Tuning Second Chern Number in a Four-Dimensional Topological Insulator by High-Frequency Time-Periodic Driving  

作　　者：刘峥嵘 陈锐 周斌 Zheng-Rong Liu;Rui Chen;Bin Zhou(Department of Physics,Hubei University,Wuhan 430062,China;Key Laboratory of Intelligent Sensing System and Security of Ministry of Education,Hubei University,Wuhan 430062,China)

机构地区：[1]Department of Physics,Hubei University,Wuhan 430062,China [2]Key Laboratory of Intelligent Sensing System and Security of Ministry of Education,Hubei University,Wuhan 430062,China

出　　处：《Chinese Physics Letters》2024年第4期77-89,共13页中国物理快报（英文版）

基　　金：supported by the National Natural Science Foundation of China(Grant Nos.12074107 and 12304195);the Program of Outstanding Young and Middle-Aged Scientific and Technological Innovation Team of Colleges and Universities in Hubei Province(Grant No.T2020001);the Innovation Group Project of the Natural Science Foundation of Hubei Province of China(Grant No.2022CFA012);the Chutian Scholars Program in Hubei Province,the Postdoctoral Fellowship Program of CPSF(Grant No.GZC20230751);the Postdoctoral Innovation Research Program in Hubei Province(Grant No.351342)。

摘　　要：Floquet engineering has attracted considerable attention as a promising approach for tuning topological phase transitions.We investigate the effects of high-frequency time-periodic driving in a four-dimensional(4D)topological insulator,focusing on topological phase transitions at the off-resonant quasienergy gap.The 4D topological insulator hosts gapless three-dimensional boundary states,characterized by the second Chern number C_(2).We demonstrate that the second Chern number of 4D topological insulators can be modulated by tuning the amplitude of time-periodic driving.This includes transitions from a topological phase with C_(2)=±3 to another topological phase with C_(2)=±1,or to a topological phase with an even second Chern number C_(2)=±2,which is absent in the 4D static system.Finally,the approximation theory in the high-frequency limit further confirms the numerical conclusions.

关 键 词：TOPOLOGICAL TRANSITIONS PERIODIC 

分 类 号：O469[理学—凝聚态物理]