Entanglement measures and purification procedures
Entanglement measures and purification procedures
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DOI：
10.1103/physreva.57.1619
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发表时间：
1997-07
影响因子：
2.9
通讯作者：
V. Vedral;M. Plenio
中科院分区：
文献类型：
--
作者：
V. Vedral;M. Plenio
我们改进了先前提出的每个纠缠测量必须满足的条件。我们提出了一类满足这些条件的纠缠测度，并证明量子相对熵和布尔度量产生了这类测度的两个测度。我们利用量子相对熵计算了一些自旋为1/2的混合系统的纠缠度，并提供了一种有效的计算方法。此外，我们证明了我们的纠缠测量的一些性质，具有重要的物理意义。我们简要地解释在量子相对熵的情况下我们测量纠缠的统计基础。然后，我们认为我们的纠缠度量决定了任何纯化过程都能得到的单重态数目的上界。
We improve previously proposed conditions each measure of entanglement has to satisfy. We present a class of entanglement measures that satisfy these conditions and show that the quantum relative entropy and Bures metric generate two measures of this class. We calculate the measures of entanglement for a number of mixed two spin-1/2 systems using the quantum relative entropy, and provide an efficient numerical method to obtain the measures of entanglement in this case. In addition, we prove a number of properties of our entanglement measure that have important physical implications. We briefly explain the statistical basis of our measure of entanglement in the case of the quantum relative entropy. We then argue that our entanglement measure determines an upper bound to the number of singlets that can be obtained by any purification procedure.