Experimental investigation of classical and quantum correlations under decoherence.
It is well known that many operations in quantum information processing depend largely on a special kind of quantum correlation, that is, entanglement. However, there are also quantum tasks that display the quantum advantage without entanglement. Distinguishing classical and quantum correlations in quantum systems is therefore of both fundamental and practical importance. In consideration of the unavoidable interaction between correlated systems and the environment, understanding the dynamics of correlations would stimulate great interest. In this study, we investigate the dynamics of different kinds of bipartite correlations in an all-optical experimental setup. The sudden change in behaviour in the decay rates of correlations and their immunity against certain decoherences are shown. Moreover, quantum correlation is observed to be larger than classical correlation, which disproves the early conjecture that classical correlation is always greater than quantum correlation. Our observations may be important for quantum information processing.
Key Laboratory of Quantum Information, University of Science and Technology of China, CAS, Hefei 230026, China.
Jin-Shi
JS
Xu
Xiao-Ye
XY
Xu
Chuan-Feng
CF
Li
Cheng-Jie
CJ
Zhang
Xu-Bo
XB
Zou
Guang-Can
GC
Guo
D008962:Models, Theoretical; D055095:Optics and Photonics / Q000379:methods*; D011789:Quantum Theory