Quantum coherence measures based on Fisher information with applications
Quantum coherence measures based on Fisher information with applications
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基于费希尔信息的量子相干性测量及其应用
DOI：
10.1103/physreva.103.012401
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发表时间：
2021-01-05
影响因子：
2.9
通讯作者：
Li, Ming
中科院分区：
文献类型：
--
作者：
Li, Lei;Wang, Qing-Wen;Li, Ming
最近，人们提出了各种量化量子态相干性的方法。本文提出了几种基于量子Fisher信息（QFI）的可靠量子相干性测度。对于纯态，该相干测度等价于基于斜信息的相干测度，而对于混合态，我们首先通过QFI定义了两个自然相干测度，发现这两个定义完全相同.利用量子比特的特殊结构，我们证明了互无偏基量子比特相干性仅受Bloch矢量长度的约束。然后，我们提供的上界的相干性措施相对于任何给定的基础和下界的情况下，一组MUB的纯态和混合状态的任意尺寸。最后，我们探讨了我们的相干性措施和量子计量学之间的联系，从而提供了这些相干性措施的操作意义。
Recently various ways to quantify coherence of a quantum state have been proposed. In this paper, several reliable quantum coherence measures based on quantum Fisher information (QFI) are presented. For pure states, this coherence measure is equivalent to that based on skew information, while for mixed states, we first define two natural coherence measures via QFI and find that the two definitions are exactly identical. By virtual of the special structure of qubit, we show that the mutual unbiased bases' (MUBs) qubit coherence is constrained only by the length of the Bloch vector. Then we provide upper bounds of the coherence measure with respect to any given basis and lower bounds in the case of a set of MUBs for both pure states and mixed states of arbitrary dimension. Finally, we investigate the connection between our coherence measures and quantum metrology, thereby providing an operational meaning for these coherence measures.