• 文献标题:   Conductivity and scattering in graphene bilayers: Numerically exact results versus Boltzmann approach
  • 文献类型:   Article
  • 作  者:   XU HY, HEINZEL T, ZOZOULENKO IV
  • 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:   Univ Dusseldorf
  • 被引频次:   11
  • DOI:   10.1103/PhysRevB.84.115409
  • 出版年:   2011

▎ 摘  要

We derive analytical expressions for the conductivity of bilayer graphene (BLG) using the Boltzmann approach within the the Born approximation for a model of Gaussian disorders describing both short- and long-range impurity scattering. The range of validity of the Born approximation is established by comparing the analytical results to exact tight-binding numerical calculations. A comparison of the obtained density dependencies of the conductivity with experimental data shows that the BLG samples investigated experimentally so far are in the quantum scattering regime where the Fermi wavelength exceeds the effective impurity range. In this regime both short-and long-range scattering lead to the same linear density dependence of the conductivity. Our calculations imply that bilayer and single-layer graphene have the same scattering mechanisms. We also provide an upper limit for the effective, density-dependent spatial extension of the scatterers present in the experiments.