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Frontiers of Physics

, 14:23501 | Cite as

Enhanced robustness of zero-line modes in graphene via magnetic field

  • Ke Wang
  • Tao Hou
  • Yafei Ren
  • Zhenhua Qiao
Letter
  • 16 Downloads

Abstract

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–Büttiker 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 μm in the presence of a disorder.

Keywords

graphene topological state zero-line state electronic transport 

Notes

Acknowledgements

This work was financially supported by the National Key Research and Development Program (Grant No. 2017YFB0405703), the China Government Youth 1000-Plan Talent Program, and the National Natural Science Foundation of China (Grant No. 11474265). We are grateful to the Supercomputing Center of USTC for providing high-performance computing assistance.

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Copyright information

© Higher Education Press and Springer-Verlag GmbH Germany, part of Springer Nature 2019

Authors and Affiliations

  1. 1.ICQD, Hefei National Laboratory for Physical Sciences at Microscale, and Synergetic Innovation Centre of Quantum Information and Quantum PhysicsUniversity of Science and Technology of ChinaHefeiChina
  2. 2.CAS Key Laboratory of Strongly-Coupled Quantum Matter Physics and Department of PhysicsUniversity of Science and Technology of ChinaHefeiChina

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