阿哈罗诺夫-玻姆相位在宇称-时间反演对称量子系统中的作用研究

Since C. M. Bender and his colleagues showed that parity-time symmetric non-Hermitian system may possess entirely real spectrum in 1998, D. N. Christodoulides and his colleagues proposed an optical waveguides system as a physical realization in 2007, and L. Yang together with her colleagues experimentally demonstrated parity-time symmetry in whispering gallery microcavities in 2014, the parity-time symmetric non-Hermitian system underwent explosive development. In 2015, the parity-time symmetry in optics is one topic in "Top 10 physics discoveries in the last 10 years" in Nature Physics. However, as photons do not interact with magnetic field, few work studied the affect of Aharonov-Bohm phase in parity-time symmetric system. As the development of artificial gauge field induced effective magnetic field in optics, it is possible to realize Aharonov-Bohm phase in a parity-time symmetric optical system. This research proposal aims at studying the novel quantum phenomena induced by the Aharonov-Bohm phase in parity-time symmetric system. For example, the fragile parity-time symmetry because of quantum phase; the asymmetric behavior from parity-time symmetry including nonreciprocal transmission, reflection, scattering spectral singularity; the topological protected parity-time symmetric edge states and so on. Parity-time symmetric optical system as a kind of novel metamaterial, can be used in quantum optics and quantum information processing, as novel optical control devices that not restricted to optical diodes.

从1998年Bender等人提出具有宇称-时间反演对称的非厄米系统可以具有完全实数本征能谱，到2007年Christodoulides等人提出光波导实现，再到2014年Yang等人的回音壁光学微腔实验，宇称-时间反演对称非厄米系统经历了快速发展。2015年，《自然物理》杂志上发表《过去十年十大物理发现》，其中就有"光学中的宇称-时间反演对称"。然而由于光子和磁场无相互作用，现阶段鲜有涉及阿哈罗诺夫-玻姆相位的研究。不过随着近年来人工规范场在光学系统中形成有效磁场的研究进展，实现具有阿哈罗诺夫-玻姆相位的宇称-时间反演对称光学系统成为可能。本课题将研究阿哈罗诺夫-玻姆相位在宇称-时间反演对称系统中产生的新颖量子现象。如：对相位异常敏感的宇称-时间对称性破缺；非对称透射、反射、能谱奇点；拓扑保护宇称-时间反演对称边缘态等。宇称-时间反演对称系统作为一种新型超材料

光学互易性的破坏需要结合光学非线性和非对称结构，亦或是利用具有磁光效应的材料。光学非线性不易精确控制，而具有强磁光效应的材料很少。这些限制了非互易光学的发展。近年来关于光子阿哈罗诺夫-波姆效应的研究出现了突破性进展，人们通过引入规范势场，实现了光学有效磁场。这可用于实现具有阿哈罗诺夫-波姆相位的PT-对称光学系统。本项目主要研究在阿哈罗诺夫-波姆效应和非厄米性的两者共同作用下，PT-对称量子系统中产生的新颖特性及量子现象。.我们通过研究发现非厄米系统中阿哈罗诺夫-波姆效应和增益耗散相结合可以实现非对称的耦合，此机制提供了一种破坏光学互易性的全新方法。我们在耦合微腔中设计了光学二极管、光学止回阀、单向激光等。取得的研究成果在光学集成、光场调控、光通信领域具有潜在应用前景[代表性成果：L. Jin* and Z. Song, Incident Direction Independent Wave Propagation and Unidirectional Lasing, Physical Review Letters, 121, 073901 (2018)]。.此外，我们利用非厄米阿哈罗诺夫-波姆效应解决了非厄米拓扑系统中的体-边对应问题。不同的非厄米拓扑系统由于非厄米性出现方式的差别，虚数的规范场有可能出现在一些非厄米拓扑系统中。虚数的规范场在周期性边界条件下将能谱拓展到复数域；而开放边界条件下，此规范场不影响系统能谱；这导致了体-边对应失效。我们指出了这个本质问题并重建了非厄米拓扑系统的体-边对应[代表性成果：L. Jin* and Z. Song, Bulk-boundary correspondence in a non-Hermitian system in one dimension with chiral inversion symmetry, Physical Review B 99, 081103(R) (2019)]。.本项目的研究成果将有助于进一步深入理解量子相位及非厄米性在开放量子系统中的影响；将有利于非厄米系统的新颖特性在量子光学、量子度量学、量子信息及拓扑量子计算等领域的应用。