Update: China claims record in quantum cat state
Mark LaPedus
5/28/2010 7:34 AM EDT
CHENGDU, China -- A research group in China recently claimed a new breakthrough and record in the so-called ''hyper-entangled Schrodinger cat state.''
In 1935, Austrian physicist Erwin Schrodinger proposed an experiment that took until the 21st century to test--namely, that a single atom could affect the state of macroscopic systems. In the experiment, the state of a single atom is linked with whether a cat in a box is alive or dead. Theoretically, the cat is both alive and dead until the state of the atom is measured, thereby sealing its fate.
The concept of Schrodinger cat states comes from a known paradox: ''There is a cat inside the box which can be simultaneously dead and alive. Although a macroscopic Schrodinger cat state does not exist in the macroworld, it does exist in the microscopic quantum world. Scientists can use photons or atoms to create such a state,'' according to the university.
Recently, the ten-qubit hyper-entangled Schrodinger cat state was generated by a research group from the Quantum Physics and Quantum Information (QPQI) Division of the Hefei National Laboratory for Physical Sciences at Microscale at the University of Science and Technology of China.
''The created state has the number of entangled quantum bits up to 10, breaking a world record of entangled state preparation,'' according to the university. ''Meanwhile, they also utilized the Schrodinger cat state to demonstrate ultra-fine phase measurement.''
Quantum entanglement is the crucial "resource" for quantum information processing, according to a paper. The work has implications for optical approaches to quantum computing and optical quantum metrology, according to the university.
In a quantum computer, a qubit, or quantum bit, takes on the property of being both a 1 and a 0 simultaneously -- a phenomenon called superposition — thereby speeding calculations by allowing operations to be performed on superimposed ones and zeros at the same time.