Correlation-driven threefold topological phase transition in monolayer OsBr_(2)

作     者：San-Dong Guo Yu-Ling Tao Wen-Qi Mu Bang-Gui Liu San-Dong Guo;Yu-Ling Tao;Wen-Qi Mu;Bang-Gui Liu

作者机构：School of Electronic EngineeringXi’an University of Posts and TelecommunicationsXi’an 710121China Beijing National Laboratory for Condensed Matter PhysicsInstitute of PhysicsChinese Academy of SciencesBeijing 100190China School of Physical SciencesUniversity of Chinese Academy of SciencesBeijing 100190China 

出 版 物：《Frontiers of physics》 (物理学前沿（英文版）)

年 卷 期：2023年第18卷第3期

页      面：121-130页

核心收录：

学科分类：070207[理学-光学] 07[理学] 08[工学] 0803[工学-光学工程] 0702[理学-物理学] 

基　　金：supported by the Natural Science Basis Research Plan in Shaanxi Province of China(No.2021JM-456) Graduate Innovation Fund Project in Xi’an University of Posts and Telecommunications(No.CXJJDL2021001) the National Natural Science Foundation of China(Grant No.11974393) the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDB33020100) 

主　　题：correlation SOC phase transition piezoelectricity 

摘      要：Spin–orbit coupling(SOC)combined with electronic correlation can induce topological phase transition,producing novel electronic ***,we investigate the impact of SOC combined with correlation effects on physical properties of monolayer OsBr_(2),based on first-principles calculations with generalized gradient approximation plus U(GGA+U)*** intrinsic out-of-plane magnetic anisotropy,OsBr_(2)undergoes threefold topological phase transition with increasing U,and valleypolarized quantum anomalous Hall insulator(VQAHI)to half-valley-metal dxy dx2−y2 dz2¯6m2(HVM)to ferrovalley insulator(FVI)to HVM to VQAHI to HVM to FVI transitions can be *** topological phase transitions are connected with sign-reversible Berry curvature and band inversion between/and *** to symmetry,piezoelectric polarization of OsBr_(2)is confined along the in-plane armchair direction,and only one d11 is *** a given material,the correlation strength should be fixed,and OsBr_(2)may be a piezoelectric VQAHI(PVQAHI),piezoelectric HVM(PHVM)or piezoelectric FVI(PFVI).The valley polarization can be flipped by reversing the magnetization of Os atoms,and the ferrovalley(FV)and nontrivial topological properties will be suppressed by manipulating out-of-plane magnetization to in-plane *** considered reasonable U range,the estimated Curie temperatures all are higher than room *** findings provide a comprehensive understanding on possible electronic states of OsBr_(2),and confirm that strong SOC combined with electronic correlation can induce multiple quantum phase transition.