Zheng Chao, Li Daili
Department of Physics, College of Science, North China University of Technology, Beijing, 100144, People's Republic of China.
Sci Rep. 2022 Feb 18;12(1):2824. doi: 10.1038/s41598-022-06808-1.
Non-Hermitian (NH) quantum systems attract research interest increasingly in recent years, among which the PT-symmetric, P-pseudo-Hermitian and their anti-symmetric counterpart systems are focused much more. In this work, we extend the usage of entropy to distinguish time-evolutions of different classes and phases of typical NH-systems. In detail, we investigate the entropy dynamics of two-level NH-systems after quantum decoherence induced by single-qubit projective measurements, finding that it depends on both the initial states and the selection of the computational bases of the measurements. In a general case, we show how to distinguish all the eight phases of the above NH-systems step by step, in which process three different initial states are necessary if the basis of measurement is fixed. We propose how the distinguishing process is realized in quantum simulation, in which quantum tomography is not needed. Our investigations can be applied to judge phase transitions of non-Hermitian systems.
近年来，非厄米（NH）量子系统越来越吸引研究兴趣，其中PT对称、P伪厄米及其反对称对应系统受到的关注更多。在这项工作中，我们扩展了熵的用法，以区分典型NH系统不同类别和相的时间演化。具体而言，我们研究了单量子比特投影测量引起量子退相干后两能级NH系统的熵动力学，发现它既取决于初始状态，也取决于测量计算基的选择。在一般情况下，我们展示了如何逐步区分上述NH系统的所有八个相，在此过程中，如果测量基固定，则需要三种不同的初始状态。我们提出了如何在量子模拟中实现区分过程，其中不需要量子层析成像。我们的研究可用于判断非厄米系统的相变。
