title: Quantum Hall to insulator transition in the bilayer quantum Hall ferromagnet.
abstract: We describe a phase transition of the bilayer quantum Hall ferromagnet at nu=1. In the presence of static disorder (modeled by a periodic potential), bosonic S=1/2 spinons undergo a superfluid-insulator transition while preserving ferromagnetism. The Mott insulating phase has an emergent U(1) photon, and the transition is between Higgs and Coulomb phases of this photon. Consequences for charge and counterflow conductivity and for interlayer tunneling conductance are discussed.
authors.affiliation: Department of Physics and Astronomy, University of Kentucky, Lexington, Kentucky 40506-0055, USA.
authors.forename: Ganpathy
authors.initials: G
authors.lastname: Murthy
authors.forename: Subir
authors.initials: S
authors.lastname: Sachdev