Exceptional points and quantum dynamics in a non-Hermitian two-qubit system  

作　　者：张益玺 张振涛 杨震山 魏晓志 梁宝龙 Yi-Xi Zhang;Zhen-Tao Zhang;Zhen-Shan Yang;Xiao-Zhi Wei;Bao-Long Liang(School of Physics Science and Information Technology,Shandong Key Laboratory of Optical Communication Science and Technology,Liaocheng University,Liaocheng 252059,China)

机构地区：[1]School of Physics Science and Information Technology,Shandong Key Laboratory of Optical Communication Science and Technology,Liaocheng University,Liaocheng 252059,China

出　　处：《Chinese Physics B》2024年第6期212-218,共7页中国物理B（英文版）

基　　金：partly funded by the Natural Science Foundation of Shandong Province of China (Grant Nos. ZR2021MA091 and ZR2018MA044);Introduction and Cultivation Plan of Youth Innovation Talents for Universities of Shandong Province (Research and Innovation Team on Materials Modification and Optoelectronic Devices at extreme conditions)。

摘　　要：We study the exceptional-point(EP) structure and the associated quantum dynamics in a system consisting of a non-Hermitian qubit and a Hermitian qubit. We find that the system possesses two sets of EPs, which divide the systemparameter space into PT-symmetry unbroken, partially broken and fully broken regimes, each with distinct quantumdynamics characteristics. Particularly, in the partially broken regime, while the PT-symmetry is generally broken in the whole four-dimensional Hilbert space, it is preserved in a two-dimensional subspace such that the quantum dynamics in the subspace are similar to those in the PT-symmetry unbroken regime. In addition, we reveal that the competition between the inter-qubit coupling and the intra-qubit driving gives rise to a complex pattern in the EP variation with system parameters.

关 键 词：non-Hermitian system exceptional point PT-SYMMETRY 

分 类 号：O413.1[理学—理论物理]