From Topological Nodal-Line Semimetals to Quantum Spin Hall Insulators in Tetragonal SnX Monolayers(X=F,Cl,Br,I)  

作　　者：朱晔 赵宝 薛阳 徐玮 徐文婷 杨中芹 Ye Zhu;Bao Zhao;Yang Xue;Wei Xu;Wenting Xu;Zhongqin Yang(State Key Laboratory of Surface Physics,Key Laboratory of Computational Physical Sciences(MOE),and Department of Physics,Fudan University,Shanghai 200433,China;Shandong Key Laboratory of Optical Communication Science and Technology,School of Physics Science and Information Technology,Liaocheng University,Liaocheng 252059,China;School of Physics,East China University of Science and Technology,Shanghai 200237,China;Shanghai Qi Zhi Institute,Shanghai 200030,China)

机构地区：[1]State Key Laboratory of Surface Physics,Key Laboratory of Computational Physical Sciences(MOE),and Department of Physics,Fudan University,Shanghai 200433,China [2]Shandong Key Laboratory of Optical Communication Science and Technology,School of Physics Science and Information Technology,Liaocheng University,Liaocheng 252059,China [3]School of Physics,East China University of Science and Technology,Shanghai 200237,China [4]Shanghai Qi Zhi Institute,Shanghai 200030,China

出　　处：《Chinese Physics Letters》2024年第6期98-111,共14页中国物理快报（英文版）

基　　金：supported by the National Natural Science Foundation of China(Grant Nos.12174059,11874117,11904101,and 11604134);the Natural Science Foundation of Shanghai(Grant No.21ZR140820)。

摘　　要：Two-dimensional(2D)topological materials have recently garnered significant interest due to their profound physical properties and promising applications for future quantum nanoelectronics.Achieving various topological states within one type of materials is,however,seldom reported.Based on first-principles calculations and tightbinding models,we investigate topological electronic states in a novel family of 2D halogenated tetragonal stanene(T-SnX,X=F,Cl,Br,I).All the four monolayers are found to be unusual topological nodal-line semimetals(NLSs),protected by a glide mirror symmetry.When spin-orbit coupling(SOC)is turned on,T-SnF and TSnCl are still ascertained as topological NLSs due to the remaining band inversion,primarily composed of Sn pxy orbitals,while T-Sn Br and T-SnI become quantum spin Hall insulators.The phase transition is ascribed to moving up in energy of Sn s orbitals and increasing of SOC strengths.The topology origin in the materials is uniformly rationalized through elementary band representations.The robust and diverse topological states found in the 2D T-SnX monolayers position them as an excellent material platform for development of innovative topological electronics.

关 键 词：TOPOLOGICAL metals quantum 

分 类 号：O469[理学—凝聚态物理]