文献类型：期刊文献

英文题名：Higher-order topological insulators in two-dimensional Dirac materials

作者：Xue, Yang[1];Huan, Hao[2,3,4];Zhao, Bao[2,3,4,5];Luo, Youhua[1];Zhang, Zhenyu[6,7];Yang, Zhongqin[2,3,4]

机构：[1]East China Univ Sci & Technol, Sch Phys, Shanghai 200237, Peoples R China;[2]Fudan Univ, State Key Lab Surface Phys, Shanghai 200433, Peoples R China;[3]Fudan Univ, Key Lab Computat Phys Sci MOE, Shanghai 200433, Peoples R China;[4]Fudan Univ, Dept Phys, Shanghai 200433, Peoples R China;[5]Liaocheng Univ, Sch Phys Sci & Informat Technol, Shandong Key Lab Opt Commun Sci & Technol, Liaocheng 252059, Shandong, Peoples R China;[6]Univ Sci & Technol China, Int Ctr Quantum Design Funct Mat ICQD, Hefei Natl Lab Phys Sci Microscale, Hefei 230026, Peoples R China;[7]Univ Sci & Technol China, CAS Ctr Excellence Quantum Informat & Quantum Phy, Hefei 230026, Peoples R China

年份：2021

卷号：3

期号：4

外文期刊名：PHYSICAL REVIEW RESEARCH

收录：EI(收录号：20220211454334);WOS:【ESCI(收录号:WOS:000736651500003)】；

基金：This work was supported by National Natural Science Foundation of China under No. 11904101, No. 11874117, and No. 11604134 and the Natural Science Foundation of Shanghai under No. 21ZR1408200.

语种：英文

外文关键词：Calculations - Electric insulators - Topology - Germanium compounds

摘要：As a novel topological state, a higher-order topological insulator has attracted enormous interest, which in d spatial dimensions has gapless boundary states at (d-n) dimensions (integer n is larger than 1). Until now, merely few two-dimensional (2D) materials have been identified as higher-order topological insulators and their experimental confirmations are still absent. Here we propose a universal strategy of antidot engineering to realize second-order topological insulators (SOTIs) in 2D Dirac materials. Based on symmetry analysis, tight-binding model, and first-principles calculations, we demonstrate SOTIs in antidot-decorated Xene (X=C, Si,and Ge) by displaying its finite bulk quadrupole moment, weak topological edge states, and in-gap topological corner states. An inherent connection is established for the existing various mechanisms of the SOTIs, including quadrupole polarization, filling anomaly, and generalized Su-Schrieffer-Heeger model on a Kekule lattice. The robustness of topological corner states of the SOTIs against edge perturbations and bulk disorders is explicitly demonstrated, rendering our strategy appealing to experimental realization of topological corner states.