Entanglement as minimal discord over state extensions
Entanglement as minimal discord over state extensions
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纠缠作为状态扩展的最小分歧
DOI：
10.1103/physreva.94.032129
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发表时间：
2016-09-29
影响因子：
2.9
通讯作者：
Luo, Shunlong
中科院分区：
文献类型：
--
作者：
Luo, Shunlong
在过去的几十年里，人们对量子相关的表征和量化进行了广泛而深入的研究，这对探索和利用量子世界起着重要的作用。特别突出和重要的是纠缠和不和谐的概念，它们通常被认为是非常独特的量子相关，后者超越了前者。在这项工作中，我们通过状态扩展建立了纠缠和不和谐之间的直接和自然的联系，并揭示了纠缠实际上是内在的不和谐，我们的意思是纠缠是从环境空间看的不和谐的不可约残余。我们的方法，考虑到量子态的上下文性和全局性，与局部操作和经典的纠缠通信范式形成鲜明对比，后者通过局部方法关注状态本身。此外，我们引入了一个优点图，一方面抓住了纠缠的本质，即相关的非局域性和量子性，另一方面，导致了总相关性的定量分解为经典相关性、不协调和纠缠。这从量子测量的角度揭开了纠缠的含义，并为量子测量和互信息方面的各种相关性的相互作用提供了一个统一的框架。
The characterization and quantification of quantum correlations, which play an instrumental role in exploring and exploiting the quantum world, have been extensively and intensively studied in the past few decades. Of special prominence and significance are the concepts of entanglement and discord, which are usually regarded as very distinctive quantum correlations, with the latter going beyond the former. In this work we establish a direct and natural link between entanglement and discord via state extensions and reveal that entanglement is actually the intrinsic discord, by which we mean that entanglement is the irreducible residue of discord viewed from ambient spaces. Our approach, taking into account the contextuality of a quantum state and being of a global nature, stands in sharp contrast to the local operations and classical communication paradigm of entanglement, which focuses on the state itself via a local approach. Furthermore, we introduce a figure of merit which, on the one hand, captures the essence of entanglement, i.e., nonlocality and quantumness of correlations, and, on the other hand, leads to a quantitative decomposition of total correlations into classical correlations, dissonance, and entanglement. This demystifies the meaning of entanglement from the perspective of quantum measurements and provides a unified framework for the interplay of various correlations in terms of quantum measurements and mutual information.