title: Anomalous exciton condensation in graphene bilayers.
abstract: In ordinary semiconductor bilayers, exciton condensates appear at total Landau-level filling factor nu{T}=1. We predict that similar states will occur in Bernal stacked graphene bilayers at many nonzero integer filling factors. For nu{T}=-3, 1 we find that the superfluid density of the exciton condensate vanishes and that a finite-temperature fluctuation-induced first order isotropic-smectic phase transition occurs when the layer densities are not balanced. These anomalous properties of bilayer graphene exciton condensates are due to the degeneracy of Landau levels with n=0 and n=1 orbital character.
authors.affiliation: National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32306, USA.
authors.forename: Yafis
authors.initials: Y
authors.lastname: Barlas
authors.forename: R
authors.initials: R
authors.lastname: Côté
authors.forename: J
authors.initials: J
authors.lastname: Lambert
authors.forename: A H
authors.initials: AH
authors.lastname: Macdonald