Emergent Z2 topological invariant and robust helical edge states in two-dimensional topological metals  

作　　者：Chui-Zhen Chen Hua Jiang Dong-Hui Xu X.C.Xie 

机构地区：[1]Institute for Advanced Study and School of Physical Science and Technology,Soochow University,Suzhou 215006,China [2]Department of Physics,Hubei University,Wuhan 430062,China [3]International Center for Quantum Materials,School of Physics,Peking University,Beijing 100871,China [4]CAS Center for Excellence in Topological Quantum Computation,University of Chinese Academy of Sciences,Beijing 100190,China [5]Beijing Academy of Quantum Information Sciences,Beijing 100193,China

出　　处：《Science China(Physics,Mechanics & Astronomy)》2020年第10期105-110,共6页中国科学：物理学、力学、天文学（英文版）

基　　金：supported by the National Basic Research Program of China(Grant No.2015CB921102);the National Natural Science Foundation of China(Grant Nos.11534001,11822407,11704106,and 11974256);the Fundamental Research Funds for the Central Universities;funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions;National Natural Science Foundation of China of Jiangsu province(Grant No.BK20190813);supported by the Chutian Scholars Program in Hubei Province。

摘　　要：In this work,we study the effects of disorder on topological metals that support a pair of helical edge modes deeply embedded inside the gapless bulk states.Strikingly,we predict that a quantum spin Hall(QSH)phase can be obtained from such topological metals without opening a global band gap.To be specific,disorder can lead to a pair of robust helical edge states which is protected by an emergent Z2 topological invariant,giving rise to a quantized conductance plateau in transport measurements.These results are instructive for solving puzzles in various transport experiments on QSH materials that are intrinsically metallic.This work also will inspire experimental realization of the QSH effect in disordered topological metals.

关 键 词：topological metal DISORDER Z2 topological invariant 

分 类 号：O469[理学—凝聚态物理]