于长水

个人信息Personal Information

教授

博士生导师

硕士生导师

主要任职:物理学院党委书记

其他任职:无

性别:男

毕业院校:大连理工大学

学位:博士

所在单位:物理学院

学科:理论物理

办公地点:313

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Quantifying coherence in terms of the pure-state coherence

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论文类型:期刊论文

发表时间:2020-06-26

发表刊物:PHYSICAL REVIEW A

收录刊物:SCIE

卷号:101

期号:6

ISSN号:1050-2947

摘要:Quantifying quantum coherence is a key task in the resource theory of coherence. Here we establish a good coherence monotone in terms of a state conversion process, which automatically endows the coherence monotone with an operational meaning. We show that any state can be produced from some input pure states via the corresponding incoherent channels. It is found that the coherence of a given state can be well characterized by the least coherence of the input pure states, so a coherence monotone is established by only effectively quantifying the input pure states. In particular, we show that our proposed coherence monotone is the supremum of all the coherence monotones that give the same coherence for any given pure state. We also prove that our coherence monotone is continuous. Considering the convexity, we prove that our proposed coherence measure is a subset of the coherence measure based on the convex roof construction. The similarities and differences between our coherence monotone and coherence cost are studied in detail. As applications, we give a concrete expression of our coherence measure by employing the geometric coherence of a pure state. We also give a thorough analysis of the states of the qubit and finally obtain a series of analytic coherence measures. The numerical examples are also given to show the difference between our coherence monotone and that based on the convex roof construction.