arXivDaily arXiv每日学术速递 周一至周五更新
arXiv周末暂无论文更新,休息一下吧,周末愉快~~
arXiv 1105.4115quant-ph
收藏

关联和纠缠的量子性

Quantumness of correlations and entanglement

A. R. Usha Devi, A. K. Rajagopal, Sudha

摘要:

本文探讨了在二分态的一部分上的广义测量方案,这将使所有可分态的集合不敏感,以便从更一般的角度理解相关性的量子性。这是通过采用与广义投影测量相关联的线性映射来完成的。广义测量对应于将一个密度矩阵映射到另一个密度矩阵的量子操作,保持其正性、厄米性和迹类。正算子值测度(POVM)--在文献中用于优化经典/quatnum相关性的测度--对应于完全正(CP)映射。另一类,不完全积极(NCP)的地图,在这里调查,在测量的背景下,第一次。结果表明,这样的NCP投射映射提供了一个新的线索,了解量子关联在一般设置。特别是,分离性经典二分法得到解决,只有当两类投影映射(CP和NCP)被纳入作为优化措施。一个明确的例子,一个可分离的状态-表现出非零quantimes不和谐时,可能的优化测量被限制到POVM-重新检查与此扩展计划,将NCP投影映射,以阐明这种方法的力量。

英文摘要:

Generalized measurement schemes on one part of bipartite states, which would leave the set of all separable states insensitive are explored here to understand quantumness of correlations in a more general perspecitve. This is done by employing linear maps associated with generalized projective measurements. A generalized measurement corresponds to a quantum operation mapping a density matrix to another density matrix, preserving its positivity, hermiticity and traceclass. The Positive Operator Valued Measure (POVM) -- employed earlier in the literature to optimize the measures of classical/quatnum correlations -- correspond to completely positive (CP) maps. The other class, the not completely positive (NCP) maps, are investigated here, in the context of measurements, for the first time. It is shown that that such NCP projective maps provide a new clue to the understanding the quantumness of correlations in a general setting. Especially, the separability-classicality dichotomy gets resolved only when both the classes of projective maps (CP and NCP) are incorporated as optimizing measurements. An explicit example of a separable state -- exhibiting non-zero quantumn discord when possible optimizing measurements are restricted to POVMs -- is re-examined with this extended scheme incorporating NCP projective maps to elucidate the power of this approach.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑