• 文献标题:   Quantum Hall effect in bilayer graphene: Disorder effect and quantum phase transition
  • 文献类型:   Article
  • 作  者:   MA R, SHENG L, SHEN R, LIU M, SHENG DN
  • 作者关键词:  
  • 出版物名称:   PHYSICAL REVIEW B
  • ISSN:   2469-9950 EI 2469-9969
  • 通讯作者地址:   Calif State Univ Northridge
  • 被引频次:   18
  • DOI:   10.1103/PhysRevB.80.205101
  • 出版年:   2009

▎ 摘  要

We numerically study the quantum Hall effect (QHE) in bilayer graphene based on tight-binding model in the presence of disorder. Two distinct QHE regimes are identified in the full energy band separated by a critical region with nonquantized Hall Effect. The Hall conductivity around the band center (Dirac point) shows an anomalous quantization proportional to the valley degeneracy, but the nu=0 plateau is markedly absent, which is in agreement with experimental observation. In the presence of disorder, the Hall plateaus can be destroyed through the float-up of extended levels toward the band center and higher plateaus disappear first. The central two plateaus around the band center are most robust against disorder scattering, which is separated by a small critical region in between near the Dirac point. The longitudinal conductance around the Dirac point is shown to be nearly a constant in a range of disorder strength, until the last two QHE plateaus completely collapse.