• 文献标题:   Quantum Hall effect in gapped graphene heterojunctions
  • 文献类型:   Article
  • 作  者:   LADO JL, GONZALEZ JW, FERNANDEZROSSIER J
  • 作者关键词:  
  • 出版物名称:   PHYSICAL REVIEW B
  • ISSN:   1098-0121 EI 1550-235X
  • 通讯作者地址:   Int Iberian Nanotechnol Lab INL
  • 被引频次:   15
  • DOI:   10.1103/PhysRevB.88.035448
  • 出版年:   2013

▎ 摘  要

We model the quantum Hall effect in heterostructures made of two gapped graphene stripes with different gaps, Delta(1) and Delta(2). We consider two main situations, Delta(1) = 0, Delta(2) not equal 0, and Delta(1) = -Delta(2). They are different in a fundamental aspect: only the latter features kink states that, when intervalley coupling is absent, are protected against backscattering. We compute the two-terminal conductance of heterostructures with channel length up to 430 nm, in two transport configurations, parallel and perpendicular to the interface. By studying the effect of disorder on the transport along the boundary, we quantify the robustness of kink states with respect to backscattering. Transport perpendicular to the boundary shows how interface states open a backscattering channel for the conducting edge states, spoiling the perfect conductance quantization featured by the homogeneously gapped graphene Hall bars. Our results can be relevant for the study of graphene deposited on hexagonal boron-nitride, as well as to model graphene with an interaction-driven gapped phase with two equivalent phases separated by a domain wall.