Polaritons and pairing phenomena in Bose-Hubbard mixtures.
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.
Bhaseen
M J
MJ
Cavendish Laboratory, University of Cambridge, Cambridge, CB3 0HE, United Kingdom.
Hohenadler
M
M
Silver
A O
AO
Simons
B D
BD