Observation of dark edge states in parity-time-symmetric quantum dynamics

作     者：Peng Xue Xingze Qiu Kunkun Wang Barry C. Sanders Wei Yi Peng Xue;Xingze Qiu;Kunkun Wang;Barry C.Sanders;Wei Yi

作者机构：Beijing Computational Science Research Center Key Laboratory of Quantum InformationUniversity of Science and Technology of China Chinese Academy of Sciences Synergetic Innovation Center in Quantum Information and Quantum PhysicsUniversity of Science and Technology of China Chinese Academy of Sciences  4. School of Physics and Optoelectronic Engineering Anhui University Shanghai BranchNational Laboratory for Physical Sciences at MicroscaleUniversity of Science and Technology of China Institute for Quantum Science and Technology University of Calgary Program in Quantum Information ScienceCanadian Institute for Advanced Research 

出 版 物：《National Science Review》 (国家科学评论(英文版))

年 卷 期：2023年第10卷第8期

页      面：156-165页

核心收录：

学科分类：07[理学] 070201[理学-理论物理] 0702[理学-物理学] 

基　　金：supported by the National Natural Science Foundation of China (92265209, 12025401, 12104009, 12088101 and 11974331) support from the National Key R&D Program of China (2017YFA0304100) 

主　　题：parity-time symmetry photonic quantum walks dark edge states topological invariants 

摘      要：Topological edge states arise in non-Hermitian parity-time(PT)-symmetric systems, and manifest themselves as bright or dark edge states, depending on the imaginary components of their eigenenergies. As the spatial probabilities of dark edge states are suppressed during the non-unitary dynamics, it is a challenge to observe them experimentally. Here we report the experimental detection of dark edge states in photonic quantum walks with spontaneously broken PT symmetry, thus providing a complete description of the topological phenomena therein. We experimentally confirm that the global Berry phase in PT-symmetric quantum-walk dynamics unambiguously defines topological invariants of the system in both the PT-symmetry-unbroken and-broken regimes. Our results establish a unified framework for characterizing topology in PT-symmetric quantum-walk dynamics, and provide a useful method to observe topological phenomena in PT-symmetric non-Hermitian systems in general.