title: Polaritons and pairing phenomena in Bose-Hubbard mixtures.
abstract: Motivated by recent experiments on cold atomic gases in ultrahigh finesse optical cavities, we consider the two-band Bose-Hubbard model coupled to quantum light. Photoexcitation promotes carriers between the bands, and we study the interplay between Mott insulating behavior and superfluidity. The model displays a U(1)xU(1) symmetry which supports the coexistence of Mott insulating and superfluid phases and yields a rich phase diagram with multicritical points. This symmetry is shared by several other problems of current experimental interest, including two-component Bose gases in optical lattices and the bosonic BEC-BCS crossover for atom-molecule mixtures induced by a Feshbach resonance. We corroborate our findings by numerical simulations.
authors.affiliation: Cavendish Laboratory, University of Cambridge, Cambridge, CB3 0HE, United Kingdom.
authors.forename: M J
authors.initials: MJ
authors.lastname: Bhaseen
authors.forename: M
authors.initials: M
authors.lastname: Hohenadler
authors.forename: A O
authors.initials: AO
authors.lastname: Silver
authors.forename: B D
authors.initials: BD
authors.lastname: Simons