Topologically protected entanglement switching around exceptional points  

作　　者：Zan Tang Tian Chen Xing Tang Xiangdong Zhang 

机构地区：[1]Key Laboratory of Advanced Optoelectronic Quantum Architecture and Measurements of Ministry of Education,Beijing Key Laboratory of Nanophotonics&Ultrafine Optoelectronic Systems,School of Physics,Beijing Institute of Technology,100081 Beijing,China

出　　处：《Light(Science & Applications)》2024年第8期1631-1644,共14页光（科学与应用)（英文版）

基　　金：supported by the National key R&D Program of China under Grant No.2022YFA1404904;the National Natural Science Foundation of China(12234004 and 12374323).

摘　　要：The robust operation of quantum entanglement states is crucial for applications in quantum information,computing,and communications^(1–3).However,it has always been a great challenge to complete such a task because of decoherence and disorder.Here,we propose theoretically and demonstrate experimentally an effective scheme to realize robust operation of quantum entanglement states by designing quadruple degeneracy exceptional points.By encircling the exceptional points on two overlapping Riemann energy surfaces,we have realized a chiral switch for entangled states with high fidelity.Owing to the topological protection conferred by the Riemann surface structure,this switching of chirality exhibits strong robustness against perturbations in the encircling path.Furthermore,we have experimentally validated such a scheme on a quantum walk platform.Our work opens up a new way for the application of non-Hermitian physics in the field of quantum information.

关 键 词：exceptional QUANTUM RIEMANN 

分 类 号：O413[理学—理论物理]