title: Temperature-induced spontaneous time-reversal symmetry breaking on the honeycomb lattice.
abstract: Phase transitions involving spontaneous time-reversal symmetry breaking are studied on the honeycomb lattice at finite hole doping with next-nearest-neighbor repulsion. We derive an exact expression for the mean-field equation of state in closed form, valid at temperatures much less than the Fermi energy. Contrary to standard expectations, we find that thermally induced intraband particle-hole excitations can create and stabilize a uniform metallic phase with broken time-reversal symmetry as the temperature is raised in a region where the ground state is a trivial metal.
authors.affiliation: Physics Department, City College of the City University of New York, New York, New York 10031, USA.
authors.forename: Wei
authors.initials: W
authors.lastname: Liu
authors.affiliation: Physics Department, City College of the City University of New York, New York, New York 10031, USA.|Instituto de Física Teórica - Universidade Estadual Paulista, R. Dr. Bento Teobaldo Ferraz 271, Barra Funda, São Paulo, São Paulo 01140-070, Brazil.
authors.forename: Alexander
authors.initials: A
authors.lastname: Punnoose