-speed communications".

Unlike traditional communication methods, quantum broadband would be unhackable, the researchers said, thanks to the laws of physics.

Anyone who tried to detect or measure the quantum bits, such as entangled photons that carry information in various quantum states, would unavoidably destroy the qubit, making the data impossible to read and alerting the recipient.

It is primarily these security reasons that the Chinese government has invested a huge amount of resources into quantum communication. The world's longest quantum network and first quantum communication satellite are both currently being constructed in China.

However, existing networks are plagued by narrow bandwidth and slow speeds, mainly due to the difficulty of maintaining fragile quantum states over long distances.

Quantum networks in use today are only able to distribute short key chains used to encrypt data transmitted on conventional networks, an improvement in security but not the dramatic step proposed by the new paper.

Professor Shi Baosen, one of the authors of the paper, said his team's work was partly the result of intense international competition.

Many countries are racing to develop the world’s first quantum communication "expressway", said Shi.

A team in the UK tried to add "fuel" to travelling qubits but increased speed also led to increased instability, leading to more accidents.

Shi’s team took a different approach. In addition to building "pump stations", they also imposed restrictions to regulate the movement of qubits and slow them down when necessary.

To achieve this they used laser to freeze fast moving photons and developed some new methods to control the network flow.

"Our cold approach is more sophisticated and required bulkier equipment setup, but it produced better results, which helped us win the race," Shi said.

The new technology would not only be useful in high speed quantum communication, but shed new light on the construction of quantum computers as well.

The broadband protocol, known as Raman quantum memory, allowed entangled photons to run around and around in a fiber loop with an optical switch that would release them whenever they were needed, thus providing a “memory chip” for quantum computers.

But Shi said that lots of work remained to be done before the first quantum broadband network could be built.

For instance, the laboratory setup was still too large, too sophisticated and too costly for mass application.

Breakthrough by Chinese scientists brings 'unhackable' quantum broadband closer to reality | South China Morning Post

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## cirr

Now we need to bring on quantum computers as early as possible。

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## AndrewJin

Another great breakthrough!

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## my2cents

cirr said:


> Now we need to bring on quantum computers as early as possible。



You missed the last line. We are talking at least a decade for quantum computers and broadband to see any commercial applications in mass scale.


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## FairAndUnbiased

Those who control information control everything, because humans need information equally as much as air, water and food. Those who fail to control information cannot even control their own destiny.

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## cirr

my2cents said:


> You missed the last line. We are talking at least a decade for quantum computers and broadband to see any commercial applications in mass scale.



I said “as early as possible”，which could be 5、10 or more years later。

Anyway，China is working flatout on quantum computers as I write these words。

Let's wait and see。Only time shall tell。

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## AndrewJin

cirr said:


> I said “as early as possible”，which could be 5、10 or more years later。
> 
> Anyway，China is working flatout on quantum computers as I write these words。
> 
> Let's wait and see。Only time shall tell。





cirr said:


> as early as possible


You know, I think they should understand "as early as possible", like Mumbai will surpass Shanghai in five years, said in 2005. Maybe they mean "as early as possible" in a Chinese way.

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## onebyone



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## AndrewJin

onebyone said:


>


What? Are u a citizen of our Ili Pika Galaxy Empire?


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## Azizam

Nothing is unhackabale. End of.

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## my2cents

Azizam said:


> Nothing is unhackabale. End of.



I guess you do not understand quantum weirdness.


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## Azizam

my2cents said:


> I guess you do not understand quantum weirdness.


For the time being, it is impenetrable but as been proven in the history, new techniques will be invented to exploit those systems too.

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## AndrewJin

Azizam said:


> For the time being, it is impenetrable but as been proven in the history, new techniques will be invented to exploit those systems too.


That's only a typical reply pattern from some members.


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## Víðarr

AndrewJin said:


> That's only a typical reply pattern from some members.





Azizam said:


> For the time being, it is impenetrable but as been proven in the history, new techniques will be invented to exploit those systems too.



As far back as 2007 quantum communications systems have been penetrated and compromised. Quantum communications and encryption work via the same principles; Quantum Wave Theory

Quantum hacking lab. Breaking quantum cryptography

Commercial Quantum Cryptography System Hacked

This white hat hacker cracks quantum encryption for fun and profit

Laws of Physics Say Quantum Cryptography Is Unhackable. It's Not

Quantum Hackers Use Lasers to Crack Powerful Encryption Without Leaving a Trace

How quantum cryptography works: And by the way, it's breakable

Researchers show how to break quantum cryptography by faking quantum entanglement

Hackers blind quantum cryptographers

Quantum cryptography is hacked

Quantum communications and encryption have been penetrated, they are secure, but not unbreakable. China isn't the only nation working on these systems, and they aren't the only ones exploring the offensive and defensive capabilities for defeating and protecting quantum communications either.

Quantum communications are cool, but they aren't unbreakable. It's just another cog in an unending arms race.

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## Azizam

Víðarr said:


> As far back as 2010 quantum communications systems have been penetrated and compromised:
> 
> Quantum hacking lab. Breaking quantum cryptography
> 
> Commercial Quantum Cryptography System Hacked
> 
> This white hat hacker cracks quantum encryption for fun and profit
> 
> Laws of Physics Say Quantum Cryptography Is Unhackable. It's Not
> 
> Quantum communications and encryption have been penetrated, they are secure, but not unbreakable. China isn't the only nation working on these systems, and they aren't the only ones explore the offensive and defense capabilities for defeating and protecting quantum communications either.


That's the beauty of network security. For new system being developed, there will be new techniques to exploit those systems. Perhaps will be different from previous techniques but will achieve the same goal. One of the biggest issues it faces is the maximum potential distance the current systems have. So to avoid it, they need to place repeaters and those repeaters are good target to intercept traffic.

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## cirr

*Gov't, business propose quantum leap*

2015-07-31 11:03

China Daily _Editor: Si Huan
_
*Alibaba will spend $4.8 million for 5 consecutive years to support creation of superfast computers*

The Chinese Academy of Sciences and Alibaba announced the establishment of a joint quantum computing laboratory on Thursday in Shanghai with the goal of developing superfast quantum computers.

Alibaba will invest 30 million yuan ($4.8 million) a year for five years to support the research, and it will recruit top scientists from around the globe to work with scientists from the Chinese Academy of Sciences.

"The research into quantum computing has been carried out by universities and research institutes for a few decades. With such a basis of fundamental research, it is time to transfer the theory into applied technology," said Pan Jianwei, founder and director of quantum physics and quantum information with the University of Science and Technology of China's Hefei National Laboratory for Physical Sciences at Microscale. The university is affiliated with the Chinese Academy of Sciences.

Quantum computing refers to a theoretical new kind of computer that uses technology that would make it capable of calculations at speeds impossible for traditional computers.

Some world-leading companies, including Google and IBM, have been racing to develop such a computer, but commercial-grade quantum computers remain an unfulfilled dream.

"In 2014, IBM announced a plan to invest $3 billion on quantum computers and other related research fields in five years, which is impossible for any public research institution to afford. And it is not possible for us to compete with IBM if we can pay only 10 to 20 percent of the salary IBM pays to a leading expert," Pan said.

"As a result, the development of quantum computers needs support from the private sector. Without that support, we will lag behind developed countries in the race for future computing," he said.

Wang Jian, chief technology officer of Alibaba, said, "If I have to choose one of the most popular frontier technologies, I will pick quantum computing.

"Quantum technology will pose a revolutionary influence to cloud computing and empower mankind with an infinite computing capacity, which will offer a great opportunity to every technology company to transform from follower to leader," he said.

*The five-year goal of the new lab is to build a quantum computer that has similar computing power to a regular commercial computer*. The two sides then will review the achievement to decide on any further investment.

*The 10-year goal is a computer that parallels the computing capacity of China's Tianhe-2 supercomputer, the world's fastest such machine*.

*Within 15 years, the capacity of the quantum computer is expected to be able to solve many currently inextricable problems*.

The University of Science and Technology of China also signed strategic cooperation agreements with the Zhangjiang National Innovation Demonstration Zone in Shanghai on Thursday.

During a visit to Shanghai in May last year, President Xi Jinping called on Shanghai to become a global center for innovation in science and technology.

Gov't, business propose quantum leap

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## cirr

Quantum satellite set for launch early 2016 onboard a CZ-2D carrier rocket

*Quantum revolution: China set to launch 'hack proof' quantum communications network*

By Taku Dzimwasha

August 30, 2015 18:09 BST 






China moves closer to “hack proof” quantum communications network (iStock)


China is set to complete the installation of the world's longest quantum communication network stretching 2,000km (1,240miles) from Beijing to Shanghai by 2016, say scientists leading the project. Quantum communications technology is considered to be "unhackable" and allows data to be transferred at the speed of light.

By 2030, the Chinese network would be extended worldwide, the South China Morning Post reported. It would make the country the first major power to publish a detailed schedule to put the technology into extensive, large-scale use.

The development of quantum communications technology has accelerated in the last five years. The technology works by two people sharing a message which is encrypted by a secret key made up of quantum particles, such as polarized photons. If a third person tries to intercept the photons by copying the secret key as it travels through the network, then the eavesdropper will be revealed by virtue of the laws of quantum mechanics – which dictate that the act of interfering with the network affects the behaviour of the key in an unpredictable manner.

If all goes to schedule, China would be the first country to put a quantum communications satellite in orbit, said Wang Jianyu, deputy director of the China Academy of Science's (CAS) Shanghai branch. *At a recent conference on quantum science in Shanghai, Wang said scientists from CAS and other institutions have completed major research and development tasks for launching the satellite equipped with quantum communications gear*, South China Morning Post said.

*The potential success of the satellite was confirmed by China's leading quantum communications scientist, Pan Jianwei, a CAS academic who is also a professor of quantum physics at the University of Science and Technology of China (USTC) in Hefei, in the eastern province of Anhui. Pan said researchers reported significant progress on systems development after conducting experiments at a test center in the northwest of China.*

The satellite would be used to transmit encoded data through a method called quantum key distribution (QKD), which relies on cryptographic keys transmitted via light pulse signals. QKD is said to be nearly impossible to hack, since any attempted eavesdropping would change the quantum states and thus could be quickly detected by dataflow monitors.

It's likely *the technology initially will be used to transmit sensitive diplomatic, government policy and military information*. *Future applications could include secure transmissions of personal and financial data*, Xinhua reported.

Governments in Europe, Japan and Canada are about to launch their own quantum communication satellite projects and a private company in the US has been seeking funding from the federal government with a proposal for a 10,000km network linking major cities.The Beijing to Shanghai project was launched last year. Although the Chinese government has not revealed the projects budget, scientists told state media that the construction cost would be ¥100m (£10.17m) for every 10,000 users, according to the South China Morning Post.

Quantum revolution: China set to launch 'hack proof' quantum communications network

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## TaiShang

A significant improvement to the nation's cyber security against the onslaught by state-sponsored cyber-terrorism led by the US..

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## thesolar65

Reminds me of the movie "Mercury Rising". Let's wait and see!!


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## cirr

*China Prepares to Build Jet Faster Than Legendary US Spy Plane?*

MILITARY & INTELLIGENCE

16:30 30.08.2015

*According to various reports, China is planning to develop a turbofan ramjet engine. Such an engine theoretically could be the basis for a jet faster than the legendary US SR-71 spy plane, the fastest aircraft, discharged in the late 1990s.*

On August 25, a report in the Chinese newspaper China Aviation News described a planned project to build China's first domestically-made turbofan-ramjet combined cycle engine, designed for an unnamed aircraft.

“The description of this engine suggests something resembling the Pratt & Whitney J58 variable cycle engine used by the SR-71 Blackbird, which is also often described as a turbofan-ramjet engine, due to its unique bleed from the compressor to the afterburner which allows for increased thrust at high speeds,” China Aviation News wrote.

_*The report went on to mention, “a source close to the PLA Air Force was cited by New Outlook as stating that this is part of a project to develop a manned supersonic aircraft, currently in the preparation stages at a domestic research institute. The aircraft is expected to have a top speed faster than the Blackbird on completion, according to the source, although the project is yet to be formally launched,” wrote The National Interest.*_

The developments in the domestic production of more-sophisticated and reliable jet engines would be a great benefit for China.

At present, China is highly dependent on Russia for fighter engines, and in fact, reports suggest that the J-20 fifth-generation fighter is driven by Moscow’s advanced engines.

The ability to develop top-tier engines for a SR-71-style plane would be a major step up for China’s engine manufacturers.

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## Viny

Go China Go...World is looking upto next round of innovations from you.
Now that you have the bases in place, I am sure you will lead world in new dimension of technology growth


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## mpk1988

Will be psuedo quantum and thus hackable.


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## Bussard Ramjet

Nothing is unhackable. 

Quantum encryption is not hackable only in theory, and in ideal world. Not in real world, where many compromises have to be made to actually implement the technology, and develop things. 

This has been proved. Search for the back and forth competition going on to prove this. Quantum encryption is formed, challenge started to invite people to hack it, and finally it actually gets hacked!


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## CAPRICORN-88

Bussard Ramjet said:


> Nothing is unhackable.
> 
> Quantum encryption is not hackable only in theory, and in ideal world. Not in real world, where many compromises have to be made to actually implement the technology, and develop things.
> 
> This has been proved. Search for the back and forth competition going on to prove this. Quantum encryption is formed, challenge started to invite people to hack it, and finally it actually gets hacked!



This one is at the moment if you truly understand the technology. What is clear is China is ahead of the game. Both USA and EU are still experimenting on it, China is implementing it.

Excerpt

Today, the Chinese claim another small victory in this quantum space race. Jian-Wei Pan at the University of Science and Technology of China in Shanghai and a few pals say they’ve bounced single photons off an orbiting satellite and detected them back on Earth. That’s significant because it simulates a satellite sending single photons from orbit to the surface, crossing off another proof-of-principle milestone in their quantum checklist.

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## cirr

DevineLight-III to be fired up in Oct。2015：

潜伏8年 激光聚变"神器"十月在川首秀 - 四川网络广播电视台 - 四川广播电视台

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## Bussard Ramjet

cirr said:


> DevineLight-III to be fired up in Oct。2015：
> 
> 潜伏8年 激光聚变"神器"十月在川首秀 - 四川网络广播电视台 - 四川广播电视台



What is this?


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## cirr

*Quantum computer that 'computes without running' sets efficiency record*
*
August 31, 2015 by Lisa Zyga feature*




(a) The pulse sequences for the generalized CFC scheme keep the system in its ‘off’ state. (b) Populations of different states as a function of the number of repetitions of pulse sequences. (c) The green curve shows the simulated efficiency (reaching 85%) with practical imperfections, while the dotted curve shows the ideal efficiency (reaching 100%). The dashed line shows the 50% limit. Credit: Kong, et al. ©2015 American Physical Society

(Phys.org)—Due to quantum effects, it's possible to build a quantum computer that computes without running—or as the scientists explain, "the result of a computation may be learned without actually running the computer." So far, however, the efficiency of this process, which is called counterfactual computation (CFC), has had an upper limit of 50%, limiting its practical applications.

Now in a new paper, scientists have experimentally demonstrated a slightly different version called a "generalized CFC" that has an efficiency of 85% with the potential to reach 100%. This improvement opens the doors to realizing a much greater variety of applications, such as low-light medical X-rays and the imaging of delicate biological cells and proteins—in certain cases, using only a single photon.

The researchers, led by Prof. *Jiangfeng Du* at the University of Science and Technology of China and Prof. *Liang Jiang* at Yale University in the US, have published a paper on the high-efficiency counterfactual computing method in a recent issue of _Physical Review Letters_.

"The main keys to achieving high-efficiency CFC include the utilization of exotic quantum features (quantum superposition, quantum measurement, and the quantum Zeno effect), as well as the use of a generalized CFC protocol," Du told _Phys.org_.

*How counterfactual computing works*

By "not running," the scientists mean that the computer—which can operate in either an "on" subspace or an "off" subspace—stays in its "off" subspace for the entire computation. Physically maintaining the computer in the "off" subspace, in this scheme, involves controlling the spin properties of a diamond system, which acts as a quantum switch. Some of the spins must be kept in a superposition state, in which they occupy two states at the same time.

To control the spin superposition, the physicists took advantage of the quantum Zeno effect, in which frequent measurements on a system can "freeze" the system in its current state. By applying a sequence of pulses to the system, the scientists could keep the system in its "off" subspace, and so keep it from running.

"The procedure comprises a quantum switch and a quantum register," Jiang explained. "For each repetition, we prepare the quantum switch into a quantum superposition state, including two coherent parts ('on' and 'off'). Then the 'algorithm,' a NOT gate on the quantum register in our case, is performed in the 'on' subspace. Although it seems the computer has run in this step, a consequent projective measurement will remove all the changes in the 'on' subspace, since the probability of the whole system collapsing into the 'off' subspace during the measurement is very large (approaches 100% as the number of repetitions tends to infinity utilizing the quantum Zeno effect)."

The researchers explain that the "on" and "off" states can be thought of as the two paths of an interferometer, where a photon may take one path or the other, but not both.

"Such a situation is very similar to the case of a photon passing through a two-way interferometer," Jiang said. "When a detector on one of the paths catches the photon, then one says the photon does not go on the other path. Similarly, when the whole system collapses into the 'off' subspace, one can conclude that the computer does not run. After each repetition, the state changes slightly. It finally evolves to a certain value after N repetitions from its initial value. By detecting its state, we get the information that is 'programmed' in the computer, although the computer has not run."

*Breaking the efficiency limit*

Previous experimental CFC protocols have faced a counterfactual efficiency limit of 50%, where the counterfactual efficiency is defined as "the average probability of learning the result of a computation without running the computer." But the generalized CFC (first proposed by G. Mitchison and R. Jozsa in 2001) does not face this limit, which allowed the researchers in the new study to experimentally demonstrate an efficiency of 85% at 17 pulse repetitions.

"The key difference between the two protocols is that the 'off' subspace of the generalized CFC is dependent on the choice of the 'algorithm' (Ur), whereas it is independent in the controlled-Ur CFC," said coauthor *Chenyong Ju* at the University of Science and Technology of China. "As a consequence of this fact, the sum of the 'volume' of each 'off' subspace, which has a direct relation to the counterfactual efficiency, is much larger for the generalized CFC than the controlled-Ur CFC."

The higher efficiency opens up the possibility of developing highly efficient yet very low-light imaging technology. This technology could be useful in any situation in which light may damage or destroy the illuminated sample, which makes the method particularly relevant for biological imaging. Applications may include imaging green fluorescent proteins that might be bleached under laser light, as well as UV imaging of cells and safe X-ray imaging. In some situations, these applications might be performed using only a single photon.

"The use of one photon is just for the special case that the object to be imaged has only one pixel being transparent, whereas the other pixels are opaque," said coauthor *Fei Kong* at the University of Science and Technology of China. "To image the object with our protocol, one may imagine that the situation in which a photon is absorbed by an opaque pixel is just like the computer evolving into the 'on' subspace. Such a process is effectively avoided in our protocol. The photon will eventually 'find' the transparent pixel and pass through it. Through a detector below, one can locate this pixel and hence accomplish the imaging with just one photon. The number of photons needed is proportional to the number of transparent pixels, whereas normal imaging methods need [many more] photons."

In the future, *the researchers also plan to investigate potential applications of counterfactual computing for secure communication*.

"We are looking forward to exploring more realistic applications of the generalized CFC," Du said. "There are several recent works on the topic of counterfactual quantum cryptography and communication. *Employing the counterfactual quantum phenomenon, several groups have proposed and demonstrated a new model of secret communication in which no physical signal particles are transmitted, which provides practical security advantages*. [For example, see here, here, and here.] We wonder what the potential of the generalized CFC is in this area."

Quantum computer that 'computes without running' sets efficiency record

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## TaiShang

cirr said:


> Prof. *Liang Jiang* at Yale University in the US



Bring Professor Liang Jiang home

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## Hamartia Antidote

Jlaw said:


> Let's wait and see. We're not indians.



It's not very hard to do. The J58 engine was built in 1958 and the A12 (SR-71 parent) flew over 50 years ago in 1962.







A-12 (circa 1962)

Keep in mind a first gen F-86 Sabre was just a little more than 10 years before it (1949).


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## Kompromat

As long as Pakistan Armed Services get this technology for safe communication I'm happy.


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## cirr

TaiShang said:


> Bring Professor Liang Jiang home



Yes and by this：

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## cirr

*AliCloud teases cloud-based quantum cryptography*

Computerworld Hong Kong staff

October 16, 2015

Alibaba's cloud computing arm AliCloud has unveiled a new public-cloud based method of securing data communications through *quantum cryptography*.

The solution, developed in partnership with the Chinese Academy of Sciences, aims to revolutionize ICT security.

It was announced at Alibaba Group's Computing Conference 2015 in Hangzhou, China on Wednesday.

Quantum cryptography promises to be immune to man-in-the-middle attacks, code-breakers and other popular hacking techniques designed to circumvent conventional encryption protocols.

Small scale tests of the technology have so far been successful, AliCloud said, and the company plans to move to large-scale proof-of-concept trials this year.

Jianwei Pan, professor and executive vice president of the University of Science and Technology of China, said the new technology has the potential to be transformational.

“The collaboration between AliCloud and CAS at the Quantum Computing Laboratory provided the perfect environment for creating a practical, reliable and completely secure quantum cryptography solution for communications,” he said.

*“The speed at which we have completed our initial trials with the AliCloud Cloud Platform shows the advanced state of both cloud and quantum information technologies within China, and our future projects are likely to benefit from the same synergy. The Internet will never be the same again.”*

AliCloud also used the conference to launch a startup incubator program in collaboration with Foxconn Technology Group.

The companies will jointly operate the Taofu Chengzhen incubator program, which will see AliCloud contribute cloud computing and big data support for participating SME startups.

Foxconn will in turn provide design, development patent and supply chain management advice and support. Both companies will collaborate with Intel, Zhubajie.com and Valley Capital to create a startup support infrastructure.

The Taofu Chengzhen project has been in trials for six months and has already supported around 280 business projects.

Successfully supported businesses include Moov, a startup from Silicon Valley developing a fitness wearable device with 3D motion capture and artificial intelligence capabilities.

“Alibaba Group is helping enterprises and start-ups progress by making computing services more accessible,” Alibab Group CTO Dr Jiang Wang said.

“The Computing Conference brings aspiring start-ups and established industry players together to help us further creativity and innovation across the cloud industry.”

AliCloud teases cloud-based quantum cryptography | Telecom Asia

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## TaiShang

cirr said:


> *AliCloud teases cloud-based quantum cryptography*
> 
> Computerworld Hong Kong staff
> 
> October 16, 2015
> 
> Alibaba's cloud computing arm AliCloud has unveiled a new public-cloud based method of securing data communications through *quantum cryptography*.
> 
> The solution, developed in partnership with the Chinese Academy of Sciences, aims to revolutionize ICT security.
> 
> It was announced at Alibaba Group's Computing Conference 2015 in Hangzhou, China on Wednesday.
> 
> Quantum cryptography promises to be immune to man-in-the-middle attacks, code-breakers and other popular hacking techniques designed to circumvent conventional encryption protocols.
> 
> Small scale tests of the technology have so far been successful, AliCloud said, and the company plans to move to large-scale proof-of-concept trials this year.
> 
> Jianwei Pan, professor and executive vice president of the University of Science and Technology of China, said the new technology has the potential to be transformational.
> 
> “The collaboration between AliCloud and CAS at the Quantum Computing Laboratory provided the perfect environment for creating a practical, reliable and completely secure quantum cryptography solution for communications,” he said.
> 
> *“The speed at which we have completed our initial trials with the AliCloud Cloud Platform shows the advanced state of both cloud and quantum information technologies within China, and our future projects are likely to benefit from the same synergy. The Internet will never be the same again.”*
> 
> AliCloud also used the conference to launch a startup incubator program in collaboration with Foxconn Technology Group.
> 
> The companies will jointly operate the Taofu Chengzhen incubator program, which will see AliCloud contribute cloud computing and big data support for participating SME startups.
> 
> Foxconn will in turn provide design, development patent and supply chain management advice and support. Both companies will collaborate with Intel, Zhubajie.com and Valley Capital to create a startup support infrastructure.
> 
> The Taofu Chengzhen project has been in trials for six months and has already supported around 280 business projects.
> 
> Successfully supported businesses include Moov, a startup from Silicon Valley developing a fitness wearable device with 3D motion capture and artificial intelligence capabilities.
> 
> “Alibaba Group is helping enterprises and start-ups progress by making computing services more accessible,” Alibab Group CTO Dr Jiang Wang said.
> 
> “The Computing Conference brings aspiring start-ups and established industry players together to help us further creativity and innovation across the cloud industry.”
> 
> AliCloud teases cloud-based quantum cryptography | Telecom Asia



A significant move to reinforce national cyber security as well as assist our partners. 

China's New Normal!

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## cirr

*Alibaba's Ma Says Data Resource Is Oil, Water of the Future*

Bloomberg News 

October 14, 2015 — 2:35 AM EDT Updated on October 14, 2015 — 5:06 AM EDT





Jack Ma, chairman of Alibaba Group Holding Ltd.

*
Startup incubator partnership formed with Foxconn Technology
Public cloud solution unveiled to protect data communications
*
Alibaba Group Holding Ltd.’s bet on data technology is driving greater investment in areas including ways to protect user privacy as it battles Amazon.com Inc. for customers globally.

The AliCloud unit of China’s biggest e-commerce operator partnered with Foxconn Technology Group for a startup incubator program, according to an e-mailed statement Wednesday. The companies also unveiled enhanced security for data communications through so-called quantum cryptography.

AliCloud opened a new data center in the U.S. last week and plans its first for Europe next year as it spends $1 billion backing its bet that demand for processing and storage from governments and companies will boost growth in the next decade. The investment also reflects Alibaba’s own demand, with billionaire Jack Ma expecting the company to handle $500 billion of transactions this year through its e-commerce platforms.

“*Data will become the biggest production material in the future, it will become a public resource like water, electricity and oil*,” Ma said in Hangzhou. “With computing capabilities and data, mankind will go through changes that flip heaven and earth.”

*Market Opportunity*

Alibaba’s cloud business only contributes a small part of total revenue, with computing and Internet infrastructure accounting for 2.6 percent of sales in the June quarter, according to data compiled by Bloomberg. AliCloud generates revenue mostly by charging clients a fee for using its computing infrastructure.

“The collaboration with Foxconn is very helpful for our own innovation,” Alibaba Chief Technology Officer Wang Jian said in an interview on Wednesday. “The startups will naturally use AliCloud and use Foxconn for manufacturing and bring us more investment opportunities.”

AliCloud could account for more than $1 billion of Alibaba’s revenue by 2018 and the public cloud presents a $120 billion global market opportunity, according to research by SunTrust Robinson Humphrey Inc.

While Alibaba is investing in centers as it battles Amazon to add clients in the U.S., it’s coming up against skepticism about data and Internet security given it’s a Chinese company.

“The largest markets will still be in the U.S., Europe and Japan,” said Steven Lu, a Shanghai-based partner at Bain & Co. “These places in the foreseeable future will continue to have entry barriers for Chinese companies.”

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## cirr

*AVIC signs quantum technology deal with Chinese science university*
*
Jon Grevatt, Bangkok* - IHS Jane's Defence Industry

15 November 2015

The Aviation Industry Corporation of China (AVIC) and the University of Science and Technology of China (USTC) have agreed to jointly develop quantum technologies for aerospace applications, AVIC has announced.

Under a framework accord signed on 13 November, the two state-owned entities will develop, over the next few years, a quantum technology research and development centre in Hefei, eastern China.

AVIC said this facility would be dedicated to developing quantum technologies for aerospace and related activities, accelerating training and technical understanding of quantum technologies, and to exploring new applications using those technologies.

Quantum technologies are believed to hold potential in a range of aerospace and defence applications including positioning, navigation, timing (PNT), remote sensing, and secure satellite communications.

To read the full article, Client Login

AVIC signs quantum technology deal with Chinese science university | IHS Jane's 360

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## cirr

*China set for quantum leaps in spook-proof communications*

PUBLISHED : Saturday, 19 December, 2015, 12:23am
UPDATED : Saturday, 19 December, 2015, 11:32am

Chow Chung-yan in Wuzhen, Zhejiang, and Stephen Chen

China is on track to launch the world’s biggest spook-proof quantum communications system in the next six months, one that could eventually cover Hong Kong, a leading Chinese scientist said on Friday.

Beijing will send the world’s first quantum communications satellite into space in June – around the same time as it aims to put the world’s longest quantum communications network into service, according to Pan Jianwei, the projects’ chief scientist.

On the sidelines of the World Internet Conference in Wuzhen, Zhejiang province, Pan said the network would stretch 2,000km from Beijing to Shanghai, and be the largest and most extensive quantum communications system in the world.

Quantum technology is considered to be unbreakable and impossible to hack. It encrypts messages with a key of quantum particles and detects third-party attempts to intercept the particles.

Pan is a physicist and vice-president of the University of Science and Technology of China in Hefei, Anhui province. His team’s groundbreaking experiment on quantum teleportation was voted the most important breakthrough in the field this year by the London-based Institute of Physics.

*READ MORE: China to launch hack-proof quantum communication network in 2016*

Pan said the country’s leadership had also designated it as a top priority science development project.

He said the projects’ applications would be experimental and small scale at first.

“But we hope the Chinese network can be extended to cover the whole globe in one or two decades,” Pan said.

He said the team was working with Alibaba, ZTE and other Chinese tech companies to commercialise the technology, and potential non-government clients included banks, financial institutes and research centres. He said they were “actively seeking cooperation with the city’s government and universities”.

“Hong Kong as a telecommunications and financial centre is ideal for quantum communication. We are talking with the Hong Kong government and universities to see how we can bring it to Hong Kong,” he said.

Pan said the quantum satellite could also benefit China’s “One Belt, One Road” strategy.

Meanwhile, *China is also investing heavily in developing quantum computing, a potentially game-changing technology that can do many calculations simultaneously trillions of times faster than the most powerful supercomputer today*.

*Pan said a Chinese quantum computer could match the power of the Tianhe 2 supercomputer in some areas in the next five years*. The Tianhe 2 is the world’s fastest supercomputer and was also built by Chinese scientists.

“I think it will still take a decade or two to see quantum computers being used in everyday life and enter the mass market. But I’m confident we will see it in our lifetime. Our age will be the quantum age,” he said.

*READ MORE: ‘Unhackable’ quantum broadband step closer after breakthrough by Chinese scientists*

Pan said China was a world leader in quantum technology but other countries were catching up.

“We are now taking the lead. I hope we won’t be behind a decade down the track,” he said.

Dai Yuhong, professor of applied mathematics at the Chinese Academy of Sciences, said society was not ready for a “quantum age”.

Dai said the first users of quantum computers would have a huge unfair advantage in areas such as the financial market.

“Quantum technology could be a monster if we know not how to control its power. So far, nobody knows,” he said.

“Let’s hope the physicists are too optimistic and the first practical quantum computer is still decades away.”

Luo Donggen, professor of neuroscience at Tsinghua University, said he was interested in quantum technology’s applications in the life sciences, such as building artificial brains to simulate or even overtake human brains.

But the risks posed by the technology should also be assessed, he said.

China set for quantum leaps in spook-proof communications | South China Morning Post

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## war&peace

Wow this is amazing and I see no parallel in west in operation...in the lab maybe....so China takes a lead here.

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## beijingwalker

*‘Push the limits’: China to create world’s first quantum info teleport in 2016*
Published time: 14 Jan, 2016 19:02





A group of Chinese scientists plans to create a quantum space communications system for the first time ever by launching a satellite that could facilitate quantum teleportation of photons between earth and space this June.
The aim of the new experiment conducted by a team led by physicist Pan Jian-Wei from the University of Science and Technology of China in Hefei is to see if the quantum property of entanglement extends over record-breaking distances of more than 1,000 kilometers.

This could potentially facilitate super-fast, long-range communications, as well as lead to the creation of unbreakable quantum communication networks.

The team also wants to use the world’s first quantum satellite to find out if it is possible to teleport information securely between Earth and space using entangled photons. The launch of the satellite is scheduled for June, the international weekly of science Nature reports.

‘Push the limits’: China to create world’s first quantum info teleport in 2016 — RT News

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## RisingShiningSuperpower

It's a shame that India is not developing her own quantum satellites. Ancient India invented quantum physics and teleportation, modern India should be a leader in this field. It's all due to Kangress traitors looting the country that India has fallen behind. With Modi-ji in charge, things will quickly turn around. I am confident that India will surpass China and America to become a superpower by 2020!



http://www.popsci.com/chinas-quantum-satellite-could-change-cryptography-forever

*CHINA'S QUANTUM SATELLITE COULD CHANGE CRYPTOGRAPHY FOREVER*




In the age of relentless cyberattacks and global electronic surveillance, nations and citizens are looking for any means to secure their communications. China is poised to launch a project that may provide the path to an uncrackable communications system, by turning messages quantum and taking them into space. The new Quantum Space Satellite (QUESS) program is no mere science experiment. China is already becoming a world leader in quantum communications technology; a satellite that delivers quantum communications will be a cornerstone for translating cutting-edge research into a strategic asset for Chinese power worldwide.

Cryptography operates through the use of an encryption key (such as a numbers pad), which, when applied to an encryption algorithm, can be used to decrypt or encrypt a message. Quantum entanglement is the act of fusing two or more particles into complementary “quantum states.” In such states, no particle can be independently described, instead the particles exist in a hazy shared quantum state that “collapses” when observed. Quantum encryption thus takes advantage of this feature, using it to detect would-be eavesdroppers, whose presence causes quantum states to collapse and reveal their spying to legitimate parties. Additionally, the complexity of quantum mechanics makes it virtually impossible to reverse engineer the quantum key generated through quantum entanglement.

Quantum keys are thus theoretically impossible to crack by even quantum computing -- a theoretical form of supercomputing that promises to defeat traditional forms of encryption. (It is important to note, however, that all is not perfectly secure. Quantum secured communications, like other forms of encryption, are vulnerable to denial of service, physically tampering of the quantum communications device, human failures in operational security and impersonation of sender).

Quantum teleportation

In addition to its own efforts, Chinese scientists are teaming up with their European counterparts on other quantum technologies such as photon teleportation, transmission error reduction and random number generators. If QUESS is successful, China will build an Asian-European quantum key distribution network by 2020, to be followed by a global quantum communications network in 2030.

QUESS is one of the National Space Science Center's "Strategic Priority Programs," which include scientific projects that look at black holes, dark matter, and cosmic background radiation. The program marks a significant shift in Chinese space programs, which have largely focused on human and robotic space exploration rather than space science. But there is no doubt of its security intent. Pan noted that the unbreakable security of quantum cryptography would be vital to any Chinese regional warfighting capabilities.

QUESS fits into a broader series of experimental quantum encryption programs which may be intended to address concerns over China's information security, particularly in the post Snowden era. Government, military, and financial networks are juicy targets for espionage, and quantum encryption promises to provide a level of potentially unbreakable encryption for these systems, as well as a sure-fire method to detect any attempts at intrusion.

_Read more about how quantum cryptography works here._


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## RealNapster

RisingShiningSuperpower said:


> Ancient India invented quantum physics and teleportation, modern India should be a leader in this field.






RisingShiningSuperpower said:


> I am confident that India will surpass China and America to become a superpower by 2020!






Good luck .. .................................................


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## beijingwalker

*China wins space race to launch world's first 'quantum communication' satellite in fight against hackers*

22:34, 24 MAY 2016
UPDATED 22:37, 24 MAY 2016
BY STEPHEN JONES
China will win the space race to launch the world's first quantum communication satellite when its rocket takes off into orbit in July.

It will assist in the sending of data securely - and be a huge benefit in the fight against hackers - but cause widespread concern that the secretive communist state is pioneering its use.

The technology the satellite encases is complex - but essentially it will allow for data that can't be copied or spied on between the space on the earth.

A leading expert in the field - Pan Jianwei of the Chinese Academy of Sciences - revealed news of the rocket launch at a seminar held in Shanghai.

Jianwei claims it will prove China leads the world in quantum communication.
http://www.mirror.co.uk/news/world-news/china-wins-space-race-launch-8043085

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## TaiShang

​

Photo taken on May 25, 2016 shows the quantum simulation laboratory under the Chinese Academy of Sciences, in Shanghai, east China. China plans to launch the world's first quantum satellite that can achieve secure communication in July. The satellite is dedicated to quantum science experiments. (Xinhua/Cai Yang)

​

Photo taken on May 25, 2016 shows the quantum satellite assembly workshop at Shanghai Engineering Center for Microsatellites, under the Chinese Academy of Sciences, in Shanghai, east China. China plans to launch the world's first quantum satellite that can achieve secure communication in July. The satellite is dedicated to quantum science experiments. (Xinhua/Cai Yang)

​

General engineer Zhu Zhencai introduces the "quantum entanglement source" on the quantum satellite at Shanghai Engineering Center for Microsatellites, under the Chinese Academy of Sciences, in Shanghai, east China, May 25, 2016. China plans to launch the world's first quantum satellite that can achieve secure communication in July. The satellite is dedicated to quantum science experiments. (Xinhua/Cai Yang)

​

Deputy chief engineer Zhou Yilin (3rd L) discusses with other technicians beside the quantum satellite at Shanghai Engineering Center for Microsatellites, under the Chinese Academy of Sciences, in Shanghai, east China, May 25, 2016. China plans to launch the world's first quantum satellite that can achieve secure communication in July. The satellite is dedicated to quantum science experiments. (Xinhua/Cai Yang)

​

General engineer Zhu Zhencai (4th R), deputy chief engineer Zhou Yilin (4th L) and other staff members pose for a group photo with the quantum satellite at Shanghai Engineering Center for Microsatellites, under the Chinese Academy of Sciences, in Shanghai, east China, May 25, 2016. China plans to launch the world's first quantum satellite that can achieve secure communication in July. The satellite is dedicated to quantum science experiments. (Xinhua/Cai Yang)

​

Pan Jianwei, a Chinese quantum scientist and professor at the University of Science and Technology of China, demonstrates quantum communication, in Shanghai, east China, May 25, 2016. China plans to launch the world's first quantum satellite that can achieve secure communication in July. The satellite is dedicated to quantum science experiments.(Xinhua/Cai Yang)




Photo taken on May 25, 2016 shows the quantum simulation laboratory under the Chinese Academy of Sciences, in Shanghai, east China. China plans to launch the world's first quantum satellite that can achieve secure communication in July. The satellite is dedicated to quantum science experiments. (Xinhua/Cai Yang)

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## LeGenD

Interesting.

China doing something unique finally.


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## beijingwalker



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## ChineseTiger1986



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## dy1022

China rules

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## TaiShang

*China Ready to Launch World's First Quantum Satellite*
2016-05-28







Pan Jianwei, an academician at the Chinese Academy of Sciences and chief scientist of the quantum satellite project, shows how to make quantum encoded calls on May 25, 2016. [Photo: Xinhua]

China is ready to launch the world's first quantum communications satellite this July, which is said to be the most secure way of communication.

The mission will be launched on the Long March 2D rocket from the Jiuquan Satellite Launch Center in the Gobi Desert.

Work began on the satellite in 2011 and assembly was completed early this year.

Scientists are conducting tests before the launch.

Zhu Zhencai, chief designer of the quantum satellite explained: "the most distinctive feature (of this satellite) is that it has to be aligned with two optical ground stations in a considerably wide range of plus-minus 90 degrees to 75 degrees. *The other feature is that the optical axes of the satellite and the ground telescope have to be aligned strictly, almost like needle-to-head, or 3.5 micro-radians."*

Pan Jianwei, an academician at the Chinese Academy of Sciences (CAS) and chief scientist of the quantum satellite, listed the three main missions of this satellite, which are quantum encoded communications, quantum entanglement and quantum teleportation.

Among them,* quantum encoded communications, hightlight of this cutting-edge technology, can be absolutely secure, which is determined by its nature: quantum information can be neither sensed (uncertainty principle) nor copied (the no-cloning theorem).*

Even the *most powerful computer cannot crack the quantum information*, said Pan.

*China is planning to launch more quantum satellites in the future, aiming for the first international macro-zonal quantum encoded information network by 2030.*

"The three missions (of the quantum satellite) are first-time attempts for China, the world, and the entire human race. Therefore, it draws global expectation," said Pan.

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## Tiqiu

TaiShang said:


> ​
> Photo taken on May 25, 2016 shows the quantum simulation laboratory under the Chinese Academy of Sciences, in Shanghai, east China. China plans to launch the world's first quantum satellite that can achieve secure communication in July. The satellite is dedicated to quantum science experiments. (Xinhua/Cai Yang)
> 
> 
> 
> ​
> Photo taken on May 25, 2016 shows the quantum satellite assembly workshop at Shanghai Engineering Center for Microsatellites, under the Chinese Academy of Sciences, in Shanghai, east China. China plans to launch the world's first quantum satellite that can achieve secure communication in July. The satellite is dedicated to quantum science experiments. (Xinhua/Cai Yang)
> 
> 
> 
> ​
> General engineer Zhu Zhencai introduces the "quantum entanglement source" on the quantum satellite at Shanghai Engineering Center for Microsatellites, under the Chinese Academy of Sciences, in Shanghai, east China, May 25, 2016. China plans to launch the world's first quantum satellite that can achieve secure communication in July. The satellite is dedicated to quantum science experiments. (Xinhua/Cai Yang)
> 
> 
> 
> ​
> Deputy chief engineer Zhou Yilin (3rd L) discusses with other technicians beside the quantum satellite at Shanghai Engineering Center for Microsatellites, under the Chinese Academy of Sciences, in Shanghai, east China, May 25, 2016. China plans to launch the world's first quantum satellite that can achieve secure communication in July. The satellite is dedicated to quantum science experiments. (Xinhua/Cai Yang)
> 
> 
> 
> ​
> General engineer Zhu Zhencai (4th R), deputy chief engineer Zhou Yilin (4th L) and other staff members pose for a group photo with the quantum satellite at Shanghai Engineering Center for Microsatellites, under the Chinese Academy of Sciences, in Shanghai, east China, May 25, 2016. China plans to launch the world's first quantum satellite that can achieve secure communication in July. The satellite is dedicated to quantum science experiments. (Xinhua/Cai Yang)
> 
> 
> 
> ​
> Pan Jianwei, a Chinese quantum scientist and professor at the University of Science and Technology of China, demonstrates quantum communication, in Shanghai, east China, May 25, 2016. China plans to launch the world's first quantum satellite that can achieve secure communication in July. The satellite is dedicated to quantum science experiments.(Xinhua/Cai Yang)
> 
> 
> 
> 
> Photo taken on May 25, 2016 shows the quantum simulation laboratory under the Chinese Academy of Sciences, in Shanghai, east China. China plans to launch the world's first quantum satellite that can achieve secure communication in July. The satellite is dedicated to quantum science experiments. (Xinhua/Cai Yang)


US state department spokesperson: The United States condemn China for hacking us and making thousands Snowden lose job.

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## TaiShang

Tiqiu said:


> US state department spokesperson: The United States condemn China for hacking us and making thousands Snowden lose job.



LOL.

They can move those redundant for domestic spying because they will need more and more in the future.

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## bobsm

*China plans to set up global quantum communications network*
(People's Daily Online) 13:37, June 07, 2016




Photo taken on May 25, 2016 shows the quantum simulation laboratory under the Chinese Academy of Sciences, in Shanghai, east China. (Xinhua Photo)
*
China leads the world in quantum communications *

China has already begun to establish quantum communications networks in several cities, and is currently building a 1,000-kilometer quantum communications line connecting Beijing and Shanghai. A quantum communications satellite will launch in July.

Based on the principles of quantum physics, quantum communication provides a new way to process information, including encoding, storage, transmission and logic operations, as well as the precise manipulation of photons, atoms and other microscopic particles. All this ensures the security of communications and enhances computing speed.

Information security is a necessity in modern society, and quantum communication features, at least theoretically, perfect, unconditional security. It has great significance when it comes to military, financial and personal privacy.

"Traditionally, secure encryption and transmission of information is dependent on complex algorithms," said Pan Jianwei, a Chinese quantum scientist and professor at the University of Science and Technology of China. "But with the increase in computing power, the complex algorithms are bound to be cracked."

Quantum communication boasts ultra-high security, as a quantum photon can neither be separated nor duplicated. It is therefore impossible to wiretap, intercept or crack information transmitted through quantum communication, said Pan.

Pan led his team to achieve secure quantum distribution using an optical fiber over a distance of 100 kilometers in 2007; in 2008, his team built the world's first all-access quantum communications network, and in 2012 they created the first large-scale quantum communications network.

Through additional research, the team hopes to transition from local quantum communications networks to building a global network, which would ensure the absolute security of information transmission.

China will launch its first experimental quantum communications satellite in July. It will be the first of its kind in the world.

Pan also predicted that within a decade or so, it will be possible to create a special quantum computer or quantum simulator, in which the computing power is 10 billion times faster than that of a conventional computer.


http://en.people.cn/n3/2016/0607/c90000-9069224.html

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## TaiShang

beijingwalker said:


> It will assist in the sending of data securely - and be a huge benefit in the fight against hackers - but cause widespread concern that the secretive communist state is pioneering its use.



Who is the concerned party?

Certain neo-fascist Western regimes?

Last time I checked, majority of the world did not care much about China's secure communication capabilities, if not supportive of it.

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## cirr

The quantum satellite is obviously the first step.

What goes inside the upcoming TianGong space station is of real interest and great significance in so far as the applications of quantum and laser technologies are concerned.

So watch out.

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## AndrewJin




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## jhungary

.................

Nothing is un-hackable......Whoever wrote this piece is obviously either do not know anything on Computer/Network Security or simply writing that in a sensationalize point of view.

Quantum Communication only secure end-to-end protocol, which mean it only make it "HARDER" for hacker to hack into the data by conventional means (by spoofing or by layering) by introducing an active check bits (by the means of protons) which indicate the data being hack.

Problem is, it does not secure the data package any better than normal end-to-end protocol. Which means, as the type (Lock and Key) and mode of transfer (Over IP) is the same. And as long as the hacker also have access to quantum computer, it can decode the information......

Think of it like this, while it's impossible to break into the keys without disturbing the sequence. However, it's still possible to spoof the data into accepting the hacker ends is the user end, the only thing the hacker needs is the same equipment that receive the quantum message. I.E. Another Quantum Computer.


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## onebyone

*Chinese satellite is one giant step for the quantum internet*
Craft due to launch in August is first in a wave of planned quantum space experiments.


Elizabeth Gibney
27 July 2016
*Article tools*

PDF
Rights & Permissions
*



*
Cai Yang/Xinhua via ZUMA Wire

China’s 600-kilogram quantum satellite contains a crystal that produces entangled photons.

China is poised to launch the world’s first satellite designed to do quantum experiments. A fleet of quantum-enabled craft is likely to follow.

First up could be more Chinese satellites, which will together create a super-secure communications network, potentially linking people anywhere in the world. But groups from Canada, Japan, Italy and Singapore also have plans for quantum space experiments.

“Definitely, I think there will be a race,” says Chaoyang Lu, a physicist at the -University of Science and Technology of China in Hefei, who works with the team behind the Chinese satellite. The 600-kilogram craft, the latest in a string of Chinese space-science satellites, will launch from Jiuquan Satellite Launch Center in August. The Chinese Academy of Sciences and the Austrian Academy of Sciences are collaborators on the US$100-million mission.

*Related stories*

China’s quantum space pioneer: We need to explore the unknown
China’s dark-matter satellite launches era of space science
Quantum ‘spookiness’ passes toughest test yet
More related stories

Quantum communications are secure because any tinkering with them is detectable. Two parties can communicate secretly — by sharing a encryption key encoded in the polarization of a string of photons, say — safe in the knowledge that any eavesdropping would leave its mark.

So far, scientists have managed to demonstrate quantum communication up to about 300 kilometres. Photons travelling through optical fibres and the air get scattered or absorbed, and amplifying a signal while preserving a photon’s fragile quantum state is extremely difficult. The Chinese researchers hope that transmitting photons through space, where they travel more smoothly, will allow them to communicate over greater distances.

At the heart of their satellite is a crystal that produces pairs of entangled photons, whose properties remain entwined however far apart they are separated. The craft’s first task will be to fire the partners in these pairs to ground -stations in Beijing and Vienna, and use them to generate a secret key.

During the two-year mission, the team also plans to perform a statistical measurement known as a Bell test to prove that entanglement can exist between particles separated by a distance of 1,200 kilometres. Although quantum theory predicts that entanglement persists at any distance, a Bell test would prove it.

The team will also attempt to ‘teleport’ quantum states, using an entangled pair of photons alongside information transmitted by more conventional means to reconstruct the quantum state of a photon in a new location.

“If the first satellite goes well, China will definitely launch more,” says Lu. About 20 satellites would be required to enable secure communications throughout the world, he adds.

The teams from outside China are taking a different tack. A collaboration between the National University of Singapore (NUS) and the University of Strathclyde, UK, is using cheap 5-kilogram satellites known as cubesats to do quantum experiments. Last year, the team launched a cubesat that created and measured pairs of ‘correlated’ photons in orbit; next year, it hopes to launch a device that produces fully entangled pairs.

Costing just $100,000 each, cubesats make space-based quantum communications accessible, says NUS physicist Alexander Ling, who is leading the project.

A Canadian team proposes to generate pairs of entangled photons on the ground, and then fire some of them to a microsatellite that weighs less than 30 kilograms. This would be cheaper than generating the photons in space, says Brendon Higgins, a physicist at the University of Waterloo, who is part of the Canadian Quantum Encryption and Science Satellite (QEYSSat) team. But delivering the photons to the moving satellite would be a challenge. The team plans to test the system using a photon receiver on an aeroplane first.

An even simpler approach to quantum space science, pioneered by a team at the University of Padua in Italy led by Paolo Villoresi, involves adding reflectors and other simple equipment to regular satellites. Last year, the team showed that photons bounced back to Earth off an existing satellite maintained their quantum states and were received with low enough error rates for quantum cryptography (G. Vallone _et al._ _Phys. Rev. Lett._ *115,* 040502; 2015). In principle, the researchers say, the method could be used to generate secret keys, albeit at a slower rate than in more-complex set-ups.

Researchers have also proposed a quantum experiment aboard the International Space Station (ISS) that would simultaneously -entangle the states of two separate properties of a photon — a technique known as hyperentanglement — to make teleportation more reliable and efficient.

As well as making communications much more secure, these satellite systems would mark a major step towards a ‘quantum internet’ made up of quantum computers around the world, or a quantum computing cloud, says Paul Kwiat, a physicist at the University of Illinois at Urbana–Champaign who is working with NASA on the ISS project.

The quantum internet is likely to involve a combination of satellite- and ground-based links, says Anton Zeilinger, a physicist at the Austrian Academy of Sciences in Vienna, who argued unsuccessfully for a European quantum satellite before joining forces with the Chinese team. And some challenges remain. Physicists will, for instance, need to find ways for satellites to communicate with each other directly; to perfect the art of entangling photons that come from different sources; and to boost the rate of data transmission using single photons from megabits to gigabits per second.

If the Chinese team is successful, other groups should find it easier to get funding for quantum satellites, says Zeilinger. The United States has a relatively low profile when it comes to this particular space race, but Zeilinger suggests that it could be doing more work on the topic that is classified.

Eventually, quantum teleportation in space could even allow researchers to combine photons from satellites to make a distributed telescope with an effective aperture the size of Earth — and enormous resolution. “You could not just see planets,” says Kwiat, “but in principle read licence plates on Jupiter’s moons.”

http://www.nature.com/news/chinese-satellite-is-one-giant-step-for-the-quantum-internet-1.20329

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## onebyone

China is planning to bring quantum physics to space. Researchers from the Chinese Academy of Sciences and the Austrian Academy of Sciences are collaborating to build a satellite that will perform the first ever quantum experiments in orbit. The experiments could have applications in future telescopes and communication technology.

The Chinese satellite will be launched sometime in August, where it will test the limits of quantum communication. Onboard the satellite will be a special crystal that generates pairs of entangled photons, which will be fired at two laboratories in Beijing and Vienna. These photons will be used to test the range of quantum entanglement and the feasibility of quantum communications.

Advertisement - Continue Reading Below

Quantum communications rely on a particular property of subatomic particles, that observing them changes their state. Researchers have previously developed ways to use this property to encrypt data, because anyone eavesdropping on communications would leave a mark. The satellite team hopes to deploy this technology in space, where transmitting quantum data is easier.






 Pin  
China's quantum satellite as it prepares for a two-year mission. Credit: Cai Yang/Xinhua via ZUMA Wire
Most


The satellite will test another peculiar quantum phenomenon: entanglement. Quantum entanglement is where two particles seem to share the same state, and changing the state of one particle will change the state of the other, even when the two are incredibly far apart. Einstein famously called this "spooky action at a distance," and the Chinese satellite will test it over the greatest distance yet. By splitting up a pair of entangled photons and sending them to Vienna and Beijing, scientists hope to study entanglement effects over more than 700 miles.

This satellite will likely be the first of many quantum satellites that China and other countries will launch over the next few years. China is planning to launch several more satellites to form a quantum communications network that will allow secure communications with anyone in the world. Other collaborations, like one between the National University of Singapore and the University of Strathclyde, proposed launching multiple small cubesats to perform entanglement experiments. A Canadian team is working on how to entangle photons on the ground and send them to a satellite in orbit.

We live in a quantum world now, and space is just beginning to reflect that.

Source: Nature
http://www.popularmechanics.com/space/satellites/a22084/china-first-quantum-satellite/

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## 艹艹艹

*
In 2016, China will have long March 7, March 5th two new generation launch vehicle will in the Wenchang satellite launch center in the first flight, which Long March 5 is in our country is developing the maximum thrust of rocket, near earth orbit carrying capacity of 25 tons will make our existing rocket carrying capacity increased by 2.5 times, greatly enhance the ability of China's entry into the space. After the first flight of the long march five rocket, will rewrite the world's active service launch vehicle rankings.

In 2016, China will launch Tiangong II space laboratory and Shenzhou 11 manned spacecraft, there will be three Chinese astronauts again battle space.*

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## 艹艹艹

2016-08-14 11:03:36 








In quantum physics, entangled particles remain connected so that actions performed by one affects the behaviour of the other, even if they are separated by huge distances.

BEIJING, Aug. 14 (Xinhua) - The imminent launch of the world's first quantum communication satellite is widely believed to herald a breakthrough in China's development of quantum technology.

Mysterious and confusing, the study of minute particles smaller than atoms has been applied in fields as diverse as computer processing, lasers and nuclear technology.

How will quantum communication change our lives - especially in the age of cyber attacks, wiretapping and information leakage?

*SUPER PROCESSING ABILITY*

Based on the quantum phenomenon that a tiny particle acts as if it's simultaneously in two locations, quantum computing could dwarf the processing power of today's supercomputers.

In normal silicon computer chips, data is rendered in one of two states: 0 or 1. However, in quantum computers, data could exist in both states simultaneously, holding exponentially more information.

One analogy to explain the concept of quantum computing is that it is like being able to read all the books in a library at the same time, whereas conventional computing is like having to read them one after another.

Scientists say that a problem that takes Tianhe-2, one of the fastest super computers in China, 100 years to solve might take a quantum computer just one hundredth of a second.

Many countries have invested heavily in the research and development of such computers.

In July 2015, a quantum-computing lab jointly established by Chinese Academy of Science and Chinese Internet giant Alibaba opened in Shanghai. The lab is expected to produce a general-purpose quantum computer prototype with 50 to 100 quantum bits by 2030.

*HACK-PROOF COMMUNUCATION*

Such powerful computing ability is also viewed as a threat in that it could make everything on a conventional computer hackable.

However, like a coin with two sides, quantum mechanics also serves as protector of information. Quantum key technology boasts ultra-high security as a photon can be neither separated nor duplicated, so it is impossible to wiretap or intercept the information transmitting through it.

Moreover, it has the ability to inform the two communicating users of the presence of any third party trying to eavesdrop. At the same time, the information being intercepted would "collapse" or self-destruct.

China will launch the world's first quantum communication satellite in a matter of days. If the satellite works well, it will pave the way to a hack-proof communication system.

Meanwhile, China will complete and put into operation the world's first secure quantum communication backbone network, the Beijing-Shanghai backbone network, later this year, according to Pan Jianwei, academician of Chinese Academy of Science and chief scientist of quantum communication satellite project.

The 2,000-kilometer backbone network will be used in the fields of finance, electronics and government affairs.

The satellite and the ground-based network will ensure the secure passage of information, Pan said.

Pan reckoned that quantum communication would enter everyday life in about 10 years, securing online banking and payments.

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## Beast

It is a technology breakthru the west do not want to talk much about it. Becos its from rising China 

http://www.nature.com/news/chinese-satellite-is-one-giant-step-for-the-quantum-internet-1.20329

*Chinese satellite is one giant step for the quantum internet*


_Craft due to launch in August is first in a wave of planned quantum space experiments.
_

_Elizabeth Gibney_
_27 July 2016_
*Article tools*

_PDF_
_Rights & Permissions_
_





Cai Yang/Xinhua via ZUMA Wire

China’s 600-kilogram quantum satellite contains a crystal that produces entangled photons.

China is poised to launch the world’s first satellite designed to do quantum experiments. A fleet of quantum-enabled craft is likely to follow.

First up could be more Chinese satellites, which will together create a super-secure communications network, potentially linking people anywhere in the world. But groups from Canada, Japan, Italy and Singapore also have plans for quantum space experiments.

“Definitely, I think there will be a race,” says Chaoyang Lu, a physicist at the -University of Science and Technology of China in Hefei, who works with the team behind the Chinese satellite. The 600-kilogram craft, the latest in a string of Chinese space-science satellites, will launch from Jiuquan Satellite Launch Center in August. The Chinese Academy of Sciences and the Austrian Academy of Sciences are collaborators on the US$100-million mission.
_
*Related stories*

_China’s quantum space pioneer: We need to explore the unknown_
_China’s dark-matter satellite launches era of space science_
_Quantum ‘spookiness’ passes toughest test yet_
_More related stories_
_
Quantum communications are secure because any tinkering with them is detectable. Two parties can communicate secretly — by sharing a encryption key encoded in the polarization of a string of photons, say — safe in the knowledge that any eavesdropping would leave its mark.

So far, scientists have managed to demonstrate quantum communication up to about 300 kilometres. Photons travelling through optical fibres and the air get scattered or absorbed, and amplifying a signal while preserving a photon’s fragile quantum state is extremely difficult. The Chinese researchers hope that transmitting photons through space, where they travel more smoothly, will allow them to communicate over greater distances.

At the heart of their satellite is a crystal that produces pairs of entangled photons, whose properties remain entwined however far apart they are separated. The craft’s first task will be to fire the partners in these pairs to ground -stations in Beijing and Vienna, and use them to generate a secret key.

During the two-year mission, the team also plans to perform a statistical measurement known as a Bell test to prove that entanglement can exist between particles separated by a distance of 1,200 kilometres. Although quantum theory predicts that entanglement persists at any distance, a Bell test would prove it.

The team will also attempt to ‘teleport’ quantum states, using an entangled pair of photons alongside information transmitted by more conventional means to reconstruct the quantum state of a photon in a new location.

“If the first satellite goes well, China will definitely launch more,” says Lu. About 20 satellites would be required to enable secure communications throughout the world, he adds.

The teams from outside China are taking a different tack. A collaboration between the National University of Singapore (NUS) and the University of Strathclyde, UK, is using cheap 5-kilogram satellites known as cubesats to do quantum experiments. Last year, the team launched a cubesat that created and measured pairs of ‘correlated’ photons in orbit; next year, it hopes to launch a device that produces fully entangled pairs.

Costing just $100,000 each, cubesats make space-based quantum communications accessible, says NUS physicist Alexander Ling, who is leading the project.

A Canadian team proposes to generate pairs of entangled photons on the ground, and then fire some of them to a microsatellite that weighs less than 30 kilograms. This would be cheaper than generating the photons in space, says Brendon Higgins, a physicist at the University of Waterloo, who is part of the Canadian Quantum Encryption and Science Satellite (QEYSSat) team. But delivering the photons to the moving satellite would be a challenge. The team plans to test the system using a photon receiver on an aeroplane first.

An even simpler approach to quantum space science, pioneered by a team at the University of Padua in Italy led by Paolo Villoresi, involves adding reflectors and other simple equipment to regular satellites. Last year, the team showed that photons bounced back to Earth off an existing satellite maintained their quantum states and were received with low enough error rates for quantum cryptography (G. Vallone et al. Phys. Rev. Lett. *115,* 040502; 2015). In principle, the researchers say, the method could be used to generate secret keys, albeit at a slower rate than in more-complex set-ups.

Researchers have also proposed a quantum experiment aboard the International Space Station (ISS) that would simultaneously -entangle the states of two separate properties of a photon — a technique known as hyperentanglement — to make teleportation more reliable and efficient.

As well as making communications much more secure, these satellite systems would mark a major step towards a ‘quantum internet’ made up of quantum computers around the world, or a quantum computing cloud, says Paul Kwiat, a physicist at the University of Illinois at Urbana–Champaign who is working with NASA on the ISS project.

The quantum internet is likely to involve a combination of satellite- and ground-based links, says Anton Zeilinger, a physicist at the Austrian Academy of Sciences in Vienna, who argued unsuccessfully for a European quantum satellite before joining forces with the Chinese team. And some challenges remain. Physicists will, for instance, need to find ways for satellites to communicate with each other directly; to perfect the art of entangling photons that come from different sources; and to boost the rate of data transmission using single photons from megabits to gigabits per second.

If the Chinese team is successful, other groups should find it easier to get funding for quantum satellites, says Zeilinger. The United States has a relatively low profile when it comes to this particular space race, but Zeilinger suggests that it could be doing more work on the topic that is classified.

Eventually, quantum teleportation in space could even allow researchers to combine photons from satellites to make a distributed telescope with an effective aperture the size of Earth — and enormous resolution. “You could not just see planets,” says Kwiat, “but in principle read licence plates on Jupiter’s moons.”

Nature

535,

478–479

(28 July 2016)

doi:10.1038/535478a_

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## cirr

Guo GuangCan and team 

http://www.nature.com/nphoton/journal/vaop/ncurrent/full/nphoton.2016.144.html











@Bussard Ramjet

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## Rockford

Congratulations China , This is where we Indians lack ,we boast and they work

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## GS Zhou

August, 14th, 2016, Jiuquan, China: China's first quantumn communication satellite has been delivered to the Jiuquan satellite launch center. The Jiuquan launch center has made four rounds of status check to the satellite. The launch will be made in 2H of August.

This is the *first quantumn communication satellite in human being's history. *The following four experiments will be conducted by this satellite on orbit:
- High-speed quantumn secret key distribution between the satellite and the ground (星地高速量子密钥分发实验)
- Wide-area networks of quantumn communication (广域量子通信网络实验)
- Quantumn entanglement distribution between satellite and ground (星地量子纠缠分发实验)
- Quantumn teleportation between the ground and the satellite (地星量子隐形传态实验)

China expects to have *20 quantumn communication satellites on orbit by 2030*.

China is the pioneer in quantumn communication technology. The experimental quantumn communication networks have been established in Beijing, Shanghai, Jinan and Hefei respectively. The launch of this satellite will expand the technology coverage to a much-wider area.






Picture of the satellite





Some loads on the satellite: High-speed quantumn secret-key generation terminal





Some loads on the satellite: High speed near infrared single photon detector

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## Kyle Sun

guys. we need to ask sheldon copper to explain us what hell it is.


sound like very very high .end .tech.

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## war&peace

Quantum leap in satellite technology by China

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## xunzi

We are going to change how information is going to process in the future.

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## Akasa

Does anybody know where I can find a live webcast for the launch?

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## cirr

Mozi is ready to go.

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## hexagonsnow



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## GS Zhou

China officially names the first quantumn satellite in human history as "Mozi".

Mozi (470 to 390 BC), a Chinese philosopher and the founder of Mohism, is the first one who mentions the principles behind the pinhole camera or camera obscura. His work initiates human's research on the theory of light.

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## cirr

Success!!

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## cirr

*Long March 2D launches world’s first quantum communications satellite*

August 15, 2016 by Rui C. Barbosa






The Chinese have launched the first satellite that can achieve quantum communications between space and Earth. The launch of the Quantum Science Satellite – called Mozi – took place at 17:40 UTC on Monday using a Long March-2D (Chang Zheng-2D) launch vehicle from the 603 Launch Pad of the LC43 complex at the Jiuquan space center.
*
Chinese Launch:*

The new satellite is dedicated to quantum science experiments. The Quantum Space Satellite, (or Quantum Experiments at Space Scale) will test the phenomena of quantum entanglement.

Operated by the China Academy of Sciences, this 500 kg satellite – announced as the name “Mozi” in honor of a fifth century BC Chinese scientist – contains a quantum key communicator, quantum entanglement emitter, entanglement source, processing unit, and a laser communicator.






QUESS will relay transmissions between two ground stations (one in China, and the other in Europe) transmitting quantum keys.

During the mission, Chinese scientists will implement a series of science missions between the satellite and quantum communication ground stations.

QSS will operate on a Sun-synchronous circular orbit with an altitude of 600 km.

One of the major objectives of the mission is to set a Quantum Key Distribution from satellite to ground, setting an ultra-long-range quantum channel between ground and satellite with the assistance of high-precision acquisition, tracking and pointing system, implement a quantum key distribution between the satellite and the ground stations, and carry out unconditional secure quantum communication experiments.






The mission will also create a global-scale quantum communication network, establishing a real wide-area network for quantum communication using the satellite repeater and two arbitrary quantum ground stations and their auxiliary local-area fiber quantum networks.

It will also test the Quantum Entanglement Distribution from satellite to two ground stations in China and in Europe, creating a real wide-area network for quantum communication using the satellite repeater and two arbitrary quantum ground stations and their auxiliary local-area fiber quantum networks.

The Austrian Academy of Sciences provided the optical receivers for the European ground stations.

Finally, the QSS plans to achieve Quantum Teleportation from ground to satellite as a totally new way of communication, quantum teleportation is the fundamental process of quantum networks and quantum computing.






A high-quality quantum entanglement source on the ground will be built to achieve ground-to-satellite teleportation experiments based on photon entanglement.

The Quantum Science Satellite consists of several different subsystems: the attitude control subsystem, power subsystem, thermal control subsystem, telemetry and command subsystem, communications subsystem, structure subsystem, and housekeeping subsystem.

In order to design the Quantum Science Satellite, the mission activities, requirements, and mission analysis have been completed at the end of 2011.

Mission definition and justification and key technique research were finalized by the end of 2012. Detailed definitions of the spacecraft were completed in March 2013.

Prototypes of on board devices and components were been built for verification and have been checked and approved at the end of August 2013. Electronic characteristic tests on the prototypes were carried out by the end of September 2013.






After that, in October 2013, the structural prototype of the satellite was assembled and the mechanical environmental simulation tests have been completed.

Subsequently, the thermal balance tests were finalized in December 2013 on the thermal characteristic prototype of the satellite.

At the end of October 2013, some prototypes of on board devices, which are designed for qualification tests, were put into production and were checked and accepted by the end of March 2014. The satellite arrived at Jiuquan on July 8, 2016.

The payload of the quantum science experimental satellite includes quantum key communicator, quantum entanglement emitter, quantum entanglement source, quantum experiment controller and processor and high-speed coherent laser communicator.






The key techniques of the optical communication terminal consist of high precision tracking and pointing, wide-band high-extinction ratio polarization-maintaining capabilities and the aviation engineering of quantum entanglement source.

Developed by the Chinese Academy of Sciences (CAS), the Quantum Science Satellite is part of China’s Strategic Priority Program on Space Science.

The first satellite of this program, a dark-matter satellite, was launched into space in December. The second, the country’s first microgravity satellite, the SJ-10, was successfully launched on April 6.

A hard X-ray telescope for black hole and neutron star studies is also expected to be launched in the second half of this year.

The launch also included a Spanish passenger in the form of a 6U CubeSat “³Cat-2” from the NanoSat lab at Universitat Politècnica de Catalunya, classed as “a novel GNSS-R payload for Earth observation”.

https://www.nasaspaceflight.com/2016/08/long-march-2d-quantum-communications-satellite/

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## cirr

*China launches world's first quantum science satellite from Jiuquan*

ANDREW JONES

2016/08/15




China's Wukong (DAMPE) dark matter probe blasts off from Jiuquan Satellite Launch Centre in the Gobi Desert on a Long March 2D rocket on December 17, 2015. (Photo: Qu Jing Liang, China Daily)

China has launched the world's first quantum science satellite designed to test the possibilities of quantum communications and verify the fundamental laws of quantum mechanics.

The Quantum Science Satellite lifted off from the Jiuquan Satellite Launch Centre at 01:40 Beijing time on Tuesday (17:40 UTC Monday), with a Long March 2D rocket sending the 620kg probe into a sun-synchronous orbit 600 km above the Earth.

Once operational, the satellite will attempt an unprecedented experiment to see if the spooky property of quantum entanglement can operate at long distance by sending entangled photons from the satellite to two ground stations separated by around 1,200 kilometres.

pic.twitter.com/VjRoEnvps3

— ChinaSpaceflight (@cnspaceflight) August 15, 2016

Also referred to as QSS or QUESS, the satellite will also test the possibilities of communication via quantum 'teleportation', using an entangled pair of photons.

If the satellite can transmit quantum information between ground stations, it could have huge implications for cryptography, as it would allow two parties to communicate secretly.

QUESS's payloads include a quantum key communicator, quantum entanglement emitter, quantum entanglement source, quantum experiment controller and processor and a laser communicator.

The instruments were developed by the National Space Science Centre (NSSC) in Beijing under the Chinese Academy of Sciences (CAS).





_Above: Payloads for China's QUESS quantum satellite (NSSC)._

The mission is the brainchild of Pan Jianwei of CAS, described by Nature as China’s quantum space pioneer. The experiments will also involve collaboration with the Austrian Academy of Sciences in Vienna.

Following this China's Tiangong-2 space lab, due to launch in mid-September, will also test space-Earth quantum key distribution (QKD), a methodology for generating and distributing random encryption keys using quantum mechanics.

The missions are part of a more ambitious target of establishing a global-scale quantum communication network.

The day before launch of QUESS the satellite was nicknamed '墨子号', referring to the ancient Chinese philosopher Mozi, also known as Micius, born around 470 BCE, who is said to have discovered that light travels in straight lines.

The launch is seen as a step forward for both natioanl security in terms of encryption, and a technological advance.

Also along for the ride on the mission was the 6-unit CubeSat³Cat-2 developed by the Nanosat lab of the Polytechnic University of Catalonia in Spain for Earth observation, and launched inside a cubesat pod manufactured by Innovative Solutions In Space of the Netherlands.

*China's space science boom*

QUESS is the third of four Chinese space science satellites that will be launched within a year of each other, marking the fruition of a CAS strategic space science programme launched in 2011.

Implemented by the NSSC, two missions – the DAMPE (Wukong) Dark Matter probe in December, and April’s Shijian-10 retrievable microgravity space science satellite – have already been launched.

The fourth, the Hard X-ray Modulation Telescope (HXMT), has recently passed factory tests and will launch late this year.

It will observe black holes, neutron stars and other phenomena based on their X-ray and gamma ray emissions over a four-year lifetime.





_Above: An illustration of HXMT, due to launch in late 2016._

And this is just the beginning of a new and exciting era of Chinese space science research.

China has produced a national roadmap for space science for 2016-2030 produced by the NSSC, and is already working on the next batch of missions, including the SMILE project in collaboration with Europe.

SMILE is one of five new space probes to study a range of Earth, solar and deep space phenomena now in development.

China’s nascent space science programme received a big budget boost earlier this year, granting around 5.9 billion yuan (US$ 910m) across five years.

"The funding means we are likely to launch 15 to 20 scientific satellites, if not more, by 2030," said Dr Wu Ji, director-general of the NSSC.

http://gbtimes.com/china/china-launches-worlds-first-quantum-science-satellite-jiuquan

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## Kyle Sun

good!

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## Economic superpower

Great to see China leading this field.

World's first

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## Bussard Ramjet

http://www.nature.com/news/chinese-satellite-is-one-giant-step-for-the-quantum-internet-1.20329

This is an exceptional piece above. 

What interested me was: 

If the Chinese team is successful, other groups should find it easier to get funding for quantum satellites, says Zeilinger. The United States has a relatively low profile when it comes to this particular space race, but Zeilinger suggests that it could be doing more work on the topic that is classified.

Zeilinger is the top scientist in the field of quantum communications. 

He must have some reason to suggest that US is working on a classified quantum communication project!

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## 艹艹艹

2016-08-15 23:16:11 GMT2016-08-16 07:16:11(Beijing Time) Xinhua English

*China successfully launched the world's first quantum satellite from the Jiuquan Satellite Launch Center in northwestern Gobi Desert at 1:40 a.m. on Tuesday.

In a cloud of thick smoke, the satellite, Quantum Experiments at Space Scale (QUESS), roared into the dark sky on top of a Long March-2D rocket.

The 600-plus-kilogram satellite will circle the Earth once every 90 minutes after it enters a sun-synchronous orbit at an altitude of 500 kilometers.

It is nicknamed "Micius," after a fifth century B.C. Chinese philosopher and scientist who has been credited as the first one in human history conducting optical experiments.

In its two-year mission, QUESS is designed to establish "hack-proof" quantum communications by transmitting uncrackable keys from space to the ground, and provide insights into the strangest phenomenon in quantum physics -- quantum entanglement.

Quantum communication boasts ultra-high security as a quantum photon can neither be separated nor duplicated. It is hence impossible to wiretap, intercept or crack the information transmitted through it.








*
(2/2)China launches the world's first quantum satellite on top of a Long March-2D rocket from the Jiuquan Satellite Launch Center in Jiuquan, northwest China's Gansu Province, Aug. 16, 2016. The world's first quantum communication satellite, which China is preparing to launch, has been given the moniker "Micius," after a fifth century B.C. Chinese scientist, the Chinese Academy of Sciences (CAS) announced Monday. (Xinhua/Jin Liwang)
*
With the help of the new satellite, scientists will be able to test quantum key distribution between the satellite and ground stations, and conduct secure quantum communications between Beijing and Xinjiang's Urumqi.

QUESS, as planned, will also beam entangled photons to two earth stations, 1,200 kilometers apart, in a move to test quantum entanglement over a greater distance, as well as test quantum teleportation between a ground station in Ali, Tibet, and itself.

"The newly-launched satellite marks a transition in China's role -- from a follower in classic information technology (IT) development to one of the leaders guiding future IT achievements," said Pan Jianwei, chief scientist of QUESS project with the Chinese Academy of Sciences (CAS).

The scientists now are expecting quantum communications to fundamentally change human development in the next two or three decades, as there are enormous prospects for applying the new generation of communication in fields like defense, military and finance.

SPOOKY & ENTANGLED

Quantum physics is the study of the basic building blocks of the world at a scale smaller than atoms. These tiny particles behave in a way that could overturn assumptions of how the world works.

One of the strange properties of quantum physics is that a tiny particle acts as if it's simultaneously in two locations -- a phenomenon known as "superposition." The noted interpretation is the thought experiment of Schrodinger's cat -- a scenario that presents a cat that may be simultaneously both alive and dead.

If that doesn't sound strange enough, quantum physics has another phenomenon which is so confounded that Albert Einstein described as "spooky action at a distance" in 1948.

Scientists found that when two entangled particles are separated, one particle can somehow affect the action of the far-off twin at a speed faster than light.

Scientists liken it to two pieces of paper that are distant from each other: if you write on one, the other immediately shows your writing.

In the quantum entanglement theory, this bizarre connection can happen even when the two particles are separated by the galaxy.

By harnessing quantum entanglement, the quantum key technology is used in quantum communications, ruling out the possibility of wiretapping and perfectly securing the communication.

A quantum key is formed by a string of random numbers generated between two communicating users to encode information. Once intercepted or measured, the quantum state of the key will change, and the information being intercepted will self-destruct.

According to Pan, scientists also plan to test quantum key distribution between QUESS and ground stations in Austria. Italy, Germany and Canada, as they have expressed willingness to cooperate with China in future development of quantum satellite constellations, said Pan.

LIFE CHANGING

With the development of quantum technology, quantum mechanics will change our lives in many ways. In addition to quantum communications, there are quantum computers that have also drawn attentions from scientists and governments worldwide.

Quantum computing could dwarf the processing power of today's supercomputers.

In normal silicon computer chips, data is rendered in one of two states: 0 or 1. However, in quantum computers, data could exist in both states simultaneously, holding exponentially more information.

One analogy to explain the concept of quantum computing is that it is like being able to read all the books in a library at the same time, whereas conventional computing is like having to read them one after another.

Scientists say that a quantum computer will take just 0.01 second to deal with a problem that costs Tianhe-2, one of the most powerful supercomputers in the world, 100 years to solve.

Many, however, is viewing this superpower as a threat: if large-scale quantum computers are ever built, they will be able to crack all existing information encryption systems, creating an enormous security headache one day.

Therefore, quantum communications will be needed to act like a "shield," protecting information from the "spear" of quantum computers, offering the new generation of cryptography that can be neither wiretapped nor decoded.

GOING GLOBAL?

With the launch of QUESS, Chinese scientists now are having their eyes on a ground-to-satellite quantum communication system, which will enable global scale quantum communications.

In past experiments, quantum communications could only be achieved in a short range, as quantum information, in principle, could travel no more than 500 kilometers through optical fibers on the land due to the loss of photons in transmission, Pan explained.

Since photons carrying information barely get scattered or absorbed when travelling through space and Earth's atmosphere, said Pan, transmitting photons between the satellite and ground stations will greatly broaden quantum communications'reach.

However, in quantum communications, an accurate transmission of photons between the "server" and the "receiver" is never easy to make, as the optic axis of the satellite must point precisely toward those of the telescopes in ground stations, said Zhu Zhencai, QUESS chief designer.

It requires an alignment system of the quantum satellite that is 10 times as accurate as that of an ordinary one and the detector on the ground can only catch one in every one million entangled photons fired, the scientist added.

What makes it much harder is that, at a speed of eight kilometers per second, the satellite flying over the earth could be continuously tracked by the ground station for merely a few minutes, scientists say.

"It will be like tossing a coin from a plane at 100,000 meters above the sea level exactly into the slot of a rotating piggy bank," said Wang Jianyu, QUESS project's chief commander.

Given the high sensitivity of QUESS, people could observe a match being lit on the moon from the Earth, Wang added.

After years of experimenting, Chinese scientists developed the world' s first-ever quantum satellite without any available reference to previous projects. Now they are waiting to see QUESS's performance in operation.

According to Pan, his team has planned to initiate new projects involving research on quantum control and light transmission in space station, as well as tests on quantum communications between satellites, all-time quantum communications and the application of quantum key network.

"If China is going to send more quantum communication satellites into orbit, we can expect a global network of quantum communications to be set up around 2030," said Pan.*

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## cirr

Laozi, Sunzi, Zhuangzi, Hanfeizi, Guiguzi.....or even Kongzi, I don't care what they launch next.

I just want to know when they are going to lob our resident @xunzi and @XiaoYaoZi into orbit!!!

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## Kyle Sun

cirr said:


> Laozi, Sunzi, Zhuangzi, Hanfeizi, Guiguzi.....or even Kongzi, I don't care what they launch next.
> 
> I just want to know when they are going to lob our resident @xunzi and @XiaoYaoZi into orbit!!!


This reply makes my day



cirr said:


> Laozi, Sunzi, Zhuangzi, Hanfeizi, Guiguzi.....or even Kongzi, I don't care what they launch next.
> 
> I just want to know when they are going to lob our resident @xunzi and @XiaoYaoZi into orbit!!!


This reply makes my day

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## Jlaw

This should be classified imo

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## Dungeness

Bussard Ramjet said:


> http://www.nature.com/news/chinese-satellite-is-one-giant-step-for-the-quantum-internet-1.20329
> 
> This is an exceptional piece above.
> 
> What interested me was:
> 
> If the Chinese team is successful, other groups should find it easier to get funding for quantum satellites, says Zeilinger. The United States has a relatively low profile when it comes to this particular space race, but Zeilinger suggests that it could be doing more work on the topic that is classified.
> 
> Zeilinger is the top scientist in the field of quantum communications.
> 
> He must have some reason to suggest that US is working on a classified quantum communication project!




Just wondering how your countrymen are going to mock China this time for "Copy and Paste".

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## GS Zhou

Congratulations to our scientists!!

In addition to world's first quantumn satellite, China is also building up world's first long-distance land-based quantumn communication network. The 2,000-km long quantumn network between Beijing and Shanghai will be completed in November this year!

量子保密通信“京沪干线”年底开通
时间：2016-06-06 浏览次数： 55 来源： 科技日报 字号：[ 大 中 小 ]

　　【科技日报北京电，记者张盖伦】　“京沪干线”不仅指能跑火车的铁轨，也指能跑量子密钥的光纤。在6月1日陈嘉庚青年科学奖颁奖会上，量子保密通信“京沪干线”项目工程总师、中科大教授陈宇翱向科技日报记者透露，该项目将于2016年年底正式交付使用。

　　*“目前工程已经完成了四分之三。量子京沪干线全长2000余公里，目前已经完成了约1500公里，而剩下的500公里预计也将于下个月打通。”陈宇翱表示，11月份左右，“京沪干线”可以达到“开始运行”的状态，年底能正式交付使用。*

　　国家发改委立项的“京沪干线”大尺度光纤量子通信骨干网工程，从北京出发，经过济南、合肥，到达上海。利用这一高可信、可扩展、军民融合的广域光纤量子通信网络，京沪两地的金融机构可以进行保密通信，包括电话、视频通话、电子邮件。

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## Economic superpower

Dungeness said:


> Just wondering how your countrymen are going to mock China this time for "Copy and Paste".



Don't respond to trolls. Put them ALL on ignore.

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## 艹艹艹

2016-08-16 10:45Xinhua_Editor: Mo Hong'e
http://www.ecns.cn/2016/08-16/222760.shtml_





China launches the world's first quantum satellite on top of a Long March-2D rocket from the Jiuquan Satellite Launch Center in Jiuquan, northwest China's Gansu Province, Aug. 16, 2016. (Photo/Xinhua)
China's successful launch of the world's first quantum satellite was "very exciting" and can help conduct experiments that may lead to "much more secure" quantum communications, a U.S. quantum expert said.

"The event is indeed very exciting and does carry global importance because this would be the first such experiment," said Alexander Sergienko, a professor of electrical and computer engineering at the Boston University.

The satellite, Quantum Experiments at Space Scale (QUESS), lifted off from China's Jiuquan Satellite Launch Center at 1:40 a.m. Tuesday, local time.

Sergienko said the quantum communication race has been going on for the last 20 years since the initial demonstration of quantum key distribution link under Lake Geneva in 1995.

After that, metropolitan secure communication networks have been developed and demonstrated in Boston, Vienna, Beijing, and Tokyo, and many more examples of quantum metropolitan networks have been demonstrated in the last five years covering Canada, Italy, U.K. and Australia, he said.

"The race is now moving in the near space in order to cover longer distances between different metropolitan areas," he said.

"I know there were plans to develop multiple point-by-point multi-city quantum communication segments to cover the distance between Shanghai and Beijing. A successful implementation of the satellite project would allow covering it in one step."

Sergienko also predicted that quantum communication and cryptography will be first used to ensure the most important communication lines such as used by the government and by major business in their communication.

China said the 600-plus-kilogram QUESS, nicknamed "Micius," is expected to circle the Earth once every 90 minutes after it enters a sun-synchronous orbit at an altitude of 500 kilometers.

In its two-year mission, QUESS is designed to establish "hack-proof" quantum communications by transmitting uncrackable keys from space to the ground, and provide insights into the strangest phenomenon in quantum physics -- quantum entanglement.

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## Bussard Ramjet

Dungeness said:


> Just wondering how your countrymen are going to mock China this time for "Copy and Paste".



Do you think US has a secret Manhattan type project for quantum computing and networks?


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## Beast

Bussard Ramjet said:


> http://www.nature.com/news/chinese-satellite-is-one-giant-step-for-the-quantum-internet-1.20329
> 
> This is an exceptional piece above.
> 
> What interested me was:
> 
> If the Chinese team is successful, other groups should find it easier to get funding for quantum satellites, says Zeilinger. The United States has a relatively low profile when it comes to this particular space race, but Zeilinger suggests that it could be doing more work on the topic that is classified.
> 
> Zeilinger is the top scientist in the field of quantum communications.
> 
> He must have some reason to suggest that US is working on a classified quantum communication project!


US don't have money. They are busy spending money on super carrier and reopen production line of sea wolf class SSN and F-22 stealth fighter. US is falling into a trap exactly setup by us 



Bussard Ramjet said:


> Do you think US has a secret Manhattan type project for quantum computing and networks?


Sourgrape spotted. Some loser want to make up some fantasy and claim some unknown project. US is one of the King of bragging. Anything they have, they would say it out. If no, means no. 

http://www.wsj.com/articles/chinas-latest-leap-forward-isnt-just-greatits-quantum-1471269555

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## xunzi

Like I said, quantum is revolutionize the next generation of technology. We are talking about going beyond the solar system type of travel here. Just imagine being able to see other planet in another farther galaxy at home excited me already!

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## Bussard Ramjet

Beast said:


> US don't have money. They are busy spending money on super carrier and reopen production line of sea wolf class SSN and F-22 stealth fighter. US is falling into a trap exactly setup by us
> 
> 
> Sourgrape spotted. Some loser want to make up some fantasy and claim some unknown project. US is one of the King of bragging. Anything they have, they would say it out. If no, means no.
> 
> http://www.wsj.com/articles/chinas-latest-leap-forward-isnt-just-greatits-quantum-1471269555



It is not me, but Anton Zeilinger claiming that US has classified stuff. It never even occurred to me once before. 

He is the leading scientist in this area. Pan Jianwei, and Lu Chaoyang both worked as students under him.


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## TaiShang

*'Micius' to create $7.5b quantum communication market*
China Daily, August 16, 2016




China launches the world's first quantum satellite on top of a Long March-2D rocket from the Jiuquan Satellite Launch Center in Jiuquan, Northwest China's Gansu province, Aug 16, 2016.[Photo/Xinhua]


China successfully launched the world's first quantum satellite "Micius", which is named after the ancient Chinese philosopher and scientist, from the Jiuquan Satellite Launch Center in northwestern Gobi Desert in the early hours of today.

*Compared with traditional communication which faces bottlenecks or downside pressure, quantum communications is expected to be widely used in government, energy, finance, broadcasting and TV sectors and create a market worth over 50 billion yuan ($7.54 billion) in the next five years, the National Business Daily reports.*

It marks a breakthrough in the development of quantum communications, communication expert Zhang Peng told the newspaper, adding that capital investment is now focusing more on satellite than internet. However, it will need more time to put the network into real use, Zhang said.

*"If China is going to send more quantum communication satellites into orbit, we can expect a global network of quantum communications to be set up around 2030,"* Pan Jianwei, chief scientist of satellite project with the Chinese Academy of Sciences, told the Xinhua News Agency.

Though it still on the start-up phase, several securities companies issued reports, saying quantum communications will enter the harvest time. "Based on the characters of confidentiality and security, in the future, it will be widely used in military, government and energy."

TF Securities said over the next three years equipment and devices of military market is expected to be valued at 30 billion yuan, plus the civilian market, the market value of energy, finance, broadcasting and TV sectors will exceed 50 billion yuan over the five years.

*So far more than 10 listed companies are involved in quantum communications, such as Kehua Tech, Sanlux Co Ltd, Zhejiang Orient Holdings Co Ltd, Kaile Science and Technology Co Ltd and Digital China Information Service Company Ltd.*

Zhejiang Orient has closed higher for three consecutive trading days as its shareholding company invested in quantum communication enterprises, Zhejiang Shenzhen Quantum Technology Co Ltd and QuantumCTek Co Ltd.

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## TaiShang

That's a billion dollar industry in the making.

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## Shotgunner51

TaiShang said:


> TF Securities said over the next three years equipment and devices of military market is expected to be valued at 30 billion yuan, plus the civilian market, the market value of energy, finance, broadcasting and TV sectors will exceed 50 billion yuan over the five years.
> 
> *So far more than 10 listed companies are involved in quantum communications, such as Kehua Tech, Sanlux Co Ltd, Zhejiang Orient Holdings Co Ltd, Kaile Science and Technology Co Ltd and Digital China Information Service Company Ltd.*



Good investments!

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## CHN Bamboo

PRISM is never to happen again.

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## onebyone

4 objects have been cataloged by USSTRATCOM:
2016-051A/41731 in 488 x 504 km x 97.36°
2016-051B/41732 in 484 x 503 km x 97.35°
2016-051C/41733 in 485 x 504 km x 97.38°
2016-051D/41734 in 218 x 541 km x 97.40° (CZ-2D 2nd stage)












QSS (Mozi); ³Cat-2; Lixing-1

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## Jlaw

Dungeness said:


> Just wondering how your countrymen are going to mock China this time for "Copy and Paste".


he's probably going to use America and mention the Manhattan project or something like that to soothe his bruised Indian ego

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## Jlaw

it's Mozi. **** westerner for fucking our names up

U.S expert excited? It's China's satellite, why so excited?

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## Beast

Jlaw said:


> it's Mozi. **** westerner for fucking our names up
> 
> U.S expert excited? It's China's satellite, why so excited?


Finally, they can't claimed it stolen but have to admit its China innovation and design. They know if they make such lies even 3 years old kid will not believe it. How can China stole things it never have before. It must be innovated.

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## Jlaw

Beast said:


> Finally, they can't claimed it stolen but have to admit its China innovation and design. They know if they make such lies even 3 years old kid will not believe it. How can China stole things it never have before. It must be innovated.


Wrong kid. China stole it from India. India invented space flight, telecommunication, and the number 0 10,000 years ago. Where was Chinese then?



Beast said:


> Finally, they can't claimed it stolen but have to admit its China innovation and design. They know if they make such lies even 3 years old kid will not believe it. How can China stole things it never have before. It must be innovated.



No such thing as stolen. If you are capable to copy and make it better that itself is harder than some people have you believe.

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## TheTheoryOfMilitaryLogistics

China must have stolen the design in white-skins' mind.

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## Beast

TheTheoryOfMilitaryLogistics said:


> China must have stolen the design in white-skins' mind.


They are crying now..

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## ebrahym

Jlaw said:


> No such thing as stolen. If you are capable to copy and make it better that itself is harder than some people have you believe


exactly no need to reinvent the wheel


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## Three_Kingdoms

Haha Micius, Confucius, Mencius, Canton, Peking, HongKong, LongMarch rockets, Yuan-. Tang-, Jin-, Xia-class ... submarines ... WTF

Hackers are going to lose their jobs in coming decades
Ranting and joking aside, a big Congrats to our Scientists

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## ChineseTiger1986

Beast said:


> US don't have money. They are busy spending money on super carrier and reopen production line of sea wolf class SSN and F-22 stealth fighter. US is falling into a trap exactly setup by us
> 
> 
> Sourgrape spotted. Some loser want to make up some fantasy and claim some unknown project. US is one of the King of bragging. Anything they have, they would say it out. If no, means no.
> 
> http://www.wsj.com/articles/chinas-latest-leap-forward-isnt-just-greatits-quantum-1471269555



The Hindu ultra-nationalist is desperate, so he can only put his hope on the US to counter against China.

Unfortunately, even the US will keep disappointing him.

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## CAPRICORN-88

That is part of the *Asymmetrical Advantages China has over her immediate adversary USA *and it scares the shit out of them.

Now USA has to borrow more money from China to develop NEW technology against China.

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## TaiShang

*Satellite to blaze trail for hack-proof communication*
China Daily, August 17, 2016




China successfully launched the world's first quantum satellite from the Jiuquan Satellite Launch Center in northwestern Gobi Desert at 1:40 am on Tuesday. [Photo/Xinhua] 


China launched the world's first quantum experiment satellite on Tuesday, taking a big step in building a space-based quantum communication network that would be virtually uncrackable.

The 631-kg satellite, named after the ancient Chinese philosopher and scientist Micius, was lifted atop a Long March 2D rocket from the Jiuquan Satellite Launch Center in the Inner Mongolia autonomous region at 1:40 am. It will operate 500 kilometers above Earth for at least two years.

It is the third of the Chinese Academy of Sciences' first space science satellites. Micius follows the Dark Matter Particle Explorer Satellite, which will help scientists deepen their understanding of the past and future of galaxies and the universe, and the Shijian 10, which carried out a series of experiments in microgravity in space, according to scientists at the academy.

The Micius will test the technology of relaying quantum keys, which can be used to encrypt or decrypt data, between ground stations and the satellite, Gong Jiancun, deputy director of the academy's National Space Science Center, told reporters at the launch center.

*He said the experiment will involve encoding and sharing of a cryptographic key using the quantum properties of photons, with the aim of paving the way for the commercial use of quantum communications.

Previous research has found that it is practically impossible to crack, intercept or wiretap quantum communications because the physical traits of the quantum key prevent it from being replicated, separated or reverse-engineered.

Any attempt to interfere with the transmission of photons would leave its mark and disrupt the communication, thereby warning the sender and receiver.*

Another task of Micius will be to conduct experiments to help scientists improve their research of quantum mechanics, Gong said.

Pan Jianwei, an academician at CAS and chief scientist for the quantum satellite project, said, "Once the tests and experiments prove successful, quantum communications technology will start to be adopted in some business sectors such as the finance and banking industries. "In the near future, say 15 years, it will also find a way into people's lives, thanks to the development of infrastructure."

Wang Jianyu, the quantum satellite project's executive deputy head, said the satellite's instruments are very advanced, so they can meet the tough requirements of the mission's experiments.

"Matching the photon beam with the ground station is like throwing coins in succession from 10,000 meters above the ground, and they must fall into the narrow slot of a moving piggy bank," he said.

"Moreover, detecting the photons requires the equipment to be so sensitive that you can use it to find a match that is on fire on the surface of the moon. The satellite's accuracy and agility are the best, compared with other Chinese satellites."
*
China's second space laboratory, Tiangong II, which will be sent into space in mid-September, will also perform quantum key distribution experiments, said Pan.*

In addition to China, researchers in Austria, Germany, Singapore, the United Kingdom, Canada and Italy are also developing quantum communication technologies, he said.

"We are in cooperation with Austrian researchers in the Micius project, while our counterparts in Germany and Italy will join us later. Canada also wants to be part of the program and is in talks with us on this matter," Pan said. "This is because Chinese scientists are good in this field."

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## dy1022



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## Nilgiri

Some Chinese always come to congratulate India when we launch something.

So let me return the favour and say a big Congrats to China for the launch and also developing something very revolutionary here.

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## cirr

GS Zhou said:


> August, 14th, 2016, Jiuquan, China: China's first quantumn communication satellite has been delivered to the Jiuquan satellite launch center. The Jiuquan launch center has made four rounds of status check to the satellite. The launch will be made in 2H of August.
> 
> This is the *first quantumn communication satellite in human being's history. *The following four experiments will be conducted by this satellite on orbit:
> - High-speed quantumn secret key distribution between the satellite and the ground (星地高速量子密钥分发实验)
> - Wide-area networks of quantumn communication (广域量子通信网络实验)
> - Quantumn entanglement distribution between satellite and ground (星地量子纠缠分发实验)
> - Quantumn teleportation between the ground and the satellite (地星量子隐形传态实验)
> 
> China expects to have *20 quantumn communication satellites on orbit by 2030*.
> 
> China is the pioneer in quantumn communication technology. The experimental quantumn communication networks have been established in Beijing, Shanghai, Jinan and Hefei respectively. The launch of this satellite will expand the technology coverage to a much-wider area.
> View attachment 326047
> 
> 
> 
> Picture of the satellite
> View attachment 326043
> 
> 
> Some loads on the satellite: High-speed quantumn secret-key generation terminal
> View attachment 326046
> 
> 
> Some loads on the satellite: High speed near infrared single photon detector
> View attachment 326045



Strange that the 5th experiment didn't get a mention: 

*中科院上海光学精密机械研究所第二代空间相干激光通信载荷：速率5Gbps*

2016/08/16

我国首次空间高速相干激光通信试验将在量子卫星上开展

2016年08月16日 11:18　来源：新华网

新华社上海8月16日电(记者王琳琳)16日，中科院上海光机所研制的空间高速相干激光通信载荷搭载量子卫星发射升空，将开展卫星与新疆、北京地面站之间的高速相干激光通信技术验证。这将是我国首次开展空间高速相干激光通信试验，标志着我国初步具备研制星间相干激光通信载荷的能力。

空间高速激光通信技术用于实现星间、星地高速数据传输，可克服高分辨率卫星成像数据传输有限的瓶颈，是空间数据中继、星间组网的重要手段，也是一项国内外航天界高度关注的前沿高科技技术。

量子卫星相干激光通信载荷指挥、中科院上海光机所副所长陈卫标表示，相干探测激光通信，具有灵敏度高、白天可工作等技术优点，特别适用于空间超远距离(数万公里)卫星间的高速激光通信。相对第一代几十、数百兆／秒速率的直接探测激光通信技术，第二代空间相干激光通信技术速率可达数千兆／秒，乃至数万兆／秒，成为国内外星间数据中继的主流方案。

此前，欧美等发达国家已投入大量人力物力开展相关技术研究，并取得重要进展。2007年，欧空局(ESA)率先在TerraSAR－X卫星与美国NFIRE卫星上采用多路复接方式实现了5.6千兆／秒的相干激光通信。2015年，欧空局又实现了低轨与高轨卫星之间的相干激光通信，通信距离达到5万公里，通信速率达到1.8千兆／秒，开辟了利用相干激光通信进行数据中继的先河。

据了解，2005年，中科院上海光机所开始空间相干激光通信技术的研究。2012年，在中科院支持下，启动相干激光通信在轨技术验证项目。通过3年多技术攻关，突破了星载高频率频率稳定人眼安全波段的光纤激光器、高速相干信息编码调制、高灵敏度相干接收、大容量实时数据处理等系列关键技术，目前已经完成星载相干激光通信发射终端和地面相干激光通信接收终端的研制工作，单路通信具备星地5.12千兆／秒速率的通信能力。

*“墨子号”上还有一个第五分系统———相干激光通信载荷*。这是一台尝试探索第二代激光通信的设备，本来并没有计划出现在“墨子号”上。研制这个载荷的是中科院上海光学精密机械研究所，他们在为量子密钥通信机、量子纠缠分发机提供信标光源的同时，提出了“加一个载荷”的设想。此时，卫星研发已启动一年多，加载荷就要赶进度，要冒这个风险吗？没有任何推诿，技物所和中科大都积极帮助光机所达成这个“心愿”。光机所副所长陈卫标说，如果研究团队各自为政，第二代激光通信试验必将推迟。

http://www.chinaspaceflight.com/default/602.html

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## GS Zhou

cirr said:


> Strange that the 5th experiment didn't get a mention:
> 
> *中科院上海光学精密机械研究所第二代空间相干激光通信载荷：速率5Gbps*
> 
> 2016/08/16
> 
> 我国首次空间高速相干激光通信试验将在量子卫星上开展
> 
> 2016年08月16日 11:18　来源：新华网
> 
> 新华社上海8月16日电(记者王琳琳)16日，中科院上海光机所研制的空间高速相干激光通信载荷搭载量子卫星发射升空，将开展卫星与新疆、北京地面站之间的高速相干激光通信技术验证。这将是我国首次开展空间高速相干激光通信试验，标志着我国初步具备研制星间相干激光通信载荷的能力。
> 
> 空间高速激光通信技术用于实现星间、星地高速数据传输，可克服高分辨率卫星成像数据传输有限的瓶颈，是空间数据中继、星间组网的重要手段，也是一项国内外航天界高度关注的前沿高科技技术。
> 
> 量子卫星相干激光通信载荷指挥、中科院上海光机所副所长陈卫标表示，相干探测激光通信，具有灵敏度高、白天可工作等技术优点，特别适用于空间超远距离(数万公里)卫星间的高速激光通信。相对第一代几十、数百兆／秒速率的直接探测激光通信技术，第二代空间相干激光通信技术速率可达数千兆／秒，乃至数万兆／秒，成为国内外星间数据中继的主流方案。
> 
> 此前，欧美等发达国家已投入大量人力物力开展相关技术研究，并取得重要进展。2007年，欧空局(ESA)率先在TerraSAR－X卫星与美国NFIRE卫星上采用多路复接方式实现了5.6千兆／秒的相干激光通信。2015年，欧空局又实现了低轨与高轨卫星之间的相干激光通信，通信距离达到5万公里，通信速率达到1.8千兆／秒，开辟了利用相干激光通信进行数据中继的先河。
> 
> 据了解，2005年，中科院上海光机所开始空间相干激光通信技术的研究。2012年，在中科院支持下，启动相干激光通信在轨技术验证项目。通过3年多技术攻关，突破了星载高频率频率稳定人眼安全波段的光纤激光器、高速相干信息编码调制、高灵敏度相干接收、大容量实时数据处理等系列关键技术，目前已经完成星载相干激光通信发射终端和地面相干激光通信接收终端的研制工作，单路通信具备星地5.12千兆／秒速率的通信能力。
> 
> *“墨子号”上还有一个第五分系统———相干激光通信载荷*。这是一台尝试探索第二代激光通信的设备，本来并没有计划出现在“墨子号”上。研制这个载荷的是中科院上海光学精密机械研究所，他们在为量子密钥通信机、量子纠缠分发机提供信标光源的同时，提出了“加一个载荷”的设想。此时，卫星研发已启动一年多，加载荷就要赶进度，要冒这个风险吗？没有任何推诿，技物所和中科大都积极帮助光机所达成这个“心愿”。光机所副所长陈卫标说，如果研究团队各自为政，第二代激光通信试验必将推迟。
> 
> http://www.chinaspaceflight.com/default/602.html



Great! Once this technology tested, we can launch the next generation Tianlian data transmission satellites (天链数据中继卫星) to the orbit.

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## Viet

GS Zhou said:


> Congratulations to our scientists!!
> 
> In addition to world's first quantumn satellite, China is also building up world's first long-distance land-based quantumn communication network. The 2,000-km long quantumn network between Beijing and Shanghai will be completed in November this year!
> 
> 量子保密通信“京沪干线”年底开通
> 时间：2016-06-06 浏览次数： 55 来源： 科技日报 字号：[ 大 中 小 ]
> 
> 【科技日报北京电，记者张盖伦】　“京沪干线”不仅指能跑火车的铁轨，也指能跑量子密钥的光纤。在6月1日陈嘉庚青年科学奖颁奖会上，量子保密通信“京沪干线”项目工程总师、中科大教授陈宇翱向科技日报记者透露，该项目将于2016年年底正式交付使用。
> 
> *“目前工程已经完成了四分之三。量子京沪干线全长2000余公里，目前已经完成了约1500公里，而剩下的500公里预计也将于下个月打通。”陈宇翱表示，11月份左右，“京沪干线”可以达到“开始运行”的状态，年底能正式交付使用。*
> 
> 国家发改委立项的“京沪干线”大尺度光纤量子通信骨干网工程，从北京出发，经过济南、合肥，到达上海。利用这一高可信、可扩展、军民融合的广域光纤量子通信网络，京沪两地的金融机构可以进行保密通信，包括电话、视频通话、电子邮件。
> 
> View attachment 326374


congrat china!

but it is still to prove that the technology works keeping all promises and what more benefits are expected. considering the current encryption technology such as RSA and AES with high number of bits are virtually uncrackable. still.

besides, quantumn encryption still has the fundamental weakness like the existing encryption technology: the operators behind computers. unless you want to elimate the human factor.

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## GS Zhou

Viet said:


> congrat china!
> 
> but it is still to prove that the technology works keeping all promises and what more benefits are expected. considering the current encryption technology such as RSA and AES with high number of bits are virtually uncrackable. still.
> 
> besides, quantumn encryption still has the fundamental weakness like the existing encryption technology: the operators behind computers. unless you want to elimate the human factor.



thanks for your congrats and comments!

That's exactly the reason we launch this satellite: test the technology, find out the weakness, improve the weakness. I believe that's the right attitude to scientific research.

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## Viet

GS Zhou said:


> thanks for your congrats and comments!
> 
> That's exactly the reason we launch this satellite: test the technology, find out the weakness, improve the weakness. I believe that's the right attitude to scientific research.


you are welcome!

I think you are on a good path. having people, money and resources is always a good thing, giving an edge over others. trials and errors is a common thing, finding out what works what not. I wish our people can learn and copy from big China. yes, I would congrat you more, but one of your researchers mentions the real intention behind all the typical phrases you hear 10,000 times elsewhere: it is for military application. so now begins the most exciting time for your potential opponents: finding out the weakness of the system in order to defeat it.

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## GS Zhou

Viet said:


> you are welcome!
> 
> I think you are on a good path. having people, money and resources is always a good thing, giving an edge over others. trials and errors is a common thing, finding out what works what not. I wish our people can learn and copy from big China. yes, I would congrat you more, but one of your researchers mentions the real intention behind all the typical phrases you hear 10,000 times elsewhere: it is for military application. so now begins the most exciting time for your potential opponents: finding out the weakness of the system in order to defeat it.



we welcome competitions in all formats, no matter it is economy competition, infrastructure competition, manufacturing industry competition, scientific research competition, or even military build-up competition. 

We are not the best yet, in many areas. But we are narrowing the gaps with the top countries in a rapid pace that hard to be imagined ten or twenty years before. So at least gap in today is smaller than that in yesterday, gap in tomorrow will be smaller than today.

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## TaiShang

Viet said:


> I think you are on a good path. having people, money and resources is always a good thing, giving an edge over others. trials and errors is a common thing, finding out what works what not. I wish our people can learn and copy from big China. yes, I would congrat you more, but one of your researchers mentions the real intention behind all the typical phrases you hear 10,000 times elsewhere: it is for military application. so now begins the most exciting time for your potential opponents: finding out the weakness of the system in order to defeat it.



Well said. It is trial and error for the innovator. And catching up and beating down for the opponent.

What matters is to be in the game.

Potential military applications cannot be denied, for sure. In fact, civilian and military dual/multi use technologies (which one is first initiated is not important) are one of the fundamentals of developed economies.

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## Viet

GS Zhou said:


> we welcome competitions in all formats, no matter it is economy competition, infrastructure competition, manufacturing industry competition, scientific research competition, or even military build-up competition.
> 
> We are not the best yet, in many areas. But we are narrowing the gaps with the top countries in a rapid pace that hard to be imagined ten or twenty years before. So at least gap in today is smaller than that in yesterday, gap in tomorrow will be smaller than today.


as said you are on a good path. sometimes I feel China is a like a man waiting in line for 100 years, now he is standing before the counter, asking the sales staff for everything. immediately.

back to the topic. this thing quantum communication is hardly to understand. I believe most of the people have no clue what it is about. I google a bit, but there are just few articles available explaining but really hardly to understand what they are talking about. can you explain in your words what quantum communication is and how encryption works?

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## bolo

CAPRICORN-88 said:


> That is part of the *Asymmetrical Advantages China has over her immediate adversary USA *and it scares the shit out of them.
> 
> Now USA has to borrow more money from China to develop NEW technology against China.


sad, but china will give

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## Nilgiri

Viet said:


> as said you are on a good path. sometimes I feel China is a like a man waiting in line for 100 years, now he is standing before the counter, asking the sales staff for everything. immediately.
> 
> back to the topic. this thing quantum communication is hardly to understand. I believe most of the people have no clue what it is about. I google a bit, but there are just few articles available explaining but really hardly to understand what they are talking about. can you explain in your words what quantum communication is and how encryption works?



@GS Zhou can add/correct to this, but having worked a while in remote sensing industry previously, I believe this is a pathfinder project to investigate communication optimization using Quantum information science. This effectively means how to reduce the amount of total bits in a stream of data being transmitted while keeping the quality of information being transmitted the exact same (when you pass the info through the various filters, stackers and processors to be able to be streamed and transmitted....classically there are ways to compress this like you may have seen in zip files in your computer....but we are hitting all the road blocks pretty fast....so we need to investigate more deeper things like quantum science to further improve this. China under_ A.C Yao_ and others has been instrumental in developing this particluar part of the science).

How this is achieved requires a broader understanding of quantum effects in practice (rather than just theory and small lab environments)...to "feel" where the best places are to continue the theory....given LEO/MEO to earth is the biggest laboratory one can have at reasonable cost these days with enough challenges to face so you can learn from it productively.

In a way it reminds me of "fuzzy logic" concept in algorithm theory.

Both seek to get more out of the same....so in the long run you have a much more capable potent system.

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## xunzi

Viet said:


> congrat china!
> 
> but it is still to prove that the technology works keeping all promises and what more benefits are expected. considering the current encryption technology such as RSA and AES with high number of bits are virtually uncrackable. still.
> 
> besides, quantumn encryption still has the fundamental weakness like the existing encryption technology: the operators behind computers. unless you want to elimate the human factor.


That is not true. All traditional and current encryption is crackable because the stages of the encryption can be wiretap and supercomputer can used brute force to guess the key. It just take longer but eventually it will be crack no matter how many bits were.

The human factor always play a role but the human factor error is limited to turning the switch on and off. Because of the unique stage of quantum entanglement effect, the act of observing will caused the encryption information to collapse automatically. You can bribe the people working behind the quantum encryption but he or she won't know the information that is store in the encryption. It will be between the sender and receiver to know. The middle man, operator don't know and simply become a switcher. LOL



Viet said:


> as said you are on a good path. sometimes I feel China is a like a man waiting in line for 100 years, now he is standing before the counter, asking the sales staff for everything. immediately.
> 
> back to the topic. this thing quantum communication is hardly to understand. I believe most of the people have no clue what it is about. I google a bit, but there are just few articles available explaining but really hardly to understand what they are talking about. can you explain in your words what quantum communication is and how encryption works?


In traditional description, key is generated to bit of 0 and 1. For example, to encrypt letter B on a simple 8-bit which stand at 33 in the alphabetical system.

for 8 bit, you go
0 1 0 0 0 0 1 0
0 1 2 4 8 16 32 64 
Here, you take 1 + 32 = 33 which is letter B.

No matter how many bit you put in, supercomputer can just run all different scenario to crack because bit encryption is transfer by the speed of light, which is constant. It is time consuming but eventually that unique key in that large number encryption will get crack.

Let me give you even a more simple example...Someone hide your son somewhere on earth, in a secret location of X,Y,Z. In traditional encryption, for you to find out the location of your son, you will need to find out which continent he was in, then which country, then which state, then which city, then which county, then which street. As you can see, you have to narrow down each step. Yes you will be able to get the information at the speed of light but still you have to ask and go step-by-step to find out.

In Quantum encryption, you don't need to take each step going at the speed of light to find out the destination. You can do so by asking all the questions at once. It will save you time and you get immediate answer.

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## Nilgiri

xunzi said:


> In traditional description, key is generated to bit of 0 and 1. For example, to encrypt letter B on a simple 8-bit which stand at 66 in the alphabetical system.
> 
> for 8 bit, you go
> 0 1 0 0 0 0 1 0
> 0 2 4 8 16 32 64 128
> Here, you take 2 + 64 = 66 which is letter B.
> 
> No matter how many bit you put in, supercomputer can just run all different scenario to crack because bit encryption is transfer by the speed of light, which is constant. It is time consuming but eventually that unique key in that large number encryption will get crack.
> 
> Let me give you even a more simple example...Someone hide your son somewhere on earth, in a secret location of X,Y,Z. In traditional encryption, for you to find out the location of your son, you will need to find out which continent he was in, then which country, then which state, then which city, then which county, then which street. As you can see, you have to narrow down each step. Yes you will be able to get the information at the speed of light but still you have to ask and go step-by-step to find out.
> 
> In Quantum encryption, you don't need to take each step going at the speed of light to find out the destination. You can do so by asking all the questions at once. It will save you time and you get immediate answer.



Thanks for explanation.

What is your profession/field if I may ask?

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## xunzi

Nilgiri said:


> Thanks for explanation.
> 
> What is your profession/field if I may ask?


I could become a computer scientist had I stay in school long but I chose to start job career early which is in IT (software development). In school, I'm always good with physics and science in general. I took quantum mechanics before.

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## Viet

xunzi said:


> That is not true. All traditional and current encryption is crackable because the stages of the encryption can be wiretap and supercomputer can used brute force to guess the key. It just take longer but eventually it will be crack no matter how many bits were.
> 
> The human factor always play a role but the human factor error is limited to turning the switch on and off. Because of the unique stage of quantum entanglement effect, the act of observing will caused the encryption information to collapse automatically. You can bribe the people working behind the quantum encryption but he or she won't know the information that is store in the encryption. It will be between the sender and receiver to know. The middle man, operator don't know and simply become a switcher. LOL
> 
> 
> In traditional description, key is generated to bit of 0 and 1. For example, to encrypt letter B on a simple 8-bit which stand at 33 in the alphabetical system.
> 
> for 8 bit, you go
> 0 1 0 0 0 0 1 0
> 0 1 2 4 8 16 32 64
> Here, you take 1 + 32 = 33 which is letter B.
> 
> No matter how many bit you put in, supercomputer can just run all different scenario to crack because bit encryption is transfer by the speed of light, which is constant. It is time consuming but eventually that unique key in that large number encryption will get crack.
> 
> Let me give you even a more simple example...Someone hide your son somewhere on earth, in a secret location of X,Y,Z. In traditional encryption, for you to find out the location of your son, you will need to find out which continent he was in, then which country, then which state, then which city, then which county, then which street. As you can see, you have to narrow down each step. Yes you will be able to get the information at the speed of light but still you have to ask and go step-by-step to find out.
> 
> In Quantum encryption, you don't need to take each step going at the speed of light to find out the destination. You can do so by asking all the questions at once. It will save you time and you get immediate answer.


so so using brute force. what do you think how long you take to crack a RSA secret key lenght 2048 bits?

don´t tell me you use quantum computer because such computer does not exist, unless you show me one.

no, key generation is usually based upon RSA, not so as basic and primitive as you showed it above. unless you show me it is chinese variant of key generation 

so in quantum communication, the secret key is stored in the hardware. what differs to the current method of storing the rsa key in hardware, for example digital cinema?

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## GS Zhou

Viet said:


> as said you are on a good path. sometimes I feel China is a like a man waiting in line for 100 years, now he is standing before the counter, asking the sales staff for everything. immediately.
> 
> back to the topic. this thing quantum communication is hardly to understand. I believe most of the people have no clue what it is about. I google a bit, but there are just few articles available explaining but really hardly to understand what they are talking about. can you explain in your words what quantum communication is and how encryption works?



Quantumn technology looks like magic to me as well. I cannot guarantee you my understanding on quantumn communication is 100% correct. So please don't laugh at me, if I say something stupid.

In the world of cryptography, the recipients needs the right secret key to translate the message received. For example, you want to send the text "ABC" to me, but what you actually type is "XYZ". And when I get the "XYZ", I'll use the pre-aligned secret key to "translate" XYZ to ABC. 

So, to any countries, the secret key system is always the top secret to protect. Even for the fastest computer today, it may still need 100+ years of calculation to conquer the best-designed key. But the invention of quantumn computer will change the entire picture. Quantumn computer may only need couple of seconds, or minutes, to guess the key. That will be a huge threat to information security to any countries. And that's why we need quantumn communication satellite. 

To my understanding, quantumn satellite transmits the secret key only. To each communication request, the satellite generates a key inside and transmit the key to both sender and recipients. So the key is always changing. Even if someone bribes/or tortures the recipients, the key sill won't be leaked, because even the recipients doesn't know what is the key.

But you can still try to hack the key. When we say "hack", it means you are observing the photons (the key is carried by the photons) sent by the satellite. Now the most magic part happens. According to the quantumn theory, an observation will change the status of the photons (when you don't open the box, Schrödinger's cat is simultaneously alive and dead; but when you open the box, the cat will be either alive or dead. So, it is your observation that decide whether the cat is alive or dead). The status change of the photons informs the recipients that someone is watching, so communication stops.

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## Viet

GS Zhou said:


> Quantumn technology looks like magic to me as well. I cannot guarantee you my understanding on quantumn communication is 100% correct. So please don't laugh at me, if I say something stupid.
> 
> In the world of cryptography, the recipients needs the right secret key to translate the message received. For example, you want to send the text "ABC" to me, but what you actually type is "XYZ". And when I get the "XYZ", I'll use the pre-aligned secret key to "translate" XYZ to ABC.
> 
> So, to any countries, the secret key system is always the top secret to protect. Even for the fastest computer today, it may still need 100+ years of calculation to conquer the best-designed key. But the invention of quantumn computer will change the entire picture. Quantumn computer may only need couple of seconds, or minutes, to guess the key. That will be a huge threat to information security to any countries. And that's why we need quantumn communication satellite.
> 
> To my understanding, quantumn satellite transmits the secret key only. To each communication request, the satellite generates a key inside and transmit the key to both sender and recipients. So the key is always changing. Even if someone bribes/or tortures the recipients, the key sill won't be leaked, because even the recipients doesn't know what is the key.
> 
> But you can still try to hack the key. When we say "hack", it means you are observing the photons (the key is carried by the photons) sent by the satellite. Now the most magic part happens. According to the quantumn theory, an observation will change the status of the photons (when you don't open the box, Schrödinger's cat is simultaneously alive and dead; but when you open the box, the cat will be either alive or dead. So, it is your observation that decide whether the cat is alive or dead). The status change of the photons informs the recipients that someone is watching, so communication stops.


I have yet to see a model of quantum computer. how it looks like how it works. is it something similar to computer today, with hardware and software as we know it today? instead of electrons it will use photons? will there be photon CPU, photon memory chips? instead of binary states 0 and 1, will there be 4 more states?

ok let assume, in 20 years we would have quantum computers capable of cracking today encryption key. but you should keep in mind, the present cryptography is designed to beat the brute force of computer power. computer technology advances, so cryptography. it is a race. in 20 years, I bet cryptography would beat quantum computing (if exists).

yes, the theory says secret key is uncrackable because photon entanglement will be destroyed if an unwanted viewer in the middle tries to see it. who will bet that nobody will ever invent a device (usually a prism) that is capable to do it without destroying photon entanglement in a distance future?

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## GS Zhou

Viet said:


> I have yet to see a model of quantum computer. how it looks like how it works. is it something similar to computer today, with hardware and software as we know it today? instead of electrons it will use photons? will there be photon CPU, photon memory chips? instead of binary states 0 and 1, will there be 4 more states?
> 
> ok let assume, in 20 years we would have quantum computers capable of cracking today encryption key. but you should keep in mind, the present cryptography is designed to beat the brute force of computer power. computer technology advances, so cryptography. it is a race. in 20 years, I bet cryptography would beat quantum computing (if exists).
> 
> yes, the theory says secret key is uncrackable because photon entanglement will be destroyed if an unwanted viewer in the middle tries to see it. who will bet that nobody will ever invent a device (usually a prism) that is capable to do it without destroying photon entanglement in a distance future?



I think what you said all makes sense to me. Who knows how far the scientific research could go in the next 10 or 20 years. For now, no one knows the answer. 

But thanks to the hard efforts of our scientists, as well as the consecutive investment from the government, China is making progress in almost all areas. 

For example, you bet cryptography would beat quantum computing, that may be right. But to achieve this, you at least should have your own quantumn computer for test. Good news to us is, we just developed our first quantum chip (an August 11th 2016 news). The chip may be still very much inmature, but that's still a great step. 






You also mentioned maybe somebody will invent a device that is capable to hack the photon, but without destroying photon entanglement. That may also be true. But to achieve this, you at least should have the capability to do the test of photon entanglement. Right? Good news is, one of the tasks for the quantumn satellite is to do the photon entanglement experiment between the space and the ground, at a distance that no one has achieved so far.

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## Nilgiri

GS Zhou said:


> I think what you said all makes sense to me. Who knows how far the scientific research could go in the next 10 or 20 years. For now, no one knows the answer.
> 
> But thanks to the hard efforts of our scientists, as well as the consecutive investment from the government, China is making progress in almost all areas.
> 
> For example, you bet cryptography would beat quantum computing, that may be right. But to achieve this, you at least should have your own quantumn computer for test. Good news to us is, we just developed our first quantum chip (an August 11th 2016 news). The chip may be still very much inmature, but that's still a great step.
> View attachment 326892
> 
> 
> You also mentioned maybe somebody will invent a device that is capable to hack the photon, but without destroying photon entanglement. That may also be true. But to achieve this, you at least should have the capability to do the test of photon entanglement. Right? Good news is, one of the tasks for the quantumn satellite is to do the photon entanglement experiment between the space and the ground, at a distance that no one has achieved so far.



I was very impressed when I visited the PW (Pratt whitney) plant in Chengdu cpl years back. They had innovated some very brilliant things by themselves in the quality control by structuring the testing and material assaying in a very novel productive way. PW incorporated this in all its facilities worldwide (I actually helped with some of it for a few months).

Next year I will be working with some of the Chinese developers there in how best to research next generation lightened blisk production. I found some workarounds for issues with the software they use in the modelling analysis so the information flow is not all one way 



GS Zhou said:


> For example, you bet cryptography would beat quantum computing, that may be right. But to achieve this, you at least should have your own quantumn computer for test. Good news to us is, we just developed our first quantum chip (an August 11th 2016 news). The chip may be still very much inmature, but that's still a great step.



Very true. I find China to be very good at hedging pragmatically.

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## Viet

GS Zhou said:


> I think what you said all makes sense to me. Who knows how far the scientific research could go in the next 10 or 20 years. For now, no one knows the answer.
> 
> But thanks to the hard efforts of our scientists, as well as the consecutive investment from the government, China is making progress in almost all areas.
> 
> For example, you bet cryptography would beat quantum computing, that may be right. But to achieve this, you at least should have your own quantumn computer for test. Good news to us is, we just developed our first quantum chip (an August 11th 2016 news). The chip may be still very much inmature, but that's still a great step.
> View attachment 326892
> 
> 
> You also mentioned maybe somebody will invent a device that is capable to hack the photon, but without destroying photon entanglement. That may also be true. But to achieve this, you at least should have the capability to do the test of photon entanglement. Right? Good news is, one of the tasks for the quantumn satellite is to do the photon entanglement experiment between the space and the ground, at a distance that no one has achieved so far.


no system is perfect. so quantum computing and encryption. the challenge is to find out its weaknesses.
if I was Barack Obama, I would send spies to China (if not already happening), trying to steal information. during the WW II, the british made several attempts to steal enigma machine, which was used by the germans for encoding and decoding messages.

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## GS Zhou

Viet said:


> no system is perfect. so quantum computing and encryption. the challenge is to find out its weaknesses.
> if I was Barack Obama, I would send spies to China (if not already happening), trying to steal information. during the WW II, the british made several attempts to steal enigma machine, which was used by the germans for encoding and decoding messages.



I never said any technology is perfect. But "not perfect yet" doesn't mean we should not research the technology: Automobile creates pollution, but it brings us convenience; nuclear power could be destructive, but it brings us energy. 

With respect to espionage, it is a threat to all countries. But this should not the the right topic in this thread, let's not be too off the topic.

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## Viet

GS Zhou said:


> I never said any technology is perfect. But "not perfect yet" doesn't mean we should not research the technology: Automobile creates pollution, but it brings us convenience; nuclear power could be destructive, but it brings us energy.
> 
> With respect to espionage, it is a threat to all countries. But this should not the the right topic in this thread, let's not be too off the topic.


I am not saying you should stop working on quantum communication. just pointing out the technology is not the end of the road, but a natural evolution of communications. it is surely a big leap forward.

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## TaiShang

*The world's first: Chinese scientist shows the importance of non-locality in quantum simulation*
(People's Daily Online) August 19, 2016






China launches the world's first quantum satellite on top of a Long March-2D rocket from the Jiuquan Satellite Launch Center in Jiuquan, northwest China's Gansu Province, Aug. 16, 2016. (Xinhua/Jin Liwang)

According to an Aug. 19 report by People's Daily, *the University of Science and Technology of China (USTC) has made an important breakthrough in quantum research.* For the first time, the importance of non-locality in quantum simulation has been demonstrated.

The research team, lead by Professor Li Chuanfeng from the university's Quantum Information Key Laboratory,* developed a non-local quantum simulator to simulate the physics phenomenon of parity.* The team's research has yielded a new direction for the quantum simulator. Renowned journal Nature Photonics recently published an account of the achievement. 

On Aug. 16, China launched the world's first quantum satellite from the Jiuquan Satellite Launch Center; as a result, many people have been curious about the research behind this scientific achievement. The quantum simulator is a computer used to solve certain scientific problems. The concept was first proposed by Richard Feynman in 1981. In modern quantum simulator research, scientists generally focus on the simulator's ability to accelerate; the more quantum bits a simulator can manipulate, the stronger its computing power is. 

*The research by USTC has now revealed another important advantage of the quantum simulator: quantum non-locality, which Einstein once described as "spooky action at a distance."* The non-local quantum simulator can be used to research subjects such as faster-than-light communications, which standard computers are unable to do.

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## ChineseTiger1986

The first batch of data from the world's first quantum satellite was received by Chinese scientists, the Chinese Academy of Sciences (CAS) said Thursday.

The data was received on Wednesday by the China Remote Sensing Satellite Ground Station (RSGS), located in Miyun on the outskirts of Beijing, at 11:56 a.m.

The 202 MB of data was in good quality and was transferred to China's National Space Science Center.

China launched world's first quantum communication satellite on Tuesday. It is nicknamed "Micius," after a fifth century B.C. Chinese philosopher and scientist.

The satellite is designed to establish "hack-proof" quantum communications by transmitting uncrackable keys from space to the ground, and provide insights into the strangest phenomenon in quantum physics -- quantum entanglement.

http://www.china.org.cn/china/2016-08/18/content_39124000.htm

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## X-2.

Thats great !! Congratulations to Chinese people  from Pakistan

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## alaungphaya

This is actually very impressive. Good work.

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## cirr

*China's scientists propose a quantum brain more complex than a galaxy*

the source of human dominance

http://www.dailygalaxy.com/my_weblo...-a-galaxy-the-source-of-human-dominance-.html

@Bussard Ramjet

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## bolo

mozi
not micus

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## JSCh

*  Experimental investigation of the no-signalling principle in parity–time symmetric theory using an open quantum system*

Jian-Shun Tang, Yi-Tao Wang, Shang Yu, De-Yong He, Jin-Shi Xu, Bi-Heng Liu, Geng Chen, Yong-Nan Sun, Kai Sun, Yong-Jian Han, Chuan-Feng Li & Guang-Can Guo

The violation of the no-signalling principle — information can be transmitted faster than light — is experimentally investigated using entangled photons. It can be simulated when the parity–time symmetrically evolved subspace is solely considered.

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## DoTell

For your knowledgeable physicists out there, is this "quantum non-locality" theory about the exact same event can happen at different locations simultaneously? If so it will be really cool that such phenomenon can be generated in a controlled environment

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## XenoEnsi-14

TaiShang said:


> quantum non-locality, which Einstein once described as "*spooky action at a distance*."


Now they speak English at the end. Note taken, read last paragraph then read the article.

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## ChineseTiger1986

bolo said:


> mozi
> not micus



That's right, I hate those romanticized names.

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## Bussard Ramjet

cirr said:


> *China's scientists propose a quantum brain more complex than a galaxy*
> 
> the source of human dominance
> 
> http://www.dailygalaxy.com/my_weblo...-a-galaxy-the-source-of-human-dominance-.html
> 
> @Bussard Ramjet



China is good at expanding on other people's theories. In the piece itself you can read that the theory of photon communication was already proposed. 

Time, China gets better at totally original breakthroughs. Quantum Satellite is a start.


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## Kiss_of_the_Dragon

Bussard Ramjet said:


> China is good at expanding on other people's theories. In the piece itself you can read that the theory of photon communication was already proposed.
> 
> Time, China gets better at totally original breakthroughs. Quantum Satellite is a start.



That how western had exploited our invention such as gun powder and allowed them expanding and make better gun powder weapons to use against China...and ironically now they accuse Chinese of doing copy and past of their design and patent...or maybe they're too scare that China will exceed them one day, I think we Chinese are awaken, we will do our best to explore western theory and walk right through the uncharted territory instead of always following Western food steps. Quantum sat is indeed the first step.

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## CAPRICORN-88

This will formed an important aspect of *China's growing ASYMMETRICAL EDGE over USA*. 

 Apart from the fact, USAF stealth warplanes including theF22, F35, B1, B2 are all visible to China defense forces and all it takes is to send some of the J-10A or its variants to shoot these lightly armed planes down.

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## xunzi

Beside the practical use of quantum mechanical understanding on technology, it will also have a profound implication on life and the universe law at large.

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## TaiShang

XenoEnsi-14 said:


> Now they speak English at the end. Note taken, read last paragraph then read the article.



Science and speculation at times are inseparable, as it seems. 

My research method professor, a social scientist, used to say, 'science starts with creativity.'

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## ChineseTiger1986

Mozi is now conducting the communication with the ground.

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## Beny Karachun

Mind explaining what's "Quantum communication" is?
Or that laser?


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## TaiShang

Beny Karachun said:


> Mind explaining what's "Quantum communication" is?
> Or that laser?



China has launched the first satellite for quantum communications, Mozi, into a 600km sun-synchronous orbit. The satellite is designed to facilitate transmission of entangled photons from a ground station in Beijing to one in Vienna; this would allow quantum key encrypted communications over about 7,000km, versus the current record of a few hundred kilometres over fibre. The satellite is also intended to demonstrate quantum teleportation over this distance, again compared to current records of a few hundred kilometres. According to one of the physicists on the team, the satellite could be followed by others if successful, allowing transmission of quantum information across the globe.

http://forum.kerbalspaceprogram.com/index.php?/topic/145987-quantum-science-satellite-mozi/

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## TaiShang

Jlaw said:


> i thought this jew was supposed to be smart. why is he asking ?



LOL.

In fact, could be anyone. The way the poster posts, I suspect a potential false-flagger. Nonetheless, the question was a concise one and allowed to put some more light on the issue.

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## Viet

TaiShang said:


> China has launched the first satellite for quantum communications, Mozi, into a 600km sun-synchronous orbit. The satellite is designed to facilitate transmission of entangled photons from a ground station in Beijing to one in Vienna; this would allow quantum key encrypted communications over about 7,000km, versus the current record of a few hundred kilometres over fibre. The satellite is also intended to demonstrate quantum teleportation over this distance, again compared to current records of a few hundred kilometres. According to one of the physicists on the team, the satellite could be followed by others if successful, allowing transmission of quantum information across the globe.
> 
> http://forum.kerbalspaceprogram.com/index.php?/topic/145987-quantum-science-satellite-mozi/


That does not explain anything how it works in principle:

photon teleportation, quantum key exchange and quantum communications between Beijing and Vienna via a satellite.

Nothing is revealed what technology is used.


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## yusheng

ANYONE want to know wha it really is, just read the following articles if you can understand.

the main author J. W. PAN is also the leader of this project (Quantum communication).

1：JWPan,ZBChen,MZukowski,HWeinfurter,AZeilinger， Multi-photon Entanglement and Interferometry，Reviews of Modern Physics 2012.[22]
2：ZSYuan,XHBao,CYLu,JZhang,CZPeng,JW Pan，Entangled Photons and Quantum Communication，Physics Reports,2010,497:1.
3：ZSYuan,YAChen,BZhao,SChen,JSchmiedmayer,JWPan,Experimental Demonstration of a BDCZ Quantum Repeater Node，Nature,2008,454：1098.
4：YAChen,SChen,ZSYuan,BZhao,CSChu,JSchmiedmayer ,JWPan ，Memory-built-in Quantum Teleportation with Photonic and Atomic Qubits,Nature Physics,2008,4:103~107.
5：ZZhao,YAChen,ANZhang,TYang,HBriegel,JW Pan，Experimental Demonstration of Five-photon Entanglement and Open- destination Quantum Teleportation，Nature,2004,430:54.
6：DBouwmeester,JWPan,KMattle,MEibl,HWeinfurter,AZeilinger,Experi mental Quantum Teleportation，Nature,1997,390：575.
7：JWPan,DBouwmeester,HWeinfurter,AZeilinger，Experimental Entanglement Swapping: Entangling Photons that Never Interacted，Physical Review Letters,1998,80：3891.
8：JWPan,DBouwmeester,MDaniell,HWeinfurter,AZeilinger， Experimental Test of Quantum Nonlocality in Three-Photon Greenberger-Horne- Zeilinger Entanglement，Nature,2000,403：515.
9：JWPan,CSimon,CBrukner,AZeilinger，Entanglement Purification for Quantum Communication，Nature,2001,410：1067.
10：JWPan,SGasparoni,MAspelmeyer,TJennwein,AZeilinger， Experimental Realization of Freely Propagating Teleported Qubits， Nature,2003,421:721.
11：JWPan,SGasparoni,RUrsin,GWeihs,AZeilinger，Experimental Entanglement Purification of Arbitrary Unknown States，Nature,2003,423:417.
12：WPhilip,JWPan,MAspelmayer,RUrsin,SGasparoni,AZeilinger,A four-photon Young s Double-slit Experiment，Nature,2004,429:158.[1]

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## yusheng

one of his article:

Quantum teleportation of multiple degrees of freedom of a single photon

Abstract
Quantum teleportation provides a 'disembodied' way to transfer quantum states from one object to another at a distant location, assisted by previously shared entangled states and a classical communication channel. As well as being of fundamental interest, teleportation has been recognized as an important element in long-distance quantum communication, distributed quantum networks and measurement-based quantum computation. There have been numerous demonstrations of teleportation in different physical systems such as photons, atoms, ions, electrons and superconducting circuits. All the previous experiments were limited to the teleportation of one degree of freedom only. However, a single quantum particle can naturally possess various degrees of freedom--internal and external--and with coherent coupling among them. A fundamental open challenge is to teleport multiple degrees of freedom simultaneously, which is necessary to describe a quantum particle fully and, therefore, to teleport it intact. Here we demonstrate quantum teleportation of the composite quantum states of a single photon encoded in both spin and orbital angular momentum. We use photon pairs entangled in both degrees of freedom (that is, hyper-entangled) as the quantum channel for teleportation, and develop a method to project and discriminate hyper-entangled Bell states by exploiting probabilistic quantum non-demolition measurement, which can be extended to more degrees of freedom. We verify the teleportation for both spin-orbit product states and hybrid entangled states, and achieve a teleportation fidelity ranging from 0.57 to 0.68, above the classical limit. Our work is a step towards the teleportation of more complex quantum systems, and demonstrates an increase in our technical control of scalable quantum technologies.

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## Beny Karachun

TaiShang said:


> China has launched the first satellite for quantum communications, Mozi, into a 600km sun-synchronous orbit. The satellite is designed to facilitate transmission of entangled photons from a ground station in Beijing to one in Vienna; this would allow quantum key encrypted communications over about 7,000km, versus the current record of a few hundred kilometres over fibre. The satellite is also intended to demonstrate quantum teleportation over this distance, again compared to current records of a few hundred kilometres. According to one of the physicists on the team, the satellite could be followed by others if successful, allowing transmission of quantum information across the globe.
> 
> http://forum.kerbalspaceprogram.com/index.php?/topic/145987-quantum-science-satellite-mozi/


Thanks


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## Viet

yusheng said:


> ANYONE want to know wha it really is, just read the following articles if you can understand.
> 
> the main author J. W. PAN is also the leader of this project (Quantum communication).
> 
> 1：JWPan,ZBChen,MZukowski,HWeinfurter,AZeilinger， Multi-photon Entanglement and Interferometry，Reviews of Modern Physics 2012.[22]
> 2：ZSYuan,XHBao,CYLu,JZhang,CZPeng,JW Pan，Entangled Photons and Quantum Communication，Physics Reports,2010,497:1.
> 3：ZSYuan,YAChen,BZhao,SChen,JSchmiedmayer,JWPan,Experimental Demonstration of a BDCZ Quantum Repeater Node，Nature,2008,454：1098.
> 4：YAChen,SChen,ZSYuan,BZhao,CSChu,JSchmiedmayer ,JWPan ，Memory-built-in Quantum Teleportation with Photonic and Atomic Qubits,Nature Physics,2008,4:103~107.
> 5：ZZhao,YAChen,ANZhang,TYang,HBriegel,JW Pan，Experimental Demonstration of Five-photon Entanglement and Open- destination Quantum Teleportation，Nature,2004,430:54.
> 6：DBouwmeester,JWPan,KMattle,MEibl,HWeinfurter,AZeilinger,Experi mental Quantum Teleportation，Nature,1997,390：575.
> 7：JWPan,DBouwmeester,HWeinfurter,AZeilinger，Experimental Entanglement Swapping: Entangling Photons that Never Interacted，Physical Review Letters,1998,80：3891.
> 8：JWPan,DBouwmeester,MDaniell,HWeinfurter,AZeilinger， Experimental Test of Quantum Nonlocality in Three-Photon Greenberger-Horne- Zeilinger Entanglement，Nature,2000,403：515.
> 9：JWPan,CSimon,CBrukner,AZeilinger，Entanglement Purification for Quantum Communication，Nature,2001,410：1067.
> 10：JWPan,SGasparoni,MAspelmeyer,TJennwein,AZeilinger， Experimental Realization of Freely Propagating Teleported Qubits， Nature,2003,421:721.
> 11：JWPan,SGasparoni,RUrsin,GWeihs,AZeilinger，Experimental Entanglement Purification of Arbitrary Unknown States，Nature,2003,423:417.
> 12：WPhilip,JWPan,MAspelmayer,RUrsin,SGasparoni,AZeilinger,A four-photon Young s Double-slit Experiment，Nature,2004,429:158.[1]


I would appreciate if any chinese poster here can explain how it works in principle to the audience, in ONE page, and not after graduating in physics, computer science and telecommunications. and after reading 12 books you listed


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## yusheng

in fact, this time, the experiment is only to test the tech applied in the fields, it is not the basic sciences experiement, don't need to reveal any secrets of the nature.

quantum physics is controversial itself， but this doesn't prevent us using quantums though they are elusive.

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## Viet

yusheng said:


> one of his article:
> 
> Quantum teleportation of multiple degrees of freedom of a single photon
> 
> Abstract
> Quantum teleportation provides a 'disembodied' way to transfer quantum states from one object to another at a distant location, assisted by previously shared entangled states and a classical communication channel. As well as being of fundamental interest, teleportation has been recognized as an important element in long-distance quantum communication, distributed quantum networks and measurement-based quantum computation. There have been numerous demonstrations of teleportation in different physical systems such as photons, atoms, ions, electrons and superconducting circuits. All the previous experiments were limited to the teleportation of one degree of freedom only. However, a single quantum particle can naturally possess various degrees of freedom--internal and external--and with coherent coupling among them. A fundamental open challenge is to teleport multiple degrees of freedom simultaneously, which is necessary to describe a quantum particle fully and, therefore, to teleport it intact. Here we demonstrate quantum teleportation of the composite quantum states of a single photon encoded in both spin and orbital angular momentum. We use photon pairs entangled in both degrees of freedom (that is, hyper-entangled) as the quantum channel for teleportation, and develop a method to project and discriminate hyper-entangled Bell states by exploiting probabilistic quantum non-demolition measurement, which can be extended to more degrees of freedom. We verify the teleportation for both spin-orbit product states and hybrid entangled states, and achieve a teleportation fidelity ranging from 0.57 to 0.68, above the classical limit. Our work is a step towards the teleportation of more complex quantum systems, and demonstrates an increase in our technical control of scalable quantum technologies.


that text is for students enrolled in university. I doubt anyone outside the subject understands it.



yusheng said:


> in fact, this time, the experiment is only to test the tech applied in the fields, it is not the basic sciences experiement, don't need to reveal any secrets of the nature.
> 
> quantum physics is controversial itself， but this doesn't prevent us using quantums though they are elusive.


the problem with made in china quantum communications is: nothing is revealed. nothing is explained. a blackbox. I expect at least Chinese would reveal what technology they use by creating photons, splitting photons, seting them in entangled state, encoding the particles before sending them via glass fibre or satellite to the opposite site.


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## yusheng

yes, that is why i know my limitations, i will not wish other to help me but study hard by myself.

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## ahojunk

yusheng said:


> ANYONE want to know wha it really is, just read the following articles if you can understand.
> 
> the main author J. W. PAN is also the leader of this project (Quantum communication).
> 
> 1：JWPan,ZBChen,MZukowski,HWeinfurter,AZeilinger， Multi-photon Entanglement and Interferometry，Reviews of Modern Physics 2012.[22]
> 2：ZSYuan,XHBao,CYLu,JZhang,CZPeng,JW Pan，Entangled Photons and Quantum Communication，Physics Reports,2010,497:1.
> 3：ZSYuan,YAChen,BZhao,SChen,JSchmiedmayer,JWPan,Experimental Demonstration of a BDCZ Quantum Repeater Node，Nature,2008,454：1098.
> 4：YAChen,SChen,ZSYuan,BZhao,CSChu,JSchmiedmayer ,JWPan ，Memory-built-in Quantum Teleportation with Photonic and Atomic Qubits,Nature Physics,2008,4:103~107.
> 5：ZZhao,YAChen,ANZhang,TYang,HBriegel,JW Pan，Experimental Demonstration of Five-photon Entanglement and Open- destination Quantum Teleportation，Nature,2004,430:54.
> 6：DBouwmeester,JWPan,KMattle,MEibl,HWeinfurter,AZeilinger,Experi mental Quantum Teleportation，Nature,1997,390：575.
> 7：JWPan,DBouwmeester,HWeinfurter,AZeilinger，Experimental Entanglement Swapping: Entangling Photons that Never Interacted，Physical Review Letters,1998,80：3891.
> 8：JWPan,DBouwmeester,MDaniell,HWeinfurter,AZeilinger， Experimental Test of Quantum Nonlocality in Three-Photon Greenberger-Horne- Zeilinger Entanglement，Nature,2000,403：515.
> 9：JWPan,CSimon,CBrukner,AZeilinger，Entanglement Purification for Quantum Communication，Nature,2001,410：1067.
> 10：JWPan,SGasparoni,MAspelmeyer,TJennwein,AZeilinger， Experimental Realization of Freely Propagating Teleported Qubits， Nature,2003,421:721.
> 11：JWPan,SGasparoni,RUrsin,GWeihs,AZeilinger，Experimental Entanglement Purification of Arbitrary Unknown States，Nature,2003,423:417.
> 12：WPhilip,JWPan,MAspelmayer,RUrsin,SGasparoni,AZeilinger,A four-photon Young s Double-slit Experiment，Nature,2004,429:158.[1]


,
@yusheng

Thank you for this list.

To be honest, I have a headache just skimming through the list. (I was not even reading!)

Come on, are there others who felt the same?

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## yusheng

ahojunk said:


> ,
> @yusheng
> 
> Thank you for this list.
> 
> To be honest, I have a headache just skimming through the list. (I was not even reading!)
> 
> Come on, are there others who felt the same?



i just playing with some trolling, dont take it seriously.

it is happy to see, with Chinese scientific development, more and more foreigners can not follow.

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## Viet

yusheng said:


> yes, that is why i know my limitations, i will not wish other to help me but study hard by myself.


ok I give you a hint: the classical approach to secure communications as we know it today is RSA, AES and DH. these are well-known cryptography technology, with asymmetric and symmetric encryption keys, key exchange, certs, hash function. all base on the promise, even the information are captured by intruders, it is impossible to decode it because of mathematical complexity and difficulty. even supercomputers need years to find out the secret key (if using high number of bits).

quantum communications uses a different approach. it relies on the premise, it is impossible for intruders to copy photon entangle states in order to decode the key, rather than mathematical complexity.


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## TaiShang

Viet said:


> that text is for students enrolled in university. I doubt anyone outside the subject understands it.
> 
> 
> the problem with made in china quantum communications is: nothing is revealed. nothing is explained. a blackbox. I expect at least Chinese would reveal what technology they use by creating photons, splitting photons, seting them in entangled state, encoding the particles before sending them via glass fibre or satellite to the opposite site.



Obviously, it is advanced tech. I am not sure there are posters here who can do all the tricky explanations in one simple page. I am not one of them, at least I know that.

As for China not sharing any data, news are coming in bit by bit, but I am sue there are lots of considerations as to what to share and what not to share.

If China bans certain drones or supercomputer tech to be imported, I am sure China also not extra willing to reveal every bot of knowledge it discovers.

Most likely, we will see the results, not the way how it is done.

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## Viet

TaiShang said:


> Obviously, it is advanced tech. I am not sure there are posters here who can do all the tricky explanations in one simple page. I am not one of them, at least I know that.
> 
> As for China not sharing any data, news are coming in bit by bit, but I am sue there are lots of considerations as to what to share and what not to share.
> 
> If China bans certain drones or supercomputer tech to be imported, I am sure China also not extra willing to reveal every bot of knowledge it discovers.
> 
> Most likely, we will see the results, not the way how it is done.


no I don´t expected detailed technical drawings, but some technical hints how Chinese quantum communication is built. otherwise I believe it is difficult to assess a blackbox.


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## xunzi

Let revolutionize how we will process our data in the future. I expect every advance nation to follow suit and make it more safer from the US teardrop. Germany is one of the country really need of this tech so they should work with us.

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## Viet

xunzi said:


> Let revolutionize how we will process our data in the future. I expect every advance nation to follow suit and make it more safer from the US teardrop. Germany is one of the country really need of this tech so they should work with us.


You live in a dream world. The likelihood Germany using Chinese encryption technology is Zero. It is not like buying cheap solar panels.


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## yusheng

@九维空间Sturman 还透露，25日，兴隆站和量子卫星成功激光光束对接，26日晚，阿里站和量子卫星成功激光光束对接。这种对接有多难：500km的轨道高度，第一宇宙速度，200mm口径的望远镜，难度相当于你站在五十公里以外把一枚一角硬币准确地扔进一列全速行驶的高铁上的一个矿泉水瓶里！
　　据量子科学实验卫星首席科学家潘建伟此前介绍，“墨子号”承担着发射和传输光信号的重要任务，要想保证距离地球表面数百公里的光信号能够顺利被地面光学天线接收，难度就好比是“针尖对麦芒”一样。
　　他解释说，由于卫星发射的光信号是极其微弱的单光子级别，在由空间向地面传输的过程中会受到许多因素的干扰，比如星光、灯光等都将成为干扰信号传输的背景噪声。此外，卫星的运动速度很快，地面的光学天线必须时刻紧跟卫星的“节奏”才有可能实现信号的准确接收。所以，在“墨子号”量子通信卫星的设计过程中，不仅要克服各种噪声的干扰保证信号源的稳定，同时还要实现与地面光学天线的准确对接。尽管是如同“针尖对麦芒”般苛刻的实验条件，但是在我国科学家的不懈努力下，如此不可思议的技术难题也依然得到了解决。
　　8月16日1时40分，我国在酒泉卫星发射中心用长征二号丁运载火箭成功将“墨子号”发射升空。
　　“墨子号”量子卫星是中国科学院空间科学先导专项首批科学实验卫星之一，其主要科学目标是借助卫星平台，进行星地高速量子密钥分发实验，并在此基础上进行广域量子密钥网络实验，以期在空间量子通信实用化方面取得重大突破；在空间尺度进行量子纠缠分发和量子隐形传态实验，开展空间尺度量子力学完备性检验的实验研究。

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## jkroo

Let's cheer the quantum technology feat.
Don't be surprise for the quantum chips you guys will see soon. Quantum computer is just on the way. 

A quantums research team from China just finished 600 pairs quantums experiment. A very very huge computing capacity can be reached.

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## xunzi

Viet said:


> You live in a dream world. The likelihood Germany using Chinese encryption technology is Zero. It is not like buying cheap solar panels.


Wait until we revolutionize quantum communication than you will see Berlin come knocking on our door. In fact, they already did. LOL

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## TaiShang

xunzi said:


> Let revolutionize how we will process our data in the future. I expect every advance nation to follow suit and make it more safer from the US teardrop. Germany is one of the country really need of this tech so they should work with us.



Wasn't Germany among the countries, along with Brazil, which were subject to extensive US spying. 

I do not know Germany would trust China or not; but hopefully they know who not to trust.

@Götterdämmerung

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## Bussard Ramjet

TaiShang said:


> Wasn't Germany among the countries, along with Brazil, which were subject to extensive US spying.
> 
> I do not know Germany would trust China or not; but hopefully they know who not to trust.
> 
> @Götterdämmerung



Germany is a military ally of the US, US has dozens of military bases in Germany, with thousands of deployed troops. While, the spying saga was a weak point in the relation, the overall relationship is still strong.


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## Viet

xunzi said:


> Wait until we revolutionize quantum communication than you will see Berlin come knocking on our door. In fact, they already did. LOL


quantum communication is all about to secure data against intruders, aka quantum encrypted communication.

why should germany use China quantum technology if everyone here fears you Chinese stealing their technologies? china quantum tech as a black box with Chinese instructions? think about it!



Bussard Ramjet said:


> Germany is a military ally of the US, US has dozens of military bases in Germany, with thousands of deployed troops. While, the spying saga was a weak point in the relation, the overall relationship is still strong.


Angela Merkel visits China more times than any of her previous counterparts. that makes her to a target of spying activities. Barack Obama wants to know what topics she talks to Xi Jinping. It is naive to believe the US would spare any nation in the world just because this and that country is ally. if it comes to core national interest, Obama relies on NSA.


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## GS Zhou

Let's not derail the discussion to diplomatic relationship. Thanks.

More pictures shared by National Astronomical Observatories of China:

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## xunzi

Viet said:


> quantum communication is all about to secure data against intruders, aka quantum encrypted communication.
> 
> why should germany use China quantum technology if everyone here fears you Chinese stealing their technologies? china quantum tech as a black box with Chinese instructions? think about it!


You don't think the German don't want quantum encryption technology? They are the most susceptible in all of western countries to be eardrop by no other than their allies due to fear of the 4th Reich.

Like I said, quantum technology require the sender and receiver to encrypt and the principle of quantum is to disrupt the encryption once it is being observed. This mean even the original creator of the tech cannot tell what is in the package that is send. Do you understand, my friend? LOL

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## Viet

xunzi said:


> You don't think the German don't want quantum encryption technology? They are the most susceptible in all of western countries to be eardrop by no other than their allies due to fear of the 4th Reich.
> 
> Like I said, quantum technology require the sender and receiver to encrypt and the principle of quantum is to disrupt the encryption once it is being observed. This mean even the original creator of the tech cannot tell what is in the package that is send. Do you understand, my friend? LOL


Have you bragged previously you are somewhat an expert in computing technology?

I suggest you remain in the subject because your knowledge on encryption technology is almost non existent. Lesser in quantum communications. And please don't talk about Germany if you know too little about the country. Thanks.


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## cirr

(1) Quantum radar successfully developed by Inst No. 14 of CEC:

http://www.mwrf.net/news/newtech/2016/19982.html





Group photo of the quantum radar team from Inst No. 14 in field trials 






No hiding for stealth targets 

(2) Nuclear Magnetic Resonance(NMR) Gyro prototype developed

http://www.dsti.net/Information/Viewpoint/71796

Another fine case in making use of quantum technology 

@Bussard Ramjet

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## gambit

cirr said:


> (1) Quantum radar successfully developed by Inst No. 14 of CEC:
> 
> http://www.mwrf.net/news/newtech/2016/19982.html
> 
> No hiding for stealth targets


The idea have been around since 2008, but only recently...

http://www.afcea.org/content/?q=Article-quantum-radar-could-render-stealth-aircraft-obsolete

The operative word here is 'could'.



> ...estimates that it could take at least 15 years before a quantum radar system is fielded.


And do not think that we have been idle in the field. Lockheed was already aware of the concept.


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## cirr

gambit said:


> The idea have been around since 2008, but only recently...
> 
> http://www.afcea.org/content/?q=Article-quantum-radar-could-render-stealth-aircraft-obsolete
> 
> The operative word here is 'could'.
> 
> 
> And do not think that we have been idle in the field. Lockheed was already aware of the concept.



Zilch for the Viets, "could" for the US and definitive for China.

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## gambit

cirr said:


> ...definitive for China.


In about 15 yrs...Sure.

But then, we will never know with 'Chinese physics'.


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## Chinese-Dragon

Wow I can't believe so many Vietnamese members are upset by this technology. 

@Viet why are you so upset? Do you think this is some sort of weapon? It's communications technology.

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## xunzi

Viet said:


> Have you bragged previously you are somewhat an expert in computing technology?
> 
> I suggest you remain in the subject because your knowledge on encryption technology is almost non existent. Lesser in quantum communications. And please don't talk about Germany if you know too little about the country. Thanks.


And you think you know more about quantum communication than me? LOL Like I told you before, the beauty of quantum is that the encryption is unbreakable due to the nature of quantum mechanics on localized entanglement.

I only spoke the truth about Germany. You think the German trust the US? If they do, they would have support the US war in the Middle-east.



Chinese-Dragon said:


> Wow I can't believe so many Vietnamese members are upset by this technology.
> 
> @Viet why are you so upset? Do you think this is some sort of weapon? It's communications technology.


He scared because the ongoing breakthrough in quantum processing speed will allow all traditional encryption to become breakable in second. This mean we will gain the supremacy in hacking into everyone system. LOL

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## TaiShang

cirr said:


> Zilch for the Viets, "could" for the US and definitive for China.



Could have, would have... The title of "could have beauty queen" has been transferred from India to the US.

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## randomradio

gambit said:


> The idea have been around since 2008, but only recently...
> 
> http://www.afcea.org/content/?q=Article-quantum-radar-could-render-stealth-aircraft-obsolete
> 
> The operative word here is 'could'.
> 
> 
> And do not think that we have been idle in the field. Lockheed was already aware of the concept.



Suddenly, it has become more believable, hasn't it?


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## cirr

TaiShang said:


> Could have, would have... The title of "could have beauty queen" has been transferred from India to the US.



For your info, the PLA is close to developing a ground-based air-defence(well, I'd say air-attack)missile capable of hitting large and high-value air-borne targets such as AWACS and aerial refuelling tankers some 2000km away.

A shipborne version with a combat range of some 1000km is also under development.

DF-XXs metamorphosing into HQ-XXs??

Chinese not innovative? 

You ain't see nothing yet. @Bussard Ramjet

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## gambit

randomradio said:


> Suddenly, it has become more believable, hasn't it?


There is nothing 'suddenly' about it. I read about concept yrs ago when 'quantum' was a buzzword everywhere. I would not be surprise if someone come up with a quantum breakfast cereal.

I have nothing against theoreticals, but in engineering, we have to deal with the real world. When a concept exit the laboratory, then we will take it seriously. Field testing is considered laboratory, lest anyone starts quibbling about the context of the word. So if a concept requires at least another decade before the engineers, regardless of country or nationality, get their greasy hands on it, it is pointless to start speculating on how effective the concept will be in a real war.

This is the progression of any technological achievement...

*First*...You have a 'science project'. It is essentially asking 'Can something be done ?'. You answer that question by putting experiments together to prove that the concept can transition to the physical realm: Proof of Concept.

*Next*...You enter 'research and development' (R/D). This is where you take cost into consideration. You have to use the lowest cost in materials to make more than just a few working models. You explore avenues of packaging. Does mobility matter ? If yes, you must 'trim the fat', so to speak.

*Next*...You enter initial manufacturing. This is where you investigate if you have the necessary industrial infrastructures to support mass production.

For example...If the item requires maraging steel, can you access it ? FYI, maraging steel is internationally controlled, meaning its production and sales are closely monitored by every major power in the world.

https://en.wikipedia.org/wiki/Maraging_steel


> ...is closely monitored by international authorities because it is particularly suited for use in gas centrifuges for uranium enrichment...


If the item requires unique electronics, do you have existing capabilities to custom manufacture said unique electronics ? If not, can you get it and in stable supplies ?

*Next*...You enter mass production. It does not matter if the item can be made by one manufacturer. The point here is that the item can be manufactured from proven processes and materials at the lowest possible cost and from steady suppliers.

This is why it can take decades for anything to go from proof of concept to mass production.

In the context of military applications, engineers and the military do not have the luxury of time. If I am to be attacked by a squadron of low radar observable enemy, I cannot console myself by thinking that my scientists are working on something that will defeat this enemy a few yrs from now.

The science world is filled with science projects that ended at the lab's doors. I joined this forum in 2009, since then, I have repeatedly said that the greatest threat to 'stealth' is the bi-static radar, but even so, the bi-static (or multi-static) radar have its weaknesses and limitations. Today, those weaknesses and limitations made the bi-static radar limited in military deployment. The Kolchuga and VERA wannabes are nowhere to be found. The greatest threat to American 'stealth' fighters fizzled out.


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## Viet

Chinese-Dragon said:


> Wow I can't believe so many Vietnamese members are upset by this technology.
> 
> @Viet why are you so upset? Do you think this is some sort of weapon? It's communications technology.


I´m upset because the poster posts nonsense. he mixes up everything into a cocktail.

look what he says:

"quantum technology require the sender and receiver to encrypt"
I would be more happy if he said: the sender encrypts the message before sending out, once received the receiver decrypts it. and vice versa.

or
"the principle of quantum is to disrupt the encryption once it is being observed. This mean even the original creator of the tech cannot tell what is in the package that is send".
really embarrassing what he states. correct is, photon entanglement will be destroyed if being observed. of course the sender knows the clear text because he possesses the secret key.


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## GeHAC

The laser and flash light in the pictures is for high speed precisive targeting,not quantum communication.The single photons for communication can only be captured by EMCCD.

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## xunzi

Viet said:


> I´m upset because the poster posts nonsense. he mixes up everything into a cocktail.
> 
> look what he says:
> 
> "quantum technology require the sender and receiver to encrypt"
> I would be more happy if he said: the sender encrypts the message before sending out, once received the receiver decrypts it. and vice versa.
> 
> or
> "the principle of quantum is to disrupt the encryption once it is being observed. This mean even the original creator of the tech cannot tell what is in the package that is send".
> really embarrassing what he states. correct is, photon entanglement will be destroyed if being observed. of course the sender knows the clear text because he possesses the secret key.


The one who post nonsense are YOU and your lack of understanding how quantum encryption works is disgusting. LOL I didn't say as a sender we don't know the message in the encryption. Duh! I said, as the creator of the quantum technology or you can call it the "provider of the quantum encryption machine", we cannot know what message is being encrypt because that is the job of the sender and the receiver to decide how they want to determine their message in the encryption. So in practice, Germany can used our quantum machine technology, and be able to communicate with your country Vietnam and we still wouldn't be able to eardrop and crack the code since of the nature in quantum entanglement which affect the state of two photons spin despite separating by distance once it is being observed. Do you understand my friend?

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## randomradio

gambit said:


> There is nothing 'suddenly' about it. I read about concept yrs ago when 'quantum' was a buzzword everywhere. I would not be surprise if someone come up with a quantum breakfast cereal.



No, no, again you misunderstand. When I first spoke about quantum, you used the words "decades" and dismissed it.



> I have nothing against theoreticals, but in engineering, we have to deal with the real world. When a concept exit the laboratory, then we will take it seriously. Field testing is considered laboratory, lest anyone starts quibbling about the context of the word. So if a concept requires at least another decade before the engineers, regardless of country or nationality, get their greasy hands on it, it is pointless to start speculating on how effective the concept will be in a real war.
> 
> This is the progression of any technological achievement...
> 
> *First*...You have a 'science project'. It is essentially asking 'Can something be done ?'. You answer that question by putting experiments together to prove that the concept can transition to the physical realm: Proof of Concept.
> 
> *Next*...You enter 'research and development' (R/D). This is where you take cost into consideration. You have to use the lowest cost in materials to make more than just a few working models. You explore avenues of packaging. Does mobility matter ? If yes, you must 'trim the fat', so to speak.
> 
> *Next*...You enter initial manufacturing. This is where you investigate if you have the necessary industrial infrastructures to support mass production.
> 
> For example...If the item requires maraging steel, can you access it ? FYI, maraging steel is internationally controlled, meaning its production and sales are closely monitored by every major power in the world.
> 
> https://en.wikipedia.org/wiki/Maraging_steel
> 
> If the item requires unique electronics, do you have existing capabilities to custom manufacture said unique electronics ? If not, can you get it and in stable supplies ?
> 
> *Next*...You enter mass production. It does not matter if the item can be made by one manufacturer. The point here is that the item can be manufactured from proven processes and materials at the lowest possible cost and from steady suppliers.
> 
> This is why it can take decades for anything to go from proof of concept to mass production.
> 
> In the context of military applications, engineers and the military do not have the luxury of time. If I am to be attacked by a squadron of low radar observable enemy, I cannot console myself by thinking that my scientists are working on something that will defeat this enemy a few yrs from now.



Okay, let me explain a bit about how open source works.

There are a few ways you get to know how to determine if something is possible or not. For one, they start talking about it. Take the PAK FA as an example. Right until the day it first flew and pictures were released, most people didn't know or didn't believe it existed. However only after the Russians started talking about it did we know more about the program, that happened 10 years later. Only in about 2011 or 2012 did we come to know that the program has been going on for a decade. We got to know about the engine program about 15 years after it started. The Russians probably revealed more about their engine because the Americans started talking about the ADVENT program about the same time, the last few years.

This is a pretty common occurrence in the civilian domain, when military projects are revealed in the civilian domain. But when this happens, you can be sure that they are talking about technologies that have surpassed most or all the hurdles that would take them from a demonstrator to a pre-production prototype. Basically, they talk about the high end tech when it has come up to TRL 6 or higher standards.

Another way is when they actually announce the program, like DARPA's program for Digital phased arrays or ISRO's RLV or China's quantum satellite and so on.

Finally, in the field of electronics, civilian tech is a decade ahead compared to the military, so it's easy to guess how advanced something can be just by studying open source materials.



> The Kolchuga and VERA wannabes are nowhere to be found. The greatest threat to American 'stealth' fighters fizzled out.



That's stuff from the 70s and 80s. These sensors work with the combination of other sensors, active and passive for stealth detection. Don't get carried away by news articles that publish only half the story.


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## gambit

randomradio said:


> No, no, again you misunderstand. When I first spoke about quantum, you used the words "decades" and dismissed it.


Yeah...It should be dismissed. The idea of a quantum radar have been around for nearly 10 yrs without the idea ever been out of the laboratory.


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## Viet

xunzi said:


> The one who post nonsense are YOU and your lack of understanding how quantum encryption works is disgusting. LOL I didn't say as a sender we don't know the message in the encryption. Duh! I said, as the *creator of the quantum technology* or you can call it the "*provider of the quantum encryption machine*", we cannot know what message is being encrypt because that is the job of the sender and the receiver to decide how they want to determine their message in the encryption. So in practice, Germany can used our quantum machine technology, and be able to communicate with your country Vietnam and we still wouldn't be able to eardrop and crack the code since of the nature in quantum entanglement which affect the state of two photons spin despite separating by distance once it is being observed. Do you understand my friend?


you are so funny. ok, let me ask you some questions. Care to explain:

- what do you mean with "the creator of the quantum technology"?

- define "provider of the quantum encryption machine"?

- why "we cannot know what message is being encrypt" if we can´t read it?

- why the hell should Germany and Vietnam use "made in china" quantum communication technology?

- can you ensure date security against Chinese spying activities if we use made in china a black-box, using made in china satellites?


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## randomradio

gambit said:


> Yeah...It should be dismissed. The idea of a quantum radar have been around for nearly 10 yrs without the idea ever been out of the laboratory.



No, the idea has been around since the 1980s. You were introduced to it 10 years ago at best. Quantum communications, computers, radars etc have been around for ages in theory and mathematics. They have been designing logic gates for quantum systems since decades, like CNOT and CCNOT gates. It's been 15 years now since nm level circuits for quantum information have been in the process of design and development.

Even 5 years is a lot of time when it comes to electronics.

Here, they have already made a functional quantum computer.

http://www.dwavesys.com/d-wave-two-system

http://news.usc.edu/104391/worlds-most-powerful-quantum-computer-now-online-at-usc/

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## gambit

randomradio said:


> No, the idea has been around since the 1980s.


And look how far have the concept been since then.


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## randomradio

gambit said:


> And look how far have the concept been since then.



This is how all of this stuff starts. The microelectronics revolution did not happen overnight. Similarly, we are now at the cusp of the photon revolution.


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## gambit

randomradio said:


> This is how all of this stuff starts. The microelectronics revolution did not happen overnight. Similarly, we are now at the cusp of the photon revolution.


And like I said that engineers and the military do not have the luxury of time.

If the military requests that I designed something to counter a potential threat, usually that threat is not hypothetical but real, in other words, a jet fighter against a jet fighter, not an F-16 against a TIE fighter from Star Wars. So until the quantum radar leave the laboratory, there is nothing the soldier can do. I do not understand why is that so difficult for you to grasp.


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## xunzi

Viet said:


> you are so funny. ok, let me ask you some questions. Care to explain:
> 
> - what do you mean with "the creator of the quantum technology"?
> 
> - define "provider of the quantum encryption machine"?
> 
> - why "we cannot know what message is being encrypt" if we can´t read it?
> 
> - why the hell should Germany and Vietnam use "made in china" quantum communication technology?
> 
> - can you ensure date security against Chinese spying activities if we use made in china a black-box, using made in china satellites?


LOL

Please allow to answer your question.

As I told you, creator of the quantum technology is the provider of the quantum encryption machine. The quantum encryption machine features method on how to encode and decode a message through the used of encrypting in a photon. 

In order to explain how a third party can't read that message, I can on and on and I"m afraid you won't be able to understanding if you don't understand quantum mechanics. So I keep it simple.

In this quantum machine, we will used LED to create photon because of LED inherently unpolarized nature. This means an unpolarized photon can exhibited all state of its spin ( like left, right, up, and down displaying all of its spin property all at once). This is what we called the wave function of how light behaves in quantum physics. And the advantage of an unpolarized photon is it makes a photon spin state unpredictable. So in order to regulate the 4 spins to a single spin property, you will need to send an unpolarized photon through a polarized filter before send off to the receiver which then used to decode the spin in the photon using the same filter the sender used, otherwise the property of the original spin in that photon message will be throw off. And spin will be represented by the traditional method of how communication technology communicate with each other, through binary of 1 and 0. This means 1 can be corresponded to left/right spin, and 0 can be up/down spin, unlike in traditional encryption, the message is displaying just binary. In quantum, you take a step further and display its spin but these spins are represented by binary, which only the sender knows because he/she is the guy that set the spin correspondence. So a third party can try to eardrop by placing a filter to intercept the message, but the beauty is like I said before, the nature of quantum entanglement caused photon spins to change once it is being observed. Thus the whole encryption will break off.

Because we are one of the few country that know how to create this quantum machine and be able to put it in space and able to deliver sensitive message over vast distance as opposed to the earlier limitation of quantum cryptography. And the fact the breakthrough in quantum communication will lead to quantum computer with the power of all known current supercomputer put together that don't even compare. So if you want to be safe from hacking proof from Uncle Sam, you might want to use our technology. This will have enormous impact in many industry that wants to keep data safe. In fact, we invest in quantum technology because we are the biggest victim of hacking groups across the world. LOL

Like I said and I predict in the future, only two countries are capable of hacking everyone system and that is us and USA because of our research in quantum computer far advance than everyone else in the world. So you can use our technology or not, it is up to you but do know if you don't, then be ready that we can hack into all of systems.

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## randomradio

gambit said:


> And like I said that engineers and the military do not have the luxury of time.
> 
> If the military requests that I designed something to counter a potential threat, usually that threat is not hypothetical but real, in other words, a jet fighter against a jet fighter, not an F-16 against a TIE fighter from Star Wars. So until the quantum radar leave the laboratory, there is nothing the soldier can do. I do not understand why is that so difficult for you to grasp.



Of course I understand that. That's also why I said there's no point having the quantum radar if it can't leave the lab.

The Russians have already finished development of the Digital PAR, while DARPA has started one now. And the Russians are now moving on to hardware that allows the creation of the Photonic PAR, the next evolution of the AESA after the Digital PAR, that's 2018. This Photonic PAR will allow the creation of the first quantum radar, that's before 2025.

Until these technologies are created and the PAK FA is operational, the Americans are going to continue to have the advantage with the F-22/F-35. The same with the Chinese. So that's not changed. But once it's ready, that means the F-22/F-35 are going to be obsolete. And it could happen in just a few years.

That's also why the US has decided to skip making a brand new fighter and just stick to modernizing an existing fighter just to keep up.
https://www.flightglobal.com/news/articles/usaf-backs-off-sixth-gen-fighter-in-quest-for-air-423994/


> “F-X would have been most likely like a sixth-generation fighter and would have had a 20 or 30-year development programme,” Holmes said at an Air Force Association forum in Washington DC on 7 April. “What we want to try to do is solve the problem faster than that by looking out across the range of options and building what we’re capable of building instead of waiting for the next generation.”



When you start looking at what others are doing, everything starts coming together. F-22/F-35 are really good today. But the Russians and maybe the Chinese are developing technologies that are going to make the jets obsolete. It starts making sense when you consider that even the Israelis believe the F-35's stealth will be useless in 5-10 years, that's about the time the Russian and Chinese fighters come online. So an aircraft that's supposed to have an RCS smaller than 0.0001m2 is going to be obsolete in just a few years time. The only answer to this drastic change is brand new technology. 

And to deal with this, the USAF has decided to junk their original plans and have their next new fighter developed in just 5-10 years now with existing technologies that will mature soon. That's a pretty big U-turn from the initial plan of making a brand new 6th gen aircraft.


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## Furqan Sarwar

China’s quantum satellite – nicknamed Micius after a Chinese scientist and philosopher – blasts off 
from the Jiuquan launch centre in Gansu province last week.

BEIJING: _The international power struggle for the control of data has intensified with a number of Chinese companies now trying to challenge entrenched cloud vendors such as Microsoft, Google and Amazon._

The growing market, targeted by Chinese players such as Huawei, Alibaba and Baidu, has raised serious questions about security of data storage and whether tech firms in China or elsewhere are vulnerable to attack.

*China last week took a major step towards resolving the cyber security challenge by launching the world’s first "hack-proof" quantum satellite.*

*"The satellite’s two-year mission will be to develop ‘hack-proof’ quantum communications, allowing users to send messages securely,"* Xinhua news agency reported.

The Quantum Experiments at Space Scale, or Quess, satellite programme is part of the Chinese leader Xi Jinping’s space programme.

_"There’s been a race to produce a quantum satellite, and it is very likely that China is going to win that race," Nicolas Gisin, a professor and quantum physicist at the University of Geneva, told The Wall Street Journal. "It shows again China’s ability to commit to large and ambitious projects and to realise them."_

The satellite is designed to *secure messages between Beijing and Urumqi*, the capital of Xinjiang, a sprawling region of deserts and snow-capped mountains in China’s extreme west.

The technology is extremely complex and based on the scientific principle of quantum entanglement.

According to this theory, two particles become "entangled" when they interact. However, any subsequent interaction with one impacts, instantaneously and regardless of distances between them, on both particles. "It is hence impossible to wiretap, intercept or crack the information transmitted through it," Xinhua reported after Tuesday’s launch.

But there are concerns about who has the keys to such technological developments and whether sensitive – or mission critical – data could be at risk in the absence of international rules and controls.

"There is a global focus on who controls data. But there is no transparency in this business," Sheila Jasanoff, director, programme on science, technology and society at Harvard Kennedy School tells The National.

"A new kind of frontier has been opened up, and it does not have any rules," she says.

There has been a proliferation of companies in the cloud computing sector, where sensitive or critical data is stored outside an organisation’s physical boundary, and very little commitment to data security, she adds.

The world market for cloud solutions is expanding rapidly. Global spending on cloud services is expected to see a compound annual growth rate (CAGR) of 19.4 per cent between 2015 and 2019, according to the statistics analyst, Statista. Amazon Web Services (AWS), the cloud arm of Amazon, generated revenues of US$7.88 billion in 2015, it says.

But the biggest hurdle for the sector is cyber security in the absence of any international treaty to enshrine it.

Cloud companies offer an extensive array of often expensive software solutions "to rent" to clients unable or unwilling to make the extremely heavy investment in money and expertise required to build such systems. As the sector expands, the leasing companies are increasingly focusing on safety in a bid to convince customers to move to cloud.

"Data security is an issue everywhere and, as [customers] move from internal IT networks largely based on computers and software located inside their own facilities to a cloud model in which the firm’s employees can use cheap mobile devices to access their IT network anywhere in the world at any time, the threats to data security grow," says Lee Branstetter, an associate professor of economics at the Heinz School of Policy and Management of the Carnegie Mellon University.

*"But the shift to cloud computing will only succeed if firms believe their essential data to be reasonably secure.

"For this reason, major players are making very large investments in technology that can ensure reasonably secure access to IT networks," he says.*

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## PaklovesTurkiye

So, when are we getting that ?  I mean we r already using Beidou navigation system. Next year we will launch our satellite too. I mean we are closely cooperating with China in this regard...

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## GS Zhou

*Key Lab of Quantum Information of CAS* (Chinese Academy of Science) recently makes a new breakthrough in quantum technology. A quantum transducer for OAM (Orbital Angular Momentum) qubits, OAM-polarization hybrid-entangled states, and OAM-entangled states, is reported for the first time. Nonclassical properties and entanglements are demonstrated following the conversion process by performing quantum tomography, interference, and Bell inequality measurements. The results *demonstrate the capability to create an entanglement link between different quantum systems operating in a photon’s OAM degrees of freedom*, which will be of great importance in building a high-capacity OAM quantum network.

The key research results are published in the [Light: Sci. & Appl. 5, e16019 (2016)], and [Phys. Rev. Lett. 117, 103601(2016)]

Background: 
Entanglement is a vital resource for realizing many tasks such as teleportation, secure key distribution, metrology, and quantum computations. To effectively build entanglement between different quantum systems and share information between them, a frequency transducer to convert between quantum states of different wavelengths while retaining its quantum features is indispensable. Information encoded in the photon’s orbital angular momentum (OAM) degrees of freedom is preferred in harnessing the information-carrying capacity of a single photon because of its unlimited dimensions. 

中国实现轨道角动量光子的量子频率转换

发布时间：2016-09-01 【字号： 小 中 大 】
　　中国科学院院士、中国科学技术大学教授郭光灿领导的中科院量子信息重点实验室在轨道角动量（OAM）光子的量子频率转换研究领域取得系列进展：该实验室教授史保森领导的小组在国际上首次实现了OAM单光子、OAM纠缠光子以及OAM与偏振组成的混合纠缠光子的频率上转换，证明了在频率变换过程中单光子的量子相干性和光子对的纠缠特性保持不变。主要研究成果分别发表在《光：科学与应用》和8月29日的《物理评论快报》上。论文的第一作者为博士后周志远。

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## cirr

"The Quantum Eye" - Single-pixel 3D camera

















This was in 2013. Don't know what headway the "Post-80s Team" from the Shanghai Institute of Optics and Fine Mechanics has made since. 

@Bussard Ramjet

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## Viet

xunzi said:


> LOL
> 
> Please allow to answer your question.
> 
> As I told you, creator of the quantum technology is the provider of the quantum encryption machine. The quantum encryption machine features method on how to encode and decode a message through the used of encrypting in a photon.
> 
> In order to explain how a third party can't read that message, I can on and on and I"m afraid you won't be able to understanding if you don't understand quantum mechanics. So I keep it simple.
> 
> In this quantum machine, we will used LED to create photon because of LED inherently unpolarized nature. This means an unpolarized photon can exhibited all state of its spin ( like left, right, up, and down displaying all of its spin property all at once). This is what we called the wave function of how light behaves in quantum physics. And the advantage of an unpolarized photon is it makes a photon spin state unpredictable. So in order to regulate the 4 spins to a single spin property, you will need to send an unpolarized photon through a polarized filter before send off to the receiver which then used to decode the spin in the photon using the same filter the sender used, otherwise the property of the original spin in that photon message will be throw off. And spin will be represented by the traditional method of how communication technology communicate with each other, through binary of 1 and 0. This means 1 can be corresponded to left/right spin, and 0 can be up/down spin, unlike in traditional encryption, the message is displaying just binary. In quantum, you take a step further and display its spin but these spins are represented by binary, which only the sender knows because he/she is the guy that set the spin correspondence. So a third party can try to eardrop by placing a filter to intercept the message, but the beauty is like I said before, the nature of quantum entanglement caused photon spins to change once it is being observed. Thus the whole encryption will break off.
> 
> Because we are one of the few country that know how to create this quantum machine and be able to put it in space and able to deliver sensitive message over vast distance as opposed to the earlier limitation of quantum cryptography. And the fact the breakthrough in quantum communication will lead to quantum computer with the power of all known current supercomputer put together that don't even compare. So if you want to be safe from hacking proof from Uncle Sam, you might want to use our technology. This will have enormous impact in many industry that wants to keep data safe. In fact, we invest in quantum technology because we are the biggest victim of hacking groups across the world. LOL
> 
> Like I said and I predict in the future, only two countries are capable of hacking everyone system and that is us and USA because of our research in quantum computer far advance than everyone else in the world. So you can use our technology or not, it is up to you but do know if you don't, then be ready that we can hack into all of systems.


ah thanks for the long post. not too bad.

quantum encryption may be uncrackable now by the current technology, but who can predict the future? can you?
besides quantum encryption strongest advantage is its biggest disadvantage: vulnerability for denial of service attack. how do you want to address this issue?

so China uses LED for emitting light aka creating photon because of its inherently unpolarized nature. how about laser light? single mode and multi-mode laser? is laser light always polarized? besides, both LED and laser are electromagnetic waves by nature, and as such they can be both.

I believe quantum has 6 states: 0, 1, early, late, overlap and nil. maybe it is china quantum tech when you say 4 states with 1 and 0, with 1 can be left/right spin and 0 can be up/down spin.

but I am not an expert in quantum physics. other can explain better.


re-edit: 6 states


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## Shotgunner51

PaklovesTurkiye said:


> So, when are we getting that ?  I mean we r already using Beidou navigation system. Next year we will launch our satellite too. I mean we are closely cooperating with China in this regard...




Can't find any news yet but is very natural for allies to use common platforms, let's wait and see.

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## xunzi

Viet said:


> ah thanks for the long post. not too bad.
> 
> quantum encryption may be uncrackable now by the current technology, but who can predict the future? can you?
> besides quantum encryption strongest advantage is its biggest disadvantage: vulnerability for denial of service attack. how do you want to address this issue?
> 
> so China uses LED for emitting light aka creating photon because of its inherently unpolarized nature. how about laser light? single mode and multi-mode laser? is laser light always polarized? besides, both LED and laser are electromagnetic waves by nature, and as such they can be both.
> 
> I believe quantum has 6 states: 0, 1, early, late, overlap and nil. maybe it is china quantum tech when you say 4 states with 1 and 0, with 1 can be left/right spin and 0 can be up/down spin.
> 
> but I am not an expert in quantum physics. other can explain better.
> 
> 
> re-edit: 6 states


Defeating quantum encryption is breaking physics at the subatomic level. That's not possible. You can't beat randomness. DOS attack is largely non-existence if the message transmission is being ping back and forth between the ground station and satellite. It is not going through optical fiber. 

The EM wave propagation of LASER, regardless of what type, has a linear electric field oscillation, which mean the direction that the spin in that photon is predicable, and thus does not exhibit the same randomness as typical light wave. This means it is not an unpolarized light that can be used for quantum computer. Though laser light is better used to trigger fusion in the energy fusion realm since it focuses on a localized target.

All lights contains both the electric and magnetic field in the EM wave but each will transverse in opposite direction. Though we concern with only the electric field here because that how you determine whether one is polarized or not polarized. In this case, the electric field which is the spin of the photon has only 4 states in the space plane, either up, down, left, right or vertical up, vertical down, horizontal left, horizontal right. Whatever the case may be, the sender can used binary of 1 and 0, like I said, to represent of each of those photon's electric spin state. But since the quantum cryptographer wants randomness or the unpredictability of the photon state to make guessing impossible before it sends to an optical filter, they want the unpolarized light.

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## PaklovesTurkiye

Shotgunner51 said:


> Can't find any news yet but is very natural for allies to use common platforms, let's wait and see.



Yes. I agree. 

Sorry, I wrote satellite will b launched next year but it is actually will be in 2018. Here is the link.......

https://propakistani.pk/2016/08/30/pakistan-china-jointly-launch-satellite-2018/

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## Shotgunner51

PaklovesTurkiye said:


> Yes. I agree.
> 
> Sorry, I wrote satellite will b launched next year but it is actually will be in 2018. Here is the link.......
> 
> https://propakistani.pk/2016/08/30/pakistan-china-jointly-launch-satellite-2018/




Look forward to that! Space is a critical frontier, if not ultimate, for civil apps as well as for top-level national security. China and Pakistan are in their own camp, developing own standards from satellite positioning to manned space explorations, let there be more joint programs!

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## Viet

xunzi said:


> Defeating quantum encryption is breaking physics at the subatomic level. That's not possible. You can't beat randomness. DOS attack is largely non-existence if the message transmission is being ping back and forth between the ground station and satellite. It is not going through optical fiber.
> 
> The EM wave propagation of LASER, regardless of what type, has a linear electric field oscillation, which mean the direction that the spin in that photon is predicable, and thus does not exhibit the same randomness as typical light wave. This means it is not an unpolarized light that can be used for quantum computer. Though laser light is better used to trigger fusion in the energy fusion realm since it focuses on a localized target.
> 
> All lights contains both the electric and magnetic field in the EM wave but each will transverse in opposite direction. Though we concern with only the electric field here because that how you determine whether one is polarized or not polarized. In this case, the electric field which is the spin of the photon has only 4 states in the space plane, either up, down, left, right or vertical up, vertical down, horizontal left, horizontal right. Whatever the case may be, the sender can used binary of 1 and 0, like I said, to represent of each of those photon's electric spin state. But since the quantum cryptographer wants randomness or the unpredictability of the photon state to make guessing impossible before it sends to an optical filter, they want the unpolarized light.


I believe hardly anyone understands 

let me make it shorter: quantum communication is all about photon polarizations. the secret key between sender and receiver is shared by matching photon both basis and polarizations.

added: photon basis


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## terranMarine

Viet said:


> I believe hardly anyone understands



Then what are you complaining about on your post #39 and previous replies? As if you are that intelligent from the very beginning, now he explains more in details you have no clue what he is talking about. Get a life man.

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## Jlaw

Chinese-Dragon said:


> Wow I can't believe so many Vietnamese members are upset by this technology.
> 
> @Viet why are you so upset? Do you think this is some sort of weapon? It's communications technology.


They are not upset. they jealous .



terranMarine said:


> Then what are you complaining about on your post #39 and previous replies? As if you are that intelligent from the very beginning, now he explains more in details you have no clue what he is talking about. Get a life man.


technology and vietnamese is oxymoron man. But i smell the fear in vietnamese people. China is so way ahead of SEA that ranting and fearing the dragon is all they can do

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## yusheng

Jlaw said:


> They are not upset. they jealous .
> 
> 
> technology and vietnamese is oxymoron man. But i smell the fear in vietnamese people. China is so way ahead of SEA that ranting and fearing the dragon is all they can do



yes, if you show a newspater report, vietnamese will say it is too simple, if you give out the formal paper, they will say too deep. what they really want is not the discussion of scientific problems but trolling, that only disclose their dark psychology.

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## FairAndUnbiased

Viet said:


> That does not explain anything how it works in principle:
> 
> photon teleportation, quantum key exchange and quantum communications between Beijing and Vienna via a satellite.
> 
> Nothing is revealed what technology is used.



Read the Nature paper when it comes out. It's not like Pan Jianwei (the project lead) has a shortage of those - he started this project 10 years ago and has demonstrated it repeatably at smaller scales, as well as won the Fresnel Prize in Quantum Optics in 2005 from the European Physical Society.

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## Viet

yusheng said:


> yes, if you show a newspater report, vietnamese will say it is too simple, if you give out the formal paper, they will say too deep. what they really want is not the discussion of scientific problems but trolling, that only disclose their dark psychology.


I never say be an expert in quantum communications. So before you start trolling me, I challenge you to find what I say on encryption technology and quantum physics is wrong!


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## jkroo

FairAndUnbiased said:


> Read the Nature paper when it comes out. It's not like Pan Jianwei (the project lead) has a shortage of those - he started this project 10 years ago and has demonstrated it repeatably at smaller scales, as well as won the Fresnel Prize in Quantum Optics in 2005 from the European Physical Society.


Bro, that's good. Can you predict how many Prof. Pan like will appear in the 10 years.


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## 艹艹艹

http://en.people.cn/n3/2016/0908/c98649-9112553.html

*China successfully develops quantum radar system*
(People's Daily Online) 14:41, September 08, 2016

China launches the world's first quantum satellite on top of a Long March-2D rocket fromthe Jiuquan Satellite Launch Center in Jiuquan, northwest China's Gansu Province, Aug. 16, 2016. This world's first quantum communication satellite is given the moniker "Micius,"after a fifth century B.C. Chinese scientist. (Xinhua/Jin Liwang)

The 14th Institute of China Electronics Technology Group Corporation (CETC) hassuccessfully developed China’s first quantum radar system last month, Xinhua NewsAgency reported. The system, which is based on the technology of single photon detection,counts as yet another major milestone for China in quantum research.

The quantum radar system was developed by the Intelligent Perception TechnologyLaboratory of the 14th Institute of CETC. Researchers completed experiments onquantum detection and target scattering characterization. In the target detectionexperiment, conducted in a real atmospheric environment, the detection ability of thesystem was proven to be over 100 kilometers. 

According to a Sept. 8 report by Mingbao Daily, the theoretical basis of the quantum radaris that an object will change its quantum properties after receiving photonic signals. Thequantum radar can easily detect stealth aircraft and is highly resistant to becomingjammed. Military experts have stated that once a stealth aircraft is located by the radar, itstands little chance to escape the strikes of air defense missiles.

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## randomradio

@gambit @moon_light @That_engineer_guy 

There you go.

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## xunzi

Good bye to the fat boy F-35. LOL

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## TheTheoryOfMilitaryLogistics

The only thing that China can do is copy.
So I guess this radar system must have been stolen from A~san's masters.
Although I can't confirm which master(the westernmedia don't tell me),
I believe that I am the nearest person to truth.

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## Jlaw

TheTheoryOfMilitaryLogistics said:


> The only thing that China can do is copy.
> So I guess this radar system must have been stolen from A~san's masters.
> Although I can't confirm which master(the westernmedia don't tell me),
> I believe that I am the nearest person to truth.



Good one bro. You know a really bad secret. You know where Ipod originated from?

Apple took the MP3 player from a SG company Creative and rebrand it into the Ipod. But of course you will not hear this in western news about Americans copying. Americans are biggest copycat in the world.

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## TaiShang

Jlaw said:


> Good one bro. You know a really bad secret. You know where Ipod originated from?
> 
> Apple took the MP3 player from a SG company Creative and rebrand it into the Ipod. But of course you will not hear this in western news about Americans copying. Americans are biggest copycat in the world.



The late Steve Jobs used to praise copying and stealing.

I will take my hat off to their marketing ability.

But, on this quantum comm. platform, China has better keep a low key. No need to get others know every single details of your (military-related) achievements.

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## cirr

http://dailycaller.com/2016/09/08/new-quantum-radar-might-see-straight-through-american-stealth/

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## Jlaw

TaiShang said:


> The late Steve Jobs used to praise copying and stealing.
> 
> I will take my hat off to their marketing ability.
> 
> But, on this quantum comm. platform, China has better keep a low key. No need to get others know every single details of your (military-related) achievements.



Too late....there's already a thread about it. Not sure why Chinese government want to leak this out

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## terranMarine

China should not have leaked it, don't know why they did it though.

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## hoangsa74

Everyone is so scared of this quantum super radar that people are keep lining up to buy the F-35, LOL


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## 艹艹艹

hoangsa74 said:


> Everyone is so scared of this quantum super radar that people are keep lining up to buy the F-35, LOL


*Because they have no other choice.*

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## TaiShang

hoangsa74 said:


> Everyone is so scared of this quantum super radar that people are keep lining up to buy the F-35, LOL



Cute mockery.

I would say ignore it. It has nothing; no meat or substance, but just empty rhetoric.

You are already too big to fail.

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## meis

Uncle Sam has wasted all his F22 Raptors for nothing. What a shame.


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## Jlaw

meis said:


> Uncle Sam has wasted all his F22 Raptors for nothing. What a shame.


i believe you are right. Now F22 , F35 can easily be detected they are vulnerable like any other airplanes. Wasted money when they could spend on this:






and this:

*The US government has a $20.4 trillion retirement problem*

http://www.businessinsider.com/us-government-7-trillion-pension-shortfall-2016-4

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## cirr

*Teleportation, the next generation: Chinese and Canadian scientists closer to a quantum internet*

Researchers teleport tiny photon particles across cities in breakthrough that could help future development of a faster, more secure ‘quantum internet’

PUBLISHED : Monday, 19 September, 2016, 11:02pm
UPDATED : Tuesday, 20 September, 2016, 9:36am

Stephen Chen

Chinese and Canadian scientists say they have successfully carried out a form of teleportation across an entire city.

The two teams working independently have teleported near-identical versions of tiny particles called photons through cables across Calgary in Canada and Hefei in Anhui province.

The forms of teleported photons were destroyed in one laboratory and recreated in another more than 8km apart in the two cities through optical fibre.

Similar experiments have been carried out before, but only within the same laboratory.

A physicist not involved in either of the studies said the research was a step forward in the development of a “quantum internet”, a futuristic particle-based information system that could be much more secure than existing forms of digital data.

Quantum networks make eavesdropping almost impossible because the particles used cannot be observed without being altered.

Teleportation, the foundation for such a network, has largely been the realm of science fiction, and other scientists say the research is still a very long way from teleporting people or objects.


But in his commentary on the research in the scientific journal _Nature Photonics,_ French physicist Frederic Grosshans said the two experiments clearly showed that teleportation across metropolitan distances was technologically feasible.

“The two papers demonstrate that the possibility of quantum [internet] networks that span a city are a realistic proposition, which is an exciting vision for the future,” Grosshans said.

Professor Zhang Qiang, one of the leaders of the Chinese team, said: “Maybe in the distant future, materials can be teleported through a fibre or even open space, too.”

The research was carried out by scientists at the University of Science and Technology of China and the University of Calgary and their papers were published in the journal on Monday.

The research concentrates on the behaviour of particles at a subatomic, or quantum level.

Researchers have long known that a photon particle can be split in two and yet the pair are still “entangled”, which means that any change in the state of one immediately affects the other, although how this happens is still unknown.

This, in theory, means it could be possible to transmit information by manipulating entangled photons, but various factors, including fluctuating temperatures, can interfere with the process over longer distances outside the laboratory.

The researchers used sophisticated equipment to counter these and other problems, allowing the Chinese team, led by Professor Pan Jianwei and Professor Zhang, to achieve “full” quantum teleportation of photons over a optical fibre network 12.5km apart.

The Canadian team led by Professor Wolfgang Tittel also teleported the particles over 8.2km. The teleported photons were a virtual copy of the original.


A team at the National Institute of Standards and Technology in the US reported last year that it had achieved quantum teleportation over a fibre optical network more than 100km in length, but the whole cable was coiled within a laboratory.

Scientists have also teleported photons through the air over 100km, but the technology can only be used at night and in remote areas because too many of the particles are generated by other sources including natural light.Using a cable shields the photons from interference and is viewed by researchers as a more practical way of harnessing the technology.

The Chinese and Canadian teams used different approaches to carry out their experiments. The Chinese team demonstrated a fuller version of the quantum network with higher reliability, but the Canadian approach was more efficient, according to Grosshans.

The Chinese method “comes at the price of a low rate of two teleported photons per hour, which would strongly limit its practical applications if it could not be improved”, he said.

The Canadian method “allows a faster teleportation rate of 17 photons per minute”, but their low accuracy during transmission “also limits its immediate practical applications”.

Zhang at the University of Science and Technology of China, said the team’s work was only a small step towards the construction of a quantum network.

Many technical hurdles, such as storage for the extremely fragile quantum data, remained and it was difficult to predict when a global quantum internet would be operational.

Grosshans said a useful quantum computer was still a few decades away and “the first ones, whether they will be built in 2030 or 2070 would be very expensive machines”.

China is at the forefront of research into quantum communications.

It is carrying out experiments on a satellite launched last month as part of efforts to develop a communications system that cannot be cracked by hackers.

The experiments involve attempting to transmit information through photons from the satellite to earth.

http://www.scmp.com/news/china/poli...nese-canadian-scientists-achieve-breakthrough

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## cirr

*CHINA SAYS IT HAS QUANTUM RADAR: WHAT DOES THAT MEAN?*

STEALTH HUNTER

By Jeffrey Lin and P.W. Singer Yesterday at 7:00pm





World Champions

Shown here are engineers from China Electronics Technology Group Corporation (CETC)'s 14th Institute, who in September 2016 announced to have built the world's longest ranged quantum radar

*China Electronics Technology Group Corporation (CETC), China's foremost military electronics company, has announced that its scientists have tested a quantum radar to the range of 100km, beating out known American and German competition by 500 percent. This is a significant claim to make, as a quantum radar would theoretically be able to detect stealth aircraft at long ranges.*

While conventional radars transmit radio waves to reflect off of targets, a quantum radar instead uses entangled photons, via fiber couplers, quantum dots or other methods. The entangled photons bounce off of the targeted object back to the quantum radar, which can extrapolate the position, radar cross section, speed, direction and other properties of the targeted object from the return time of the photons. Also, attempts to spoof the quantum radar would be immediately noticed, since any attempt to alter or duplicate the entangled photons would be detected by the radar.

Because stealth aircraft are optimized for stealth against radio waves used by conventional radars, they would be much more susceptible to detection by the photon waves of a quantum radar. Additionally, the quantum radar could 'observe' on the composition of the target, since in the state of entanglement, the entangled photons remaining in the radar would show the same changes that transmitted photons would have when interacting with the target (known as quantum correlation). That would also be very valuable in missile defense, where one could differentiate between an actual nuclear warhead against inflatable decoys.

There is, of course, a wide difference between a claim of a laboratory "proof of concept" and the deployment of an actual working quantum radar. Indeed, US defense contractor Lockheed Martin has been attempting to build its own quantum radar for long range detection since 2007, with no public reports of deployment. A number of hurdles have to be overcome not just in making the system work, but also truly useful. A major obstacle towards an operational quantum radar is the problem of quantum decoherence; as a quantum system like entangled particles spends more time in the environment, the longer exposure to the outside environment will cause the quantum system to 'decay' (to lose its quantum behavior). This imposes range limitations on current quantum radar prototypes, since longer range equals more time spent exposed to its surroundings. While a 100km-range quantum radar may seem impressive by scientific research standards, the demands of air defense against stealth bombers or missiles would require a much greater range to be of optimal military use.

*Whatever happens next with the quantum radar project, CETC's announcement is a useful reminder of both the impressive array of research activities in China and how breakthroughs in technology can quickly turn the tables on once powerful weapons.*

http://www.popsci.com/china-says-it-has-quantum-radar-what-does-that-mean

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## randomradio

100Km is an unbelievable achievement. You need some insane memory for that.

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## cirr




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## dadeechi

Is Chinese Radar ahead of Chinese missiles...


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## beijingwalker

*China’s 2,000-km Quantum Link Is Almost Complete*
*The Beijing-Shanghai project will form the backbone of the nation’s quantum communications network*
By Rachel Courtland
Posted 26 Oct 2016 | 15:00 GMt




*Quantum Space Link:* Staff work on China’s quantum research satellite, which launched in August. It is part of a larger effort in the country to push the limits of quantum key distribution.

By the end of this year, a team led by researchers from the University of Science and Technology of China, in Hefei, aims to put the finishing touches on a 2,000-kilometer-long fiber-optic link that will wind its way from Beijing in the north to the coastal city of Shanghai.

What will distinguish this particular stretch of fiber from myriad other long-distance links is its intended application: the exchange of quantum keys for secure communication—a sophisticated gambit to protect data from present and future hackers. If all goes according to plan, this Beijing–Shanghai line will connect quantum networks in four cities. And this large-scale terrestrial effort now has a partner in space: A quantum science satellite was launched in August with a research mission that includes testing the distribution of keys well beyond the country’s borders.

With these developments, China is poised to vastly extend the reach of quantum key distribution (QKD), an approach for creating shared cryptographic keys—sequences of random bits—that can be used to encrypt and decrypt data. Thanks to the fundamental nature of quantum mechanics, QKD has the distinction of being, in principle, unhackable. A malicious party that attempts to eavesdrop on a quantum transmission won’t be able to do so without creating detectable errors.

QKD has already made its way into the real world. In 2007, the scheme was used to secure the transmission of votes in a Swiss election. Several years ago, the U.S.-based firm Battelle began to use the approach to exchange information securely over kilometers of fiber between its corporate headquarters in Columbus, Ohio, and a production facility in Dublin, Ohio.

But despite great progress, there has been a stumbling block to wide distribution. “The problem we’ve got is distance,” says Tim Spiller, director of the United Kingdom’s Quantum Communications Hub, a nationally funded project that is building and connecting quantum networks in Bristol and Cambridge, in England.

The challenge is that QKD encodes information in the states of individual photons. And those photons can’t travel indefinitely in fiber or through the air; the longer the distance, the greater the chance they will be absorbed or scattered.

This characteristic has a direct impact on how quickly a quantum key can be generated, explains physicist Jian-Wei Pan, who leads the Chinese projects. If researchers attempted to send signals directly down 1,000 kilometers of fiber, Pan says, “even using all the best technology, we would only manage to send 1 bit of secure key over 300 years.”

Instead, QKD fiber links must have a way to refresh the signal every 100 km or so to maintain a reasonable bit rate. But this can’t be done with conventional telecommunications equipment. The same rules that protect quantum transmission against eavesdropping also prohibit a quantum key from being copied without corrupting it. The solution has been to concatenate, creating a daisy chain of individual quantum links connected by physically secured spots, or “trusted nodes.” Each intermediate node measures the key and then transmits it with fresh photons to the next node in the chain.






The Beijing–Shanghai line will use 32 trusted nodes to create the 2,000-km line. This approach isn’t ideal for security. Because each trusted node has to convert the quantum key back into classical (nonquantum) information before passing it on, an eavesdropper at the node could potentially hack the data stream there undetected. “That’s the drawback,” Pan says. But the approach is “still much better than traditional communications… [where] there is the possibility of performing eavesdropping” at every point along the route, he says. Here, the problem is limited to 32 spots under lock and key.

“A long-distance chain link like this, [it’s] really the first time it’s been done,” says Grégoire Ribordy of ID Quantique, based in Geneva, which makes hardware for QKD networks. “It’s inspiring other people to try to do similar things around the world.”

If you want to avoid even the small vulnerability of trusted nodes, Spiller says, long-distance QKD must use quantum entanglement, a property that can link the states of photons separated by great physical distance and that can be exchanged between photons. “Quantum repeaters,” used in place of trusted nodes, could take advantage of this phenomenon to relay a quantum key without having to measure it. But this technology is still in an early stage of development, says Spiller; among other things, a quantum repeater will likely require a form of quantum memory to help coordinate communication.

“[If you] don’t have to trust any of the nodes along the network, that will broaden the applicability of QKD,” says Michele Mosca, cofounder of the Institute for Quantum Computing at the University of Waterloo, in Ontario, Canada. One reason to improve QKD’s reach is to protect communications from tomorrow’s quantum computers, which could make short work of the public-key cryptography that underpins Internet security and many other applications.

But Mosca notes that QKD is not the only possible way to address this threat; many cryptographers are exploring new “post-quantum” algorithms to replace our existing public-key systems. QKD offers an “extra degree of assurance,” he says, but improved conventional cryptography will be a cheaper and more practical solution for many applications. Both will likely have a role to play in the coming years.
http://spectrum.ieee.org/telecom/security/chinas-2000km-quantum-link-is-almost-complete

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## PatriotNaz

Ive watched how these satellites work when sending data and it still baffling and i love science


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## cirr

*Synopsis: Quantum Cryptography Goes a Long Way*

November 2, 2016

*A protocol for secure quantum communications has been demonstrated over a record-breaking distance of 404 km.
*




Y. Hua-Lei _et al_., Phys. Rev. Lett. (2016)

Encryption is critical in many aspects of modern life, such as the millions of credit card transactions that occur every day. However, perfectly secure communication can only be achieved using the strong correlations, or entanglement, between quantum objects. *Now, Jian-Wei Pan at the University of Science and Technology of China and his colleagues have experimentally shown that a secure quantum protocol known as measurement-device-independent quantum key distribution (MDIQKD) can be implemented over a distance of 404 km. The result breaks the previous MDIQKD record by over a factor of 2 and paves the way for secure quantum communications between distant cities.*

MDIQKD—a protocol proposed in 2012—functions even when it uses photon detectors that are not ideal and have, for example, low detection efficiencies. It can also overcome security loopholes of quantum communication schemes by sending out decoy pulses of light to detect eavesdropping attacks. Pan and his team sent pulses of infrared photons through optical fibers with lengths between 102 and 404 km and optimized the MDIQKD scheme by tuning several parameters, such as the average number of photons per pulse. The protocol was found to be secure up to the longest distance. For each length, the researchers also determined the maximum speed by which cryptographic keys could be securely distributed. Compared with earlier experiments, they demonstrated a 500-fold increase in speed, reaching a key-distribution rate that would be sufficient to ensure encrypted voice transmission by telephone.

This research is published in _Physical Review Letters_.

–Katherine Kornei

http://physics.aps.org/synopsis-for/10.1103/PhysRevLett.117.190501

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## AndrewJin

The year of 2016 is a little bit overwhelming, scientifically.....

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## Shotgunner51

*Chinese Physicists Achieve Record-Breaking Quantum Cryptography Breakthrough*

by Giulio Prisco November 4, 2016

*Researchers at the University of Science and Technology of China and other Chinese labs, with the collaboration of a lab in the US, have implemented a secure quantum protocol known as Measurement-Device-Independent Quantum Key Distribution (MDIQKD), suitable for practical networks and devices, over a distance of 404 km. The breakthrough, which doubles the previous MDIQKD record, opens the door to secure wide area quantum communication networks.*






The research was published earlier this week (November 2) in _Physical Review Letters_ with the title “Measurement-Device-Independent Quantum Key Distribution Over a 404 km Optical Fiber.” A companion “Synopsis: Quantum Cryptography Goes a Long Way” was published in _APS Physics_.

The researchers note that, while the potential of Quantum Key Distribution (QKD) to provide unconditional secure communication between two distant parties is undisputed, its feasibility has been questioned due to certain limitations in the practical application of real-life QKD systems. The new method is seen as an important step toward practical, operational QKD networks.

Quantum Key Distribution permits securely sharing keys for one-time pad (OTP) cryptography. OTP encryption is mathematically guaranteed to be unbreakable, but only if the keys are not compromised. Therefore, secure key transmission and storage is the main challenge for ultra-secure OTP cryptography. But quantum entanglement – long-range instant correlations between photons – can be used to establish a shared key in such a way as to permit detecting any attempt to eavesdrop on the key. Therefore, quantum encryption offers complete, invulnerable security based on the laws of fundamental physics.

Quantum computing, a complementary quantum technology, first proposed by Nobel laureate Richard P. Feynman in 1982 (see also _Feynman’s Lectures on Computation_), could in the future permit cracking all traditional encryption schemes with sophisticated algorithms and superior computing power. But quantum encryption is invulnerable to quantum computing attacks.




*Toward fast, Secure, Unbreakable Wide Area Quantum Encryption Network* 

MDIQKD – a quantum cryptography protocol first proposed in 2012 – tolerates relatively inefficient photon detectors and permits improving the security of quantum communication by using “decoy” photons to detect eavesdropping attacks. The researchers sent infrared photons through optical fibers with lengths between 102 and 404 km, and demonstrated security up to the longest distance.

“Measurement-device-independent quantum key distribution (MDIQKD) with the decoy-state method negates security threats of both the imperfect single-photon source and detection losses,” reads the paper’s abstract. “Lengthening the distance and improving the key rate of quantum key distribution (QKD) are vital issues in practical applications of QKD. Herein, we report the results of MDIQKD over 404 km of ultralow-loss optical fiber and 311 km of a standard optical fiber while employing an optimized four-intensity decoy-state method.”

MDIQKD had proven very slow so far, compared to the requirements for practical QKD. “The best demonstration so far sent information over a distance of 200 kilometers at a data rate of just 0.018 bits per second,” noted a _MIT Technology Review_ commentary to a draft version of the paper. “At this rate, perfectly secure quantum cryptography would never be practical.” But now the Chinese scientists have achieved a very significant increase in speed compared to previous results.

_"In addition to the long transmission distances, our system generates a 1.38 kbits per second secure finite key at 102 km, therefore constituting a strong candidate for a metropolitan quantum network with an unreliable relay"_​
The scientists added that system performance could be further improved by increasing the system clock rate and the efficiency of the photon detectors.

Physicists at Corning Inc., a research company headquartered in Corning, New York, and specialized in materials science and optical physics, have participated in the research. Among them, fiber optics and quantum communication specialist Daniel Nolan.

But it appears that China is pursuing a government-supported, well-funded quantum technology development effort for both civilian and military applications, ranging from unbreakable encrypted communication networks to combat support operations, more aggressively than the US. Early results of China’s quantum technology program are the world’s first quantum satellite and a “quantum radar” able to detect stealth planes 100km away, both recently covered by _Hacked_.

https://hacked.com/chinese-physicists-achieve-record-breaking-quantum-cryptography-breakthrough/

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## 艹艹艹

https://www.rt.com/news/367549-china-quantum-communication-line/
*China launches world’s longest super-secure quantum communication line*
Published time: 20 Nov, 2016 11:33
Get short URL




© Jose Miguel Gomez / Reuters

China has launched a quantum communication line 712 kilometers in length that is meant to safely transmit sensitive information. It is expected to be extended to 2,000 kilometers soon.
The line connecting Hefei, the capital of Anhui Province, and Shanghai, a coastal trade hub, has 11 trusted nodes along its length, Xinhua news agency reported on Sunday.

It transmitted a secure video conference between the two cities in one of its first test communications.

The line, already three years in the making and yet to be finished, will ultimately connect Shanghai to China’s capital, Beijing, and run through another major city, Jinan, with a total of 32 relay points. The entire project was expected to be finished in November, but the completion date has been moved back until at least the end of the year.

Quantum communication uses quantum entanglement of photons to ensure that nobody taps into the line, as doing so would inevitably corrupt the signal. The relay nodes are weak points, because the information is translated back into regular form there before being re-entangled and sent further along the optic fiber link.

The Chinese network is valuable for both research on how the technology can be used, and practical purposes, such as delivering secure messages between the connected cities.

China has already launched a quantum communication satellite that will eventually be connected to the Shanghai-Beijing line via a station in Beijing.

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## AndrewJin

This technology is gradually becoming reality.

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## Star Expedition

We can earn lots of money now

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## cirr

*Can China’s quantum radar become even more powerful? Scientists may have found the key*

*Experiment may extend range of systems that detect stealth aircraft, but Tsinghua physicist warns it could just be a ‘mathematical illusion’*

PUBLISHED : Thursday, 15 December, 2016, 1:32pm
UPDATED : Thursday, 15 December, 2016, 10:02pm

*Chinese researchers have conducted an experiment that could lead to a way to extend the range at which quantum radar systems can detect stealth aircraft.*

In a paper in the journal _Physical Review Letters_ early this month, the team from the University of Science and Technology of China (USTC) in Hefei, Anhui province, detailed an experiment that showed for the first time that weak-value-based metrology, an emerging quantum measurement technique, could detect previously undetectable signals.

The technology used very “gentle” methods to measure the quantum states of subatomic particles repeatedly and could be particularly useful in the detection of extremely weak signals, such as the radar signature of a stealth jet.

A quantum physicist at Nanjing University in Jiangsu province, who was not involved in the research, cautioned that it was “laboratory work, not mature enough for immediate field deployment”, but added that it could “boost the range of quantum radar, among other things”.

Quantum physicists at USTC have built the world’s first quantum satellite, which was launched in August, and its longest ground-based quantum communication network.

USTC researchers also participated in the development of China’s first quantum radar system, according to China Electronics Technology Group Corporation (CETC), a state-owned arms supplier.

Earlier this year, CETC announced the effective range of Chinese quantum radar technology had reached 100km, five times the potential range of an overseas prototype.

China regards the stealth aircraft flown by the United States and its allies as a major threat to its regional interests. Japan received its first F-35 stealth fighter last month and in the years ahead China faces the likelihood of being surrounded by more stealth fighters and bombers.

Quantum radar systems generate pairs of entangled light particles known as photons. One photon in the pair is beamed into the air while the other is kept at the radar station. If a target is located, some photons bounce back and can be identified by matching them with the entangled photons kept at the radar station. By measuring the returning photons, researchers can calculate the physical properties of the target, such as its size, shape, speed and angle of attack.

However, a major challenge faced by quantum radar has been the small number of photons that return, with their number diminishing as the distance to a target increases. The theoretical bottom line was called the shot noise limit, beyond which a target could not be detected even in the best observation conditions.

Beyond the shot noise limit, the information carried by photons would be overwhelmed by the subatomic noises occurring within the photons themselves, and the detector would be unable to take a reliable measurement because the photons would hit the detector like random shots, hence the name.

The USTC team, led by professors Guo Guangcan and Li Chuanfeng, said they broke the shot noise limit by using a refined version of weak quantum measurement technology, which allowed them to accurately detect the presence of a even a very small number of photons.

The technology stems from a paradox in quantum physics. In the subatomic world, measurement means destruction. When you measure a subatomic particle you inevitably destroy its original quantum states.

But in the late 1980s, scientists came up with a solution. A weak measurement did not cause a collapse of quantum states. Even though each weak measurement could only obtain a small amount of information, by repeating the measurement on the same particles many times a statistically robust value, or a correct guess, about the properties trying to be measured could be obtained.

However, the original weak measurement scheme was inefficient. It could only measure a small proportion of the photons within detection range, with the rest discarded as waste.

In recent years scientists came up with a new method called power recycle measurement which could cycle the photons in a special device to reduce the number being wasted.

*The USTC team conducted an experiment measuring laser beam deflection to demonstrate how the method could break the shot noise limit and push the sensitivity of a signal detector more than 200 per cent beyond it. They recorded detection at a signal strength less than half the shot noise limit while boosting the accuracy by 150 per cent, they said.*

*The Nanjing University professor, who requested anonymity, said the technology could “definitely” be used in quantum radar.*

But a Tsinghua University quantum physicist expressed doubts about whether the technology would find a practical use any time soon, if at all.

“So far I have not heard of any real application of the weak metrology,” he said, also requesting anonymity. “Weak measurement is still a measurement, it will inevitably change the state of the object it measures, and that will set a limit to how far it can go.

“There is still ongoing debate whether the weak measurement is showing us real physical observation or just mathematical illusion.”

http://www.scmp.com/news/china/arti...cientists-show-how-extend-range-quantum-radar

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## Nan Yang

*Chinese scientists solve quantum communication’s ‘nocturnal curse’, allowing sending of secure messages 24/7*

Using photons with a longer wavelength makes long-distance transmission possible during daylight hours

STEPHEN CHEN

BINGLIN.CHEN@SCMP.COM

PUBLISHED : Tuesday, 03 January, 2017, 10:25am
UPDATED : Tuesday, 03 January, 2017, 9:36pm

UPDATED : Tuesday, 03 January, 2017, 9:36pm

Professor Pan Jianwei delivers a lecture at Hong Kong University of Science and Technology in September. Photo: Dickson Lee
A breakthrough by Chinese quantum satellite researchers could pave the way for a “constellation” of hack-proof satellites capable of transmitting secure messages 24 hours a day.

In a recent ground-based experiment on Qinghai Lake, in northwestern China, they found a solution to the “nocturnal curse” that had restricted quantum satellite activities to nighttime.

The researchers, from the University of Science and Technology of China (USTC) in Hefei, Anhui province, beamed single photons carrying quantum information over a distance of 53km during daylight hours, several times longer than the previous daytime record and with unprecedented signal quality.

“Our work proves the feasibility of a low-Earth-orbit quantum satellite constellation which works mostly in the daylight,” the researchers, led by Professor Pan Jianwei, said in a draft paper released on the website arXiv.org earlier.

The quantum satellite constellation would help China build a “global-scale quantum communication network”, they added.

Professor Pan Jianwei demonstrates quantum communication in Shanghai in May. Photo: Xinhua

Pan’s team developed the world’s first quantum satellite, Micius, which was launched into orbit in August. It was designed to use the laws of quantum physics to achieve unbreakable communication, and China, intrigued by the military and economic potential, invested heavily in the technology.

Micius uses photons in various quantum states to transmit encrypted information. But such photons are almost invisible in daylight, with the useful signals lost in background noise. That meant the satellite has only been able to operate at night, and it could take up to three days to transmit a message from Beijing to the Chinese embassy in Washington.
The USTC team solved the problem by tweaking the photon’s wavelength.

Light’s behaviour can be described either as a particle or a wave. Human eyes can see light with wavelengths of between 400 and 700 nanometres, with most of the light produced by the sun falling within that range.

The wavelength of existing quantum communication technology falls between 700 and 800nm, very close to visible light and easily affected by natural light pollution.

Pan’s team developed a new system to produce and detect photons with a wavelength of 1,550nm.

The intensity of sunlight at 1,550nm is about five times weaker than at 800nm, which allowed the researchers to reduce the background noise to a very low level – only about 3 per cent of that experienced in earlier experiments.

More...
http://m.scmp.com/news/china/articl...antum-communications-nocturnal-curse-allowing

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## onebyone

*Safe technology: Quantum communication goes commercial in China*
TECH & SCI
By Gong Zhe
2017-03-11 22:43:50






China has built the first commercial quantum communication trunk line linking Shanghai Municipality and the eastern city of Hangzhou with uncompromised safety.

The line, named "Shanghai-Hangzhou Quantum Communication Commercial Trunk Line," is 260 kilometers long, with a price tag of nearly 25 million US dollars. It was built with absolute safety in mind.

"The line uses photons to carry information, which cannot be divided. The quantum status of these photons cannot be cloned, either. Thus there is just no way to wiretap the communication through our line," said Qian Xin, Vice President of Hangzhou Shenzhou Quantum Communication Technology Co. Ltd., the company behind the project.





_A researcher from the Chinese Academy of Sciences (CAS) explains why quantum communication is safe at the World Internet Conference in eastern China's Wuzhen on November 16, 2017. /CFP Photo_

Qian also said the operators of the line are trying to connect local government, banks and enterprises to the network.

The line is part of a larger project that links Shanghai directly to Beijing, which will be about 1,200 kilometers in length -- nearly five times longer than the current one.

China's Ministry of Industry and Information Technology praised the construction of the line as the start of the commercial use of quantum communication across the world.

Quantum communication is one of the major goals of China's technological advancement in this and the next decade. China's Minister of Science and Technology Wan Gang reiterated the importance of this cutting-edge technology in a press conference on Saturday.

He announced that the country will launch all 15 of its major science innovation projects, including the manufacturing of advanced quantum computers, this year.

https://news.cgtn.com/news/3d59444e316b6a4d/share_p.html?t=1489243431125

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## cirr

This is the first commercial truckline?

I thought this was the third trunk line after the Beijing-Hefei-Shanghai trunk line and the Hefei-Wuhan trunk line.

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## cirr

*Scientists Achieve Direct Counterfactual Quantum Communication For The First Time*
*
1 day ago

IN BRIEF*

For the first time in the history of quantum mechanics, scientists have been able to transmit a black and white image without having to send any physical particles. The phenomenon can be explained using the Zeno effect, the same effect that explains that movement itself is impossible.

*COUNTERFACTUAL COMMUNICATION*

Quantum communication is a strange beast, but one of the weirdest proposed forms of
it is called counterfactual communication – a type of quantum communication where no particles travel between two recipients.

Theoretical physicists have long proposed that such a form of communication would be possible, but now, for the first time, researchers have been able to experimentally achieve it – transferring a black and white bitmap image from one location to another without sending any physical particles.

If that sounds a little too out-there for you, don’t worry, this is quantum mechanics, after all. It’s meant to be complicated. But once you break it down, counterfactual quantum communication actually isn’t as bizarre as it sounds.

First up, let’s talk about how this differs from regular quantum communication, also known as quantum teleportation because isn’t that also a form of particle-less information transfer?

Well, not quite. Regular quantum teleportation is based on the principle ofentanglement – two particles that become inextricably linked so that whatever happens to one will automatically affect the other, no matter how far apart they are.

This is what Einstein referred to as “spooky action at a distance“, and scientists have already used it to send messages over vast distances.

But that form of quantum teleportation still relies on particle transmission in some form or another. The two particles usually need to be together when they’re entangled before being sent to the people on either end of the message (so, they start in one place, and need to be transmitted to another before communication can occur between them).

*ENTER ZENO*

Alternatively, particles can be entangled at a distance, but it usually requiresanother particle, such as photons (particles of light), to travel between the two.

Direct counterfactual quantum communication, on the other hand, relies on something other than quantum entanglement. Instead, it uses a phenomenon called the quantum Zeno effect.

Very simply, the quantum Zeno effect occurs when an unstable quantum system is repeatedly measured.

In the quantum world, whenever you look at a system, or measure it, the system changes. And in this case, unstable particles can never decay while they’re being measured (just like the proverbial watched kettle that will never boil), so the quantum Zeno effect creates a system that’s effectively frozen with a very high probability.

If you want to delve a little deeper, the video below gives a great explanation:

https://futurism.com/scientists-ach...ual-quantum-communication-for-the-first-time/

Counterfactual quantum communication is based on this quantum Zeno effect, and is defined as the transfer of a quantum state from one site to another without any quantum or classical particle being transmitted between them.

This requires a quantum channel to run between two sites, which means there’s always a small probability that a quantum particle will cross the channel. If that happens, the system is discarded and a new one is set up.

To set up such a complex system, researchers from *the University of Science and Technology of China* placed two single-photon detectors in the output ports of the last of an array of beam splitters.

Because of the quantum Zeno effect, the system is frozen in a certain state, so it’s possible to predict which of the detectors would ‘click’ whenever photons passed through. A series of nested interferometers measure the state of the system to make sure it doesn’t change.

It works based on the fact that, in the quantum world, all light particles can be fully described by wave functions, rather than as particles. So by embedding messages in light the researchers were able to transmit this message without ever directly sending a particle.

*THE ANSWER IN LIGHT*

The team explains that the basic idea for this set up came from holography technology.

“In the 1940s, a new imaging technique – holography – was developed to record not only light intensity but also the phase of light,” the researchers write in the journal _Proceedings of the National Academy of Sciences._

“One may then pose the question: Can the phase of light itself be used for imaging? The answer is yes.”

The basic idea is this – someone wants to send an image to Alice using only light (which acts as a wave, not a particle, in the quantum realm).

Alice transfers a single photon to the nested interferometer, where it can be detected by three single-photon detectors: D0, D1, and Df.

If D0 or D1 ‘click’, Alice can conclude a logic result of one or zero. If Df clicks, the result is considered inconclusive.

As Christopher Packham explains for Phys.org:

*“After the communication of all bits, the researchers were able to reassemble the image – a monochrome bitmap of a Chinese knot. Black pixels were defined as logic 0, while white pixels were defined as logic 1 …

In the experiment, the phase of light itself became the carrier of information, and the intensity of the light was irrelevant to the experiment.”*

Not only is this a big step forward for quantum communication, the team explains it’s technology that could also be used for imaging sensitive ancient artefacts that couldn’t surprise direct light shined on them.

The results will now need to be verified by external researchers to make sure what the researchers saw was a true example of counterfactual quantum communication.

Either way, it’s a pretty cool demonstration of just how bizarre and unexplored the quantum world is.

The research has been published in the journal _Proceedings of the National Academy of Sciences._

https://futurism.com/scientists-ach...ual-quantum-communication-for-the-first-time/

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## cirr

*Quantum Domain Breakthrough: For The First Time, Scientists Demonstrate Counterfactual Communication*

*Communicating without the use of particles to transmit information is no longer just a theory.*

May 14, 2017 WSP







*Counterfactual communication is a kind of quantum communication where no particles travel between recipients to transmit information. For the first time ever, a team of Chinese scientists has successfully demonstrated, at least experimentally, that this type of communication is possible. Specifically, the team was able to transfer a monochromatic bitmap image from one location to another without making use of any physical particle to achieve the transfer. And they did it by applying the quantum Zeno effect.*

Don’t worry if you got lost in those statements somewhere. We’re delving into the quantum world, after all. And in there, nothing is really simple. In fact, everything about it is like straight out of science fiction. So just brace yourself for more quantum weirdnesss.

The quantum Zeno effect is something that happens when an unstable quantum system is measured over and over. As it is, when you observe or measure a system in the quantum world, the system changes. Following this principle, unstable particles in the quantum world can never decay as they are being measured, meaning, the quantum Zeno effect creates a system that is effectively frozen.

Applying this effect, the research team designed a set-up consisting of two single-photon detectors placed in the output ports of an array of beam splitters, with nested interferometers measuring the system to ensure it doesn’t change. In theory, because of the quantum Zeno effect, it should be possible to predict which of the single-photon detectors will click when photons are allowed to pass through. This also incorporates the idea that counterfactuality requires a quantum channel between sites, and if a quantum particle happens to cross that channel, the system will have to be reset.

The experiment, as described in Phys.org, went as follows: ‘Alice transfers a single photon to the nested interferometer; it is detected by three single photon detectors, D0, D1 and Df. If D0 or D1 click, Alice concludes a logic result of one or zero. If Df clicks, the result is considered inconclusive, and is discarded in post-processing.’

When the communication of all bits was done following the given process, with logic 0 corresponding to black pixels and logic 1 corresponding to white pixels, the team was able to recreate the image being transferred — a black and white bitmap of a Chinese knot.

The idea for the experiment stemmed from the imaging technique known as holography which was developed to record both the phase of light and its intensity. The scientists wanted this question answered: can the phase of light be used for imaging? Based on the result of their experiment, the answer is yes — the phase of light became the carrier of information.

According to the team, aside from applications in quantum communication, their technique could also be used for activities such as ‘imaging ancient artifacts that would be damaged by directly shining light’ because as their experiment showed, only the phase of light mattered; its intensity was irrelevant.

The research was recently published in the journal Proceedings of the National Academy of Sciences.

http://wallstreetpit.com/113449-qua...sts-demonstrate-counterfactual-communication/

@Bussard Ramjet

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## Shotgunner51

cirr said:


> *Quantum Domain Breakthrough: For The First Time, Scientists Demonstrate Counterfactual Communication*


Good job!


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## onebyone

By Roland PeaseBBC Radio Science Unit

3 hours ago

From the sectionScience & Environment




Image copyrightGETTY IMAGES
Image captionMicius went up from the Jiuquan Satellite Launch Centre in China's north west
The term "spy satellite" has taken on a new meaning with the successful test of a novel Chinese spacecraft.

The mission can provide unbreakable secret communications channels, in principle, using the laws of quantum science.

Called Micius, the satellite is the first of its kind and was launched from the Gobi desert last August.

It is all part of a push towards a new kind of internet that would be far more secure than the one we use now.

The experimental Micius, with its delicate optical equipment, continues to circle the Earth, transmitting to two mountain-top Earth bases separated by 1,200km.

The optics onboard are paramount. They're needed to distribute to the ground stations the particles, or photons, of light that can encode the "keys" to secret messages.

"I think we have started a worldwide quantum space race," says lead researcher Jian-Wei Pan, who is based in Hefei in China's Anhui Province.

*'Messy business'*
Quantum privacy in many ways should be like the encryption that already keeps our financial data private online.

Before sensitive information is shared between shopper and online shop, the two exchange a complicated number that is then used to scramble the subsequent characters. It also hides the key that will allow the shop to unscramble the text securely.

The weakness is that the number itself can be intercepted, and with enough computing power, cracked.

Quantum cryptography, as it is called, goes one step further, by using the power of quantum science to hide the key.

As one of the founders of quantum mechanics Werner Heisenberg realised over 90 years ago, any measurement or detection of a quantum system, such as an atom or photon of light, uncontrollably and unpredictably changes the system.

This quantum uncertainty is the property that allows those engaged in secret communications to know if they are being spied on: the eavesdropper's efforts would mess up the connection.




Image copyrightNSSC
Image captionArtwork: The two Earth stations are 1,200km apart

The idea has been developed since it was first understood in the 1980s.

Typically, pairs of photons created or born simultaneously like quantum twins will share their quantum properties no matter how long they are separated or how far they have travelled. Reading the photons later, by shopper and shop, leads to the numerical key that can then be used to encrypt a message. Unless the measurements show interference from an eavesdropper.

A network established in Vienna in 2008 successfully used telecommunications fibre optics criss-crossing the city to carry these "entangled photons", as they are called. But even the clearest of optical fibres looks foggy to light, if it's long enough. And an ambitious 2,000km link from Beijing to Shanghai launched last year needs repeater hubs every 100km or so - weak points for quantum hackers of the future to target.

And that, explains Anton Zeilinger, one of the pioneers of the field and creator of the Vienna network, is the reason to communicate via satellite instead.

"On the ground, through the air, through glass fibres - you cannot go much further than 200km. So a satellite in outer space is the choice if you want to go a really large distance," he said.

The point being that in the vacuum of space, there are no atoms, or at least hardly any, to mess up the quantum signal.

That is what makes the tests with Micius, named after an ancient Chinese philosopher, so significant. They have proved a spaced-based network is possible, as revealed in the latest edition of the journal Science.

*Technical tour de force*
Not that it is easy. The satellite passes 500km over China for just less than five minutes each day - or rather each night, as bright sunlight would easily swamp the quantum signal. Micius' intricate optics create the all-important photon pairs and fires them down towards telescopes on some of China's high mountains.

"When I had the idea of doing this in 2003, many people thought it was a crazy idea," Jian-Wei Pan told the BBC World Service from his office in the University of Science and Technology of China. "Because it was very challenging already doing the sophisticated quantum optics experiments in a lab - so how can you do a similar experiment at a thousand-kilometre distance and with optical elements moving at a speed of 8km/s?"

Additional lasers steered the satellite's optics as it flew over China, keeping them pointed at the base stations. Nevertheless, owing to clouds, dust and atmospheric turbulence, most of the photons created on the satellite failed to reach their target: only one pair of the 10 million photon pairs generated each second actually completed the trip successfully.

But that was enough to complete the test successfully. It showed that the photons that did arrive preserved the quantum properties needed for quantum crypto-circuits.

"The Chinese experiment is a quite remarkable technological achievement," enthused mathematician Artur Ekert in an e-mail to the BBC. It was as a student in quantum information at Oxford University in the 1990s that Ekert proposed the paired-photon approach to cryptography. Relishing the pun, he added wryly "when I proposed the scheme, I did not expect it to be elevated to such heights."

Alex Ling from the National University of Singapore is a rival physicist. His first quantum minisatellite blew up shortly after launch in 2014, but he is generous in his praise of the Micius mission: "The experiment is definitely a technical tour de force.

"We are pretty excited about this development, and hope it heralds a new era in quantum communications capability."




Image copyrightSPL
Image captionJian-Wei Pan is now set to team up with his old PhD supervisor, Anton Zeilinger, who is based in Vienna
The next step will be a collaboration between Jian-Wei Pan and his former PhD supervisor, Anton Zeilinger in the University of Vienna - to prove what can be done across a single nation can also be achieved between whole continents, still using Micius.

"The idea is the satellite flies over China, establishes a secret key with a ground station; then it flies over Austria, it establishes another secret key with that ground station. Then the keys 

are combined to establish a key between say Vienna and Beijing," he told the BBC's Science in Action programme.
Pan says his team will soon arrive in Vienna to start those tests.

Meanwhile, Zeilinger is working on Qapital, a quantum network connecting many of the capitals of Europe, Vienna and Bratislava. Existing optic fibres laid alongside data networks but not currently used could make the backbone of this network, Zeilinger believes.

"A future quantum internet," he says, "will consist of fibre optic networks on the ground that will be connected to other fibre networks by satellites overhead. I think it will happen."

Pan is already planning the details of the satellite constellation that will make this possible.

The need? Secrecy is the stuff of spy agencies, who have large budgets. But financial institutions which trade billions of dollars internationally day by day also have valuable resources to protect.

Although some observers are sceptical they would want to pay for a quantum internet, Pan, Zeilinger and the other technologists think the case will be irresistible once one exists.

http://www.bbc.com/news/science-environment-40294795

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## onebyone

1
*China's quantum satellite achieves 'spooky action' at record distance*
By Gabriel PopkinJun. 15, 2017 , 2:00 PM

Quantum entanglement—physics at its strangest—has moved out of this world and into space. In a study that shows China's growing mastery of both the quantum world and space science, a team of physicists reports that it sent eerily intertwined quantum particles from a satellite to ground stations separated by 1200 kilometers, smashing the previous world record. The result is a stepping stone to ultrasecure communication networks and, eventually, a space-based quantum internet.

"It's a huge, major achievement," says Thomas Jennewein, a physicist at the University of Waterloo in Canada. "They started with this bold idea and managed to do it."

Entanglement involves putting objects in the peculiar limbo of quantum superposition, in which an object's quantum properties occupy multiple states at once: like Schrödinger's cat, dead and alive at the same time. Then those quantum states are shared among multiple objects. Physicists have entangled particles such as electrons and photons, as well as larger objects such as superconducting electric circuits.
Theoretically, even if entangled objects are separated, their precarious quantum states should remain linked until one of them is measured or disturbed. That measurement instantly determines the state of the other object, no matter how far away. The idea is so counterintuitive that Albert Einstein mocked it as "spooky action at a distance."

Starting in the 1970s, however, physicists began testing the effect over increasing distances. In 2015, the most sophisticated of these tests, which involved measuring entangled electrons 1.3 kilometers apart, showed once again that spooky action is real.

Beyond the fundamental result, such experiments also point to the possibility of hack-proof communications. Long strings of entangled photons, shared between distant locations, can be "quantum keys" that secure communications. Anyone trying to eavesdrop on a quantum-encrypted message would disrupt the shared key, alerting everyone to a compromised channel.

But entangled photons degrade rapidly as they pass through the air or optical fibers. So far, the farthest anyone has sent a quantum key is a few hundred kilometers. "Quantum repeaters" that rebroadcast quantum information could extend a network's reach, but they aren't yet mature. Many physicists have dreamed instead of using satellites to send quantum information through the near-vacuum of space. "Once you have satellites distributing your quantum signals throughout the globe, you've done it," says Verónica Fernández Mármol, a physicist at the Spanish National Research Council in Madrid. "You've leapfrogged all the problems you have with losses in fibers."






CREDITS: (GRAPHIC) C. BICKEL/_SCIENCE_; (DATA) JIAN-WEI PAN
Jian-Wei Pan, a physicist at the University of Science and Technology of China in Shanghai, got the chance to test the idea when the Micius satellite, named after an ancient Chinese philosopher, was launched in August 2016. The satellite is the foundation of the $100 million Quantum Experiments at Space Scale program, one of several missions that China hopes will make it a space science power on par with the United States and Europe.

In their first experiment, the team sent a laser beam into a light-altering crystal on the satellite. The crystal emitted pairs of photons entangled so that their polarization states would be opposite when one was measured. The pairs were split, with photons sent to separate receiving stations in Delingha and Lijiang, 1200 kilometers apart. Both stations are in the mountains of Tibet, reducing the amount of air the fragile photons had to traverse. This week in _Science_, the team reports simultaneously measuring more than 1000 photon pairs. They found the photons had opposite polarizations far more often than would be expected by chance, thus confirming spooky action over a record distance (though the 2015 test over a shorter distance was more stringent).

The team had to overcome many hurdles, including keeping the beams of photons focused on the ground stations as the satellite hurtled through space at nearly 8 kilometers per second. "Showing and demonstrating it is quite a challenging task," says Alexander Ling, a physicist at the National University of Singapore. "It's very encouraging." However, Ling notes that Pan's team recovered only about one photon out of every 6 million sent from the satellite—far better than ground-based experiments but still far too few for practical quantum communication.

Pan expects China's National Space Science Center to launch additional satellites with stronger and cleaner beams that could be detected even when the sun is shining. (Micius operates only at night.) "In the next 5 years we plan to launch some really practical quantum satellites," he says. In the meantime, he plans to use Micius to distribute quantum keys to Chinese ground stations, which will require longer strings of photons and additional steps. Then he wants to demonstrate intercontinental quantum key distribution between stations in China and Austria, which will require holding one half of an entangled photon pair on board until the Austrian ground station appears within view of the satellite. He also plans to teleport a quantum state—a technique for transferring quantum-encoded information without moving an actual object—from a third Tibetan observatory to the satellite.

Other countries are inching toward quantum space experiments of their own. Ling is teaming up with physicists in Australia to send quantum information between two satellites, and the Canadian Space Agency recently announced funding for a small quantum satellite. European and U.S. teams are also proposing putting quantum instruments on the International Space Station. One goal is to test whether entanglement is affected by a changing gravitational field, by comparing a photon that stays in the weaker gravitational environment of orbit with an entangled partner sent to Earth, says Anton Zeilinger, a physicist at the Austrian Academy of Sciences in Vienna. "There are not many experiments which test links between gravity and quantum physics."

The implications go beyond record-setting demonstrations: A network of satellites could someday connect the quantum computers being designed in labs worldwide. Pan's paper "shows that China is making the right decisions," says Zeilinger, who has pushed the European Space Agency to launch its own quantum satellite. "I'm personally convinced that the internet of the future will be based on these quantum principles."

Posted in: 

Physics
Space
DOI: 10.1126/science.aan6972

http://www.sciencemag.org/news/2017...ellite-achieves-spooky-action-record-distance

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## bobsm

*China Shatters “Spooky Action at a Distance” Record, Preps for Quantum Internet*

Results from the Micius satellite test quantum entanglement, pointing the way toward hack-proof global communications—and a new space race

By Lee Billings on June 15, 2017

In a landmark study, a team of Chinese scientists using an experimental satellite has tested quantum entanglement over unprecedented distances, beaming entangled pairs of photons to three ground stations across China—each separated by more than 1,200 kilometers. The test verifies a mysterious and long-held tenet of quantum theory, and firmly establishes China as the front-runner in a burgeoning “quantum space race” to create a secure, quantum-based global communications network—that is, a potentially unhackable “quantum internet” that would be of immense geopolitical importance. The findings were published Thursday in Science.

*“China has taken the leadership in quantum communication,” says Nicolas Gisin, a physicist at the University of Geneva who was not involved in the study. “This demonstrates that global quantum communication is possible and will be achieved in the near future.”*

The concept of quantum communications is considered the gold standard for security, in part because any compromising surveillance leaves its imprint on the transmission. Conventional encrypted messages require secret keys to decrypt, but those keys are vulnerable to eavesdropping as they are sent out into the ether. In quantum communications, however, these keys can be encoded in various quantum states of entangled photons—such as their polarization—and these states will be unavoidably altered if a message is intercepted by eavesdroppers. Ground-based quantum communications typically send entangled photon pairs via fiber-optic cables or open air. But collisions with ordinary atoms along the way disrupt the photons’ delicate quantum states, limiting transmission distances to a few hundred kilometers. Sophisticated devices called “quantum repeaters”—equipped with “quantum memory” modules—could in principle be daisy-chained together to receive, store and retransmit the quantum keys across longer distances, but this task is so complex and difficult that such systems remain largely theoretical.

more@ https://www.scientificamerican.com/...ance-rdquo-record-preps-for-quantum-internet/

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## Pangu

*China's quantum satellite clears major hurdle on way to ultrasecure communications*


Probe sends entangled photons — which could underpin quantum-based data encryption — over unprecedented distance.


Davide Castelvecchi
15 June 2017
*Article tools*
Rights & Permissions





Jin Liwang/Xinhua via ZUMA Wire

A composite photo from December 2016 shows a link established between China's quantum satellite Micius and a ground station in the Tibet Autonomous Region.

Just months into its mission, the world’s first quantum-communications satellite has achieved one of its most ambitious goals.

Researchers report in _Science_1 that, by beaming photons between the satellite and two distant ground stations, they have shown that photons can remain in a linked quantum state at a record-breaking distance of more than 1,200 kilometres. That phenomenon, known as quantum entanglement, could be used as the basis of a future secure quantum-communications network.

The feat is the first result reported from China’s Quantum Experiments at Space Scale (QUESS) mission, also known as Micius after an ancient Chinese philosopher. Launched last August, the craft is designed to demonstrate principles underlying quantum communication. The team is likely to launch more quantum-enabled satellites to start building a network.

Quantum communication is secure because any interference is detectable. Two parties can exchange secret messages by sharing an encryption key encoded in the properties of entangled particles; any eavesdropper would affect the entanglement and so be detected.

The Micius team has already done experiments exploring whether it is possible to create such encryption keys using entangled photons, and even 'teleport' information securely between Earth and space, says Pan Jian-Wei, a physicist at the University of Science and Technology of China in Hefei and the main architect of the probe. But he says that his team is not yet ready to announce the results.

*Bell test*
In theory, entangled particles should remain linked at any separation. That can be checked using a classic experiment called a Bell test.

Central to QUESS's experiments is a laser beam mounted on the satellite. For the Bell test, the beam was split to generate pairs of photons that share a common quantum state, in this case related to polarization. The entangled photons were funnelled into two onboard telescopes that fired them at separate stations on the ground: one in Delingha, on the northern Tibetan Plateau, and the other 1,203 kilometres south, at Gaomeigu Observatory in Lijiang. Once the particles arrived, the team used the Bell test to confirm that they were still entangled.

The researchers had a window of less than 5 minutes each night when the satellite, which orbits at an altitude of about 500 kilometres, was in view of both observatories. Within weeks of launch, they were able to transmit a pair of entangled photons per second — a rate ten times faster than they had hoped. The crucial experiment was completed before the end of the year, says Pan: “We are very happy that the whole system worked properly.” The previous record for such an experiment was 144 kilometres2.

“This proves that one can perform quantum communications at continental distances,” says Frédéric Grosshans, a quantum-communications physicist at the University of Paris South in Orsay. Entangled particles are the “workhorse” of quantum communications, he adds.

China launched the world's first quantum-enabled satellite in August 2016.

Jin Liwang/Xinhua via ZUMA Wire

*Next-generation satellite*
“I am really impressed by the result of the Chinese group,” says Wolfgang Tittel, a physicist at the University of Calgary in Canada. “To me, it was not clear after the satellite launch if they would succeed,” he says, or whether they would use it to learn for the next improved mission.

Pan says that in addition to the quantum-key and teleportation experiments, the team also plans to use Micius to test how gravity affects the quantum state of photons. And they want to launch a second, improved, quantum satellite in two years. A major challenge, he says, will be to upgrade the technology so that it can send and receive signals during the day, when there are many more photons around and it is harder to pick out the ones coming from the satellite.

For now, Pan feels vindicated about the first spacecraft’s design. Colleagues thought that it was too ambitious, he says, because it produced the entangled photons in space and required two photon-firing systems.

Similar missions in the planning stages — such as Canada’s Quantum Encryption and Science Satellite (QEYSSat) — use a simpler approach, creating the entangled photons on Earth and beaming them to a satellite. In a study3 published last week, the QEYSSat team reported a successful test of its technology, transmitting photons from the ground to an aircraft as much as 10 kilometres in the air.

Thomas Jennewein, who is at the University of Waterloo in Canada and part of the Candanian mission, says that his group and others around the world are now racing to catch up with the Chinese effort. “They are now clearly the world leader in quantum satellites,” he says.

Nature

doi:10.1038/nature.2017.22142

Link: https://www.nature.com/news/china-s...-on-way-to-ultrasecure-communications-1.22142

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## Han Patriot

Pangu said:


> *China's quantum satellite clears major hurdle on way to ultrasecure communications*
> 
> 
> Probe sends entangled photons — which could underpin quantum-based data encryption — over unprecedented distance.
> 
> 
> Davide Castelvecchi
> 15 June 2017
> *Article tools*
> Rights & Permissions
> 
> 
> 
> 
> 
> Jin Liwang/Xinhua via ZUMA Wire
> 
> A composite photo from December 2016 shows a link established between China's quantum satellite Micius and a ground station in the Tibet Autonomous Region.
> 
> Just months into its mission, the world’s first quantum-communications satellite has achieved one of its most ambitious goals.
> 
> Researchers report in _Science_1 that, by beaming photons between the satellite and two distant ground stations, they have shown that photons can remain in a linked quantum state at a record-breaking distance of more than 1,200 kilometres. That phenomenon, known as quantum entanglement, could be used as the basis of a future secure quantum-communications network.
> 
> The feat is the first result reported from China’s Quantum Experiments at Space Scale (QUESS) mission, also known as Micius after an ancient Chinese philosopher. Launched last August, the craft is designed to demonstrate principles underlying quantum communication. The team is likely to launch more quantum-enabled satellites to start building a network.
> 
> Quantum communication is secure because any interference is detectable. Two parties can exchange secret messages by sharing an encryption key encoded in the properties of entangled particles; any eavesdropper would affect the entanglement and so be detected.
> 
> The Micius team has already done experiments exploring whether it is possible to create such encryption keys using entangled photons, and even 'teleport' information securely between Earth and space, says Pan Jian-Wei, a physicist at the University of Science and Technology of China in Hefei and the main architect of the probe. But he says that his team is not yet ready to announce the results.
> 
> *Bell test*
> In theory, entangled particles should remain linked at any separation. That can be checked using a classic experiment called a Bell test.
> 
> Central to QUESS's experiments is a laser beam mounted on the satellite. For the Bell test, the beam was split to generate pairs of photons that share a common quantum state, in this case related to polarization. The entangled photons were funnelled into two onboard telescopes that fired them at separate stations on the ground: one in Delingha, on the northern Tibetan Plateau, and the other 1,203 kilometres south, at Gaomeigu Observatory in Lijiang. Once the particles arrived, the team used the Bell test to confirm that they were still entangled.
> 
> The researchers had a window of less than 5 minutes each night when the satellite, which orbits at an altitude of about 500 kilometres, was in view of both observatories. Within weeks of launch, they were able to transmit a pair of entangled photons per second — a rate ten times faster than they had hoped. The crucial experiment was completed before the end of the year, says Pan: “We are very happy that the whole system worked properly.” The previous record for such an experiment was 144 kilometres2.
> 
> “This proves that one can perform quantum communications at continental distances,” says Frédéric Grosshans, a quantum-communications physicist at the University of Paris South in Orsay. Entangled particles are the “workhorse” of quantum communications, he adds.
> 
> China launched the world's first quantum-enabled satellite in August 2016.
> 
> Jin Liwang/Xinhua via ZUMA Wire
> 
> *Next-generation satellite*
> “I am really impressed by the result of the Chinese group,” says Wolfgang Tittel, a physicist at the University of Calgary in Canada. “To me, it was not clear after the satellite launch if they would succeed,” he says, or whether they would use it to learn for the next improved mission.
> 
> Pan says that in addition to the quantum-key and teleportation experiments, the team also plans to use Micius to test how gravity affects the quantum state of photons. And they want to launch a second, improved, quantum satellite in two years. A major challenge, he says, will be to upgrade the technology so that it can send and receive signals during the day, when there are many more photons around and it is harder to pick out the ones coming from the satellite.
> 
> For now, Pan feels vindicated about the first spacecraft’s design. Colleagues thought that it was too ambitious, he says, because it produced the entangled photons in space and required two photon-firing systems.
> 
> Similar missions in the planning stages — such as Canada’s Quantum Encryption and Science Satellite (QEYSSat) — use a simpler approach, creating the entangled photons on Earth and beaming them to a satellite. In a study3 published last week, the QEYSSat team reported a successful test of its technology, transmitting photons from the ground to an aircraft as much as 10 kilometres in the air.
> 
> Thomas Jennewein, who is at the University of Waterloo in Canada and part of the Candanian mission, says that his group and others around the world are now racing to catch up with the Chinese effort. “They are now clearly the world leader in quantum satellites,” he says.
> 
> Nature
> 
> doi:10.1038/nature.2017.22142
> 
> Link: https://www.nature.com/news/china-s...-on-way-to-ultrasecure-communications-1.22142


Pan could be the next Nobel prize winner.

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## JSCh

*China's quantum satellite achieves 'spooky action' at record distance*
By Gabriel Popkin
Jun. 15, 2017 , 2:00 PM

Quantum entanglement—physics at its strangest—has moved out of this world and into space. In a study that shows China's growing mastery of both the quantum world and space science, a team of physicists reports that it sent eerily intertwined quantum particles from a satellite to ground stations separated by 1200 kilometers, smashing the previous world record. The result is a stepping stone to ultrasecure communication networks and, eventually, a space-based quantum internet.

"It's a huge, major achievement," says Thomas Jennewein, a physicist at the University of Waterloo in Canada. "They started with this bold idea and managed to do it."

Entanglement involves putting objects in the peculiar limbo of quantum superposition, in which an object's quantum properties occupy multiple states at once: like Schrödinger's cat, dead and alive at the same time. Then those quantum states are shared among multiple objects. Physicists have entangled particles such as electrons and photons, as well as larger objects such as superconducting electric circuits.

Theoretically, even if entangled objects are separated, their precarious quantum states should remain linked until one of them is measured or disturbed. That measurement instantly determines the state of the other object, no matter how far away. The idea is so counterintuitive that Albert Einstein mocked it as "spooky action at a distance."

Starting in the 1970s, however, physicists began testing the effect over increasing distances. In 2015, the most sophisticated of these tests, which involved measuring entangled electrons 1.3 kilometers apart, showed once again that spooky action is real.

Beyond the fundamental result, such experiments also point to the possibility of hack-proof communications. Long strings of entangled photons, shared between distant locations, can be "quantum keys" that secure communications. Anyone trying to eavesdrop on a quantum-encrypted message would disrupt the shared key, alerting everyone to a compromised channel.

But entangled photons degrade rapidly as they pass through the air or optical fibers. So far, the farthest anyone has sent a quantum key is a few hundred kilometers. "Quantum repeaters" that rebroadcast quantum information could extend a network's reach, but they aren't yet mature. Many physicists have dreamed instead of using satellites to send quantum information through the near-vacuum of space. "Once you have satellites distributing your quantum signals throughout the globe, you've done it," says Verónica Fernández Mármol, a physicist at the Spanish National Research Council in Madrid. "You've leapfrogged all the problems you have with losses in fibers."





CREDITS: (GRAPHIC) C. BICKEL/_SCIENCE_; (DATA) JIAN-WEI PAN​
Jian-Wei Pan, a physicist at the University of Science and Technology of China in Shanghai, got the chance to test the idea when the Micius satellite, named after an ancient Chinese philosopher, was launched in August 2016. The satellite is the foundation of the $100 million Quantum Experiments at Space Scale program, one of several missions that China hopes will make it a space science power on par with the United States and Europe.

In their first experiment, the team sent a laser beam into a light-altering crystal on the satellite. The crystal emitted pairs of photons entangled so that their polarization states would be opposite when one was measured. The pairs were split, with photons sent to separate receiving stations in Delingha and Lijiang, 1200 kilometers apart. Both stations are in the mountains of Tibet, reducing the amount of air the fragile photons had to traverse. This week in _Science_, the team reports simultaneously measuring more than 1000 photon pairs. They found the photons had opposite polarizations far more often than would be expected by chance, thus confirming spooky action over a record distance (though the 2015 test over a shorter distance was more stringent).

The team had to overcome many hurdles, including keeping the beams of photons focused on the ground stations as the satellite hurtled through space at nearly 8 kilometers per second. "Showing and demonstrating it is quite a challenging task," says Alexander Ling, a physicist at the National University of Singapore. "It's very encouraging." However, Ling notes that Pan's team recovered only about one photon out of every 6 million sent from the satellite—far better than ground-based experiments but still far too few for practical quantum communication.

Pan expects China's National Space Science Center to launch additional satellites with stronger and cleaner beams that could be detected even when the sun is shining. (Micius operates only at night.) "In the next 5 years we plan to launch some really practical quantum satellites," he says. In the meantime, he plans to use Micius to distribute quantum keys to Chinese ground stations, which will require longer strings of photons and additional steps. Then he wants to demonstrate intercontinental quantum key distribution between stations in China and Austria, which will require holding one half of an entangled photon pair on board until the Austrian ground station appears within view of the satellite. He also plans to teleport a quantum state—a technique for transferring quantum-encoded information without moving an actual object—from a third Tibetan observatory to the satellite.

Other countries are inching toward quantum space experiments of their own. Ling is teaming up with physicists in Australia to send quantum information between two satellites, and the Canadian Space Agency recently announced funding for a small quantum satellite. European and U.S. teams are also proposing putting quantum instruments on the International Space Station. One goal is to test whether entanglement is affected by a changing gravitational field, by comparing a photon that stays in the weaker gravitational environment of orbit with an entangled partner sent to Earth, says Anton Zeilinger, a physicist at the Austrian Academy of Sciences in Vienna. "There are not many experiments which test links between gravity and quantum physics."

The implications go beyond record-setting demonstrations: A network of satellites could someday connect the quantum computers being designed in labs worldwide. Pan's paper "shows that China is making the right decisions," says Zeilinger, who has pushed the European Space Agency to launch its own quantum satellite. "I'm personally convinced that the internet of the future will be based on these quantum principles."


China's quantum satellite achieves 'spooky action' at record distance | Science | AAAS

Juan Yin, Yuan Cao, Yu-Huai Li, Sheng-Kai Liao, Liang Zhang, Ji-Gang Ren, Wen-Qi Cai, Wei-Yue Liu, Bo Li, Hui Dai, Guang-Bing Li, Qi-Ming Lu, Yun-Hong Gong, Yu Xu, Shuang-Lin Li, Feng-Zhi Li, Ya-Yun Yin, Zi-Qing Jiang, Ming Li, Jian-Jun Jia, Ge Ren, Dong He, Yi-Lin Zhou, Xiao-Xiang Zhang, Na Wang, Xiang Chang, Zhen-Cai Zhu, Nai-Le Liu, Yu-Ao Chen, Chao-Yang Lu, Rong Shu, Cheng-Zhi Peng, Jian-Yu Wang, Jian-Wei Pan. Satellite-based entanglement distribution over 1200 kilometers. _Science _(2017). DOI: 10.1126/science.aan3211

*Space calling Earth, on the quantum line*
A successful quantum communication network will rely on the ability to distribute entangled photons over large distances between receiver stations. So far, free-space demonstrations have been limited to line-of-sight links across cities or between mountaintops. Scattering and coherence decay have limited the link separations to around 100 km. Yin _et al._ used the Micius satellite, which was launched last year and is equipped with a specialized quantum optical payload. They successfully demonstrated the satellite-based entanglement distribution to receiver stations separated by more than 1200 km. The results illustrate the possibility of a future global quantum communication network.

_Science_, this issue p. 1140

*Abstract*
Long-distance entanglement distribution is essential for both foundational tests of quantum physics and scalable quantum networks. Owing to channel loss, however, the previously achieved distance was limited to ~100 kilometers. Here we demonstrate satellite-based distribution of entangled photon pairs to two locations separated by 1203 kilometers on Earth, through two satellite-to-ground downlinks with a summed length varying from 1600 to 2400 kilometers. We observed a survival of two-photon entanglement and a violation of Bell inequality by 2.37 ± 0.09 under strict Einstein locality conditions. The obtained effective link efficiency is orders of magnitude higher than that of the direct bidirectional transmission of the two photons through telecommunication fibers.
​

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## cirr

Prof. Pan and team have decided to hold back on disclosing experimental results obtained on the instantaneous transmission of information:

中国“墨子”团队负责人潘建伟表示，他们已经开始实验运用量子纠缠技术创建密钥，以实现天地间的信息瞬时传输。不过潘建伟说，暂时并不准备对外公布实验结果。

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## GS Zhou

This is the work Pan and his team done in Dec. 2016. Since another 6 months passed, I'm curious to know their newest achievement at the current moment.

China is considering to launch a new and improved quantum satellite in two years. The new satellite can perform the quantum experiments in day time, when there are many more photons around and it is harder to pick out the ones coming from the satellite.

In addition, China has started to make the Standard on quantum communication. This is a clear signal of the commercialization of quantumn communication!

中国通信标准化协会量子通信与信息技术特设任务组成立
我要分享 
文章来源：中国科学院控股有限公司 发布时间：2017-06-15 【字号： 小 中 大 】
　　6月14日上午，中国通信标准化协会量子通信与信息技术特设任务组成立暨第一次会议在北京举行。工业和信息化部党组成员、总工程师张峰，中国科学院党组成员、秘书长邓麦村，国家密码管理局商密办副主任安晓龙出席会议并致辞，会议由中国通信标准化协会副理事长兼秘书长杨泽民主持。

　　张峰在致辞中指出，量子通信技术作为第二次量子革命的代表，为信息通信产业发展提供了革命性的技术手段，成为主要发达国家和地区关注的焦点和热点，我国也已进行战略规划布局，并取得了一批重要成果。成立特设任务组，能够将标准化工作与技术创新和产业发展有机衔接，充分发挥标准对产业发展的支撑和促进作用。

　　邓麦村在致辞中强调，中科院作为国家科研机构和战略科技力量，始终高度重视量子信息技术的发展。当前，量子通信技术正处于系统集成、工程化和产业化阶段，特设任务组的成立，必将有力推动量子通信与信息技术的标准化进程，为抢占国际科技竞争和未来产业发展制高点奠定坚实基础。中科院将全力支持，与相关单位共同推动我国量子信息技术和产业的发展。

　　量子通信与信息技术特设任务组由中国科学院控股有限公司（简称“国科控股”）牵头发起，国科量子通信网络有限公司总裁戚巍当选为任务组组长并主持了任务组第一次会议，科大国盾量子技术股份有限公司总裁兼总工程师赵勇作为量子通信子组组长在会上做了题为“量子信息技术的产业机遇与挑战”的专家技术报告。

　　标准化是量子通信从实用化迈向产业化发展的关键一步，通过设立量子通信与信息技术特设任务组，开展量子信息技术方面的标准研究和制订工作，能够促进量子保密通信与现有ICT应用的灵活集成，提升量子通信网络的可扩展性和部署的灵活性，保证量子通信系统、产品及核心器件的安全性。

　　中国电信、中国移动、中国联通三大运营商以及北邮、华为、中兴、爱立信、上海贝尔等30多家会员单位的80余位代表参加了会议。

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## TaiShang

*Spotlight: Chinese scientists successfully beam 'entangled' photons from space in landmark experiment*
(Xinhua) 10:05, June 16, 2017

WASHINGTON, June 15 -- In "a major technical accomplishment" on quantum communication, Chinese scientists on Thursday reported a successful transmission of "entangled" photon pairs from space to the Earth in efforts to prove that a physical phenomenon once described by Albert Einstein as "spooky" exists at a large distance.

By distributing such entangled photons, or light particles, from a satellite 500 km above the Earth's surface, China once again demonstrates its leading position in the field of quantum research, which, though still in its infancy, has already been deemed as a competition hotspot for all major countries across the world, experts said.

The study, published as a cover story by the U.S. journal Science, "lays a reliable technical foundation for large-scale quantum networking and quantum communication experimental research, as well as experimental testing of basic principles of physics such as general theory of relativity and quantum gravity in outer space in the future," Pan Jianwei, chief scientist for Micius, the first quantum satellite in China, told Xinhua.

*WORLD RECORD*

*Quantum entanglement, which Einstein referred to as "a spooky action at a distance," is a curious phenomenon in which particles are "linked" together in such a way that they affect one another regardless of distance. It is of great significance for secure communications, quantum computation and simulation, and enhanced metrology.*

Yet, efforts to entangle quantum particles, such as photons, have been limited to about 100 km, mostly because the entanglement is lost as they are transmitted along optical fibers, or through open space on land, Pan said.

One way to overcome this issue is to break the line of transmission into smaller segments and use so-called quantum repeaters to repeatedly swap, purify and store quantum information along the optical fiber, while another approach is to make use of satellite-based technologies.

*In the new study, Pan, a professor at the University of Science and Technology of China, and his colleagues used the Chinese satellite Micius, launched last year and equipped with specialized quantum tools, to demonstrate the latter feat.*

*The Micius satellite was used to communicate with two ground stations 1,203 km apart, located in Delingha in northwest China's Qinghai Province and Lijiang in Yunnan Province in southwest China, separately. The distance between the orbiting satellite and the two ground stations varies from 500 km to 2,000 km.

By combining so-called narrow-beam divergence with a high-bandwidth and high-precision acquiring, pointing, and tracking technique to optimize link efficiency, the team established entanglement between two single photons, separated at a distance of over 1,200 km apart, for the first time, Pan said.*

In addition, compared with previous methods using the best performance and most common commercial telecommunication fibers, the effective link efficiency of the satellite-based approach is 12 and 17 orders of magnitude higher respectively.

*GIANT STEP*

An immediate application of distributed entangled photons, said Pan, is for entanglement-based quantum key distribution to establish secure keys for quantum communication. Another is to exploit distributed entanglement to perform a variant of quantum teleportation protocol for remote preparation and control of quantum states.

According to Pan, peer reviewers of the paper praised his work as "a major technical accomplishment with potential practical applications as well as being of fundamental scientific importance" that "will have a very large impact, both within the scientific community and in the grand public."

A number of experts spoke highly of the new achievement from China.

This demonstration of the photon entanglement distribution from a satellite to very distant ground bases is "a giant step" forward in quantum information and quantum networking development, Alexander Sergienko, a quantum physicist at Boston University, told Xinhua.

*"This is a heroic experiment because so many detrimental factors were working against researchers (and) attempting to destroy a quantum nature of the photonic entanglement in this landmark experiment," Sergienko said. "It is hard to overestimate the impact of this result on the development of modern quantum physics."*

*"Chinese researchers deserve a greatest praise and acknowledgement of their skills, persistence, and devotion to science,"* said Sergienko.

Seth Lloyd, director of the Center for Extreme Quantum Information Theory at the Massachusetts Institute of Technology, expressed similar views, calling this work "a true breakthrough" in the technology of entanglement distribution.

"The experiment shows that long-range quantum communication is indeed technologically feasible and holds out the promise of the construction of long-range quantum communication networks in the near future," Lloyd told Xinhua.

*QUANTUM RACE*

China's Micius, with a design life of two years, was the world's first satellite launched to do quantum experiments. Teams from Canada, Germany, Austria, Singapore and other countries also have plans for quantum space experiments.

"I heard that," Pan said. "Following our first success, many groups worldwide are now trying to develop quantum science satellites or payloads."

Thomas Jennewein, an associate professor of quantum information at the University of Waterloo, who is currently pursuing a quantum communication satellite project in Canada, said that there is a "quantum space race."

"I would like to say that the Chinese group has overcome several major technical and scientific challenges and clearly demonstrated their world leadership in the field of quantum communication," Jennewein told Xinhua.

"I expect that the results from the Chinese mission will even enhance the international efforts to perform quantum satellite missions," said the expert.

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## Bussard Ramjet

Han Patriot said:


> Pan could be the next Nobel prize winner.



Yeah he could. Among a handful of Nobel Prize contenders in China.

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## onebyone

*Quantum secure internet is possible*
brian wang | June 16, 2017 | 




China launched a quantum satellite called Micius from the Gobi desert last August. It is all part of a push towards a new kind of internet that would be far more secure than the one we use now. The experimental Micius, with its delicate optical equipment, continues to circle the Earth, transmitting to two mountain-top Earth bases separated by 1,200km.

The optics onboard are paramount. They’re needed to distribute to the ground stations the particles, or photons, of light that can encode the “keys” to secret messages.

“I think we have started a worldwide quantum space race,” says lead researcher Jian-Wei Pan, who is based in Hefei in China’s Anhui Province.





quantum satellite



Science – Satellite-based entanglement distribution over 1200 kilometers

A successful quantum communication network will rely on the ability to distribute entangled photons over large distances between receiver stations. So far, free-space demonstrations have been limited to line-of-sight links across cities or between mountaintops. Scattering and coherence decay have limited the link separations to around 100 km. Yin et al. used the Micius satellite, which was launched last year and is equipped with a specialized quantum optical payload. They successfully demonstrated the satellite-based entanglement distribution to receiver stations separated by more than 1200 km. The results illustrate the possibility of a future global quantum communication network.

*Abstract*

Long-distance entanglement distribution is essential for both foundational tests of quantum physics and scalable quantum networks. Owing to channel loss, however, the previously achieved distance was limited to ~100 kilometers. Here we demonstrate satellite-based distribution of entangled photon pairs to two locations separated by 1203 kilometers on Earth, through two satellite-to-ground downlinks with a summed length varying from 1600 to 2400 kilometers. We observed a survival of two-photon entanglement and a violation of Bell inequality by 2.37 ± 0.09 under strict Einstein locality conditions. The obtained effective link efficiency is orders of magnitude higher than that of the direct bidirectional transmission of the two photons through telecommunication fibers.

https://www.nextbigfuture.com/2017/06/quantum-secure-internet-is-possible.html

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## Shotgunner51

JSCh said:


>


Stunning video!


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## onebyone

*Factbox: Quantum communication and its application*
Source: Xinhua| 2017-06-16 15:30:54|Editor: An





BEIJING, June 16 (Xinhua) -- Chinese scientists on Thursday reported a major breakthrough in quantum communication: A pair of entangled photons over a distance of 1,200 km have been successfully transmitted from space to Earth. The previous record was about 100 km.

What is quantum communication and why should we care about it? The following are some basic introductions about the theory:

Quantum communication is based on the principle of quantum entanglement -- a magnificent phenomenon in which particles are "linked" together in such a way that they affect one another regardless of distance.

Some scientists liken it to two pieces of paper that are distant from each other; if you write on one, the other immediately shows your message. In the quantum entanglement theory, this spectacular connection can happen even when the two particles are separated by a galaxy.

That is what Einstein referred to as "a spooky action at a distance,"

The theory is of great significance for secure communications. In quantum communication, any interference is detectable. Two parties can exchange secret messages by sharing an encryption key encoded in the properties of entangled particles.

The successful transmission of entangled photon pairs this time is carried out by "Micius", the world's first quantum satellite launched by China on Aug. 16, 2016.
http://news.xinhuanet.com/english/2017-06/16/c_136371159.htm

*China' s quantum satellite establishes photon entanglement over 1,200 km*
Source: Xinhua| 2017-06-16 12:39:09|Editor: Yamei












Pan Jianwei, chief scientist for the quantum satellite project, speaks at a press conference at the University of Science and Technology of China, in Hefei, east China's Anhui Province, June 16, 2017. A team of Chinese scientists have realized the satellite-based distribution of entangled photon pairs over 1,200 kilometers. The photon pairs were demonstrated to be still entangled after travelling long distances. This satellite-based technology opens up bright prospects for both practical quantum communications and fundamental quantum optics experiments at distances previously inaccessible on the ground, said Pan Jianwei, an academician of the Chinese Academy of Sciences. (Xinhua/Jin Liwang)

HEFEI, June 16 (Xinhua) -- A team of Chinese scientists have realized the satellite-based distribution of entangled photon pairs over 1,200 kilometers. The photon pairs were demonstrated to be still entangled after travelling long distances.

This satellite-based technology opens up bright prospects for both practical quantum communications and fundamental quantum optics experiments at distances previously inaccessible on the ground, said Pan Jianwei, an academician of the Chinese Academy of Sciences.

The achievement was made based on the world' s first quantum satellite, Quantum Experiments at Space Scale (QUESS), also dubbed Micius, launched by China on August 16, 2016, and was published as a cover article in the latest issue of academic journal Science.

This experiment was made through two satellite-to-ground downlinks with a total length varying from 1,600 to 2,400 kilometers. The obtained link efficiency is many times higher than that of the direct bidirectional transmission of the two photons through telecommunication fibers, said Pan, who is also the lead scientist of QUESS.

Quantum entanglement is a phenomenon in quantum physics, which is so confounding that Albert Einstein described it as "spooky action at a distance" in 1948.

Scientists found that when two entangled particles are separated, one particle can somehow affect the action of the far-off twin instantly.

Scientists liken it to two pieces of paper that are distant from each other: if you write on one, the other immediately shows your writing.

The mystery of quantum entanglement has been puzzling scientists since it was detected.

Quantum physicists have a fundamental interest in distributing entangled particles over increasingly long distances and studying the behavior of entanglement under extreme conditions.

In theory, this bizarre connection can exist over any distance, but scientists want to see if there' s some physical limit. "If you want to explore new physics, you must push the limits," Pan said.

Previously, entanglement distribution had only been achieved at a distance up to 100 kilometers due to photon loss in optical fibers or terrestrial free space.

One way to improve the distribution lies in the protocol of quantum repeaters, whose practical usefulness, however, is hindered by the challenges of quantum storage and readout efficiency, Pan said.

Another approach is making use of satellite-based and space-based technologies, as a satellite can conveniently cover two distant locations on Earth. The main advantage of this approach is that most of the photons' transmission path is almost in a vacuum, with almost zero absorption and de-coherence, Pan said.

After feasibility studies, Chinese scientists developed and launched QUESS for the mission of entanglement distribution. Cooperating with QUESS are three ground stations: Delingha Observatory in Qinghai, Nanshan Observatory in Xinjiang and Gaomeigu Observatory in Yunan.

For instance, one photon of an entangled pair was beamed to Delingha and the other to Gaomeigu. The distance between the two ground stations is 1,203 kilometers. The distance between the orbiting satellite and the ground stations varies from 500 to 2,000 kilometers, said Pan.

Due to the fact that the entangled photons cannot be amplified as classical signals, new methods must be developed to reduce the link attenuation in the satellite-to-ground entanglement distribution. To optimize the link efficiency, Chinese scientists combined a narrow beam divergence with a high-bandwidth and a high-precision acquiring, pointing, and tracking (APT) technique.

An accurate transmission of photons between the "server" and the "receiver" is never easy, as the optic axis of the satellite must point precisely toward those of the telescopes in the ground stations, said Zhu Zhencai, QUESS chief designer.

What makes it much harder is that the satellite flying over the Earth at a speed of 8 kilometers per second can be continuously tracked by the ground station for just a few minutes.

"It is like tossing a coin from a plane at 100,000 meters above sea level exactly into the slot of a rotating piggy bank," said Wang Jianyu, QUESS project's chief commander.

The highly sensitive QUESS could make visible from the Earth a match being lit on the Moon, Wang added.

By developing an ultra-bright space-borne two-photon entanglement source and the high-precision APT technology, the team established entanglement between two single photons separated by 1,203 kilometers.

Compared with the previous methods of entanglement distribution by direct transmission of the same two-photon source -- using the best performance and most common commercial telecommunication fibers respectively -- the effective link efficiency of the satellite-based approach is 12 and 17 orders of magnitude higher, Pan said.

He said the distributed entangled photons are readily useful for entanglement-based quantum key distribution, which, so far, is the only way to establish secure keys between two distant locations on Earth without relying on trustful relay.

QUESS is also designed to establish "hack-proof" quantum communications by transmitting uncrackable keys from space to the ground, as well as test quantum teleportation with a ground station in Ali, Tibet.

Pan revealed they also want to see if it' s possible to distribute entanglement between the Earth and the Moon in future
http://news.xinhuanet.com/english/2017-06/16/c_136370736.htm

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## onebyone

China hits milestone in race to create hack-proof communications

*China has taken a big step forward in its pursuit of a hack-proof communications network.*
Chinese researchers say they have used a satellite in space to beam tiny particles over a record-breaking distance, according to an article in the latest issue of research journal Science.


The milestone highlights China's emergence as a major player in quantum technology, a field of science that aims to use subatomic particles in areas like secure communications and medical imaging.

"In terms of quantum communications and satellite technology, certainly the Chinese are in front," said Ben Buchler, professor of physics at Australian National University.





China's Micius satellite sent photons to ground stations in the mountains of Tibet.


Scientists say quantum communications are highly secure because subatomic particles can be used to create a secret key for the sender and receiver of information. Any attempt to eavesdrop would disturb the particles and be discovered.

Governments and private companies are sinking billions of dollars into research and development of quantum technology. There are plenty of possible uses, from securely distributing military information to protecting the private details of consumers.

China became the first country to launch a quantum technology satellite last year, giving it an edge in the global cybersecurity race. Now, that move is starting to bear fruit.

Related: China launches satellite aimed at hack-proof communications

The satellite -- named "Micius" after an ancient Chinese philosopher and scientist -- beamed pairs of entangled photons to ground stations that lie 1,200 kilometers (745 miles) apart.

Scientists have previously sent entangled photons through fiber optics, but the distance covered was just a few hundred kilometers.

Related: China eclipses U.S. to become undisputed king of supercomputers

But despite China's latest achievement, the effort to build a useable quantum communications network still has a long way to go.

Photons are extremely fragile: they travel more smoothly in the near vacuum of space than in the earth's atmosphere.

The Micius satellite sent photons to ground stations in the mountains of Tibet, reducing the amount of air they had to pass through, according to the Science article.

And even then, the physicists reported that just 1 in 6 million photons were collected at the base stations.
http://money.cnn.com/2017/06/16/technology/china-quantum-satellite-success/index.html

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## onebyone

*Chinese satellite makes breakthrough in quantum communication*

For the first time, a space-based device has successfully distributed a pair of entangled photons to two stations on land


PUBLISHED : Friday, 16 June, 2017, 11:39pm
UPDATED : Saturday, 17 June, 2017, 12:14am

China has carried out the first quantum entanglement from space, according to the team behind the project, in what promises to be a significant step towards a new era of “hack-proof” communication.

The nation’s Micius satellite achieved quantum entanglement between two scientific facilities 1,200km apart on the Tibetan Plateau, according to a paper published in _Science_ magazine on Thursday.

Entanglement refers to a feature of quantum physics whereby two particles separated by a distance are mysteriously linked in existence, so that if the status of one is measured or disturbed, the other changes immediately.

Led by Pan Jianwei, a quantum physicist at the University of Science and Technology of China, the team generated a pair of entangled photons on Micius and distributed one to a receiving station in Delingha and the other to a station in Lijiang.










One challenge, among many, was to make sure the single photons from the rapidly moving satellite hit a one-metre target at a telescope on the ground.

Each second, the two stations successfully received one pair of the entanglement photons as Micius flew over, according to Wang Jianyu, executive deputy head of the Micius project and a corresponding author of the _Science_ paper. Previous attempts on the ground to carry out such transmissions were limited to a little over a hundred metres in distance.

China hits milestone in developing quantum computer ‘to eclipse all others’

Wang said the breakthrough might soon lead to important applications. “The progress achieved by China will give scientists in other countries more encouragement and hope. It is a small but important step of humans into the quantum age,” he said.

With a quantum internet, messages would be transmitted by entangled particles, and any attempt to eavesdrop would disrupt the message flow and trigger an alert.

“It’s a huge, major achievement,” said Thomas Jennewein, a physicist at the University of Waterloo in Canada. “They started with this bold idea and managed to do it,” he was quoted by _Science_ as saying.

Anton Zeilinger, a physicist at the Austrian Academy of Sciences in Vienna and one of the first to propose the idea of a quantum internet, told _Science_ the experiment “shows that China is making the right decisions”.

“I’m personally convinced that the internet of the future will be based on these quantum principles,” he added.









But critics said the technology was still far from practical. For instance, the experiment recovered only about one photon out of every 6 million sent.

Pan said that China would build and launch more satellites in the next few years to address this and other issues, such as day-time communication. The Micius could only communicate with the ground at night because the sunlight interfered with the light signal.

The Chinese team had already solved the day-time communication issue in ground experiments, according to Pan. “In the next five years, we plan to launch some really practical quantum satellites,” he was quoted by _Science_ as saying.

China’s hack-proof quantum satellite leap into space leads the world

Wang said that Micius, the world’s first quantum satellite, had finished all its designated experiments, and more ground-breaking results would be published soon in top research journals.

“Its performance is near-perfect. If the total score is 100, I will give it 98 to 100,” he said.

Other countries have joined the race for space-based quantum communication. The Canadian Space Agency, for instance, recently approved funding for a small quantum satellite, while research teams in Europe and the United States have proposed to mount quantum devices on the International Space Station.


http://www.scmp.com/news/china/poli.../chinese-satellite-makes-breakthrough-quantum

*“It’s a huge, major achievement,” said Thomas Jennewein, a physicist at the University of Waterloo in Canada. “They started with this bold idea and managed to do it,” he was quoted by Science as saying.*

*Anton Zeilinger, a physicist at the Austrian Academy of Sciences in Vienna and one of the first to propose the idea of a quantum internet, told Science the experiment “shows that China is making the right decisions”.

“I’m personally convinced that the internet of the future will be based on these quantum principles,” he added.*

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## AndrewJin

onebyone said:


> *Chinese satellite makes breakthrough in quantum communication*
> 
> For the first time, a space-based device has successfully distributed a pair of entangled photons to two stations on land
> 
> 
> PUBLISHED : Friday, 16 June, 2017, 11:39pm
> UPDATED : Saturday, 17 June, 2017, 12:14am
> 
> China has carried out the first quantum entanglement from space, according to the team behind the project, in what promises to be a significant step towards a new era of “hack-proof” communication.
> 
> The nation’s Micius satellite achieved quantum entanglement between two scientific facilities 1,200km apart on the Tibetan Plateau, according to a paper published in _Science_ magazine on Thursday.
> 
> Entanglement refers to a feature of quantum physics whereby two particles separated by a distance are mysteriously linked in existence, so that if the status of one is measured or disturbed, the other changes immediately.
> 
> Led by Pan Jianwei, a quantum physicist at the University of Science and Technology of China, the team generated a pair of entangled photons on Micius and distributed one to a receiving station in Delingha and the other to a station in Lijiang.
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> One challenge, among many, was to make sure the single photons from the rapidly moving satellite hit a one-metre target at a telescope on the ground.
> 
> Each second, the two stations successfully received one pair of the entanglement photons as Micius flew over, according to Wang Jianyu, executive deputy head of the Micius project and a corresponding author of the _Science_ paper. Previous attempts on the ground to carry out such transmissions were limited to a little over a hundred metres in distance.
> 
> China hits milestone in developing quantum computer ‘to eclipse all others’
> 
> Wang said the breakthrough might soon lead to important applications. “The progress achieved by China will give scientists in other countries more encouragement and hope. It is a small but important step of humans into the quantum age,” he said.
> 
> With a quantum internet, messages would be transmitted by entangled particles, and any attempt to eavesdrop would disrupt the message flow and trigger an alert.
> 
> “It’s a huge, major achievement,” said Thomas Jennewein, a physicist at the University of Waterloo in Canada. “They started with this bold idea and managed to do it,” he was quoted by _Science_ as saying.
> 
> Anton Zeilinger, a physicist at the Austrian Academy of Sciences in Vienna and one of the first to propose the idea of a quantum internet, told _Science_ the experiment “shows that China is making the right decisions”.
> 
> “I’m personally convinced that the internet of the future will be based on these quantum principles,” he added.
> 
> 
> 
> 
> 
> 
> 
> 
> 
> But critics said the technology was still far from practical. For instance, the experiment recovered only about one photon out of every 6 million sent.
> 
> Pan said that China would build and launch more satellites in the next few years to address this and other issues, such as day-time communication. The Micius could only communicate with the ground at night because the sunlight interfered with the light signal.
> 
> The Chinese team had already solved the day-time communication issue in ground experiments, according to Pan. “In the next five years, we plan to launch some really practical quantum satellites,” he was quoted by _Science_ as saying.
> 
> China’s hack-proof quantum satellite leap into space leads the world
> 
> Wang said that Micius, the world’s first quantum satellite, had finished all its designated experiments, and more ground-breaking results would be published soon in top research journals.
> 
> “Its performance is near-perfect. If the total score is 100, I will give it 98 to 100,” he said.
> 
> Other countries have joined the race for space-based quantum communication. The Canadian Space Agency, for instance, recently approved funding for a small quantum satellite, while research teams in Europe and the United States have proposed to mount quantum devices on the International Space Station.
> 
> 
> http://www.scmp.com/news/china/poli.../chinese-satellite-makes-breakthrough-quantum
> 
> *“It’s a huge, major achievement,” said Thomas Jennewein, a physicist at the University of Waterloo in Canada. “They started with this bold idea and managed to do it,” he was quoted by Science as saying.*
> 
> *Anton Zeilinger, a physicist at the Austrian Academy of Sciences in Vienna and one of the first to propose the idea of a quantum internet, told Science the experiment “shows that China is making the right decisions”.
> 
> “I’m personally convinced that the internet of the future will be based on these quantum principles,” he added.*


Great news


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## cirr

AndrewJin said:


> Great news



Quantum radar

16.06.2017
http://mp.weixin.qq.com/s/ESn7YfdG0pl7uuX5bppl3Q

量子雷达原理样机的验收只能在夜间进行，日落之后的海北高原更加寒冷，项目组把验收专家送往县城的宾馆休息，立即联系相关单位，并连夜在实验舱中整理设备，随时准备恢复试验。终于，在半夜12点左右，供电恢复了。*凌晨6点的外场，寒冷、安静，量子雷达的发射端缓缓转动，20公里外的、50公里外的目标一一被探测到，随后，转台转向某角度，屏幕上显示在数百公里外的位置忽然检测出明显的信号，国内首台威力突破百公里量级的同类型雷达样机通过验收！*

就在高原湖畔，我们量子雷达研究团队*对量子雷达样机进行了远程探测试验，一举突破了同类雷达的探测极限，在国际上首次实现量子层次的远程雷达探测*。2016年，美国智库caps援引了我国量子雷达团队的研究进展，指出中国完成了量子雷达样机的远程试验走到了世界的前列。

@AndrewJin

Reactions: Like Like:
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## GS Zhou

cirr said:


> Quantum radar
> 
> 16.06.2017
> http://mp.weixin.qq.com/s/ESn7YfdG0pl7uuX5bppl3Q
> 
> 量子雷达原理样机的验收只能在夜间进行，日落之后的海北高原更加寒冷，项目组把验收专家送往县城的宾馆休息，立即联系相关单位，并连夜在实验舱中整理设备，随时准备恢复试验。终于，在半夜12点左右，供电恢复了。*凌晨6点的外场，寒冷、安静，量子雷达的发射端缓缓转动，20公里外的、50公里外的目标一一被探测到，随后，转台转向某角度，屏幕上显示在数百公里外的位置忽然检测出明显的信号，国内首台威力突破百公里量级的同类型雷达样机通过验收！*
> 
> 就在高原湖畔，我们量子雷达研究团队*对量子雷达样机进行了远程探测试验，一举突破了同类雷达的探测极限，在国际上首次实现量子层次的远程雷达探测*。2016年，美国智库caps援引了我国量子雷达团队的研究进展，指出中国完成了量子雷达样机的远程试验走到了世界的前列。
> 
> @AndrewJin


The 14th Research Institute of CETC (China Electronic Technology Corporation) is amazing! The AESA radars on 052C/D, 055, Type 001/001A carriers, KJ200/500/2000 AWACS, J20, etc., all developed by 14th Institute. Now even Quantum Radar! I'm wondering what will be the next excitement 14th Institute brings to us

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## onebyone

*Chinese city to launch ‘unhackable’ quantum network*

Tests on system in Jinan in Shandong province complete and service for nearly 200 users to begin next month, state-run media report


PUBLISHED : Monday, 10 July, 2017, 7:02am
UPDATED : Monday, 10 July, 2017, 10:14am










Stephen Chen
China’s first citywide commercial communications system using “unhackable” quantum technology is expected to be up and running next month, mainland media reported on Sunday.

Tests on the system in Jinan in the east province of Shandong had been completed and the network would start operations next month to provide extremely secure communication for nearly 200 users, state-run China Central Television reported.

Zhou Fei, assistant to the director at the Jinan Institute of Quantum Technology, said the first users would be in the government, military, finance and electricity sectors.

“This is a milestone for quantum communication in China and the world,” CCTV quoted Zhou as saying.

How quantum satellite launch is helping China develop a communications system that ‘cannot be hacked’

The quantum network uses particles of light to encrypt information. If a third party tries to intercept the information, the particles change characteristics, making it impossible to steal the information without alerting the network. It is understood to be impossible for any computer to decipher a message encrypted by a quantum key.









China built its first large-scale quantum communication network in Hefei, Anhui province, in 2012, according to _People’s Daily_. Work finished last year on the world’s longest land-based quantum link between Beijing and Shanghai, while a number of other big cities including Wuhan, are also building their own quantum networks.

Though also as touted commercially viable, these systems were at least in part sharing existing optical fibre lines with traditional telecommunications networks. The “hybrid” structure might compromise security in some cases.

But the Jinan network was an “exclusive” system dedicated to quantum communications, CCTV reported. The information exchange between two users was protected by more than 4,000 qubits per second to achieve “absolute secrecy”.

Chinese satellite makes breakthrough in quantum communication

The network had more than 50 rounds of tests at terminals in Jinan government agencies and various Communist Party offices. The users were spread across several hundred square kilometres, and the test results were “satisfactory”, the report said.

China last month announced its quantum satellite has successfully distributed a pair of entangled photons to two stations on land.

http://www.scmp.com/news/china/poli...hinese-city-launch-unhackable-quantum-network

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## randomradio

Pretty impressive.


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## ashok321

*Chinese city to launch ‘unhackable’ quantum network*

A case of _far cry_ as of now:

*Unhackable quantum cryptography can be hacked : Tech : iTech Post*


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## Beast

ashok321 said:


> *Chinese city to launch ‘unhackable’ quantum network*
> 
> A case of _far cry_ as of now:
> 
> *Unhackable quantum cryptography can be hacked : Tech : iTech Post*
> 
> 
> View attachment 410093


This is outdated news. Check the latest one , verify by Chinese experiment. The one you quote is based on old outdated theory. Now we are in 2017, no more 2013.

https://www.theverge.com/2017/6/15/...uantum-network-encryption-entanglement-micius

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## ashok321

The link does not talk about hack.

@Beast


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## JSCh

*First Object Teleported from Earth to Orbit*
*Researchers in China have teleported a photon from the ground to a satellite orbiting more than 500 kilometers above.*

by Emerging Technology from the arXiv
July 10, 2017
Last year, a Long March 2D rocket took off from the Jiuquan Satellite Launch Centre in the Gobi Desert carrying a satellite called Micius, named after an ancient Chinese philosopher who died in 391 B.C. The rocket placed Micius in a Sun-synchronous orbit so that it passes over the same point on Earth at the same time each day.

Micius is a highly sensitive photon receiver that can detect the quantum states of single photons fired from the ground. That’s important because it should allow scientists to test the technological building blocks for various quantum feats such as entanglement, cryptography, and teleportation.

Today, the Micius team announced the results of its first experiments. The team created the first satellite-to-ground quantum network, in the process smashing the record for the longest distance over which entanglement has been measured. And they’ve used this quantum network to teleport the first object from the ground to orbit.




Teleportation has become a standard operation in quantum optics labs around the world. The technique relies on the strange phenomenon of entanglement. This occurs when two quantum objects, such as photons, form at the same instant and point in space and so share the same existence. In technical terms, they are described by the same wave function.

The curious thing about entanglement is that this shared existence continues even when the photons are separated by vast distances. So a measurement on one immediately influences the state of the other, regardless of the distance between them.

Back in the 1990s, scientists realized they could use this link to transmit quantum information from one point in the universe to another. The idea is to “download” all the information associated with one photon in one place and transmit it over an entangled link to another photon in another place.

This second photon then takes on the identity of the first. To all intents and purposes, it becomes the first photon. That’s the nature of teleportation and it has been performed many times in labs on Earth.

Teleportation is a building block for a wide range of technologies. “Long-distance teleportation has been recognized as a fundamental element in protocols such as large-scale quantum networks and distributed quantum computation,” says the Chinese team.

In theory, there should be no maximum distance over which this can be done. But entanglement is a fragile thing because photons interact with matter in the atmosphere or inside optical fibers, causing the entanglement to be lost.

As a result, the distance over which scientists have measured entanglement or performed teleportation is severely limited. “Previous teleportation experiments between distant locations were limited to a distance on the order of 100 kilometers, due to photon loss in optical fibers or terrestrial free-space channels,” says the team.

But Micius changes all that because it orbits at an altitude of 500 kilometers, and for most of this distance, any photons making the journey travel through a vacuum. To minimize the amount of atmosphere in the way, the Chinese team set up its ground station in Ngari in Tibet at an altitude of over 4,000 meters. So the distance from the ground to the satellite varies from 1,400 kilometers when it is near the horizon to 500 kilometers when it is overhead.

To perform the experiment, the Chinese team created entangled pairs of photons on the ground at a rate of about 4,000 per second. They then beamed one of these photons to the satellite, which passed overhead every day at midnight. They kept the other photon on the ground

Finally, they measured the photons on the ground and in orbit to confirm that entanglement was taking place, and that they were able to teleport photons in this way. Over 32 days, they sent millions of photons and found positive results in 911 cases. “We report the first quantum teleportation of independent single-photon qubits from a ground observatory to a low Earth orbit satellite—through an up-link channel— with a distance up to 1400 km,” says the Chinese team.

This is the first time that any object has been teleported from Earth to orbit, and it smashes the record for the longest distance for entanglement.

That’s impressive work that sets the stage for much more ambitious goals in the future. “This work establishes the first ground-to-satellite up-link for faithful and ultra-long-distance quantum teleportation, an essential step toward global-scale quantum internet,” says the team.

It also shows China’s obvious dominance and lead in field that, until recently, was led by Europe and the U.S.—Micius would surely have been impressed. But an important question now is how the West will respond.

Ref: arxiv.org/abs/1707.00934: Ground-to-satellite quantum teleportation


First Object Teleported from Earth to Orbit - MIT Technology Review

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## onebyone

View photos
earth


Shutterstock" data-reactid="31" style="margin-bottom: 1em;">Shutterstock

Not long ago, in the early 1990s, scientists only speculated that teleportation using quantum physics could be possible.

&nbsp;world's first quantum teleportation outside of a laboratory.

&nbsp;_few_&nbsp;steps further: they&nbsp;successfully teleported a photon from Earth to a satellite orbiting more than 500 km (311 mi) away.

&nbsp;highly sensitive photo receiver capable of detecting the quantum states of single photons fired from the ground. Micius was launched to allow scientists to test various technological building blocks for quantum feats including entanglement, cryptography, and teleportation.

This teleportation feat was announced as one of the first results of these experiments. Not only did the team teleport the first object ever from the ground to orbit, they also created the first satellite-to-ground quantum network, smashing the record for the longest distance for which entanglement has been measured.

&nbsp;_MIT Technology Review. _"Previous teleportation experiments between distant locations were limited to a distance on the order of 100 kilometers, due to photon loss in optical fibers or terrestrial free-space channels."





View photos
quantum teleportation
Science/AAAS" data-reactid="58" style="margin-bottom: 1em;">Science/AAAS

*Defining teleportation*
What comes to mind when you think of teleportation?

Your brain might conjure images of Scotty beaming up the Enterprise crew in Star Trek, but it's actually quite a different process than sci-fi films present.

Quantum teleportation relies on quantum entanglement — a situation where one set of quantum objects (such as photons) form at the same instant and point in space. In this way, they share the same existence. This shared existence continues even when the photons are separated – meaning a measurement on one immediately influences the state of the other, regardless of the distance between them.

This link can be used to transmit quantum information by "downloading" the information associated with one photon over an entangled link to another photon. This second photon takes on the identity of the first.





View photos
star trek beyond paramount

Paramount Pictures" data-reactid="88" style="margin-bottom: 1em;">Paramount Pictures

Voilà. Teleportation.

In this particular instance, the Chinese team created entangled pairs of photons on the ground at a rate of about 4,000 per second.

They then beamed one of these photons to the satellite, and kept the other photon on the ground. Finally, they measured the photons on the ground and in orbit to confirm that entanglement was taking place.

It's worth noting that there are some limits to this technology. Transporting anything large, for instance, is a ways off.

In theory, there's also no maximum transportation distance, but entanglement is fragile, and the links can easily be broken.

Despite these limits, this research paves the way for even more ambitious studies of quantum teleportation. "This work establishes the first ground-to-satellite up-link for faithful and ultra-long-distance quantum teleportation, an essential step toward global-scale quantum internet," says the team.


See Also:" data-reactid="96" style="margin-bottom: 1em;">See Also:


This 150-year-old colonial mansion houses one of the world's fanciest McDonald's restaurants
Labour shadow minister: It is not morally acceptable to use Uber
Cryptocurrency Ethereum is crashing

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## onebyone

https://uk.news.yahoo.com/chinese-just-teleported-object-earth-225500655.html

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## Stuttgart001

onebyone said:


> View photos
> earth
> 
> 
> Shutterstock" data-reactid="31" style="margin-bottom: 1em;">Shutterstock
> 
> Not long ago, in the early 1990s, scientists only speculated that teleportation using quantum physics could be possible.
> 
> &nbsp;world's first quantum teleportation outside of a laboratory.
> 
> &nbsp;_few_&nbsp;steps further: they&nbsp;successfully teleported a photon from Earth to a satellite orbiting more than 500 km (311 mi) away.
> 
> &nbsp;highly sensitive photo receiver capable of detecting the quantum states of single photons fired from the ground. Micius was launched to allow scientists to test various technological building blocks for quantum feats including entanglement, cryptography, and teleportation.
> 
> This teleportation feat was announced as one of the first results of these experiments. Not only did the team teleport the first object ever from the ground to orbit, they also created the first satellite-to-ground quantum network, smashing the record for the longest distance for which entanglement has been measured.
> 
> &nbsp;_MIT Technology Review. _"Previous teleportation experiments between distant locations were limited to a distance on the order of 100 kilometers, due to photon loss in optical fibers or terrestrial free-space channels."
> 
> 
> 
> 
> 
> View photos
> quantum teleportation
> Science/AAAS" data-reactid="58" style="margin-bottom: 1em;">Science/AAAS
> 
> *Defining teleportation*
> What comes to mind when you think of teleportation?
> 
> Your brain might conjure images of Scotty beaming up the Enterprise crew in Star Trek, but it's actually quite a different process than sci-fi films present.
> 
> Quantum teleportation relies on quantum entanglement — a situation where one set of quantum objects (such as photons) form at the same instant and point in space. In this way, they share the same existence. This shared existence continues even when the photons are separated – meaning a measurement on one immediately influences the state of the other, regardless of the distance between them.
> 
> This link can be used to transmit quantum information by "downloading" the information associated with one photon over an entangled link to another photon. This second photon takes on the identity of the first.
> 
> 
> 
> 
> 
> View photos
> star trek beyond paramount
> 
> Paramount Pictures" data-reactid="88" style="margin-bottom: 1em;">Paramount Pictures
> 
> Voilà. Teleportation.
> 
> In this particular instance, the Chinese team created entangled pairs of photons on the ground at a rate of about 4,000 per second.
> 
> They then beamed one of these photons to the satellite, and kept the other photon on the ground. Finally, they measured the photons on the ground and in orbit to confirm that entanglement was taking place.
> 
> It's worth noting that there are some limits to this technology. Transporting anything large, for instance, is a ways off.
> 
> In theory, there's also no maximum transportation distance, but entanglement is fragile, and the links can easily be broken.
> 
> Despite these limits, this research paves the way for even more ambitious studies of quantum teleportation. "This work establishes the first ground-to-satellite up-link for faithful and ultra-long-distance quantum teleportation, an essential step toward global-scale quantum internet," says the team.
> 
> 
> See Also:" data-reactid="96" style="margin-bottom: 1em;">See Also:
> 
> 
> This 150-year-old colonial mansion houses one of the world's fanciest McDonald's restaurants
> Labour shadow minister: It is not morally acceptable to use Uber
> Cryptocurrency Ethereum is crashing


At last, one dream when i studied in university comes close to be true.

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## onebyone

*What ‘teleporting’ a photon to space means*
*Using quantum entanglement and a purpose-built satellite, first successful ‘quantum teleportation’ brings a quantum internet a step closer.*

*




*

*Apparatus for an entanglement experiment in a normal, non-orbital laboratory.
VOLKER STEGER / SCIENCE PHOTO LIBRARY / GETTY

A team of Chinese researchers has reported the first successful ‘quantum teleportation’ to space. Using the Micius satellite, launched in August 2016 specifically to perform such cutting-edge quantum experiments, the scientists used pairs of entangled particles to recreate exactly the properties of a photon on Earth in a photon in orbit.
Ji-Gang Ren, of the University of Science and Technology of China, and colleagues write that they have accomplished “the first quantum teleportation of independent single-photon qubits from a ground observatory to a low Earth orbit satellite—through an up-link channel – with a distance up to 1,400 km”.

Though this feat is called quantum teleportation, no actual teleportation of objects occurs. It’s a way of transmitting information about a particle; while it sounds exotic, it is routinely used in laboratories on Earth.

Entanglement is a property of particles created at the same time which exist in a shared state, such that actions affecting one particle also affect the other. This holds even when the particles are separated by a great distance.

In 1993, physicists realised entanglement could be used to effectively copy the quantum state of a particle and paste it onto another particle, making the second particle identical to the first in all respects except location. It is as if the first particle has been cloned, or teleported.

Since the teleportation copies the quantum state of the first particle exactly, it could be used to transmit qubits, the quantum bits used in quantum computation.

Given there is no physical teleportation and, as noted above, the experiment is commonly performed in ground-based labs, what’s the big deal?

First, it’s an astonishing engineering achievement to manage the required precision and sensitivity when a distant satellite moving at great speed is involved. Second, the researchers have their eyes on what comes next, and they’re thinking big: as they note, this is “the first ground-to-satellite up-link for faithful and ultra-long-distance quantum teleportation, an essential step toward global-scale quantum internet”.

The paper describing the experiment has been published to the Arxiv preprint server.

https://cosmosmagazine.com/physics/chinese-scientists-teleport-a-photon-to-space
*

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## !eon

Stuttgart001 said:


> At last, one dream when i studied in university comes close to be true.


You studied at Stuttgart ?


----------



## Boomin' Bomber I.J.

Not willing to accept....


----------



## El Sidd

Teleport Jerusalem.

World peace


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## BRAVO_

amazing ..... when i initially red the news i thought its one more gossip but after watching so many credible sources in favor of this news at google.... i would like to congratulate the Micius team who created the first satellite-to-ground quantum network....

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## JSCh

Sheng-Kai Liao, Hai-Lin Yong, Chang Liu, Guo-Liang Shentu, Dong-Dong Li, Jin Lin, Hui Dai, Shuang-Qiang Zhao, Bo Li, Jian-Yu Guan, Wei Chen, Yun-Hong Gong, Yang Li, Ze-Hong Lin, Ge-Sheng Pan, Jason S. Pelc, M. M. Fejer, Wen-Zhuo Zhang, Wei-Yue Liu, Juan Yin, Ji-Gang Ren, Xiang-Bin Wang, Qiang Zhang, Cheng-Zhi Peng & Jian-Wei Pan. *Long-distance free-space quantum key distribution in daylight towards inter-satellite communication. *_Nature Photonics_ (2017). DOI: 10.1038/nphoton.2017.116

*Abstract*
In the past, long-distance free-space quantum communication experiments could only be implemented at night. During the daytime, the bright background sunlight prohibits quantum communication in transmission under conditions of high channel loss over long distances. Here, by choosing a working wavelength of 1,550 nm and developing free-space single-mode fibre-coupling technology and ultralow-noise upconversion single-photon detectors, we have overcome the noise due to sunlight and demonstrate free-space quantum key distribution over 53 km during the day. The total channel loss is ∼48 dB, which is greater than the 40 dB channel loss between the satellite and ground and between low-Earth-orbit satellites. Our system thus demonstrates the feasibility of satellite-based quantum communication in daylight. Moreover, given that our working wavelength is located in the optical telecom band, our system is naturally compatible with ground fibre networks and thus represents an essential step towards a satellite-constellation-based global quantum network.​

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## JSCh

JSCh said:


> Sheng-Kai Liao, Hai-Lin Yong, Chang Liu, Guo-Liang Shentu, Dong-Dong Li, Jin Lin, Hui Dai, Shuang-Qiang Zhao, Bo Li, Jian-Yu Guan, Wei Chen, Yun-Hong Gong, Yang Li, Ze-Hong Lin, Ge-Sheng Pan, Jason S. Pelc, M. M. Fejer, Wen-Zhuo Zhang, Wei-Yue Liu, Juan Yin, Ji-Gang Ren, Xiang-Bin Wang, Qiang Zhang, Cheng-Zhi Peng & Jian-Wei Pan. *Long-distance free-space quantum key distribution in daylight towards inter-satellite communication. *_Nature Photonics_ (2017). DOI: 10.1038/nphoton.2017.116
> 
> *Abstract*
> In the past, long-distance free-space quantum communication experiments could only be implemented at night. During the daytime, the bright background sunlight prohibits quantum communication in transmission under conditions of high channel loss over long distances. Here, by choosing a working wavelength of 1,550 nm and developing free-space single-mode fibre-coupling technology and ultralow-noise upconversion single-photon detectors, we have overcome the noise due to sunlight and demonstrate free-space quantum key distribution over 53 km during the day. The total channel loss is ∼48 dB, which is greater than the 40 dB channel loss between the satellite and ground and between low-Earth-orbit satellites. Our system thus demonstrates the feasibility of satellite-based quantum communication in daylight. Moreover, given that our working wavelength is located in the optical telecom band, our system is naturally compatible with ground fibre networks and thus represents an essential step towards a satellite-constellation-based global quantum network.​


*Quantum Cryptography System Breaks Daylight Distance Record*
By Charles Q. Choi
Posted 24 Jul 2017 | 15:26 GMT



Illustration: Nature Photonics

Satellites can now set up quantum communications links through the air during the day instead of just at night, potentially helping a nigh-unhackable space-based quantum Internet to operate 24-7, a new study from Chinese scientists finds.

Quantum cryptography exploits the quantum properties of particles such as photons to help encrypt and decrypt messages in a theoretically unhackable way. Scientists worldwide are now endeavoring to develop satellite-based quantum communications networks for a global real-time quantum Internet.

However, prior experiments with long-distance quantum communications links through the air were mostly conducted at night because sunlight serves as a source of noise. Previously, “the maximum range for day-time free-space quantum communication was 10 kilometers,” says study co-senior author Qiang Zhang, a quantum physicist at the University of Science and Technology of China in Shanghai.

Now researchers led by quantum physicist Jian-Wei Pan at the University of Science and Technology of China at Hefei have successfully established 53-kilometer quantum cryptography links during the day between two ground stations. This research suggests that such links could work between a satellite and either a ground station or another satellite, they say.

To overcome interference from sunlight, the researchers switched from the roughly 700-to-900-nanometer wavelengths of light used in all prior day-time free-space experiments to roughly 1,550 nm. The sun is about one-fifth as bright at 1,550 nanometers as it is at 800 nanometers, and 1,550-nanometer light can also pass through Earth's atmosphere with virtually no interference. Moreover, this wavelength is also currently widely used in telecommunications, making it more compatible with existing networks.

Previous research was reluctant to use 1,550-nanometer light because of a lack of good commercial single-photon detectors capable of working at this wavelength. But the Shanghai group developed a compact single-photon detector for 1,550-nanometer light that could work at room temperature. Moreover, the scientists developed a receiver that needed less than one tenth of the field of view that receivers for night-time quantum communications links usually need to work. This limited the amount of noise from stray light by a factor of several hundred.

In experiments, the scientists repeatedly established quantum communications links across Qinghai Lake, the biggest lake in China, from 3:30 p.m. to 5 p.m. local time on several sunny days, achieving transmission rates of 20 to 400 bits per second. Furthermore, they could establish these links despite roughly 48 decibels of loss in their communications channel, which is more than the roughly 40 to 45 decibels of loss typically seen in communications channels between satellites and the ground and between low-Earth-orbit satellites, Zhang says. In comparison, previous day-time free-space quantum communications experiments could only accommodate roughly 20 decibels of noise.

The researchers note that their experiments were performed in good weather, and that quantum communication is currently not possible in bad weather with today’s technology. Still, they note that bad weather is only a problem for ground-to-space links, and that it would not pose a problem for links between satellites.

In the future, the researchers expect to boost transmission rates and distance using better single-photon detectors, perhaps superconducting ones. They may also seek to exploit the quantum phenomenon known as entanglement to carry out more sophisticated forms of quantum cryptography, although this will require generating very bright sources of entangled photons that can operate in a narrow band of wavelengths, Zhang says.

The scientists detailed their findings online 24 July in the journal _Nature Photonics_.


Quantum Cryptography System Breaks Daylight Distance Record - IEEE Spectrum

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## JSCh

*Qubits can swim through seawater*
Aug 25, 2017





Down periscope: could submarines use quantum encryption?​
Photon-based qubits and entangled states have been transmitted up to 3 m in sea water by Xian-Min Jin and colleagues at Shanghai Jiao Tong University and the University of Science and Technology of China. While this distance pales in comparison with the 1400 km satellite-to-ground transmission achieved earlier this year by another team in China, the ability to send quantum information through seawater is a significant challenge because the liquid medium is much more absorptive of light than air.

Photons make very good qubits (quantum bits of information) because they can travel long distances without interacting with transmission media such as an optical fibre or air. These interactions destroy quantum information and therefore at first glance water should be a poor medium for qubits because it is much more absorptive of light than optical fibres or air.

*Window of opportunity*
The team managed to get around this problem by using photons with wavelengths of 405 nm, which falls within the "blue-green" window in which light absorption in water is relatively low. They also worked out that encoding quantum information in the polarization states of a photon gives the qubit its best chance of surviving its watery journey. This is because seawater is isotropic and therefore there should be no strong de-polarization effects. Indeed, the team's calculations suggest that the polarization of a photon can survive multiple collisions with molecules in seawater – and any depolarization that does occur can be dealt with by filtering out the affected photons.

Jin and colleagues showed that quantum information encoded in single 405 nm photons can be transmitted 3 m with a fidelity of greater than 98%. The team also did a separate experiment involving entangled pairs of 810 nm photons. Although these photons experience about 300 times more absorption than their 405 nm counterparts, they found that quantum entanglement is preserved to a very high degree after one of the photon pair is transmitted 3 m through seawater.

*Secure submarines*
The transmission of qubits and quantum entanglement play roles in quantum key distribution (QKD), which uses the laws of quantum mechanics to ensure that messages can be sent securely between two parties. It could be possible, therefore, to use QKD on a submerged submarine, for example. The problem, however, is that seawater is highly absorptive of light even at 405 nm, so communicating over distances of a kilometre or more would require huge numbers of photons.

The research is described in _Optics Express_.


*About the author*
Hamish Johnston is editor of _physicsworld.com

_
Qubits can swim through seawater - physicsworld.com

Ling Ji, Jun Gao, Ai-Lin Yang, Zhen Feng, Xiao-Feng Lin, Zhong-Gen Li, and Xian-Min Jin.* Towards quantum communications in free-space seawater*. _Optics Express_ (2017). DOI: 10.1364/OE.25.019795​

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## GS Zhou

The Beijing to Shanghai quantum communication line completes the final tests! 


国家量子保密通信“京沪干线”项目通过总技术验收
2017-09-04

2017年8月30日下午，国家量子保密通信“京沪干线”技术验证及应用示范项目技术验收评审会在中国科学技术大学举行，评审专家组听取了项目组关于项目建设基本情况和分系统验收情况的汇报，经现场质询和讨论，专家组认为项目已完成了预期的技术验证和应用示范任务，具备开通条件，同意通过技术验收。

“京沪干线”项目是2013年7月由国家发改委批复立项，由安徽省、山东省共同配套投资建设并得到了上海市、北京市的大力支持，由中科院领导、中国科学技术大学作为项目建设主体承担，中国有线电视网络有限公司、山东信息通信技术研究院、中国科大先进技术研究院、中国银行业监督管理委员会等单位协作建设。

本项目的应用示范主要合作单位有中国银行业监督管理委员会，包括由银监会统一协调和指导下的中国工商银行、中国民生银行、北京农商银行等各银行单位。

在各单位的配合下，工作人员经过42个月的艰苦努力，突破了高速量子密钥分发、高速高效率单光子探测、可信中继传输和大规模量子网络管控等系列工程化实现的关键技术，克服了施工难度大、协同协调复杂等难关，最终于2016年底顺利完成全线贯通，搭建了连接北京、济南、合肥、上海的全长2000余公里的量子保密通信骨干线路，进行了大尺度量子保密通信技术试验验证，开展了远程高清量子保密视频会议系统和其他多媒体跨域互联应用研究，完成了金融、政务领域的远程或同城数据灾备系统、金融机构数据采集系统等应用示范，在半年多时间里，一直进行着各分系统的应用测试和720小时长时间稳定性测试，测试结果表明系统的各项技术性能指标均达到了设计要求，全线路密钥率大于20kbps，可满足万用户的密钥分发业务需求。同时，京沪干线北京接入点实现与“墨子号”量子科学实验卫星兴隆地面站的连接，全线密钥率大于5kbps，已形成星地一体的广域量子通信网络雏形，大大扩展了京沪干线应用能力。

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## Nilgiri

GS Zhou said:


> The Beijing to Shanghai quantum communication line completes the final tests!
> 
> 
> 国家量子保密通信“京沪干线”项目通过总技术验收
> 2017-09-04
> 
> 2017年8月30日下午，国家量子保密通信“京沪干线”技术验证及应用示范项目技术验收评审会在中国科学技术大学举行，评审专家组听取了项目组关于项目建设基本情况和分系统验收情况的汇报，经现场质询和讨论，专家组认为项目已完成了预期的技术验证和应用示范任务，具备开通条件，同意通过技术验收。
> 
> “京沪干线”项目是2013年7月由国家发改委批复立项，由安徽省、山东省共同配套投资建设并得到了上海市、北京市的大力支持，由中科院领导、中国科学技术大学作为项目建设主体承担，中国有线电视网络有限公司、山东信息通信技术研究院、中国科大先进技术研究院、中国银行业监督管理委员会等单位协作建设。
> 
> 本项目的应用示范主要合作单位有中国银行业监督管理委员会，包括由银监会统一协调和指导下的中国工商银行、中国民生银行、北京农商银行等各银行单位。
> 
> 在各单位的配合下，工作人员经过42个月的艰苦努力，突破了高速量子密钥分发、高速高效率单光子探测、可信中继传输和大规模量子网络管控等系列工程化实现的关键技术，克服了施工难度大、协同协调复杂等难关，最终于2016年底顺利完成全线贯通，搭建了连接北京、济南、合肥、上海的全长2000余公里的量子保密通信骨干线路，进行了大尺度量子保密通信技术试验验证，开展了远程高清量子保密视频会议系统和其他多媒体跨域互联应用研究，完成了金融、政务领域的远程或同城数据灾备系统、金融机构数据采集系统等应用示范，在半年多时间里，一直进行着各分系统的应用测试和720小时长时间稳定性测试，测试结果表明系统的各项技术性能指标均达到了设计要求，全线路密钥率大于20kbps，可满足万用户的密钥分发业务需求。同时，京沪干线北京接入点实现与“墨子号”量子科学实验卫星兴隆地面站的连接，全线密钥率大于5kbps，已形成星地一体的广域量子通信网络雏形，大大扩展了京沪干线应用能力。



That's awesome.

Is there something significant about 2032 as seen in the text?

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## bobsm

Nilgiri said:


> That's awesome.
> 
> Is there something significant about 2032 as seen in the text?



Total length of 2032 km.

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## JSCh

*World’s first secure quantum communication line in China gets green light*
By Zhang Huan (People's Daily Online) 17:11, September 05, 2017




The world’s first secure quantum communication line in China has passed technical inspection and is able to operate, according to the University of Science and Technology of China on Sept. 4.

The secure quantum communication line spans more than 2,000 kilometers, linking the four cities of Beijing, Jinan, Hefei, and Shanghai.

Construction of the line, approved by China’s National Development and Reform Commission in July 2013, was completed late last year after 42 months of effort in overcoming technical difficulties to achieve quantum key distribution, technology of single photon detection, and reliable data transmission.

Quantum communication is ultra-secure, as a quantum photon can neither be separated nor duplicated. Accordingly, it is impossible to wiretap, intercept, or crack the information it transmits.

China has achieved many “firsts” in the field of quantum communication, such as the world’s first secure quantum communication line connecting Beijing and Shanghai, and the first quantum communication satellite nicknamed “Micius.”

The success in building the line shows that China continues to lead the world in practical application and industrialization of quantum technology.

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## cirr

2016年8月，中国第一次在报道中宣布：首部基于单光子检测的量子雷达系统研制成功，实际测试工作可能在2015年底，完成了量子探测机理、目标散射特性研究以及量子探测原理的实验验证，并且在外场完成真实大气环境下目标探测试验，获得百公里级探测能力，探测灵敏度极大提高，指标均达到预期效果。

Quantum radar prototype now able to detect stealth target hundreds(notice the plural) of kms away

也许100公里级的探测能力谈不上高，但是在量子雷达领域却可以说，或许已领先了美国，目前国外最远也只有20公里。*据新消息，2017年8月，中国电科十四所透露，量子雷达原理样机已能探测到数百公里外的目标，成功地通过验收，从而成为了中国首台威力突破百公里量级的量子雷达样机，且取得了白天开机工作的重大突破，这标志着中国量子雷达技术再获重大突破！

http://www.chinatimes.com/cn/realtimenews/20170907001175-260417*

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## terranMarine

cirr said:


> 2016年8月，中国第一次在报道中宣布：首部基于单光子检测的量子雷达系统研制成功，实际测试工作可能在2015年底，完成了量子探测机理、目标散射特性研究以及量子探测原理的实验验证，并且在外场完成真实大气环境下目标探测试验，获得百公里级探测能力，探测灵敏度极大提高，指标均达到预期效果。
> 
> Quantum radar prototype now able to detect stealth target hundreds(notice the plural) of kms away
> 
> 也许100公里级的探测能力谈不上高，但是在量子雷达领域却可以说，或许已领先了美国，目前国外最远也只有20公里。*据新消息，2017年8月，中国电科十四所透露，量子雷达原理样机已能探测到数百公里外的目标，成功地通过验收，从而成为了中国首台威力突破百公里量级的量子雷达样机，且取得了白天开机工作的重大突破，这标志着中国量子雷达技术再获重大突破！*


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## JSCh

* China's first commercial quantum private communication network completed *
_ Source: Xinhua_|_ 2017-09-12 20:37:53_|_Editor: Xiang Bo_





JINAN, Sept. 12 (Xinhua) -- China's first commercial quantum private communication network has been completed in Shandong Province, local government said Tuesday.

The network is exclusively for 242 Party and government users in the provincial capital of Jinan. Hundreds of pieces of equipment connected by hundreds of kilometers of fiber optics were installed within five months.

Based on decoy-state quantum key distribution and trusted relay groups, the network provides secure telephone and data communication services.

The network is expected to be connected to the Beijing-Shanghai quantum communication network.

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## TaiShang

*Largest quantum facility to equip stealth submarines*
China Plus, September 13, 2017

Chinese authorities are reportedly preparing to start construction on what will be the world's largest quantum research facility, reports the South China Morning Post.

*The facility is reportedly being built in Anhui's provincial capital, Hefei. It's to be home to research into new technologies.*

The report suggests the scientists will be working on the *development of "quantum metrology,"* a process which *could help improve submarine's stealth operations.*

Submarines equipped with a quantum navigation system should - theoretically - be able to operate underwater for more than 3 months without having to surface to receive satellite positioning signals.

The South China Morning Post is also reporting the facility in Hefei will be used to develop a quantum computer capable of decoding encrypted messages within seconds.

Developers will be invited to bid for the contract later this month. Construction is expected be completed by 2020.

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## TaiShang

*China leads global quantum communication development*
Xinhua, October 3, 2017

After saying nihao, or hello, to his Austrian counterpart some 7,000 kilometers away, Bai Chunli, president of the Chinese Academy of Sciences, completed the world's first intercontinental quantum communication in Beijing.

The dialogue between Bai and Anton Zeilinger, Austrian quantum physicist and President of the Austrian Academy of Sciences, on Sept. 29 could be ultra-secret if they keep it private between them.

Encrypted by quantum communication technology, what they said could not be wiretapped, intercepted or cracked.

Bai's greeting was first sent out through a control center in Beijing along the Beijing-Shanghai Trunk Line, the first of its kind for secure quantum telecommunication open for use the same day.

*The 2,000-km trunk line had been connected through a ground station to the world's first quantum satellite Micius launched by China in August last year.*

Micius was named after a fifth century B.C. Chinese philosopher and scientist who was credited as the first person to conduct optical experiments.

During their talk, Zeilinger expressed congratulations on the achievements Chinese scientists made in quantum communication and hoped to strengthen cooperation.

Earlier that day, Bai had video talks with staff in Hefei, Jinan, Shanghai and Urumqi ground stations through the trunk line.

Pan Jianwei, chief scientist of the trunk line, said the video call between Bai and Zeilinger involved a long distance and multiple nodes.

Given that some nodes were not built by Chinese scientists, the tests showed the ground-space quantum communication network was stable, compatible and good for practical use, said Pan.

Chinese businesses, including the Bank of Communications, the Industrial and Commercial Bank of China (ICBC) and Alibaba, have used the quantum communication technology for information transmission.

Zhu Yu, deputy head of the China Information Industry Association, expected the tests would attract more companies into the sector of quantum communication, and a brand new industrial chain would come into shape.

A number of encryption communication products including quantum USB key, a protecting device for mobile payment, have been put to the market.

In one or two years, China is likely to issue national standards for quantum key distribution equipment, according to sources close to the trunk line project.

http://china.org.cn/business/2017-10/03/content_41682008.htm

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## JSCh

Juan Yin, Yuan Cao, Yu-Huai Li, Ji-Gang Ren, Sheng-Kai Liao, Liang Zhang, Wen-Qi Cai, Wei-Yue Liu, Bo Li, Hui Dai, Ming Li, Yong-Mei Huang, Lei Deng, Li Li, Qiang Zhang, Nai-Le Liu, Yu-Ao Chen, Chao-Yang Lu, Rong Shu, Cheng-Zhi Peng, Jian-Yu Wang, and Jian-Wei Pan. *Satellite-to-Ground Entanglement-Based Quantum Key Distribution*. _Phys. Rev. Lett. _(2017). DOI: https://doi.org/10.1103/PhysRevLett.119.200501

*Abstract*

We report on entanglement-based quantum key distribution between a low-Earth-orbit satellite equipped with a space borne entangled-photon source and a ground observatory. One of the entangled photons is measured locally at the satellite, and the other one is sent via a down link to the receiver in the Delingha ground station. The link attenuation is measured to vary from 29 dB at 530 km to 36 dB at 1000 km. We observe that the two-photon entanglement survives after being distributed between the satellite and the ground, with a measured state fidelity of ≥0.86. We then perform the entanglement-based quantum key distribution protocol and obtain an average final key rate of 3.5  bits/s at the distance range of 530–1000 km.​

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## JSCh

JSCh said:


> *Physicists use quantum memory to demonstrate quantum secure direct communication*
> June 12, 2017 by Lisa Zyga
> 
> 
> 
> ​Experimental set-up of quantum secure direct communication with quantum memory. Credit: Zhang et al. ©2017 American Physical Society
> 
> For the first time, physicists have experimentally demonstrated a quantum secure direct communication (QSDC) protocol combined with quantum memory, which is essential for storing and controlling the transfer of information. Until now, QSDC protocols have used fiber delay lines as a substitute for quantum memory, but the use of quantum memory is necessary for future applications, such as long-distance communication over secure quantum networks.
> 
> The researchers, Wei Zhang et al., from the University of Science and Technology of China and Nanjing University of Posts and Telecommunications, have published a paper on their experimental demonstration in a recent issue of _Physical Review Letters_.
> 
> QSDC is one of several different types of quantum communication methods, and has the ability to directly transmit secret messages over a quantum channel. Unlike most other quantum communication methods, QSDC does not require that the two parties communicating share a private key in advance. Similar to other kinds of quantum communication, the security of the method relies on some of the basic principles of quantum mechanics, such as the uncertainty principle and the no-cloning theorem.
> 
> As the physicists explain, a quantum memory is necessary for QSDC protocols in order to effectively control the transfer of information in future quantum networks. However, experimentally realizing quantum memory with QSDC is challenging because it requires storing entangled single photons and establishing the entanglement between separated memories.
> 
> In their experiments, the researchers demonstrated most of the essential steps of the protocol, including entanglement generation; channel security; and the distribution, storage, and encoding of entangled photons. Due to the difficulty of decoding entangled photons in the optimal way (which requires distinguishing between four quantum states), the researchers used an alternative decoding method that is easier to implement.
> 
> In the future, the researchers expect that it will be possible to demonstrate QSDC across distances of 100 km or more in free space, similar to the recent demonstrations of quantum key distribution, quantum teleportation and entanglement distribution over these distances. Achieving this goal will mark an important step in realizing satellite-based long-distance and global-scale QSDC in the future.
> 
> *More information:* Wei Zhang et al. "Quantum Secure Direct Communication with Quantum Memory." _Physical Review Letters_. DOI: 10.1103/PhysRevLett.118.220501
> 
> 
> https://phys.org/news/2017-06-physicists-quantum-memory.html


Public Release: 30-Nov-2017
* Secure information transmission over 500m fiber links based on quantum technologies *
Science China Press




Experimental system of quantum secure direct communication over optical fibers. 
Credit: ©Science China Press

Quantum secret communication realizes secure information transmission based on principles of quantum mechanism, which is an important field in quantum information sciences and technologies. At present, the most developed quantum secret communication schemes are based on quantum key distribution. In these schemes, the quantum function is limited to realize secret key generation and transmission, while the information transmission still depends on classical communication technologies. These schemes developed rapidly in recent years, which are mature enough to start commercial applications. On the other hand, researchers in the field of quantum communications still devote their efforts into exploring novel communication schemes based on quantum information theories and technologies, which are beyond quantum key distribution. A representative topic is quantum secure direct communication (QSDC). The first QSDC protocol is based on quantum entanglement, which is proposed in 2000 by Prof. Long in Tsinghua University, China. It has been deeply investigated theoretically, however, there is no break though in experiment for this protocol. The reason is that it requires many complicated quantum functions such as entangled Bell state generation, Bell state measurement and quantum memories for photons, which are difficult to be realized, especially at telecom band.

Recently, Prof. Zhang's group in Tsinghua University and Prof. Sheng in Nanjing University of Posts and Telecommunications realized the first entanglement based QSDC experiment based on technologies of fiber optics, in which two optical fibers of 500 meters are used as quantum channels. The Cover shows their experimental system of quantum secure direct communication over optical fibers.

Firstly, according to the requirement of entanglement based QSDC, they proposed and developed a novel fiber based quantum light source for polarization entangled Bell state generation at telecom band. The key point of this quantum light source is how to split the two photons in a pair, which are both polarization entangled and frequency degenerate. The researchers introduce vector spontaneous four wave mixing effects into a fiber Sagnac loop bi-directionally, splitting the two photons in a pair by the two-photon interference effect at the output ports of the fiber Sagnac loop. This quantum light source paves the way to realize the entanglement based QSDC over optical fibers. Then, the researchers establish the experimental system for entanglement based QSDC based on technologies of fiber optics, realizing the polarization entangled Bell state measurement system by fiber components and using dispersion shifted fibers as the quantum memories for photons. In this system, they demonstrate two crucial functions of entanglement based QSDC successfully, security test by the measurement of polarization entanglement and encoding/decoding processes based on the manipulation and measurement of the polarization entangled Bell states. Experiment results show that the entanglement based QSDC could be realized over fiber links.

This work is the first entanglement based QSDC experiment with full functions, using optical fibers of 500 meters as the quantum channels and realizing all the functions based on technologies of fiber optics, including polarization entangled Bell state generation and measurement, and the quantum memories. It shows that QSDC can be realized by on-shelf technologies of optical communications, which is preferred to its future applications in optical fiber networks. Theoretical analysis shows that the scheme in this work has the potentials on applications in metropolitan, access and local networks. This work has been looked as an important step stone for future application of QSDC, which has attracted broad attention.

###​
Feng Zhu, Wei Zhang, Yubo Sheng, Yidong Huang. Experimental long-distance quantum secure direct communication. _Science Bulletin_, 2017,62(22)1519-1524 https://www.sciencedirect.com/science/article/pii/S2095927317305546



Secure information transmission over 500m fiber links based on quantum technologies | EurekAlert! Science News

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## JSCh

*Year in Review *https://www.sciencenews.org/search?tt=47
Quantum Physics, 2017 Top 10
*A quantum communications satellite proved its potential in 2017*
*Intercontinental video call sets distance record for cryptography via entangled photons*

By Emily Conover
8:28am, December 13, 2017 



*SPACING OUT* Quantum communication through space is possible thanks to a Chinese satellite that beams particles of light down to telescopes like this one in Xinglong, China (shown here tracking the satellite’s location with a laser).
Jian-Wei Pan





During the world’s first telephone call in 1876, Alexander Graham Bell summoned his assistant from the other room, stating simply, “Mr. Watson, come here. I want to see you.” In 2017, scientists testing another newfangled type of communication were a bit more eloquent. “It is such a privilege and thrill to witness this historical moment with you all,” said Chunli Bai, president of the Chinese Academy of Sciences in Beijing, during the first intercontinental quantum-secured video call.
The more recent call, between researchers in Austria and China, capped a series of milestones reported in 2017 and made possible by the first quantum communications satellite, Micius, named after an ancient Chinese philosopher (_SN: 10/28/17, p. 14_).

Created by Chinese researchers and launched in 2016, the satellite is fueling scientists’ dreams of a future safe from hacking of sensitive communiqués. One day, impenetrable quantum cryptography could protect correspondences. A secret string of numbers known as a quantum key could encrypt a credit card number sent over the internet, or encode the data transmitted in a video call, for example. That quantum key would be derived by measuring the properties of quantum particles beamed down from such a satellite. Quantum math proves that any snoops trying to intercept the key would give themselves away.

“Quantum cryptography is a fundamentally new way to give us unconditional security ensured by the laws of quantum physics,” says Chao-Yang Lu, a physicist at the University of Science and Technology of China in Hefei, and a member of the team that developed the satellite.

But until this year, there’s been a sticking point in the technology’s development: Long-distance communication is extremely challenging, Lu says. That’s because quantum particles are delicate beings, easily jostled out of their fragile quantum states. In a typical quantum cryptography scheme, particles of light called photons are sent through the air, where the particles may be absorbed or their properties muddled. The longer the journey, the fewer photons make it through intact, eventually preventing accurate transmissions of quantum keys. So quantum cryptography was possible only across short distances, between nearby cities but not far-flung ones.

With Micius, however, scientists smashed that distance barrier. Long-distance quantum communication became possible because traveling through space, with no atmosphere to stand in the way, is much easier on particles.

*Making connections*
Entangled photons were sent to Delingha and Lijiang in China with the quantum communications satellite Micius (illustrated).



JIAN-WEI PAN

In the spacecraft’s first record-breaking accomplishment, reported June 16 in _Science_, the satellite used onboard lasers to beam down pairs of entangled particles, which have eerily linked properties, to two cities in China, where the particles were captured by telescopes (_SN: 8/5/17, p. 14_). The quantum link remained intact over a separation of 1,200 kilometers between the two cities — about 10 times farther than ever before. The feat revealed that the strange laws of quantum mechanics, despite their small-scale foundations, still apply over incredibly large distances.

Next, scientists tackled quantum teleportation, a process that transmits the properties of one particle to another particle (_SN Online: 7/7/17_). Micius teleported photons’ quantum properties 1,400 kilometers from the ground to space — farther than ever before, scientists reported September 7 in _Nature_. Despite its sci-fi name, teleportation won’t be able to beam Captain Kirk up to the _Enterprise_. Instead, it might be useful for linking up future quantum computers, making the machines more powerful.

The final piece in Micius’ triumvirate of tricks is quantum key distribution — the technology that made the quantum-encrypted video chat possible. Scientists sent strings of photons from space down to Earth, using a method designed to reveal eavesdroppers, the team reported in the same issue of _Nature_. By performing this process with a ground station near Vienna, and again with one near Beijing, scientists were able to create keys to secure their quantum teleconference. In a paper published in the Nov. 17 _Physical Review Letters_, the researchers performed another type of quantum key distribution, using entangled particles to exchange keys between the ground and the satellite.

The satellite is “a major development,” says quantum physicist Thomas Jennewein of the University of Waterloo in Canada, who is not involved with Micius. Although quantum communication was already feasible in carefully controlled laboratory environments, the Chinese researchers had to upgrade the technology to function in space. Sensitive instruments were designed to survive fluctuating temperatures and vibrations on the satellite. Meanwhile, the scientists had to scale down their apparatus so it would fit on a satellite. “This has been a grand technical challenge,” Jennewein says.

Eventually, the Chinese team is planning to launch about 10 additional satellites, which would fly in formation to allow for coverage across more areas of the globe.

_Citations_

J.-G. Ren et al. Ground-to-satellite quantum teleportation. _Nature_. Vol. 549, September 7, 2017, p. 70. doi: 10.1038/nature23675.
S.-K. Liao et al. Satellite-to-ground quantum key distribution. _Nature_. Vol. 549, September 7, 2017, p. 43. doi: 10.1038/nature23655.
J. Yin et al. Satellite-based entanglement distribution over 1200 kilometers. _Science_. Vol. 356, June 16, 2017, p. 1140. doi: 10.1126/science.aan3211.
J. Yin et al. Satellite-to-ground entanglement-based quantum key distribution. _Physical Review Letters_. Vol. 119, November 17, 2017, p. 200501. doi: 10.1103/PhysRevLett.119.200501.


A quantum communications satellite proved its potential in 2017 | Science News

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## JSCh

*Focus: Intercontinental, Quantum-Encrypted Messaging and Video*
January 19, 2018• _Physics_ 11, 7
_China and Austria used a satellite link to exchange quantum encrypted data for images and a video stream, a first step toward a secure “quantum internet.”_



​J.-W. Pan/USTC
*Eye in the Sky.* The satellite _Micius_ relayed quantum-secure signals between China and Austria. This time-lapse photo shows the Xinglong observatory’s red laser tracking the satellite as it moves across the sky, emitting a green laser beam that appears as a single point at any instant. 

Communication with digital signals encrypted quantum-mechanically can be more secure than with classical signals, prompting forecasts of a “quantum internet” for global data protection. Such a project now looks more feasible thanks to a demonstration in which researchers shared images and a video connection that were quantum-mechanically secure between stations in China and Austria, linked by a satellite.

Like any form of digital encryption, quantum cryptography uses a string of bits (1’s and 0’s) called a key to encode and decode information. But in the quantum version, the bits are represented as quantum states—for example, the polarization states of photons. Pairs of quantum bits (qubits) in the key are quantum-entangled, meaning that the states of the pair are interdependent; the sender keeps one qubit and sends the other to the receiver. The laws of quantum mechanics make it physically impossible for the transmitted qubits to be intercepted and read without this eavesdropping being detectable by the sender and receiver.

Quantum key distribution (QKD) is the process of sending the key in this quantum-secure way, which keeps the encoded message safe, even if the message is sent without a quantum protocol. QKD between two remote locations has previously been demonstrated for signals sent along optical fibers over many kilometers [1, 2], but light signals sent using a satellite relay would suffer less attenuation en route. Recently, Jian-Wei Pan of the University of Science and Technology of China (USTC) in Hefei and his co-workers reported QKD using laser beams between the Xinglong observatory in China and a low-orbit satellite called _Micius_ [3]. This satellite is the first to have quantum-processing capability and was launched by China in 2016. Pan’s group, in collaboration with Anton Zeilinger and others at the University of Vienna, has now extended the satellite link so as to permit QKD between Xinglong and Graz, Austria, via _Micius_, over a distance of 7600 km.

_Micius_ can create quantum keys and can also broadcast and measure quantum-encrypted signals. It can send separate, single-use, random quantum keys to the Xinglong and Graz stations by laser pulses as it passes over each location. The sender—say, at Graz—uses the _Micius_-Graz key to encode data, and _Micius_ can then include this key in the signal it sends to Xinglong, encrypted with a different _Micius_-Xinglong key.

To demonstrate the cryptographic link, the researchers sent two images between China and Austria via the satellite and used fiber-optic networks to extend the connection from Graz to Vienna and from Xinglong to Beijing. They sent a digitized image of Micius (the Chinese philosopher after whom the satellite is named) from Beijing to Vienna and a picture of the quantum physicist Erwin Schrödinger (who worked in Vienna) from Vienna to Beijing. Each file contained about 5 kilobytes of data.

In a further demonstration of the scope of the link, it was used for a secure videoconference between the Chinese Academy of Sciences in Beijing and the Austrian Academy of Sciences in Vienna—a 75-minute discussion that required 2 gigabytes of data. The capability demonstrated here, says Pan, “is sufficient for the very early stages of a quantum internet, similar to the state of cell phones in the 1970s.” He anticipates that the first real applications of this network will include encrypted voice calls, faxes, and email for transmitting sensitive financial or diplomatic information.

“This is the first demonstration of intercontinental quantum key distribution of any kind, and it will stand as a milestone towards future quantum networks,” says Ronald Hanson of the Technical University of Delft in the Netherlands, who is working on long-distance quantum telecommunication for a quantum internet.

_Micius_ is a critical component of a larger, Chinese-led, international project called Quantum Experiments at Space Scale, which includes plans to launch satellites with higher orbits and to construct a constellation of such satellites. Three low-orbit satellites could distribute secure quantum keys at a rate of several gigabits per year, says Pan. Coauthor Chao-Yang Lu of the Hefei and Shanghai campuses of USTC says that using the highest security, this amount of quantum key data could protect an equal amount of data in secure messages, but with slightly lower security, the volume of data could be much greater.

This research is published in _ Physical Review Letters_.

–Philip Ball

*Satellite-Relayed Intercontinental Quantum Network*
Sheng-Kai Liao _et al._
Phys. Rev. Lett. *120*, 030501 (2018)
Published January 19, 2018


Physics - Focus: Intercontinental, Quantum-Encrypted Messaging and Video

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## JSCh

*USTC Realizes Small-Packet-and-Long-Distance Quantum Key Distribution*
Jan 29, 2018

The round-robin-differential-phase-shift (RRDPS) is a new quantum key distribution protocol proposed by Japanese and American scientists in 2014. This protocol can estimate the information leakage without monitoring signal disturbance parameters, which breaks through the design of quantum key distribution protocol. 

In practical applications, free of monitoring channel disturbance also brings the advantages of simplified system and high error rate tolerance. However, there are still some key problems not solved in the protocol. 

Quantum Cryptographic Research Group of University of Science and Technology of China (USTC) of Chinese Academy of Sciences perfected the security proof of RRDPS quantum key distribution theoretically. The RRDPS protocol with the lowest number of packet and the longest achievable distance was realized in the world for the first time. The problems of large pulse number and low efficiency were solved. The results were published in _Nature Communications_. 

The researchers first improved the security proof of the RRDPS protocol theoretically. By constructing the eavesdropper's general collective attack model and fully considering the decoherence effect caused by the random phase on the eavesdropper's auxiliary state in each pulse of the encoding state, a tight bound of the eavesdropper's information was given.

This theory further optimized the estimation of eavesdropping information by combining the parameters of channel disturbance. The novel security proof clearly demonstrated the security mechanism of the RRDPS protocol, and the performance of the RRDPS was significantly improved. This new idea provided by this security proof is also useful for other high-dimensional QKD protocols. 

The simulation results showed that based on the new security proof, the secret key rate and the security distance of RRDPS protocol were significantly improved. The pulse number of each packet L was greatly reduced compared with the original one.

In order to verify this theory, researchers also realized the simplest RRDPS demonstration experiment with L = 3. Key distribution without monitoring signal disturbance is achieved on 30 km fiber channel. If combined with channel disturbance parameters, this distance can reach 140 km.

These results had important reference value for enriching the theories and methods of security analysis of high dimensional quantum key distribution and improving the practicability of the system.

The study was funded by Ministry of Science and Technology, National Natural Science Foundation of China and Chinese Academy of Sciences.

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## TaiShang

*Chinese physicists’ quantum achievement signals dawn of supercomputer*

By Yin Han and Deng Xiaoci Source:Global Times Published: 2018/7/3 21:58:40


*Quantum achievement signals dawn of supercomputer*

*Chinese physicists realized a genuine entanglement of 18 quantum particles, beating their own world record set in 2016*, *while the team has set their next goal at 50-qubit entanglement. *

The result of the study was published in the US journal Physical Review Letters on June 28.

Chinese leading quantum physicist Pan Jianwei led the project. Together with his team, Pan earlier demonstrated quantum entanglement with 10 quantum bits, or "qubits," in 2016, according to a report sent by Pan's team to Global Times on Tuesday.

Quantum entanglement is a weird phenomenon which Einstein called "spooky action at a distance" where quantum particles are connected "even if they are at opposite ends of the universe," an Australia-based Cosmos Magazine reported. 

The preparation and manipulation of multiple qubit in entangled states are "core indicators for the development of quantum computing," which could be used to process information exponentially faster than conventional computing, Wang Xilin, a member of Pan's team told Global Times on Tuesday.

"The speed of quantum computing grows exponentially as the number of qubits in an entangled state increases … the achievement of an 18-qubit entanglement this time has set the world record for largest entanglement state in all physical systems," Wang said. 

For the next step, the team will attempt to demonstrate the abilities of quantum computing devices to solve problems that classical computers cannot, an experiment called "the quantum supremacy experiment" in international academia, said Wang. 

"With that goal, the team's next step will be to realize a 50-qubit entanglement and manipulation," Wang said.

The outlook of future applications of quantum computing has been widely reported upon and become a field full of mystery and magic to the public.

According to a report by the US Business Insider, Quantum computing could make traffic jams an event of the past by conducting complex and rapid analysis to work out the best route for travelers.

It can also be used to strengthen national defense through image analysis capability to catch any details in photographs and videos that humans could overlook. 

"The potential applications of quantum computing are huge, so are the challenges faced," Wang said, adding that quantum computing has become one of the most competitive fields in the world.

The US House Science Committee has introduced a bill creating a 10-year National Quantum Initiative aimed at developing quantum information science and technology.

http://www.globaltimes.cn/content/1109354.shtml

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## JSCh

*China, Italy set quantum technology test*
By Xing Yi in Shanghai | China Daily | Updated: 2018-08-28 09:23















Scientists work on China's first quantum science satellite at a research center of the Chinese Academy of Sciences in Shanghai in May last year. [Photo/Xinhua]

China and Italy are preparing for the world's third intercontinental quantum communication test as early as September, allowing scientists to have a better understanding of this hackproof technology's applications across great distances in space.

Pan Jianwei, chief scientist for China's quantum-science satellite, which goes by the nickname "Micius", revealed the news on the sidelines of the 8th International Conference on Quantum Cryptography in Shanghai on Monday.

The test will be conducted using several ground stations in China and Italy's Space Geodesy Centre in Matera - a distance of more than 8,000 kilometers.

"We had a successful quantum communication with Austria last year, and with Tenerife in the Canary Islands off the coast of northwestern Africa earlier this year," Pan said. "Next will be with Italy in September or October."

"We are open to working with teams in other countries, and to sharing our experiences in quantum communication," he said, adding that cooperation with Japan and the United States is under discussion.

The China-Italy intercontinental communication test will be conducted through Micius, the world's first and only operating quantum communication satellite. It allows quantum keys and encrypted messages to be sent and received.

Launched in August 2016, Micius was designed with a service life of 2 years, but it is still functioning well, project experts said.

Paolo Villoresi, Italian professor of physics at University of Padua, confirmed the collaboration and said the test will help scientists better understand how quantum communication works in space.

"We didn't have an active signal source in space for our experiments before China sent Micius," he said.

In July, two Chinese scientists on Pan's team went to Italy to help their counterparts track Micius and learn its parameters for the upcoming test.

"We are really looking forward to the collaboration and to gathering interesting results," Villoresi added.

One of the featured applications of quantum communication lies in quantum cryptography, which enables security through quantum key distribution technology.

Quantum communication is regarded as the most secure because its encryption is based on quantum entanglement, in which two or more subatomic particles affect each other simultaneously, regardless of the distance between them.

At the same time, the particles cannot be destroyed or duplicated. Any eavesdropper will disrupt the entanglement and alert the authorities.

This year's quantum cryptography conference has drawn some 500 leading scholars and experts from home and abroad in the field of quantum communication and cryptography. It's the first time China has hosted this conference.

With significant progress being made in quantum cryptography in recent years, quantum communication has started to be used in real life in China, where a space-to-ground quantum communication network is taking shape.

The 2,000-km Beijing-Shanghai main quantum fiber link was put into service in September, and 32 local quantum node stations along the link have been built.

Micius was integrated into the network last year, creating the world's first integrated quantum network capable of sending messages via landlines and from space.

Zhao Bo, manager of applied product department of QuantumCTek, one of China's main manufacturers of quantum key distribution devices, said their clients include IT companies, banks and governments.

"Quantum cryptography technology can improve the security of communications, which is becoming more and more crucial in this digital world," Zhao said.

Industrial and Commercial Bank of China has introduced quantum communication devices into their Beijing and Shanghai data centers, and many local provinces are building quantum communication networks, he added.

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## JSCh

*Beiijng-Guangzhou Quantum Communication Trunk Line Is Under Construction*
LIAO SHUMIN 
DATE: THU, 08/30/2018 - 15:31 / SOURCE:YICAI 

(Yicai Global) Aug. 30 -- With quantum communication network development gathering pace in China, many medium- to high-orbit and low-orbit QC satellites are under development in the country and construction of the quantum communication trunk line linking Beijing with Guangzhou is also in full swing.

“Our goal of is to build a quantum communication network that integrates space-air-ground facilities in future,” Prof. Zhang Qiang at the University of Science and Technology of China told state news outlet The Paper at the Engineering Center of USTC Shanghai Institute for Advanced Studies in Shanghai’s Pudong New Area.

China launched its first QC science experiment satellite Mozi on Aug. 16, 2016, and the 2,000-kilometer-long Beijing-Shanghai Secure Quantum Communication Trunk Line passed acceptance checks about a year later. It is dubbed the first ‘high-speed rail’ of QC in the country. The USTC engineering center serves as the control center for both the Mozi satellite and the secure QC trunk line.

“By analogy, ground quantum communication networks are high-speed rail, and QC satellites are aircraft. China has successfully launched the first QC satellite Mozi, and the ground communication network, Beijing-Shanghai trunk line, has gone into operation. The country also plans to launch many small satellites, and the second trunk line that runs from Beijing to Guangzhou has also been approved by the National Development and Reform Commission,” Zhang said.

In the broad sense, QC refers to the process of transmitting information encoded in quantum state from one place to another, which involves quantum teleportation, quantum entanglement swapping and quantum key distribution. In its narrow signification, the term means quantum key distribution -- key distribution through quantum-state microscopic particles.

Quantum is non-clonal and indivisible, and salient features of quantum communication include unique keys for different data transmissions and completely random key generation. Any interception can be detected, and it is impossible to crack quantum-encrypted data, making QC unconditionally secure in theory.

Mozi now has five aerial stations -- Urumqi (Xinjiang), Ali (Tibet), Graha (Qinghai), Lijiang (Yunnan) and Xinglong (Beijing), with all connected with the satellite, Zhang explained.

On the ground, four metropolitan area networks have sprung up along the Beijing-Shanghai trunk, and they function like subway networks in a city. Many more cities have started building local MANs. Once completed, they will connect to the trunk line using certain routing mechanisms.

The metropolitan area network built in Jinan in eastern Shandong province in 2013, for example, has 56 nodes and is the largest MAN in the world today. It has run operation since 2013 and has a failure-free operation rate as high as 99.7 percent. “The 0.3 percent failure rate means that the QC network can meet modern communication requirements,” he noted.

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## hiseen

All is stealing the technology of SP12~

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## JSCh

Yang Liu, Qi Zhao, Ming-Han Li, Jian-Yu Guan, Yanbao Zhang, Bing Bai, Weijun Zhang, Wen-Zhao Liu, Cheng Wu, Xiao Yuan, Hao Li, W. J. Munro, Zhen Wang, Lixing You, Jun Zhang, Xiongfeng Ma, Jingyun Fan, Qiang Zhang & Jian-Wei Pan. *Device-independent quantum random-number generation*. _Nature _(2018). DOI: 10.1038/s41586-018-0559-3.

*Abstract*
Randomness is critical for many information processing applications, including numerical modelling and cryptography1,2. Device-independent quantum random-number generation (DIQRNG)3,4 based on the loophole-free violation of Bell inequality produces unpredictable genuine randomness without assumptions on the inner working of devices and is therefore an ultimate goal in the field of quantum information science5–7. Previously reported experimental studies of DIQRNG8,9 were not proven to be secure against the most general attacks. Here we present fully functional DIQRNG against both quantum and classical adversaries10–12. By exploiting the state-of-art quantum optical technology, we achieve an efficiency of more than 78 per cent from creation to detection of entangled photon pairs at a distance of about 100 metres, which largely exceeds the efficiency threshold besides satisfying the no-signaling condition to realize a robust loophole-free violation of Bell inequality. This allows us to realize the security analysis of the Bell test outcomes against the general quantum side information and without assuming independent and identical distribution. As a demonstration, by applying a large Toeplitz matrix (137.90 Gb × 62.469 Mb) hashing technique, we obtain 6.2469 × 107 quantum-certified random bits in 96 hours or 181 bits per second with a total failure probability within 10−5, marking a critical step to bring DIQRNG from the concept towards practical applications. We anticipate that our work may help in understanding the origin of randomness from a fundamental perspective, and also in generating genuine randomness for practical applications demanding better security levels7.​

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## JSCh

JSCh said:


> Yang Liu, Qi Zhao, Ming-Han Li, Jian-Yu Guan, Yanbao Zhang, Bing Bai, Weijun Zhang, Wen-Zhao Liu, Cheng Wu, Xiao Yuan, Hao Li, W. J. Munro, Zhen Wang, Lixing You, Jun Zhang, Xiongfeng Ma, Jingyun Fan, Qiang Zhang & Jian-Wei Pan. *Device-independent quantum random-number generation*. _Nature _(2018). DOI: 10.1038/s41586-018-0559-3.
> 
> *Abstract*
> Randomness is critical for many information processing applications, including numerical modelling and cryptography1,2. Device-independent quantum random-number generation (DIQRNG)3,4 based on the loophole-free violation of Bell inequality produces unpredictable genuine randomness without assumptions on the inner working of devices and is therefore an ultimate goal in the field of quantum information science5–7. Previously reported experimental studies of DIQRNG8,9 were not proven to be secure against the most general attacks. Here we present fully functional DIQRNG against both quantum and classical adversaries10–12. By exploiting the state-of-art quantum optical technology, we achieve an efficiency of more than 78 per cent from creation to detection of entangled photon pairs at a distance of about 100 metres, which largely exceeds the efficiency threshold besides satisfying the no-signaling condition to realize a robust loophole-free violation of Bell inequality. This allows us to realize the security analysis of the Bell test outcomes against the general quantum side information and without assuming independent and identical distribution. As a demonstration, by applying a large Toeplitz matrix (137.90 Gb × 62.469 Mb) hashing technique, we obtain 6.2469 × 107 quantum-certified random bits in 96 hours or 181 bits per second with a total failure probability within 10−5, marking a critical step to bring DIQRNG from the concept towards practical applications. We anticipate that our work may help in understanding the origin of randomness from a fundamental perspective, and also in generating genuine randomness for practical applications demanding better security levels7.​


*Safest random numbers generated*
Source:Global Times Published: 2018/9/20 22:53:41

*Researchers eye broad applications*

A recent study by Chinese scientists for the first time revealed the safest random numbers in the world, which cannot be detected or hacked even by the most advanced computers and has a broad application in areas such as cryptography. 

The results of the study were published on _Nature_, the international journal of science, on Thursday. 

The project was jointly conducted by a team of top Chinese quantum physicist Pan Jianwei from the University of Science and Technology of China (USTC), Shanghai Institute of Microsystems and Information Technology of the Chinese Academy of Sciences and Japan's NTT Basic Research Laboratories and NTT Research Center for Theoretical Quantum Physics, according to a press release the USTC sent to the Global Times on Thursday. 

The study is about device-independent quantum random number generation, which produces unpredictable genuine randomness without assumptions on the inner workings of devices, and is the ultimate goal in the field of quantum information science, according to project information published on Nature.

"The generator of device-independent quantum random numbers is the safest production device for random numbers, and the random numbers it generates cannot be detected even by the world's most powerful quantum computer eavesdroppers have," the press release said.

Many countries are also researching such generators and the US' National Institute of Standards and Technology is attempting to use such a generator to establish a national standard on random numbers, according to the press release. 

"There will be a random number leakage if we accidentally used the quantum random number generator produced by a malicious third party, and our new achievement ensures that even using the malicious third party provided generator, it could still produce genuine random numbers which could not be leaked," Pan was quoted by the People's Daily as saying on Thursday. 

The random numbers have significant applications in both science and daily life in weather forecasting, research and development on medication and nuclear weapons and design of new materials, the press release said. 

The random numbers could control the evolution of the system needed in artificial intelligence, and is also the safe foundation for communication security and modern cryptography. 

Scientists from USTC will establish stable and high-speed device-independent quantum random number generators, and provide safe random numbers, and even help form a new international standard for random numbers, the People's Daily reported Thursday.

Pan's team has engaged in leading research in quantum science and technology. 

In June, Pan's team set a world record for entanglement of 18 quantum bits, keeping their lead in the field of quantum computing.

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## JSCh

PUBLIC RELEASE: 10-OCT-2018
*Measurement-device-independent quantum communication without encryption*
SCIENCE CHINA PRESS



​Illustration of the MDI-QSDC protocol. *CREDIT: *©Science China Press

Confidential communication is vital in modern society. Quantum secure direct communication is a new kind of secure communication with no encryption. In a classical secure communication, the sender and the receiver have to share a secret key in advance, then a plaintext is encoded into ciphertext, and sent to receiver through a classical channel. The ciphertext is then decoded to plaintext by receiver to complete the communication. In this structure, there exist three potential security loopholes, which are: (1) loss of key during the distribution process; (2) loss of key in storage and management; (3) interception of ciphertext by Eve for later cryptanalysis. With the development of supercomputers and quantum computers, these threats become more and more serious.

Quantum communication whose security is guarded by quantum physics principles is an important scheme resists these attacks. Quantum secure direct communication (QSDC) is a unique in its kind of secure communication, which does not require key distribution, key storage and management, and does not use ciphertext. It eliminates the three loopholes in classical secure communication efficiently.

The key problem of practical QSDC is that apparatuses used in practical quantum communication system have some defects, and these imperfections, especially defects in the measurement devices, can lead to leakage of information and affect the security of practical QSDC. Recently, a research team led by Prof. Gui-Lu Long from Tsinghua University proposed a measurement- device- independent (MDI) QSDC protocol using Einstein-Podolsky-Rosen pairs. This protocol eliminates all loopholes related to measurement devices, overcoming a key obstacle of practical QSDC. Besides, the MDI-QSDC has a twice communication distance, and a high communication capacity.


Measurement-device-independent quantum communication without encryption | EurekAlert! Science News

Peng-Hao Niu, Zeng-Rong Zhou, Zai-Sheng Lin, Yu-Bo Sheng, Liu-Guo Yin, and Gui-Lu Long. *Measurement-Device-Independent Quantum Communication without Encryption*, _Science Bulletin _(2018), DOI: doi.org/10.1016/j.scib.2018.09.009​


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## JSCh

*QUANTUM INFORMATION | *23 OCTOBER 2018
*Teleportation over a 6-kilometre cable, courtesy of quantum powers*
‘Continuous-variable’ quantum teleportation is accomplished outside the lab with fibre-optic gear.

The fibre-optic cables that carry Internet traffic can also be used for a powerful form of the strange phenomenon known as quantum teleportation.

According to quantum mechanics, two particles can become ‘entangled’, meaning that the quantum properties of one are tightly linked to the properties of the other, no matter how far apart the particles. Quantum teleportation enlists a pair of entangled particles to transmit information about a third particle, such as a photon, from a sender to a receiver.

In continuous-variable quantum teleportation, entangled particles help to transmit a stream of information comprising numerical values that can range widely, such as the amplitudes of a laser’s light waves. But until now, this form of teleportation has been achieved only over very short distances in the lab.

Xiaojun Jia and his colleagues at Shanxi University in Taiyuan, China, used common optical fibre to carry out continuous-variable teleportation of laser-light values across a distance of 6 kilometres. The information was replicated at the receiving location with a higher accuracy than would have been possible using classical physics.

This approach could allow optical fibre to be used for powerful forms of quantum computing.

_Sci. Adv._ (2018)​


Teleportation over a 6-kilometre cable, courtesy of quantum powers : Research Highlights | Nature.com
​


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## JSCh

*New quantum communication landline connecting East, Central China put into service*
By Cao Siqi in Wuhan Source:Global Times Published: 2018/11/13 19:03:39




Screenshot shows an extension quantum communication landline connecting East China's Anhui Province and Central China's Hubei Province.Photo: Cao Siqi/GT

An extension quantum communication landline connecting East China's Anhui Province and Central China's Hubei Province was put into service on Tuesday, marking a significant milestone in China's quantum infrastructure construction that scientists say makes China the new leader in quantum communication. 

The Wuhan-Hefei landline was launched on Tuesday at the Third Optics Valley Aerospace Laser and Quantum Technology International Forum hosted by China Aerospace Science and Industry Corporation, the network's major builder. 

The company, which primarily develops and produces missiles and carrier rockets and also invests heavily in laser technologies and weapons, said the network is now connected to the world's first quantum communication landline opened between Beijing and Shanghai in September 2017.

Quantum communications feature ultra-high security. Information running through it is difficult to tap, intercept or crack, experts said. 

An insider who declined to be named told the Global Times that the quantum communication network plays a crucial role in military operations in the information age. 

"In future combat, the competition lies in the speed of transferring information. The network could help transmit classified information to the command center and then quickly instruct a combat unit," he said.

"It is fast and free from outside disturbances," he noted.

China's quantum communication ground network is connected to the world's first quantum satellite launched by China in August 2016. 

The satellite is called "Micius," after a 400 BC Chinese philosopher and scientist credited as the first person to conduct optical experiments. 

The company said the network can be used not only for confidential military and national defense communications but also for financial and energy purposes and other government fields.

Meanwhile, it is also expected to be used in civil communications such as on mobile phones and networks, Wu said.

According to the company, the new quantum communication landline will build 11 stations in cities in Anhui and Hubei provinces, and is 609 kilometers long.

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## JSCh

Letter | Published: 21 January 2019
*Entanglement of three quantum memories via interference of three single photons*

Bo Jing, 
Xu-Jie Wang, 
Yong Yu, 
Peng-Fei Sun, 
Yan Jiang, 
Sheng-Jun Yang, 
Wen-Hao Jiang, 
Xi-Yu Luo, 
Jun Zhang, 
Xiao Jiang, 
Xiao-Hui Bao & 
Jian-Wei Pan 
_Nature Photonics_ (2019) 

*Abstract*
Quantum memory networks as an intermediate stage in the development of a quantum internet1 will enable a number of significant applications2,3,4,5. To connect and entangle remote quantum memories, it is best to use photons. In previous experiments6,7,8,9,10,11,12,13, entanglement of two memory nodes has been achieved via photon interference. Going beyond the state of the art by entangling many quantum nodes at a distance is highly sought after. Here, we report the entanglement of three remote quantum memories via three-photon interference. We employ laser-cooled atomic ensembles and make use of a ring cavity to enhance the overall efficiency of our memory–photon entanglement. By interfering three single photons from three separate set-ups, we create entanglement of three memories and three photons. Then, by measuring the photons and applying feed-forward, we achieve heralded entanglement between the three memories. Our experiment may be employed as a building block to construct larger and complex quantum networks14,15.​

Entanglement of three quantum memories via interference of three single photons | Nature Photonics

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## JSCh

JSCh said:


> Letter | Published: 21 January 2019
> *Entanglement of three quantum memories via interference of three single photons*
> 
> Bo Jing,
> Xu-Jie Wang,
> Yong Yu,
> Peng-Fei Sun,
> Yan Jiang,
> Sheng-Jun Yang,
> Wen-Hao Jiang,
> Xi-Yu Luo,
> Jun Zhang,
> Xiao Jiang,
> Xiao-Hui Bao &
> Jian-Wei Pan
> _Nature Photonics_ (2019)
> 
> *Abstract*
> Quantum memory networks as an intermediate stage in the development of a quantum internet1 will enable a number of significant applications2,3,4,5. To connect and entangle remote quantum memories, it is best to use photons. In previous experiments6,7,8,9,10,11,12,13, entanglement of two memory nodes has been achieved via photon interference. Going beyond the state of the art by entangling many quantum nodes at a distance is highly sought after. Here, we report the entanglement of three remote quantum memories via three-photon interference. We employ laser-cooled atomic ensembles and make use of a ring cavity to enhance the overall efficiency of our memory–photon entanglement. By interfering three single photons from three separate set-ups, we create entanglement of three memories and three photons. Then, by measuring the photons and applying feed-forward, we achieve heralded entanglement between the three memories. Our experiment may be employed as a building block to construct larger and complex quantum networks14,15.​
> 
> Entanglement of three quantum memories via interference of three single photons | Nature Photonics


*USTC Achieves Entanglement of Three Quantum Memories via Three-Photon Interference*
Jan 31, 2019 

In a study published in _Nature Photonics_, Prof. PAN Jianwei and Prof. BAO Xiaohui at the University of Science and Technology of China (USTC) of Chinese Academy of Sciences realized the entanglement of three remote atomic-ensemble quantum memories via interference of three single photons, which paves a way towards long-distance quantum networks and multi-party quantum communication.

As an intermediate stage of quantum internet development, quantum memory networks are distinguished by the capability of the end nodes to have local memory while simultaneously allowing universal local control. This will enable a number of significant applications such as quantum teleportation and distributed quantum computing.

The most promising approach to build quantum networks is using an architecture combining photons as flying qubits with stationary matter-based quantum memories. A crucial requirement for the matter system is the ability to entangle with photons efficiently.

To improve the efficiency, Prof. PAN and Prof. BAO's group made use of a ring cavity to enhance the light-matter interaction and managed to use the ring cavity itself as a frequency filter to eliminate noise photons, which avoids unwanted losses comparing to frequently-used external frequency filters.

In addition, they use a Hermite-Gaussian mode for the cavity locking beam, which reduces its leakage into the single-photon channels significantly.

By harnessing the high-performance light-matter interface (_Nat. Photon._ 10, 381, 2016) and Rydberg blockade (_Phys. Rev. Lett._ 117, 180501, 2016), the node number can hopefully be further increased. Extension of distances for memory separations can be realized by converting photon wavelength to the telecom band and using low-loss fibre for transmission.

This work was supported by National Key R&D Program of China, Anhui Initiative in Quantum Information Technologies, National Natural Science Foundation of China and the Chinese Academy of Sciences.


USTC Achieves Entanglement of Three Quantum Memories via Three-Photon Interference---Chinese Academy of Sciences

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## TaiShang

*China's quantum communication satellite to extend working lifetime by two yrs: scientist*

(Xinhua) 14:40, February 15, 2019


WASHINGTON, Feb. 14 (Xinhua) -- A Chinese researcher said China's satellite Quantum Experiments at Space Scale (QUESS) or Micius would work at least two more years beyond its two-year working lifetime and carry out more international cooperation.

Yin Juan, a member of the QUESS team who received the annual Newcomb Cleveland Prize in Washington on Thursday night said so in an interview with Xinhua.

In the next two years, the QUESS team is expected to have the inter-continental quantum key distribution experiments with those from Italy, Russia and South Korea.

"We are open to international cooperation," said Yin, a professor of the University of Science and Technology of China. A team of 34 Chinese physicists led by Pan Jianwei with the university won the annual award that honors the most impactful research paper published in the journal Science.

The paper published in the journal Science in June 2017 reported the experiment that sends entangled photon pairs through the near-vacuum of space, measuring the quantum keys at receiving stations over 1,200 km apart.

Quantum key distribution (QKD), quantum entanglement distribution and quantum teleportation are three major scientific tasks done by QUESS, Yin said.

Based on the QKD technology, Chinese researchers could launch three more small-size satellites in the next three to five years to form a network that can fulfill more quantum communication tasks, a critical step to create the infrastructure of a globalized quantum internet one day, said Yin.

The QUESS team won the prize delivered by the American Association for the Advancement of Science as it laid the groundwork for ultra-secure communication networks of the future.

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## JSCh

*Global First Quantum-Enabled Satellite Achieves Data Safety Goals Faster Than Expected*
QIAN TONGXIN
DATE : MAR 12 2019/SOURCE : YICAI





Global First Quantum-Enabled Satellite Achieves Data Safety Goals Faster Than Expected​
(Yicai Global) March 12 -- The world's first quantum-enabled satellite Quantum Experiments at Space Scale has performed better than expected. The space station has a goal to make data privacy between different continents much safer. 

QESS, nicknamed Micius or Mozi after the ancient Chinese philosopher, has reached a level of prowess that was anticipated to take two years, in just two to three months, Pan Jianwei, a quantum physics professor and an academician at Chinese Academy of Sciences, told Yicai Global. He was speaking at the ongoing top-level political conference of Two Sessions. 

Communication safety is important not only to the nation but also to individuals, Pan noted. Researchers are striving to expand the coverage of quantum information technology, he said, adding that after reducing costs, it can benefit the public.

Since the launch in August 2016, Mozi achieved the global first space-ground integrated quantum communication network after one year of service. 

The nation plans to develop a medium earth orbit satellite that can work around the clock to apply Mozi's findings as soon as possible, Pan said. The space station can only work at night in order to avoid solar background noise. 

The satellite is primarily made for research and not for commercial use, Pan said, adding that it has increased the number of encryption keys by 40 times in the past two years so that about 400,000 encrypted quantum keys can be transmitted within one second.

Those 400,000 encryption keys can convey 40 kilobytes of data every second, Zhang Wenzhuo, an associate research fellow at the University of Science and Technology of China, told Yicai Global. The more keys, the larger the potential for commercial use, he added.

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## Galactic Penguin SST

JSCh said:


> *Global First Quantum-Enabled Satellite Achieves Data Safety Goals Faster Than Expected*
> QIAN TONGXIN
> DATE : MAR 12 2019/SOURCE : YICAI
> 
> 
> 
> 
> 
> Global First Quantum-Enabled Satellite Achieves Data Safety Goals Faster Than Expected​
> (Yicai Global) March 12 -- The world's first quantum-enabled satellite Quantum Experiments at Space Scale has performed better than expected. The space station has a goal to make data privacy between different continents much safer.
> 
> QESS, nicknamed Micius or Mozi after the ancient Chinese philosopher, has reached a level of prowess that was anticipated to take two years, in just two to three months, Pan Jianwei, a quantum physics professor and an academician at Chinese Academy of Sciences, told Yicai Global. He was speaking at the ongoing top-level political conference of Two Sessions.
> 
> Communication safety is important not only to the nation but also to individuals, Pan noted. Researchers are striving to expand the coverage of quantum information technology, he said, adding that after reducing costs, it can benefit the public.
> 
> Since the launch in August 2016, Mozi achieved the global first space-ground integrated quantum communication network after one year of service.
> 
> The nation plans to develop a medium earth orbit satellite that can work around the clock to apply Mozi's findings as soon as possible, Pan said. The space station can only work at night in order to avoid solar background noise.
> 
> The satellite is primarily made for research and not for commercial use, Pan said, adding that it has increased the number of encryption keys by 40 times in the past two years so that about 400,000 encrypted quantum keys can be transmitted within one second.
> 
> Those 400,000 encryption keys can convey 40 kilobytes of data every second, Zhang Wenzhuo, an associate research fellow at the University of Science and Technology of China, told Yicai Global. The more keys, the larger the potential for commercial use, he added.



Alas, as we suspected, quantum encryption turns out to be another *hollow hoax*!

_*Quantum encryption surprises: Shanghai Jiaotong University team penetrated the "strongest encryption shield", the experimental success rate was as high as 60%!*

量子加密惊现破绽：上海交大团队击穿“最强加密之盾”，实验成功率竟高达60%！ 

2019-3-12 13:24

今日，一篇在预印本 arXiv 上发表的文章显示，上海交通大学研究团队近來在经过不断的实验与尝试之后，发现了现有量子加密技术可能隐藏着极为重大的缺陷，攻破这个最强的加密之盾却不需要什么神兵利器，而是利用“盾”本身就存在的物理缺陷。这个研究这将可能导致量子加密从原本印象中的坚不可破，转而变成脆弱不堪。

因为，以上海交通大学团队所发表的研究来看，上海交通大学的研究人员们成功发现目前被广泛应用在量子通信中的 QKD（Quantum Key Distribution，量子密钥分发）方法并不完美，研究团队通过将具有不同种子频率的光子注入激光腔 ( lasing cavity) 来改变激光频率的方法，进而观察注入光子的半导体激光器的动态，最终居然获得高达 60％的信息盗取成功率。


http://www.lianmenhu.com/blockchain-9355-1​_

*Commentary*

As previously correctly assessed, quantum encryption is unsafe as it could anyway be hacked by targeting terminal hardware.

Therefore the real potential of this technology, if not secured, lies in the speed, allowing supraluminal communication in outer space, and making it "instantaneous" instead of the 3 to 21 minutes from Mars to Earth, 33 to 53 minutes from Jupiter and 5 hours from Pluto.

More below:

*China's Deep Space Quantum Communications Capability V1.1*
https://defence.pk/pdf/threads/chin...ons-news-updates.464793/page-53#post-11188985


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## Menthol

So basically Quantum Communication have been breached.

Its not as safe as the theory said.

I think the science community in China is still in early day, as China tend to boosting it without checking it more further. They are too focusing on achievement and then almost never thought the other implications that follow later.


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## JSCh

There’s a new way to break quantum cryptography - MIT Technology Review


> The attacks have ruthlessly exploited imperfections in the equipment used to send quantum information. In doing so, hackers have shown that even if the laws of physics offer perfect security, equipment can never be perfect. And these imperfections create loopholes that can be exploited.



Also see,

Device-independent quantum cryptography - Wikipedia

And also,



JSCh said:


> PUBLIC RELEASE: 10-OCT-2018
> *Measurement-device-independent quantum communication without encryption*
> SCIENCE CHINA PRESS
> 
> 
> 
> ​Illustration of the MDI-QSDC protocol. *CREDIT: *©Science China Press
> 
> Confidential communication is vital in modern society. Quantum secure direct communication is a new kind of secure communication with no encryption. In a classical secure communication, the sender and the receiver have to share a secret key in advance, then a plaintext is encoded into ciphertext, and sent to receiver through a classical channel. The ciphertext is then decoded to plaintext by receiver to complete the communication. In this structure, there exist three potential security loopholes, which are: (1) loss of key during the distribution process; (2) loss of key in storage and management; (3) interception of ciphertext by Eve for later cryptanalysis. With the development of supercomputers and quantum computers, these threats become more and more serious.
> 
> Quantum communication whose security is guarded by quantum physics principles is an important scheme resists these attacks. Quantum secure direct communication (QSDC) is a unique in its kind of secure communication, which does not require key distribution, key storage and management, and does not use ciphertext. It eliminates the three loopholes in classical secure communication efficiently.
> 
> The key problem of practical QSDC is that apparatuses used in practical quantum communication system have some defects, and these imperfections, especially defects in the measurement devices, can lead to leakage of information and affect the security of practical QSDC. Recently, a research team led by Prof. Gui-Lu Long from Tsinghua University proposed a measurement- device- independent (MDI) QSDC protocol using Einstein-Podolsky-Rosen pairs. This protocol eliminates all loopholes related to measurement devices, overcoming a key obstacle of practical QSDC. Besides, the MDI-QSDC has a twice communication distance, and a high communication capacity.
> 
> 
> Measurement-device-independent quantum communication without encryption | EurekAlert! Science News
> 
> Peng-Hao Niu, Zeng-Rong Zhou, Zai-Sheng Lin, Yu-Bo Sheng, Liu-Guo Yin, and Gui-Lu Long. *Measurement-Device-Independent Quantum Communication without Encryption*, _Science Bulletin _(2018), DOI: doi.org/10.1016/j.scib.2018.09.009​

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## Menthol

JSCh said:


> There’s a new way to break quantum cryptography - MIT Technology Review
> 
> 
> Also see,
> 
> Device-independent quantum cryptography - Wikipedia
> 
> And also,



I understand now, its in the device.

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## TaiShang

*How do you teach a 1-year-old quantum physics?*

By ZHANG ZHOUXIANG | China Daily | Updated: 2019-04-06 





One-year-old Zhang Junyao reads a book beside her small bookshelf. Photo by Wang Jingjing / For China Daily

Like most fathers, I have kept up the habit of buying cartoon books for my baby girl, who is now one year old, to encourage her to develop an interest in the outside world.

However, as I opened a new box of books last week, I thought I had placed the wrong order. On the cover of the first book the boldly colored headline jumped out: Quantum Physics. The second book I picked up was titled Quarks. The third one, Aerospace Engineering, looked a little more practical at first glance. However, it was only after much closer examination of the cover that I found two much smaller words prefixing each of the headlines: Baby Loves.

Wow! Do the authors of the books expect a 1-year-old girl to learn what her father did not study until the third year of university? How could I explain such complex concepts as, say, superposition states, to my 1-year-old daughter?

Yet, as I started this "mission impossible", I soon realized it might not be as difficult as I first thought. The quantum physics book is, like all the books I buy for her, still a cartoon book, containing very few words.

Open the first page and you see a baby running after a cat, drawn in a simple, colorful style that every infant will fall in love with at first sight.

Then the story became faster-paced. The cat jumped into a box and the box shut automatically. The baby sat next to the closed box, not knowing what his furry friend was doing inside.

"Is the cat asleep or awake?" A question emerged from the book, with the answer on the next page: "It can be both and in quantum physics. We call it a superposition state of being asleep and awake. When the baby opens the box, the superposition becomes a sure position."

Having been taught the whole thing with interest by me, my daughter picked up our dog and tried to undertake a similar experiment, which I fortunately, managed to stop in time. I am pretty sure she still knows little about quantum physics and won't understand the concept behind it for at least another decade.

However, at least she has been told the story and will find it of interest when the teacher mentions it in class.

*More importantly, for her, physics won't be the boring subject that many consider it to be. It won't be full of concepts that perplex her mind, but of funny stories that she's glad to hear about.*

And this is the direction that all primary education institutions should be looking to take.

As a result of the accumulated wisdom of the top thinkers over the centuries, natural science is a really difficult subject to learn for those without a strong interest in it. The more quantum physics books that are tailored toward infants, the more children will develop an appetite for the subject in their early years.

More importantly, these science books are written in a way that most young children can understand. Inste ad of throwing a complicated concept at the infant reader, it puts everything into a small story that the reader can enjoy with the help of their parents.

Honestly speaking, I would have preferred my quantum physics textbooks in university to have been written in this way, instead of the traditional way. Maybe I could have attained higher marks if my professor had brought a cat into the classroom to explain Schrodinger's thought experiment using an actual cat, instead of simply telling me about it.

But the idea of making science interesting doesn't just apply to children's education. A survey by the Chinese Association for Science and Technology found that only about 3.3 percent of China's total population have a basic knowledge of natural science, compared to figure of over 10 percent who do in developed countries. A key reason for that, according to experts, is the lack of proper scientific learning materials, especially those for adults.

This in turn explains, at least in part, why Chinese engineers have been faring better than Chinese scientists. A certain proportion of the population with a good understanding of natural science should be the basis for a nation to produce large numbers of excellent scientists, which in turn will render firm support to the prosperity of the nation.

Having finished the book on quantum physics, I made a thorough check of my daughter's little bookshelf and divided her books into a few different categories. The topics of the books ranged from dinosaurs to animal tongues, then to everyday wisdom, yet they all had one thing in common: They were interesting.

Dinosaurs

Besides the Baby Loves Quantum Physics book, there were books like How Dinosaurs Lived and Why Dogs Are Your Friends. These cartoon books tell stories just like animations, with the only difference being is that they're printed on paper, not viewed on an LED display.

In one of the books, different kinds of dinosaurs appear in both a logical and engaging order, passing along the infant protagonist to one dinosaur after another. They introduce themselves so that the reader gains a clear understanding about their names and their height, weight, favorite food, etc.

*Animal tongues*

In another book about the tongues of animals, the author and cartoonist not only drew different kinds of animals and their tongues in various ways, but also fixed certain materials to related parts of the animals so they feel like real ones. For example, when the reader touches the head of the camel, they feel actual camel hair. When they touch the tail of the snub-nosed monkey, they touch a small piece of cloth that's feels like a real tail.

My daughter's favorite is the tongue of the frog, made of plastic with a rough surface.

*Zoo sounds*

Another series of interactive books my daughter likes contain audio elements. Each of the pages is about 3 to 4 millimeters thick, with electric wires hidden inside, linking a small piece of metal to a tiny speaker and battery. When she taps the metal pad with her finger, animal sounds emanate from the page.

*Flexible strips*

Another book in the series is Baby Visits the Zoo. Each of the pages has flexible strips that the reader can move with their little fingers; When she finishes sliding them, the strips in their correct positions form a picture of an animal in the zoo.

Thanks to this book, my daughter has learned about the zebra, the lion, the elephant, the tiger, as well as the bonobo.

*Chicks and daily behavior*

Another series of books called The Polite Chickie stars a newborn chick named Qiuqiu, which means "ball" in Chinese because it resembles a furry ball. In the books, she learns how to talk with others, speak with her mummy, and how to play outside without risking falling out of her chair. She has already taken the chick around with her for company, just like our furry canine friend.

I am now planning to place an order for Baby Loves Programming for my daughter. I was a coding monkey in the lab during my university days and I hope she can have a taste of that. *Happy coding!*

http://www.chinadaily.com.cn/a/201904/06/WS5ca7e842a3104842260b4a03.html


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## JSCh

NEWS RELEASE 29-MAY-2019
*Secure metropolitan quantum networks move a step closer*
IOP PUBLISHING

Successful new field tests of a continuous-variable quantum key distribution (CV-QKD) system over commercial fiber networks could pave the way to its use in metropolitan areas.

That is the key achievement from a joint team of Chinese scientists, published today in _Quantum Science and Technology_, which demonstrates CV-QKD transmission over commercial deployed fiber link with a distance of 50 kilometres.

Team leader and lead author, Prof. Hong Guo, from a joint team of Peking University and Beijing University of Posts and Telecommunications (PKU-BUPT joint team), Beijing, said: "CV-QKD provides, in principle, unconditional secret keys to protect people's data - such as banking information, emails and passwords.

"It has attracted much attention in the past few years, because it uses standard telecom components that operate at room temperature, instead of specific quantum devices such as single photon detectors etc, and it has potentially much higher secret key rates. However, most previous long-distance CV-QKD demonstrations were only done in laboratory fiber, without the disturbances caused by the field environment."

Lead authors Dr. Yichen Zhang and Prof. Song Yu, from the PKU-BUPT joint team, Beijing, said: "There are several challenges to bringing a practical CV-QKD system from a laboratory setup to the real world. Deployed commercial dark fibers are inevitably subject to much stronger perturbations from changing environmental conditions and physical stress. This in turn causes severe disturbances of the transmitted quantum states.

"They also suffer from higher losses due to splices, sharp bends and inter-fiber couplings. The software and hardware of CV-QKD modules must not only be designed to cope with all the conditions affecting the transmission fiber, but must also be robustly engineered to operate in premises designed for standard telecom equipment. Furthermore, as the systems need to run continuously and without frequent attention, they need to be designed to automatically recover from any errors and shield end users from service interruptions."

The PKU-BUPT joint research team carried out two field tests of CV-QKD over commercial fiber networks in two cities of China - Xi'an and Guangzhou - achieving transmission distances of 30.02 km (12.48 dB loss) and 49.85 km (11.62 dB loss), respectively.

Prof. Hong Guo said: "The longest previous field tests of a CV-QKD system were over a 17.52 km deployed fiber (10.25 dB loss) and a 17.7 km deployed fiber (5.6 dB loss), where the secret key rates were 0.2 kbps and 0.3 kbps, respectively.

"Comparing with these results, our results show a more than twice transmission distance, and a two orders-of-magnitude higher secret key rates, though in more lossy commercial fiber links.

"This is a significant step in bringing CV-QKD closer to everyday use. It has pushed CV-QKD towards a more practical setting, and, naturally, one may expect that a quantum-guaranteed secure metropolitan network could be built within reach of current technologies."


Secure metropolitan quantum networks move a step closer | EurekAlert! Science News


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## JSCh

*Beating the Fundamental Rate-Distance Limit in a Proof-of-Principle Quantum Key Distribution System*
Shuang Wang, De-Yong He, Zhen-Qiang Yin, Feng-Yu Lu, Chao-Han Cui, Wei Chen, Zheng Zhou, Guang-Can Guo, and Zheng-Fu Han

Phys. Rev. X 9, 021046 – Published 4 June 2019
DOI: https://doi.org/10.1103/PhysRevX.9.021046

*POPULAR SUMMARY*
Quantum key distribution (QKD), which exploits the laws of quantum physics to share encryption keys between two remote users, is a promising technology to revolutionize information security. To maximize the probability that keys are successfully transmitted across lossy fiber-optic channels, it will be necessary to boost the rate at which users share keys. However, theory indicates that, without the aid of quantum repeaters, there is a fundamental limit to how quickly keys can be shared over any given distance. We implement a QKD system that overcomes these limits, achieving a key transmission rate 3 times higher than the predicted bound across a 300-km-long optical fiber.

Our scheme is based on a recently proposed protocol known as “twin-field QKD (TF-QKD) without phase postelection.” Two users prepare pairs of weak coherent light pulses with phase and frequency locked, encode their key bits as one of two optical phases, and send the pulses to an untrusted middle station, which measures the phase difference of the pulses in each pair. To achieve stable and high-visibility single-photon interference, we compensate for the fast phase evolution of the twin pulses traveling across hundreds of kilometers of fiber channels. Finally, we confirm the feasibility of TF-QKD and its prominent superiority in real fiber channels for the first time.

Our demonstration shows that achieving a high key rate is feasible in long-distance-fiber QKD implementations, which offers a new approach to large networks.


----------



## JSCh

18 Jun 2019 | 20:00 GMT
*World's First "Quantum Drone" for Impenetrable Air-to-Ground Data Links Takes Off*
Chinese researchers are developing an airborne quantum communications network with drones as nodes

By Charles Q. Choi

Quantum drones under development in China could lead to nigh unhackable airborne quantum communication networks, a new study finds.


...

World's First "Quantum Drone" for Impenetrable Air-to-Ground Data Links Takes Off - IEEE Spectrum


----------



## JSCh

Article | Published: 24 June 2019

*Experimental quantum repeater without quantum memory*

Zheng-Da Li,
Rui Zhang,
Xu-Fei Yin,
Li-Zheng Liu,
Yi Hu,
Yu-Qiang Fang,
Yue-Yang Fei,
Xiao Jiang,
Jun Zhang,
Li Li,
Nai-Le Liu,
Feihu Xu,
Yu-Ao Chen &
Jian-Wei Pan
_Nature Photonics_ (2019)

*Abstract*
Quantum repeaters—important components of a scalable quantum internet—enable entanglement to be distributed over long distances. The standard paradigm for a quantum repeater relies on the necessary, demanding requirement of quantum memory. Despite significant progress, the limited performance of quantum memory means that making practical quantum repeaters remains a challenge. Remarkably, a proposed all-photonic quantum repeater avoids the need for quantum memory by harnessing the graph states in the repeater nodes. Here we perform an experimental demonstration of an all-photonic quantum repeater. By manipulating a 12-photon interferometer, we implement a 2 × 2 parallel all-photonic quantum repeater, and observe an 89% enhancement of entanglement-generation rate over standard parallel entanglement swapping. These results provide a new approach to designing repeaters with efficient single-photon sources and photonic graph states, and suggest that the all-photonic scheme represents an alternative path—parallel to matter-memory-based schemes—towards realizing practical quantum repeaters.


Experimental quantum repeater without quantum memory | Nature Photonics


----------



## JSCh

First Object Teleported from Earth to Orbit - MIT Technology Review


> Researchers in China have teleported a photon from the ground to a satellite orbiting more than 500 kilometers above.
> by Emerging Technology from the arXiv
> Jul 10, 2017



*Ground-to-satellite quantum teleportation*
Ji-Gang Ren, Ping Xu, Hai-Lin Yong, Liang Zhang, Sheng-Kai Liao, Juan Yin, Wei-Yue Liu, Wen-Qi Cai, Meng Yang, Li Li, Kui-Xing Yang, Xuan Han, Yong-Qiang Yao, Ji Li, Hai-Yan Wu, Song Wan, Lei Liu, Ding-Quan Liu, Yao-Wu Kuang, Zhi-Ping He, Peng Shang, Cheng Guo, Ru-Hua Zheng, Kai Tian, Zhen-Cai Zhu, Nai-Le Liu, Chao-Yang Lu, Rong Shu, Yu-Ao Chen, Cheng-Zhi Peng, Jian-Yu Wang, Jian-Wei Pan
(Submitted on 4 Jul 2017)
An arbitrary unknown quantum state cannot be precisely measured or perfectly replicated. However, quantum teleportation allows faithful transfer of unknown quantum states from one object to another over long distance, without physical travelling of the object itself. Long-distance teleportation has been recognized as a fundamental element in protocols such as large-scale quantum networks and distributed quantum computation. However, the previous teleportation experiments between distant locations were limited to a distance on the order of 100 kilometers, due to photon loss in optical fibres or terrestrial free-space channels. An outstanding open challenge for a global-scale "quantum internet" is to significantly extend the range for teleportation. A promising solution to this problem is exploiting satellite platform and space-based link, which can conveniently connect two remote points on the Earth with greatly reduced channel loss because most of the photons' propagation path is in empty space. Here, we report the first quantum teleportation of independent single-photon qubits from a ground observatory to a low Earth orbit satellite - through an up-link channel - with a distance up to 1400 km. To optimize the link efficiency and overcome the atmospheric turbulence in the up-link, a series of techniques are developed, including a compact ultra-bright source of multi-photon entanglement, narrow beam divergence, high-bandwidth and high-accuracy acquiring, pointing, and tracking (APT). We demonstrate successful quantum teleportation for six input states in mutually unbiased bases with an average fidelity of 0.80+/-0.01, well above the classical limit. This work establishes the first ground-to-satellite up-link for faithful and ultra-long-distance quantum teleportation, an essential step toward global-scale quantum internet.​Comments: 16 pages, 3 figures

Subjects: Quantum Physics (quant-ph); Optics (physics.optics); Space Physics (physics.space-ph)
DOI: 10.1038/nature23675
Cite as: arXiv:1707.00934 [quant-ph]
(or arXiv:1707.00934v1 [quant-ph] for this version)


----------



## JSCh

JSCh said:


> Article | Published: 24 June 2019
> 
> *Experimental quantum repeater without quantum memory*
> 
> Zheng-Da Li,
> Rui Zhang,
> Xu-Fei Yin,
> Li-Zheng Liu,
> Yi Hu,
> Yu-Qiang Fang,
> Yue-Yang Fei,
> Xiao Jiang,
> Jun Zhang,
> Li Li,
> Nai-Le Liu,
> Feihu Xu,
> Yu-Ao Chen &
> Jian-Wei Pan
> _Nature Photonics_ (2019)
> 
> *Abstract*
> Quantum repeaters—important components of a scalable quantum internet—enable entanglement to be distributed over long distances. The standard paradigm for a quantum repeater relies on the necessary, demanding requirement of quantum memory. Despite significant progress, the limited performance of quantum memory means that making practical quantum repeaters remains a challenge. Remarkably, a proposed all-photonic quantum repeater avoids the need for quantum memory by harnessing the graph states in the repeater nodes. Here we perform an experimental demonstration of an all-photonic quantum repeater. By manipulating a 12-photon interferometer, we implement a 2 × 2 parallel all-photonic quantum repeater, and observe an 89% enhancement of entanglement-generation rate over standard parallel entanglement swapping. These results provide a new approach to designing repeaters with efficient single-photon sources and photonic graph states, and suggest that the all-photonic scheme represents an alternative path—parallel to matter-memory-based schemes—towards realizing practical quantum repeaters.
> 
> 
> Experimental quantum repeater without quantum memory | Nature Photonics


*Scientists Firstly Realize All-photonic Quantum Repeater*
Jul 12, 2019

Quantum repeaters, as the important components of a scalable quantum internet, enable the distribution of quantum states over long distances. The standard paradigm for a quantum repeater consists of three basic technologies, i.e., entanglement swapping, entanglement purification, and quantum memory. However, the limited performance of current quantum memories remains a major obstacle in realizing practical quantum repeaters.

Recently, the research team led by Prof. PAN Jianwei, Prof. CHEN Yuao and Prof. XU Feihu from University of Science and Technology of China of Chinese Academy of Sciences has demonstrated the all-photonic quantum repeater which eliminates the need for matter quantum memories, offering a new approach to construct the long-distance optical quantum internet. The study was published in _Nature Photonics_.

Scientists conducted the experiment which adopted a GHZ state and a passive scheme to realize the selective Bell measurement in the repeater nodes. By manipulating a 12-photon interferometer, they implemented a 2×2 parallel all-photonic quantum repeater, and observed an 89% enhancement of entanglement-generation rate over standard parallel entanglement swapping.

These results provided a new approach to design quantum repeaters with efficient single-photon sources and photonic graph states, and suggested that the all-photonic scheme represents an alternative path towards realizing practical quantum repeaters.

In the future, the research team will be devoted to combining the all-photonic scheme with the matter-memory-based scheme. These two schemes are important parallel research directions towards achieving a practical quantum repeater. By doing so, the repeater graph state (RGS) can relax the requirement of long coherent time of quantum memory, while a quantum memory can reduce the requirement of large size for the RGS.

The successful demonstration of all-photonic quantum repeater suggests that the quantum memory is no longer a necessary condition for building a quantum repeater, which opens up a new way for the research on long-distance quantum communications and networks.




Experimental set-up. (Image by PAN Jianwei’s team) 


Scientists Firstly Realize All-photonic Quantum Repeater---Chinese Academy of Sciences

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## JSCh

*Quantum teleportation moves into the third dimension – Physics World*
07 Aug 2019



​
Physicists in China and Austria have shown for the first time they can teleport multi-dimensional states of photons. Carrying out experiments using photons encoded via three spatial states, they say their scheme can be extended to arbitrarily high numbers of dimensions and is a vital step in teleporting the entire quantum state of a particle. The work could also improve technology used in quantum communications and quantum computing.

Quantum mechanics forbids the quantum state of one particle from being copied precisely to another particle. But teleportation – the instantaneous transfer of a state between particles separated by a long distance – offers an alternative. The process involves no physical transfer of matter and erases the state of the particle to be copied.

The basic idea is that Alice and Bob share a pair of entangled particles (in the terminology of quantum cryptography, Alice being the sender of a message and Bob the receiver). Then Alice interacts a third particle – in an unknown state – with her half of the entangled pair, measures the outcome of the interaction, and then tells Bob the result via a classical channel. Given that information and a measurement on his half of the entangled pair, Bob is able to work out the original unknown state – which is what has been teleported.

First proposed theoretically in 1993, quantum teleportation has since been demonstrated in many different guises. It has been carried out using two-level states of a single photon, a single atom and a trapped ion – among other quantum objects – and also using two photons. Then in 2015 Chaoyang Lu, Jian-Wei Pan and colleagues at the University of Science and Technology of China in Hefei demonstrated teleportation of two degrees of freedom – spin and orbital angular momentum – between single photons.

In the latest work, the same group, working with Anton Zeilinger and colleagues at the University of Vienna in Austria, has demonstrated teleportation of higher-dimensional states. As Lu explains, being able to transfer multiple degrees of freedom is only part of the challenge. That’s because particles in nature have properties that can take on many possible values, rather than the simple binary states (qubits) used in experiments to date. He says that even the simplest atom – hydrogen – can potentially exist in four different ground states and many excited states.

*Measuring the Bell state*
The chief difficulty in doing this, says Lu, is Alice’s initial measurement of the “Bell state” between the photon to be teleported and her half of the entangled pair. That measurement requires that the two photons interact with one another, but that interaction is extremely weak. There is a straightforward way around this problem when dealing with two dimensions, he says, but not for any higher number.

In two dimensions there are four possible Bell states, given that each photon can exist as a 1 or a 0: 00+11, 00-11, 01+10 and 01-10. Because three out of these four states are “symmetric” – meaning that switching the two particles leaves the combined wavefunction unchanged – the fourth “asymmetric” state can be unambiguously identified, allowing the state to be teleported successfully. However, in three dimensions there are nine possible states, three of which are antisymmetric, while the remaining six are neither symmetric nor antisymmetric.



​Teleporting photons in three dimensions (Courtesy: C-Y Lu)

To overcome this problem, the researchers built a complex network of linear optical components linking multiple inputs with multiple outputs. The trick was to tap four different photons – the one to be teleported, the two being entangled and an extra one to enable successful Bell-state measurements. The photons were generated by a pulsed ultraviolet laser and then split along three different paths – to represent the three dimensions – with the three photons at Alice’s end then interfering with one another. The patterns of clicks from detectors recording the interferometers’ output revealed whether the three photons had been projected into a specific Bell state and could therefore be used for teleportation.

In a paper posted on arXiv, and accepted for publication in _Physical Review Letters_, Lu and colleagues report having successfully teleported photons 75% of the time – by preparing the input photons in a known, specific state and comparing them with the teleported photons (a standard procedure in teleportation experiments). This fidelity of 0.75, they point out, is well above the upper limit of 0.5 possible without entanglement, as well as the 0.66 that could conceivably be achieved with qubits only.

*Towards higher dimensions*
Lu says that the scheme could be scaled up quite easily to four, five or more dimensions mainly by adding a few more beam splitters, although he reckons that integrating the components on a photonic chip might be more practical for very large numbers of dimensions. More generally, his group is now looking to combine these higher dimensions with multiple degrees of freedom to try to teleport complete particles. “That is a necessary step if we ever want to teleport complex systems,” he says.

Technologically, Lu says that high-dimensional teleportation could be used to extend quantum communication networks – potentially providing higher bandwidth, more secure repeaters than could be achieved using qubits. It might also speed up logic operations inside quantum computers, he reckons. What’s more, he says, higher-dimensional Bell tests could provide greater scrunity of Einstein’s idea of local realism, since they would yield an even more extreme difference between classical and quantum measurements.

Lu and colleagues are not the only researchers to have demonstrated higher-dimensional teleportation. Guang-Can Guo and co-workers, also based at the University of Science and Technology of China in Hefei, have likewise reported teleporting photons in three-dimensions. Their scheme was quite similar to Lu’s but relied on two extra photons to carry out the Bell state measurement, rather than one. They also appear to have achieved a slightly lower fidelity – reporting a figure of “above 0.63”.

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## JSCh

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*Physics - Synopsis: Quantum Teleportation Now Comes in 3D*
August 15, 2019

The first experiment to teleport qutrits rather than qubits paves the way to teleporting the complete quantum state of a particle.



R. Zhou/USTC

Quantum teleportation is the transfer of quantum information—for instance, a particle’s quantum state—between distant systems without moving a physical particle. All demonstrations of the phenomenon so far have transferred the state of a qubit—a simple two-level system. This is a far cry from teleporting the complete quantum state of a particle, involving multiple degrees of freedom, each with many possible values. A collaboration between groups at the University of Science and Technology of China, Hefei, and at the University of Vienna has taken a step towards that goal by demonstrating the transfer of a 3D quantum state, or qutrit.

The team shared a pair of entangled photons between the transmitter (Alice) and the receiver (Bob). Each photon could take one of three possible paths whose superposition yielded a 3D entangled state, a qutrit. An additional photon at Alice’s end—also in a 3D quantum state—provided the state to be teleported. The researchers made this third photon interfere with Alice’s half of the entangled pair and performed a state measurement on all three. This measurement resulted in the transfer of the 3D state to the photon held by Bob.

The scheme may be useful in high-speed quantum communications, since a qutrit can carry more information than a qubit. The approach could be generalized to teleport quantum states involving any degree of freedom with more than two levels (photon orbital angular momentum, for example). The authors also suggest that they could extend their scheme to an arbitrarily high number of dimensions by adding more paths for the photons. These features could eventually allow the complete state of a complex quantum particle to be transferred.

This research is published in _Physical Review Letters_.

–Marric Stephens
Marric Stephens is a freelance science writer based in Bristol, UK.

*Quantum Teleportation in High Dimensions*
Yi-Han Luo, Han-Sen Zhong, Manuel Erhard, Xi-Lin Wang, Li-Chao Peng, Mario Krenn, Xiao Jiang, Li Li, Nai-Le Liu, Chao-Yang Lu, Anton Zeilinger, and Jian-Wei Pan

Phys. Rev. Lett. 123, 070505 (2019)

Published August 15, 2019​

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## JSCh

*Physics - Synopsis: Long-Haul Quantum Key Distribution*
September 5, 2019

Two independent studies demonstrate the practicality of twin-field quantum key distribution—a promising approach to performing quantum cryptography over long distances.


Micius Saloon

Governments and corporations are investing in quantum key distribution (QKD)—a theoretically invulnerable encryption technology—but several barriers still hamper its application. In particular, light attenuation in the optical fibers carrying the quantum signals limits the range over which QKD can work. Recently, researchers have demonstrated an alternative approach—“twin-field” QKD—that could potentially extend QKD’s range by hundreds of kilometers. Its practicality, however, remains questionable. Now, two independent groups, led by Jian-Wei Pan at the University of Science and Technology of China in Shanghai and by Hoi-Kwong Lo at the University of Toronto, have brought the method’s application a step closer by solving a key practical problem.

In the twin-field technique, two distant parties (“Alice” and “Bob”) encode qubits in single photons, which are made to interfere at the detectors of an intermediary (“Charlie”). Theory shows that the better performance, compared to standard QKD, stems from the rate at which transmission encryption keys can be exchanged: this rate scales more favorably with distance in the twin-field version. The scheme is difficult to implement, however, because quantum interference requires that the single photons generated by remote sources maintain their phase over large distances.

The teams demonstrate two ways of addressing this challenge. Pan’s team uses a stable cavity to lock the phase of Alice and Bob’s independent lasers. With such sources, they provide the first demonstration of twin-field QKD in a real optical fiber, reaching distances of up to 300 km. Lo’s group uses instead an interferometric configuration in which light travels both ways in an optical fiber loop, automatically compensating for phase fluctuations. Their scheme simplifies the twin-field QKD setup by removing the need for complex active circuitry for phase stabilization. Both experiments show that twin-field QKD breaks fundamental rate-distance limits that apply to standard QKD.

This research is published in _Physical Review Letters_.

–Matteo Rini
Matteo Rini is the Deputy Editor of _Physics_.


*Experimental Twin-Field Quantum Key Distribution through Sending or Not Sending*
Yang Liu, Zong-Wen Yu, Weijun Zhang, Jian-Yu Guan, Jiu-Peng Chen, Chi Zhang, Xiao-Long Hu, Hao Li, Cong Jiang, Jin Lin, Teng-Yun Chen, Lixing You, Zhen Wang, Xiang-Bin Wang, Qiang Zhang, and Jian-Wei Pan

Phys. Rev. Lett. 123, 100505 (2019)

Published September 5, 2019


*Proof-of-Principle Experimental Demonstration of Twin-Field Type Quantum Key Distribution*
Xiaoqing Zhong, Jianyong Hu, Marcos Curty, Li Qian, and Hoi-Kwong Lo

Phys. Rev. Lett. 123, 100506 (2019)

Published September 5, 2019

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## JSCh

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*Scientists Verify Feasibility of Long-distance Twin-field Quantum Key Distribution---Chinese Academy of Sciences*
Sep 18, 2019

Quantum key distribution (QKD) can offer secure private communication. However, there are still some technical limitations on practical long distance quantum communication, among which channel loss and the detector noise are two most severe limitations, given that quantum signals cannot be amplified. 

The new-found twin-field QKD (TFQKD) increases the relationship between code rate and distance from the linear relationship of general QKD to the square root level. Therefore, the code distance far beyond the general QKD scheme can be obtained, and theoretically the code rate far higher than the general QKD scheme can be obtained, which provides a new direction for long-distance, high-performance QKD. However, the demanding conditions for the experimental implementation of the TFQKD scheme are hard to realize. 

Recently, a research team led by Prof. PAN Jianwei, Prof. ZHANG Qiang and Prof. LIU Yang from the University of Science and Technology of China of the Chinese Academy of Sciences (CAS), and the collaborators from Tsinghua University and Shanghai Institute of Microsystem and Information Technology of CAS, demonstrated TFQKD through the sending-or-not-sending protocol with a realistic phase drift over 300 km optical fiber spools on the basis of a single photon detector with a high detection rate. 

The researchers realized the TFQKD on a 300-kilometer fiber channel with a sharp phase change in the real environment. Taking theoretical requirements such as statistical fluctuation and finite length analysis into consideration, they made the key generation rate reach at 300 km. The key generation rate is 50 times than that of the 2016 experiment and broke the theoretical limit of the highest rate of code for the general non-relay QKD scheme.

This study demonstrated the generation of secure keys at fiber distances of up to 300 km, yielding a higher key rate than the repeater less secret key capacity. The key rate calculation guaranteed the security in a practical situation. With existing technology and the results of theoretical simulations with practical parameters, the researchers expect that distribution distances of more than 500 km can be achieved in the near future. 

Besides, this study verified the feasibility of the long-distance TFQKD scheme, and proved that the scheme has long-distance, high-code-rate performance and is very suitable for using in inter-city quantum key distribution backbone links.

Compared with the existing published TFQKD experiment, this study is the only one that considers the finite code length effect. In addition, the researchers also analyzed that the program can perform long-distance QKD over 700 kilometers under conditions such as improved detector performance. 

The study, published in _Physical Review Letters,_ was selected as the "Editor's Choice" by the _Physical Review Letter_, and featured highlights by Physics of American Physical Society.

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## JSCh

*QuantumCTek Gets Go-Ahead for China's First Quantum Coms IPO*
TANG SHIHUA
DATE : NOV 14 2019/SOURCE : YICAI





QuantumCTek Gets Go-Ahead for China's First Quantum Coms IPO​
(Yicai Global) Nov. 14 -- QuantumCTek may become the first quantum communications company to get listed in China.

QuantumCTek got the green light to go public on Shanghai's Star Market, the Shanghai Stock Exchange said in a statement yesterday. The Star Market is the eastern city's new Nasdaq-style tech board.

The firm plans to raise CNY304 million (USD43.3 million) by issuing 20 million shares, the Hefei-based developer of quantum information products said in its prospectus. More than four-fifths of that will be used for a network equipment project and the rest to build a research & development center.

Founded in 2009, QuantumCTek has independent intellectual property rights on core quantum cryptography technologies and its clients include related network builders and system integrators, according to its prospectus.

China has been exploring long-distance quantum communications for many years. In 2016, a pioneering Pan Jianwei-led team sent the Micius satellite, named after an ancient Chinese philosopher, to space to help develop safer and more efficient ways of transmitting information. Pan, an academician of the Chinese Academy of Sciences, has an 11 percent stake in QuantumCTek. 

However, the controlling equity holder of QuantumCTek is the asset management unit of Hefei's University of Science and Technology of China, a leader in the scientific field, holding an 18 percent stake.

QuantumCTek posted CNY295.6 million revenue and CNY32.4 million in net profit in the first three quarters of this year, its filing shows.

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## JSCh

*我国首个可移动量子卫星地面站与“墨子号”成功实现空地握手*
2019-12-31 17:16:00

12月30日晚，重量仅80多公斤的小型化可移动量子卫星地面站，通过卫星设备，成功与经过中国上空、距离地面500公里的“墨子号”量子卫星实现了对接。标志着我国在量子通信产业化、工程化领域迈出重要一步。

23时31分44秒，量子卫星地面站经过自动搜寻实现了与“墨子号”卫星的对接，完成对接后，地面站对“墨子号”分发的量子密匙，进行量子保密通信，整个对接过程持续了近8分钟。

*China's First Portable/Mobile Quantum Satellite Ground Station and Micius Satellite Successfully Realize Air-to-ground Handshake*
2019-12-31 17:16:00

On the evening of December 30, a miniaturized mobile quantum satellite ground station weighing only over 80 kilograms successfully connect through satellite equipment with the Micius or Mozi quantum satellite passing 500 kilometers above China. It indicates that China has taken an important step in the industrialization and engineering of quantum communication.

At 23:31:44, the quantum satellite ground station automatically searched and achieve linkage with the Mozi satellite. After the connection was completed, the ground station performed quantum encrypted communication with the quantum key distributed by Mozi. The communication process lasted nearly 8 minutes.

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## JSCh

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*China tests world's 1st mobile quantum satellite ground station*
By Deng Xiaoci Source:Global Times Published: 2020/1/1 17:38:41



Composite photo taken on Dec. 9, 2016 shows a satellite-to-earth link established between quantum satellite "Micius" and the quantum teleportation experiment platform in Ali, southwest China's Tibet Autonomous Region.(Xinhua/Jin Liwang)

China's Quantum Experiments at Space Scale, or better known as the Micius, have successfully conducted an eight-minute-long encrypted data transmission with a mobile ground station, marking a world's first.

A Global Times reporter learned from the project research team on Wednesday that the successful space-ground quantum communication experiment was conducted around midnight on Monday in Jinan, East China's Shandong Province. The project is led by Pan Jianwei, a quantum physicist from the University of Science and Technology of China (UTSC).

The mobile quantum satellite ground station weighing slightly over 80 kilograms and the size of a paint bucket, was jointly developed by the UTSC, QuantumC Tek, a leading manufacturer and provider of QIT-enabled ICT security products and services and the Jinan Institute of Quantum Technology. It is the first of its kind in the world. 

Pan's team said the development of the ground station started in 2019, and was completed on December 24. The successful communication with the Micius satellite marked the completion of construction of China's first mobile quantum satellite ground station.

The transmission lasted some eight minutes, and a great amount of encrypted information was sent to the ground station, the team said.

The previous ground station for the Micius satellite weighed more than 10 tons. Developers conducted hundreds of experiments in order to miniaturize the ground station.

The mobile version of the ground station can be installed on a vehicle, work anytime and anywhere, and its significantly reduced manufacturing cost paves the way for mass production in the future, the team said.

An experimental quantum communication network has already connected to the "Beijing-Shanghai Backbone" quantum communication link forming a national network, Pan's team said.

The project includes verifications and equipment based on key technologies used in long-distance quantum communications.

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## JSCh

*China is developing drones that use quantum physics to send unhackable messages*

Particles can carry information securely because intercepting them would alter the message and alert the receiver or sender
Researchers in Nanjing have condensed the quantum equipment and packed it into a drone
Stephen Chen in Beijing
Published: 5:15am, 10 Jan, 2020

Chinese scientists say they have developed the world’s first fleet of drones equipped with quantum communication technology so that robots can share information securely with each other and human operators.

Researchers at Nanjing University, in eastern China, built drones able to generate pairs of “entangled” particles of light that could carry information in quantum states such as charges or polarisations representing 0 or 1, according to their paper published this month in the journal _National Science Review_.


....

China is developing drones that use quantum physics to send unhackable messages | South China Morning Post

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## JSCh

*Mixing Quantum States Boosts Fiber Communications*
By Neil Savage
Posted 24 Jan 2020 | 19:00 GMT



Photo: Wits University

It’s difficult to send quantum information over the fiber-optic networks that carry most of the world’s data, but being able to would allow people to encrypt their messages with secret codes made unbreakable by the laws of physics. Now researchers have found a way to allow the transmission of such codes over long distances, by combining different quantum properties on the same photons.

Quantum communications works through a process called entanglement, which creates a pair of photons with complementary properties—one might be polarized so its waves move horizontally, while its twin is vertically polarized. Because the two are linked, determining the property of one automatically tells you the property of the other, no matter how far apart they are. It allows for secure communications, because if someone intercepts a photon and reads it, that action changes the photon, exposing the interception.

Another quantum property is orbital angular momentum (OAM), which looks like the spiral path around a corkscrew. OAM comes in an infinite set of patterns of electromagnetic waves, so it could encode vastly more information than the simple on/off of polarization states. The problem is that one type of fiber, single-mode, can only carry one pattern, or mode, at a time, limiting its capacity. The other type, multimode fiber, can carry many patterns, but over distance they tend to transfer energy among them, destroying the quantum information; the furthest entangled states have traveled over standard multimode fiber is about 1 meter.

Researchers Jian Wang of Huazhong University of Science and Technology in Wuhan, China, and Andrew Forbes of University of the Witwatersrand, South Africa, have combined polarization and OAM into a hybrid state on their entangled photons. In the latest issue of _Science Advances_, they describe how they first split one photon into two lower-energy photons, A and B, with different OAMs. They then pass photon A through a set of optics that gives it a particular polarization. Because the polarization state is just one mode, they can send it along a 250-meter-long single-mode fiber.



Illustration: Wits University
Two photons are entangled in this illustration—one in polarization and the other in orbital angular momentum (or twisted light). By passing the first photon through fiber and keeping the other one in air, it’s possible to transport multiple dimensions of entanglement even over single-mode fiber.

They send the photons to separate detectors, and measure the polarization of photon A and the OAM of photon B. Because the two are entangled, information about photon B has been carried through the fiber by photon A. “The trick works because the photons don’t know what they are until we measure them, so the state is unaware that we have multiple patterns in the game,” Forbes says. “But by the time we measure them and indicate the patterns, the one photon has already passed through the fiber.”

The trick essentially expands the alphabet of quantum states that can encode information. Forbes says it’s similar to how having multiple quantum bits in a quantum computer quickly add up to extraordinary computing power; a machine with roughly 60 qubits can outperform a supercomputer.

Now it’s up to researchers to develop communications protocols that can take advantage of this new technique. And Forbes expects to reach greater transmission distances than the 250 meters of their demonstration. “It should be possible to get across 100 km of fiber, which would make it practical,” he says.


Mixing Quantum States Boosts Fiber Communications - IEEE Spectrum


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## JSCh

*Record-breaking quantum memory brings quantum internet one step closer*
12 February 2020
By Leah Crane



Optic fibres could be used to build a quantum internet
Federico Caputo / Alamy

Two clouds of atoms that store quantum information, called quantum memories, have been connected across a longer distance than ever before. They could prove useful for building a quantum version of the internet

Quantum communication relies on a phenomenon called entanglement. When a pair of particles or systems are quantum entangled, measuring one of them instantly influences the measured state of the other, regardless of the distance between them.

These connections can’t directly transfer information, because that would mean information is travelling faster than light, but entanglement can be used to create encrypted communications channels, secured against hacking by the laws of quantum physics.

Individual photons have been entangled across distances exceeding 1000 kilometres, but for larger systems of particles, which hold more information, maintaining this entanglement is harder. The maximum distance between a pair of entangled quantum memories so far is just 1.3 kilometres.

Xiao-Hui Bao at the University of Science and Technology of China and his colleagues have now smashed that record, entangling two quantum memories over 22 kilometres of fibre-optic cable installed underground.

Their quantum memories were each made of about 100 million extremely cold rubidium atoms in a vacuum chamber. The quantum state of each system of atoms was entangled with the state of a single photon, and the researchers sent those photons through the fibre-optic cables.

When a particular observation called a Bell measurement was performed on the two photons simultaneously, the quantum memories with which the photons were paired before the measurement became entangled to one another.

In a slightly different experiment using cables that weren’t installed underground but just coiled up in the lab, Bao and his team entangled quantum memories across 50 kilometres.

The end goal of this work is to create a quantum repeater that can receive and then retransmit quantum information so that it can be sent over long distances, eventually building up a secure internet of quantum information.

“Honestly, there is still a long way to go in order to see the quantum repeater working in real long-distance situations,” says Bao, but he thinks that building a small-scale prototype quantum network using quantum memories will be possible in the next few years.

Journal reference: _Nature_, DOI: 10.1038/s41586-020-1976-7



Record-breaking quantum memory brings quantum internet one step closer | New Scientist

Yong Yu, Fei Ma, Xi-Yu Luo, Bo Jing, Peng-Fei Sun, Ren-Zhou Fang, Chao-Wei Yang, Hui Liu, Ming-Yang Zheng, Xiu-Ping Xie, Wei-Jun Zhang, Li-Xing You, Zhen Wang, Teng-Yun Chen, Qiang Zhang, Xiao-Hui Bao & Jian-Wei Pan. *Entanglement of two quantum memories via fibres over dozens of kilometres*. _Nature _(2020). DOI: 10.1038/s41586-020-1976-7​

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## JSCh

*Sending-or-Not-Sending with Independent Lasers: Secure Twin-Field Quantum Key Distribution over 509 km*
Jiu-Peng Chen, Chi Zhang, Yang Liu, Cong Jiang, Weijun Zhang, Xiao-Long Hu, Jian-Yu Guan, Zong-Wen Yu, Hai Xu, Jin Lin, Ming-Jun Li, Hao Chen, Hao Li, Lixing You, Zhen Wang, Xiang-Bin Wang, Qiang Zhang, and Jian-Wei Pan

*Phys. Rev. Lett. 124, 070501 – Published 20 February 2020*

*ABSTRACT*
Twin-field (TF) quantum key distribution (QKD) promises high key rates over long distances to beat the rate-distance limit. Here, applying the sending-or-not-sending TF QKD protocol, we experimentally demonstrate a secure key distribution that breaks the absolute key-rate limit of repeaterless QKD over a 509-km-long ultralow loss optical fiber. Two independent lasers are used as sources with remote-frequency-locking technique over the 500-km fiber distance. Practical optical fibers are used as the optical path with appropriate noise filtering; and finite-key effects are considered in the key-rate analysis. The secure key rate obtained at 509 km is more than seven times higher than the relative bound of repeaterless QKD for the same detection loss. The achieved secure key rate is also higher than that of a traditional QKD protocol running with a perfect repeaterless QKD device, even for an infinite number of sent pulses. Our result shows that the protocol and technologies applied in this experiment enable TF QKD to achieve a high secure key rate over a long distribution distance, and is therefore practically useful for field implementation of intercity QKD.


Phys. Rev. Lett. 124, 070501 (2020) - Sending-or-Not-Sending with Independent Lasers: Secure Twin-Field Quantum Key Distribution over 509 km

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## JSCh

↑↑↑
MARCH 9, 2020 
*Study achieves a new record fiber QKD transmission distance of over 509 km*
by Ingrid Fadelli , Phys.org

The sending-or-not-sending twin-field (SNS-TF) protocol has so far proved to be a highly promising strategy for achieving high rates over long distances in quantum key distribution (QKD) applications. In fact, by tolerating large misalignment errors, this protocol can surpass the repeaterless bound in more effective ways, which is a crucial factor in the realization of long-distance QKD.

Jian-Wei Pan, Qiang Zhang, Xiang-Bin Wang and other researchers at the University of Science and Technology of China and Tsinghua University have recently achieved an unprecedented QKD transmission distance using the SNS-TF protocol. Their paper, published in _Physical Review Letters_, reports QKD with a secure key distribution breaking the repeaterless bound over a 509-km-long optical fiber.


...

https://phys.org/news/2020-03-fiber-qkd-transmission-distance-km.html

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## JSCh

__ https://twitter.com/i/web/status/1239751158564093952

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## JSCh

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*One-kilometer Breakthrough Made in Quantum Field----Chinese Academy of Sciences*
By ZHANG Nannan | Mar 20, 2020

A team led by Prof. GUO Guangcan from University of Science and Technology of China (USTC) of the Chinese Academy of Sciences (CAS) and collaborators first realized distribution of high-dimensional orbital angular momentum entanglement over a 1 km few-mode fiber. The result is published in _Optica._

Increasing the channel capacity and tolerance to noise in quantum communications is a strong practical motivation for encoding quantum information in multilevel systems, qudits as opposed to qubits. From a foundational perspective, entanglement in higher dimensions exhibits more complex structures and stronger non-classical correlations. High-dimensional entanglement has demonstrated its potential for increasing channel capacity and resistance to noise in quantum information processing. Despite these benefits, the distribution of high-dimensional entanglement is relatively new and remains challenging. 

The orbital angular momentum of photon is a high dimensional system which has been paid much attention to in recent years. However, orbital angular momentum entanglement is susceptible to atmospheric turbulence or mode crosstalk and mode dispersion in optical fibers. It can only transmit a few meters, and is limited to two-dimensional entanglement distribution.

In this work, researchers reported the first distribution of three-dimensional orbital angular momentum (OAM) entanglement via a 1-km-long few-mode optical fiber.

Using an actively stabilizing phase precompensation technique, they successfully transported one photon of a three-dimensional OAM entangled photon pair through the fiber. With their measures, they are able to certify three-dimensional entanglement via a fidelity to the three-dimensional maximally entangled state (MES) of 0.71, and a violation of a Collins–Gisin–Linden–Massar–Popescu (CGLMP) inequality.

In addition, they certified that the high-dimensional quantum entanglement survives the transportation by violating a generalized Bell inequality, obtaining a violation of ～ 3 standard deviations.

They showed that preserving the wavefront is possible with precompensation, potentially enabling further information processing after the fiber. The method developed can be extended to a higher OAM dimension and larger distances in principle. 

Their work is a significant step forward for distributing high-dimensional entanglement in the transverse spatial modes of photons. In the future, they hope that together with recent results on the noise resilience exploiting higher dimensions, the work will motivate further experimental research into novel protocols that involve long-distance high-dimensional quantum communications through fiber.



Schematic of the experimental setup for high-dimensional orbital angular momentum entanglement distribution. (Image by CAO Huan and other researchers)


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## JSCh

__ https://twitter.com/i/web/status/1259874615750529025


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## JSCh

15 Jun 2020 | 15:00 GMT
*Quantum Satellite Links Extend More Than 1,000 Kilometers*
*New system one step closer to practical quantum cryptography*
By Charles Q. Choi

A space-based, virtually unhackable quantum Internet may be one step closer to reality due to satellite experiments that linked ground stations more than 1,000 kilometers apart, a new study finds.

...

Quantum Satellite Links Extend More Than 1,000 Kilometers - IEEE Spectrum


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## JSCh

↑↑↑
*Scientists set milestone in quantum tech*
By Zhang Zhihao | China Daily | Updated: 2020-06-16 09:20




Quantum scientist Pan Jianwei works in the quantum lab of the Univerisity of Science and Technology of China on April 20, 2017. [Photo/Xinhua]

Chinese scientists have achieved the world's first quantum key distribution over 1,120 kilometers without relying on any intermediate security relays, according to a study published in the journal _Nature _on Monday.

Experts said this represents a major milestone in building a practical global-scale, ultra-secure quantum internet, but the actual technology might still be years away.

Quantum key distribution, known as QKD, is a technique used to achieve secure communication that uses cryptographic protocols based on the laws of quantum mechanics. Today's QKD is mostly conducted through optical fibers on the ground, with few exceptions using quantum satellites.

These protocols can generate secret security keys that enable more secured data transfer between devices by allowing authorities to spot eavesdroppers trying to intercept communications.

"QKD is theoretically highly secured. But in reality, imperfections in equipment such as photon sources and detectors may lead to security risks," said Pan Jianwei, noted quantum physicist and the lead scientist behind the study.

Moreover, QKD via optical fibers are susceptible to interference and cannot be sent over ultralong distance without relying on intermediate repeaters to boost the signals, he said.

To tackle these issues, Pan and his team tested a new QKD protocol method that uses satellites instead of ground-based relays.

They achieved this by using China's quantum science satellite Micius to send a secret key at the rate of 0.12 bits per second between the ground stations at Delingha and Urumqi, separated by around 1,120 kilometers.

Peer-reviewed comments called the study a "groundbreaking experiment", and a "significant step toward establishing a global network for QKD, and more generally, a quantum internet for quantum communication."

Gilles Brassard, one of the founders of quantum cryptography, said if the technology for secured, long distance quantum communication finally arrives, "this would achieve the Holy Grail that all cryptographers have been dreaming of for thousands of years."

Wang Jianyu, a researcher from the Shanghai Institute of Technological Physics of the Chinese Academy of Sciences, said now that the study has proved that the new technique is technically feasible, the next step should be increasing its communication capacity to make it useful.

"It is still too soon to say when the technology will reach the mass market," he said. "But in the next three to five years, we might see another leap in this method's efficiency, and that might be enough to support a nation's financial and security communication needs."

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## JSCh

Academician and quantum physicist - Pan Jianwei in the picture of the article above, is the second biggest shareholder, with his holding now worth more that 2.4 billion yuan.

*QuantumCTek Sets China Stock Record, Rallying Up to 1,000% on First Trading Day*
XU WEI
DATE: 18 HOURS AGO / SOURCE: YICAI




QuantumCTek Sets China Stock Record, Rallying Up to 1,000% on First Trading Day​
(Yicai Global) July 9 -- QuantumCTek, a developer of quantum communications products, notched up China’s biggest ever first-day trading gain by surging as much as 1,000 percent in its Shanghai market debut.

Shares of QuantumCTek [SHA: 688027] closed at CNY370.45 (USD53.04) on the Nasdaq-style Star market, almost 924 percent higher than their initial offering price of CNY36.18 (USD5.18) each.

The previous record holder was Tinavi Medical Technologies, a Beijing-based medical devices maker, which shot up 614 percent in its Star Market debut just two days ago.

QuantumCTek’s stellar market entry comes amid a bull run. The CSI 300 index of Shanghai and Shenzhen-traded shares, a key gauge of mainland equities, climbed almost 7.7 percent last month and had climbed almost 14.7 percent this month as of yesterday.

Net profit at Hefei-based QuantumCTek slid 32 percent to CNY49.3 million (USD7.06 million) last year from 2018, after dipping 2.5 percent that year to CNY72.5 million. It had a net loss of CNY8.8 million in the first quarter of this year on a 5.5 percent decline in operating revenue from a year earlier to CNY1.5 million.

Editor: Peter Thomas


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## JSCh

*Chinese scientists implement the world’s first quantum secure direct communication system*
Source: Global Times Published: 2020/9/20 13:57:20



photo: web

A Chinese research team has implemented the world's first quantum secure direct communication (QSDC) system. The breakthrough provides a promising solution to counter threats in the area of communication security.

Beijing Academy of Quantum Information Sciences revealed at the 2020 ZGC Forum on Saturday that they have implemented the world's first QSDC system.

The present system can operate with a communication rate of 4kb/s at a distance of 10 kilometers, bringing QSDC further toward practical applications.

QSDC was proposed by Long Guilu, adjunct member of Beijing Academy of Quantum Information Sciences in 2000.

As an important branch of quantum communication, secret information can be directly transmitted without key distribution, which eliminates further security loopholes associated with key storage and attacks, according to Gui.

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## JSCh

*China speeds up construction of space-ground integrated quantum network*
By Pan Xutao (People's Daily Overseas Edition) 09:32, November 12, 2020



Photo taken on Nov. 9 shows the construction site of the quantum information and quantum technology innovation research institute of the Chinese Academy of Sciences (CAS) in the High-tech Industry Development Zone of Hefei, east China''s Anhui province. (People’s Daily Online/Ruan Xuefeng)

Origin Quantum Computing Technology Co., Ltd., one of the over 20 quantum-related companies densely distributed along the 2,000-meter-long “quantum avenue”, or Yunfei Road, in the High-tech Industry Development Zone of Hefei, east China’s Anhui province, has almost been overwhelmed by various capital that came to it in the recent month.

“More than 30 investment institutions came to us, and eventually we chose 11 of them,” said Zhang Hui, vice president of the company. In the past, the man had to toss about the country for financing.

Government departments at different levels have also reached the company to offer help, according to Zhang.

“Many government departments visited our company for investigation and inspection, aiming to discuss and formulate industrial policies and help us solve practical difficulties,” Zhang noted, who has been invigorated by such efforts.

On Oct. 16, the Political Bureau of the Communist Party of China (CPC) Central Committee held the 24th group study session on the research and application of quantum science and technology.

The session has promoted strategic planning and forward-looking layout for the development of quantum science and technology in China, signaling an important period of development opportunities for the application of quantum science and technology, according to Zhang.

The applications of quantum science and technology specifically involve three fields: quantum communication, quantum computation and quantum precision measurement.

China is among the global leaders in the field of quantum communication.

According to the Ministry of Science and Technology (MOST), China has made a great number of major new and high-tech achievements during the 13th Five-Year Plan period (2016-2020).

Experiments including the quantum science satellite Mozi and the quantum communication line between Beijing and Shanghai conducted by Chinese scientists have enabled the country to build the prototype of the first space-ground integrated quantum communication network, said Qin Yong, director-general of the Department of High and New Technology of the MOST at a press conference held by the State Council Information Office on Oct. 21.

Quantum computation is also an important field for applications of quantum science and technology.

On the whole, China is at the same level with developed countries in the field of quantum computation, according to Pan Jianwei, executive vice president of the University of Science and Technology of China (USTC) and academician at the Chinese Academy of Sciences (CAS).

The research and development of quantum computers is a hotspot of the current international competition in the area of science and technology.

At the end of 2019, Chinese scientists teamed up with their counterparts from Germany and the Netherlands and realized the Boson sampling quantum computation by feeding 20 photons into a 60×60 mode interferometer for the first time in the world, setting new world records in four key indicators.

There is still a gap between China and developed countries in the field of quantum precision measurement, but the country is seeing rapid development in the field, Pan said.

In October this year, the USTC announced that its research team, in cooperation with scientists from the U.S. and Germany, observed strength compression on single-photon source devices with high purity, high indistinguishability and high efficiency.

The discovery, while marking the first time that scientists directly observed strength compression in the system after 20 years of efforts, has laid a foundation for single-photon sources-based quantum precision measurement and represented an important progress in the field of quantum precision measurement.

At present, theoretical research results in quantum science and technology are adapted for practical use and engineering at a faster pace, while more and more enterprises are joining in the force driving the development of quantum science and technology.

Among the three major fields for the application of quantum science and technology, quantum communication has witnessed the most commercial results and the birth of a lot of upstream and downstream firms in the field.

Compared with quantum communication, the value of quantum computation is yet to be brought into full play through practical applications.

However, quantum computation is regarded as the key engine of the next generation of information revolution, as it enjoys great prospects in such areas as cryptanalysis, weather forecast, oil exploration, as well as drug design.

Although it takes time to realize large-scale application of quantum computation, many companies are speeding up efforts in the field to seize the initiative in the development of relevant applications.

Back in 2015, Aliyun, Alibaba’s cloud computing subsidiary, joined hands with the CAS to start exploration of quantum computation. Later, Alibaba established a quantum computing lab.

In September 2019, the quantum computing lab completed the development task of the first controllable quantum bit.

Quantum precision measurement seems more mysterious compared with quantum communication and quantum computation.

Quantum measurement can help precisely monitor electric current and voltage in power grid. When used in prospection, quantum measurement can enable people to measure the geological composition of the surrounding area during well drilling. In addition, quantum measurement can help conduct accurate analysis of the content of trace substances in blood.

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## JSCh

__ https://twitter.com/i/web/status/1341777945086615556








Securing a Wireless Link with Quantum Physics


Researchers shared tamper-proof quantum information across nearly 20 km of open air in an urban environment.




physics.aps.org

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## JSCh

JANUARY 6, 2021
*The world's first integrated quantum communication network*
by University of Science and Technology of China



Chinese scientists have established the world's first integrated quantum communication network, combining over 700 optical fibers on the ground with two ground-to-satellite links to achieve quantum key distribution over a total distance of 4,600 kilometers for users across the country. Credit: University of Science and Technology of China

Chinese scientists have established the world's first integrated quantum communication network, combining over 700 optical fibers on the ground with two ground-to-satellite links to achieve quantum key distribution over a total distance of 4,600 kilometers for users across the country. The team, led by Jianwei Pan, Yuao Chen, Chengzhi Peng from the University of Science and Technology of China in Hefei, reported in _Nature_ their latest advances towards the global, practical application of such a network for future communications.

Unlike conventional encryption, quantum communication is considered unhackable and therefore the future of secure information transfer for banks, power grids and other sectors. The core of quantum communication is quantum key distribution (QKD), which uses the quantum states of particles—e.g. photons—to form a string of zeros and ones, while any eavesdropping between the sender and the receiver will change this string or key and be noticed immediately. So far, the most common QKD technology uses optical fibers for transmissions over several hundred kilometers, with high stability but considerable channel loss. Another major QKD technology uses the free space between satellites and ground stations for thousand-kilometer-level transmissions. In 2016, China launched the world's first quantum communication satellite (QUESS, or Mozi/Micius) and achieved QKD with two ground stations which are 2,600 km apart. In 2017, an over 2,000-km long optical fiber network was completed for QKD between Beijing and Shanghai.

Using trusted relays, the ground-based fiber network and the satellite-to-ground links were integrated to serve more than 150 industrial users across China, including state and local banks, municipal power grids, and e-government websites. "Our work shows that quantum communication technology is sufficiently mature for large-scale practical applications," said Jianwei Pan, Professor of USTC. Similarly, a global quantum communication network can be established if national quantum networks from different countries are combined, and if universities, institutions and companies come together to standardize related protocols, hardware, etc., he added.

In the last couple of years, the team extensively tested and improved the performance of different parts of the integrated network. For instance, with an increased clock rate and more efficient QKD protocol, the satellite-to-ground QKD now has an average key generation rate of 47.8 kilobits per second, which is 40 times higher than the previous rate. The researchers have also pushed the record for ground-based QKD to beyond 500 km using a new technology called twin-field QKD (TF-QKD).

Next up, the team will further expand the network in China and with their international partners from Austria, Italy, Russia and Canada. They also aim to develop small-scale, cost-efficient QKD satellites and ground-based receivers, as well as medium and high earth orbit satellites to achieve all-time, ten-thousand-km-level QKD.









The world's first integrated quantum communication network


Chinese scientists have established the world's first integrated quantum communication network, combining over 700 optical fibers on the ground with two ground-to-satellite links to achieve quantum key distribution over a total distance of 4,600 kilometers for users across the country. The team...




phys.org

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## JSCh

__ https://twitter.com/i/web/status/1347586610888646656PhysOrg Physics News @physorg_physics

Researchers realize efficient generation of high-dimensional quantum #teleportation

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## JSCh

JSCh said:


> *China is developing drones that use quantum physics to send unhackable messages*
> 
> Particles can carry information securely because intercepting them would alter the message and alert the receiver or sender
> Researchers in Nanjing have condensed the quantum equipment and packed it into a drone
> Stephen Chen in Beijing
> Published: 5:15am, 10 Jan, 2020
> 
> Chinese scientists say they have developed the world’s first fleet of drones equipped with quantum communication technology so that robots can share information securely with each other and human operators.
> 
> Researchers at Nanjing University, in eastern China, built drones able to generate pairs of “entangled” particles of light that could carry information in quantum states such as charges or polarisations representing 0 or 1, according to their paper published this month in the journal _National Science Review_.
> 
> 
> ....
> 
> China is developing drones that use quantum physics to send unhackable messages | South China Morning Post




__ https://twitter.com/i/web/status/1350147520387837952

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## TaiShang

According to the University of Science and Technology of China (USTC), important new progress has been made in the research of quantum communication and quantum networks. Taking advantage of high-quality entangled photon pair sources, scientists have realized long-distance quantum entanglement purification through 11 km fiber for the first time, with purification efficiency more than 6,000 times higher than the international level.

The work was conducted by a research group headed by Li Chuanfeng and Liu Biheng as part of Academician Guo Guangcan's team at USTC, in cooperation with researchers from Nanjing University of Posts and Telecommunications. The results were published in the internationally renowned journal Physical Review Letters on Jan. 8.

High-quality long-distance entanglement is essential for both quantum communication and scalable quantum networks. The previous significant entanglement purification experiments require two pairs of low-quality entangled states and were demonstrated in tabletop.

The USTC researchers proposed a high-efficiency and long-distance entanglement purification using only one pair of hyperentangled state. In their studies, one pair of polarization spatial-mode hyperentanglement was distributed over 11 km multicore fiber (noisy channel).

The results show that after purification, the fidelity of polarization entanglement increased from 0.771 to 0.887. Moreover, by using one pair of hyperentanglement, the total purification efficiency can be estimated as 6.6×103 times the experiment using two pairs of entangled states with spontaneous parametric down-conversion sources.

The research results provide important technical support for the realization of highly efficient quantum relay in the future.



http://t.m.china.org.cn/convert/c_xyptxCvl.html

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## JSCh

__ https://twitter.com/i/web/status/1351546206556737539IEEE Spectrum @IEEESpectrum

The latest #quantum #cryptography system has notched an open-air milestone. Chinese researchers have hardened it such that receiving stations can even be hacked, and the cryptographic key will still get through, undisturbed.




New and Hardened Quantum Crypto System Notches​spectrum.ieee.org​
11:05 PM · Jan 19, 2021

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## JSCh

__ https://twitter.com/i/web/status/1390221714118770690Global Times @globaltimesnews
China state-affiliated media

#Exclusive: Chinese scientists achieve #quantum information masking in lab, enabling non-copyable keys hidden in quantum mixed states. This would lead the way to extremely secure communication, likely applicable in 5 to 10 years.



​Exclusive: Chinese scientists achieve quantum information masking, paving way for encrypted...​globaltimes.cn​​4:27 PM · May 6, 2021


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## JSCh

*Researchers Construct Multiplexed Quantum Repeater Based on Absorptive Quantum Memories*
Editor: LIU Jia | Jun 03, 2021
   
Chinese researchers realized an elementary link of a quantum repeater based on absorptive quantum memories (QMs) and demonstrated the multiplexed quantum repeater for the first time. The study was published in _Nature_.

The fundamental task of a quantum network is to distribute quantum entanglement between two remote locations. However, the transmission loss of optical fiber has limited the distance of entanglement distribution to approximately 100 km on the ground. Quantum repeaters can overcome this difficulty by dividing long-distance transmission into several short-distance elementary links. The entanglement of two end nodes of each link is created firstly. Then the entanglement distance is gradually expanded through entanglement swapping between each link.

--> Researchers Construct Multiplexed Quantum Repeater Based on Absorptive Quantum Memories----Chinese Academy of Sciences









Heralded entanglement distribution between two absorptive quantum memories - Nature


Heralded entanglement is realized between two solid-state absorptive quantum memories 3.5 metres apart and with a bandwidth of 1 gigahertz, and with a fidelity of approximately 80%.




www.nature.com

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## JSCh

Demonstrating Quantum Communication Under Realistic Conditions


Researchers achieve secure “real-world” quantum communication along 428 km of optical fiber, the longest terrestrial distance outside of a lab setting.




physics.aps.org












Field Test of Twin-Field Quantum Key Distribution through Sending-or-Not-Sending over 428 km


Researchers achieve secure ``real-world'' quantum communication along 428 km of optical fiber, the longest terrestrial distance outside of a lab setting.




journals.aps.org


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## JSCh

Radar ‘closer to spotting stealth jets’ with Chinese quantum project


Quantum particles in a man-made electromagnetic storm bounced back after hitting stealth object, increasing chance of detection, according to Tsinghua University team.




www.scmp.com

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## JSCh

City-wide quantum data network in China is the largest ever built


A quantum network linking 40 computers in Hefei, China, is the largest demonstration to date of how a future quantum internet might work




www.newscientist.com

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## JSCh

__ https://twitter.com/i/web/status/1440835805954461704








A 15-user quantum secure direct communication network - Light: Science & Applications


A 15-user quantum secure direct communication (QSDC) network is experimentally demonstrated, and any two users can perform QSDC task over 40 kilometers of optical fiber.




www.nature.com

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## JSCh

New record for fibre-based quantum key distribution. 

__ https://twitter.com/i/web/status/1483532035620696065

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## JSCh

Chinese scientists from Tsinghua University for the 1st time realized world's longest quantum secure direct communication distance over 100 km fiber with time-bin and phase quantum states, contributing to inter-city quantum secure direct communication under relay-less conditions.

__ https://twitter.com/i/web/status/1513743714698498048

__ https://twitter.com/i/web/status/1511919729341964289

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## JSCh

A fiber-based quantum cryptography network can moonlight as a vibration sensor system.

__ https://twitter.com/i/web/status/1521146648210071554


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## Song Hong

JSCh said:


> Chinese scientists from Tsinghua University for the 1st time realized world's longest quantum secure direct communication distance over 100 km fiber with time-bin and phase quantum states, contributing to inter-city quantum secure direct communication under relay-less conditions.
> 
> __ https://twitter.com/i/web/status/1513743714698498048
> 
> __ https://twitter.com/i/web/status/1511919729341964289




read this paper -- which is why I feel Quantum is a scam in most cases. I reckon it will not even reach 1k bps in 100 years.

The pre-requisite for spectral purity to excite photons or particles is incredibly large and very wasteful. FYI, I did quantum engineering in industries for 2 years.

********************************

This QSDC system has dispensed of quantum memory, and significantly increased the secure information rate as well. Explicitly, it realized secure transmission at *3.2 bps* through an 18 km fiber at a clock-rate of 1 MHz.


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## JSCh

Three research groups have independently performed proof-of-principle experiments of an unhackable quantum encryption method. Researchers call the demonstrations “a major breakthrough for cybersecurity.” Read the story by 
@sophurky

__ https://twitter.com/i/web/status/1552334472158265344


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## JSCh

Researchers have demonstrated an optically connected pair of entangled quantum memories separated by 12.5 km; the longest physical separation so far achieved.

__ https://twitter.com/i/web/status/1552672634114117632


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## JSCh

Compact QKD system paves the way to cost-effective #satellite-based quantum networks 
@opticalsociety

@OpticalSociety
https://doi.org/gqn4nc

__ https://twitter.com/i/web/status/1560319128279334912


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## JSCh

Paving the Way for Satellite Quantum Communications


A series of demonstrations by Micius—a low-orbit satellite with quantum capabilities—lays the groundwork for a satellite-based quantum communication network.




physics.aps.org


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## Splurgenxs

Song Hong said:


> read this paper -- which is why I feel Quantum is a scam in most cases. I reckon it will not even reach 1k bps in 100 years.
> 
> The pre-requisite for spectral purity to excite photons or particles is incredibly large and very wasteful. FYI, I did quantum engineering in industries for 2 years.


Why is it wasteful, is it not based on q coupling and splitting particles and measuring the state on the other end?


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## JSCh

Dawn of solid-state quantum networks


Researchers demonstrated high-visibility quantum interference between two independent semiconductor quantum dots — an important step toward scalable quantum networks



spie.org





__ https://twitter.com/i/web/status/1608278832556933120


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## K_Bin_W

MeshFree said:


> If the quantum communication is intercepted, the information contained will be destroyed automatically. Meanwhile, communicators know that this communication is intercepted.
> 
> That's the whole point because it cannot be intercepted,


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