Observable Correlations in Two-Qubit States
Observable Correlations in Two-Qubit States
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DOI：
10.1007/s10955-009-9779-0
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发表时间：
2009-07
影响因子：
1.6
通讯作者：
S. Luo;Qiang Zhang
中科院分区：
文献类型：
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作者：
S. Luo;Qiang Zhang
二分量子态中的总关联可以通过量子互信息很好地量化，量子互信息的量不一定可以通过局部测量完全提取。可观测的相关性是可以通过局部测量提取的最大相关性，并且具有作为经典相关性的度量的直观解释。我们评估了一般两量子比特态的可观测相关性，并在某些特定情况下得到了解析表达式。总的，量子和经典的相关性之间的复杂和微妙的关系说明在可观察的相关性。在课程中，我们还反驳了Lindblad的一个直觉猜想，该猜想指出经典相关至少占总相关的一半，或者等价地，相关比量子更经典。
The total correlations in a bipartite quantum state are well quantified by the quantum mutual information, the amount of which is not necessarily fully extractable by local measurements. The observable correlations are the maximal correlations that can be extracted via local measurements, and have an intuitive interpretation as a measure of classical correlations. We evaluate the observable correlations for generic two-qubit states and obtain analytical expressions in some particular cases. The intricate and subtle relationships among the total, quantum and classical correlations are illustrated in terms of observable correlations. In the course, we also disprove an intuitive conjecture of Lindblad which states that the classical correlations account for at least half of the total correlations, or equivalently, correlations are more classical than quantum.