• 文献标题:   Enhanced robustness of zero-line modes in graphene via magnetic field
  • 文献类型:   Article
  • 作  者:   WANG K, HOU T, REN YF, QIAO ZH
  • 作者关键词:   graphene, topological state, zeroline state, electronic transport
  • 出版物名称:   FRONTIERS OF PHYSICS
  • ISSN:   2095-0462 EI 2095-0470
  • 通讯作者地址:   Univ Sci Technol China
  • 被引频次:   3
  • DOI:   10.1007/s11467-018-0869-9
  • 出版年:   2019

▎ 摘  要

We systematically studied the influence of magnetic field on zero-line modes (ZLMs) in graphene and demonstrated the physical origin of their enhanced robustness by employing nonequilibrium Green's functions and the Landauer-Buttiker formula. We found that a perpendicular magnetic field can separate the wavefunctions of the counter-propagating kink states into opposite directions. Specifically, the separation vanishes at the charge neutrality point and increases as the Fermi level deviates from the charge neutrality point and can reach a magnitude comparable to the wavefunction spread at a moderate field strength. Such spatial separation of oppositely propagating ZLMs effectively suppresses backscattering and is more significant under zigzag boundary condition than under armchair boundary condition. Moreover, the presence of magnetic field enlarges the bulk gap and suppresses the bound states, thereby further reducing the scattering. These mechanisms effectively increase the mean free paths of the ZLMs to approximately 1 mu m in the presence of a disorder.