对“混合态相位的奇异性”的答复

对“关于循环演化过程中混合态的几何相位”一文的答复

Reply to "comment on Geometric phases for mixed states during cyclic evolutions"

我们证明了2004年J. Phys. A 37 3699提出的循环演化过程中混合态的几何相位是U（1）不变的，并且可以用现代技术观测到。

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Reply to Comment

在评论（quant-ph/0103003）中，Eggeling、Vollbrecht和Wolf怀疑我们在quant-ph/0102133中的方法不实用。在这里，我们解释我们的结果和方法，并表明我们的例子可以告诉一个如何判断一个可分离的状态，所以我们的方法是实用的，至少对许多混合状态。

Reply to Comment on "Quantification of Macroscopic Quantum Superpositions within Phase Space"

Gong points out [quant-ph arXiv:1106.0062] a "direct connection" between our measure [PRL 106, 220401 (2011)] recently proposed to quantify macroscopic quantum superpositions and a previously studied quantity introduced to study classical and quantum chaos. We point out that the two measures are obviously different for some mixed states, and the previous one does not work as a sensible measure to quantify quantum superpositions.

Reply to "Comment on `Winding around non-Hermitian singularities' by Zhong et al., Nat. Commun. 9, 4808 (2018)"

A comment has been recently posted on the arXiv (arXiv:1902.07504) that discuss our recent work on encircling multiple exceptional points in Nat. Commun. 9, 4808 (2018). In that comment, the authors claim that our approach is prone to errors. In discussing their findings, they also indicate that a method presented by their team in Phys. Rev. A 98, 023818 (2018) (presumed to give correct results in all situations) was published prior to our work. First, we would like to note that both their work and ours were posted on the arXiv within a week from each other. Second and more importantly, as we …

纯态或混合态量子系统方差的使用与误用

Use and misuse of variances for quantum systems in pure or mixed states

本文讨论了Fratini和Hayrapetyan在2011年利用自旋分量方差对量子态公设合理性的质疑，澄清了其中的歧义，并探讨了相关概念在辩论中的正确使用与误用。

关于混合态相位的奇异性

On singularities of the mixed state phase

本文分析了Sjoqvist等人最近提出的将Pancharatnam的纯态相位差判据推广到量子力学混合态的建议，指出了混合态粒子干涉实验参数空间中相位奇异性的存在。在这些奇异点附近，相位急剧变化，并且精确地在这些点处，相位变得不确定。参数空间中围绕这些点的闭合电路导致等于2nπ的可测量相移，其中n是整数。这种效应在早期的干涉实验中已经观察到了光的纯偏振态，一个同构于量子力学中自旋1/2系统的系统。讨论了相位奇异性对部分极化和非极化中子实验解释的影响。新的拓扑相位涉及变量表示纯态的退相干（去极化）的预测和实验，以验证他们的建议。