Formation of topological domain walls and quantum transport properties of zero-line modes in commensurate bilayer graphene systems  

作　　者：Junjie Zeng Rui Xue Tao Hou Yulei Han Zhenhua Qiao 

机构地区：[1]ICQD,Hefei National Laboratory for Physical Sciences at Microscale,CAS Key Laboratory of Strongly-Coupled Quantum Matter Physics,Department of Physics,University of Science and Technology of China,Hefei 230026,China [2]Department of Physics,Fuzhou University,Fuzhou 350108,China

出　　处：《Frontiers of physics》2022年第6期95-105,共11页物理学前沿（英文版）

基　　金：supported by the National Natural Science Foundation of China(Grant Nos.51672171,51861145315,11804216,and 11974327);The supercomputing services from AM-HPC,the Chinese Scholarship Council,Fundamental Research Funds for the Central Universities(Nos.WK3510000010 and WK2030020032),Anhui Initiative in Quantum Information Technologies.

摘　　要：We study theoretically the construction of topological conducting domain walls with a finite width between AB/BA stacking regions via finite element method in bilayer graphene systems with tunable commensurate twisting angles.We find that the smaller is the twisting angle,the more significant the lattice reconstruction would be,so that sharper domain boundaries declare their existence.We subsequently study the quantum transport properties of topological zero-line modes which can exist because of the said domain boundaries via Green’s function method and Landauer–Büttiker formalism,and find that in scattering regions with triintersectional conducting channels,topological zero-line modes both exhibit robust behavior exemplified as the saturated total transmission Gtot≈2e_(2)/h and obey a specific pseudospin-conserving current partition law among the branch transport channels.The former property is unaffected by Aharonov–Bohm effect due to a weak perpendicular magnetic field,but the latter is not.Results from our genuine bilayer hexagonal system suggest a twisting angle aroundθ≈0.1°for those properties to be expected,consistent with the existing experimental reports.

关 键 词：twistronics lattice reconstruction topological domain wall zero-line mode quantum transport 

分 类 号：O41[理学—理论物理]