title: Fractional quantum Hall States of Dirac electrons in graphene.
abstract: We have investigated the fractional quantum Hall states of Dirac electrons in a graphene layer in different Landau levels. The relativistic nature of the energy dispersion relation of electrons in graphene significantly modifies the interelectron interactions. This results in a specific dependence of the ground state energy and the energy gaps for electrons on the Landau-level index. For the valley-polarized states, i.e., at nu=1/m, m being an odd integer, the energy gaps have the largest values in the n=1 Landau level. For the valley-unpolarized states, e.g., for the 2/3 state, the energy gaps are suppressed for n=1 as compared to those at n=0. For both n=1 and n=0, the ground state of the 2/3 system is fully valley-unpolarized.
authors.affiliation: Department of Physics and Astronomy, Georgia State University, Atlanta, GA 30303, USA.
authors.forename: Vadim M
authors.initials: VM
authors.lastname: Apalkov
authors.forename: Tapash
authors.initials: T
authors.lastname: Chakraborty