title: Odd-integer quantum Hall effect in graphene: interaction and disorder effects.
abstract: We study the competition between the long-range Coulomb interaction, disorder scattering, and lattice effects in the integer quantum Hall effect (IQHE) in graphene. By direct transport calculations, both nu=1 and nu=3 IQHE states are revealed in the lowest two Dirac Landau levels. However, the critical disorder strength above which the nu=3 IQHE is destroyed is much smaller than that for the nu=1 IQHE, which may explain the absence of a nu=3 plateau in recent experiments. While the excitation spectrum in the IQHE phase is gapless within numerical finite-size analysis, we do find and determine a mobility gap, which characterizes the energy scale of the stability of the IQHE. Furthermore, we demonstrate that the nu=1 IQHE state is a Dirac valley and sublattice polarized Ising pseudospin ferromagnet, while the nu=3 state is an xy plane polarized pseudospin ferromagnet.
authors.affiliation: Department of Physics and Texas Center for Superconductivity, University of Houston, Houston, TX 77204, USA.
authors.forename: L
authors.initials: L
authors.lastname: Sheng
authors.forename: D N
authors.initials: DN
authors.lastname: Sheng
authors.forename: F D M
authors.initials: FD
authors.lastname: Haldane
authors.forename: Leon
authors.initials: L
authors.lastname: Balents