The classical-quantum boundary for correlations: Discord and related measures
The classical-quantum boundary for correlations: Discord and related measures
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DOI：
10.1103/revmodphys.84.1655
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发表时间：
2012-11-26
影响因子：
44.1
通讯作者：
Vedral, Vlatko
中科院分区：
文献类型：
--
作者：
Modi, Kavan;Brodutch, Aharon;Vedral, Vlatko
量子系统中非经典性的最佳特征之一是存在没有经典对应物的关联。在过去十年中，用于量化关联的量子部分和经典部分的不同方法是量子信息理论中研究较为活跃的课题之一。纠缠是这些关联中最显著的，但在许多情况下，非纠缠态也表现出非经典行为。因此，区分除纠缠之外的量子关联能更好地划分量子世界和经典世界，特别是在考虑混合态时。这里回顾了由量子失谐和其他相关度量所量化的经典和量子关联的不同概念。在前半部分，回顾了量子关联度量的数学性质，讨论了它们之间的相互关系以及它们共有的经典 - 量子划分。在后半部分，表明这些度量能够识别并量化在各种量子信息处理任务、量子热力学、开放系统动力学和多体物理学中偏离经典性的程度。结果表明，在许多情况下，量子关联表明量子方法相对于经典方法具有优势。美国物理学会
One of the best signatures of nonclassicality in a quantum system is the existence of correlations that have no classical counterpart. Different methods for quantifying the quantum and classical parts of correlations are among the more actively studied topics of quantum-information theory over the past decade. Entanglement is the most prominent of these correlations, but in many cases unentangled states exhibit nonclassical behavior too. Thus distinguishing quantum correlations other than entanglement provides a better division between the quantum and classical worlds, especially when considering mixed states. Here different notions of classical and quantum correlations quantified by quantum discord and other related measures are reviewed. In the first half, the mathematical properties of the measures of quantum correlations are reviewed, related to each other, and the classical-quantum division that is common among them is discussed. In the second half, it is shown that the measures identify and quantify the deviation from classicality in various quantum-information-processing tasks, quantum thermodynamics, open-system dynamics, and many-body physics. It is shown that in many cases quantum correlations indicate an advantage of quantum methods over classical ones.American Physical Society