Fragile topological band in the checkerboard antiferromagnetic monolayer FeSe

作     者：Aiyun Luo Zhida Song Gang Xu 

作者机构：Wuhan National High Magnetic Field Center&School of PhysicsHuazhong University of Science and TechnologyWuhan430074China Department of PhysicsPrinceton UniversityPrincetonNJ08544USA 

出 版 物：《npj Computational Materials》 (计算材料学（英文）)

年 卷 期：2022年第8卷第1期

页      面：218-222页

核心收录：

学科分类：080705[工学-制冷及低温工程] 07[理学] 070205[理学-凝聚态物理] 08[工学] 0807[工学-动力工程及工程热物理] 0702[理学-物理学] 

基　　金：This work was supported by the National Key Research and Development Program of China(2018YFA0307000) the National Natural Science Foundation of China(11874022) 

主　　题：topological monolayer topology 

摘      要：By means of the first-principles calculations and magnetic topological quantum chemistry,we demonstrate that the low-energy physics in the checkerboard antiferromagnetic(AFM)monolayer FeSe,very close to an AFM topological insulator that hosts robust edge states,can be well captured by a double-degenerate nearly flat band with fragile topology just below the Fermi *** Wilson loop calculations identify that such fragile topology is protected by the S_(4z) symmetry,which gives rise to a 2D second-order topological insulator that supports the bound state with fractional charge e/2 at the sample *** work provides a platform to study the intriguing properties of magnetic fragile topological electronic *** observations of the edge states and bound states in checkerboard AFM monolayer FeSe can also be well understood in our work.