PT-symmetry berry phases,topology and PT-symmetry breaking

作     者：Jinghui Pi NingNing Sun Rong Lü Jinghui Pi;NingNing Sun;Rong Lü

作者机构：Department of PhysicsTsinghua UniversityBeijing 100084China Frontier Science Center for Quantum InformationBeijingChina State Key Laboratory of Low-Dimensional Quantum PhysicsBeijingChina 

出 版 物：《Communications in Theoretical Physics》 (理论物理通讯（英文版）)

年 卷 期：2020年第72卷第4期

页      面：45-51页

核心收录：

学科分类：07[理学] 0809[工学-电子科学与技术（可授工学、理学学位）] 070205[理学-凝聚态物理] 08[工学] 0704[理学-天文学] 0702[理学-物理学] 

基　　金：supported by the NSFC under Grant No.11874234 and No.11425419 

主　　题：PT symmetry Berry phases topology PT symmetry breaking 

摘      要：We study the complex Berry phases in non-Hermitian systems with parity-and time-reversal(PT)*** investigate a kind of two-level system with PT *** find that the real part of the the complex Berry phases have two quantized values and they are equal to either 0 orΠ,which originates from the topology of the Hermitian *** also find that if we change the relative parameters of the Hamiltonian from the unbroken-PT-symmetry phase to the broken-PT-symmetry phase,the imaginary part of the complex Berry phases are divergent at the exceptional *** exhibit two concrete examples in this work,one is a two-level toys model,which has nontrivial Berry phases;the other is the generalized Su-Schrieffer-Heeger(SSH)model that has physical loss and gain in every *** results explicitly demonstrate the relation between complex Berry phases,topology and PT-symmetry breaking and enrich the field of the non-Hermitian physics.