It is shown that a choice of degrees of freedom of a bipartite continuous variable system determines the amount of non-classical correlations (quantified by discord) in the system's state. Non-classical correlatio...It is shown that a choice of degrees of freedom of a bipartite continuous variable system determines the amount of non-classical correlations (quantified by discord) in the system's state. Non-classical correlations (that include entanglement as a special kind of correlations) are ubiquitous for such systems. For a quantum state, if there are not non-classical correlations (quantum discord is zero) for one, there are in general non-classical correlations (quantum discord is non-zero) for another set of the composite system's degrees of freedom. The physical relevance of this "quantum correlations relativity" is emphasized also in the more general context.展开更多
基金Supported by the National Fundamental Research Program under Grant No.2007CB925204the National Natural Science Foundation of China under Grant Nos.10775048 and 10325523the Education Committee of Hunan Province under Grant No.08W012
基金supported by Ministry of Science Serbia (Grant No. 171028)in partfor MD by the ICTP-SEENET-MTP grant PRJ-09 "Strings and Cosmology"in frame of the SEENET-MTP Network
文摘It is shown that a choice of degrees of freedom of a bipartite continuous variable system determines the amount of non-classical correlations (quantified by discord) in the system's state. Non-classical correlations (that include entanglement as a special kind of correlations) are ubiquitous for such systems. For a quantum state, if there are not non-classical correlations (quantum discord is zero) for one, there are in general non-classical correlations (quantum discord is non-zero) for another set of the composite system's degrees of freedom. The physical relevance of this "quantum correlations relativity" is emphasized also in the more general context.
