Discovery of higher-order topological insulators using the spin Hall conductivity as a topology signature  

作　　者：Marcio Costa Gabriel R.Schleder Carlos Mera Acosta Antonio C.M.Padilha Frank Cerasoli Marco Buongiorno Nardelli Adalberto Fazzio 

机构地区：[1]Department of Physics,Fluminense Federal University,Niterói,Rio de Janeiro,Brazil [2]Brazilian Nanotechnology National Laboratory(LNNano),CNPEM,Campinas,Brazil [3]Center for Natural and Human Sciences,Federal University of ABC,Santo André,SP,Brazil [4]Department of Physics and Department of Chemistry,University of North Texas,Denton,TX,USA

出　　处：《npj Computational Materials》2021年第1期457-462,共6页计算材料学（英文）

基　　金：M.C.,G.R.S.,C.M.A.,A.C.M.P.,and A.F.acknowledges financial support from the Fundação de AmparoàPesquisa do Estado de São Paulo(FAPESP),project numbers 16/14011-2,17/18139-6,18/11856-7,18/05565-0,17/02317-2.

摘　　要：The discovery and realization of topological insulators,a phase of matter which hosts metallic boundary states when the ddimension insulating bulk is confined to(d−1)-dimensions,led to several potential applications.Recently,it was shown that protected topological states can manifest in(d−2)-dimensions,such as hinge and corner states for three-and two-dimensional systems,respectively.These nontrivial materials are named higher-order topological insulators(HOTIs).Here we show a connection between spin Hall effect and HOTIs using a combination of ab initio calculations and tight-binding modeling.The model demonstrates how a non-zero bulk midgap spin Hall conductivity(SHC)emerges within the HOTI phase.Following this,we performed high-throughput density functional theory calculations to find unknown HOTIs,using the SHC as a criterion.We calculated the SHC of 693 insulators resulting in seven stable two-dimensional HOTIs.Our work guides novel experimental and theoretical advances towards higher-order topological insulator realization and applications.

关 键 词：TOPOLOGICAL INSULATOR CONDUCTIVITY 

分 类 号：TM21[一般工业技术—材料科学与工程]