Dissipative coupling and weak lasing of exciton-polariton condensates
B. Altshuler, Columbia University, New York
In spite of having finite life-time exciton-polaritons in microcavities are known to condense at strong enough pumping of the reservoir. I will discuss an analytical theory of such Bose-condensates on a set of localized one-particle states: condensation centers. To understand physics of these arrays one has to supplement the Josephson coupling by the dissipative coupling caused by the interference between the bosons emitted by different centers. Combination of these couplings with the one-site interaction between the bosons leads to a rich nonlinear dynamics. In particular, a new regime of radiation appears. This regime can be called weak lasing: the centers have macroscopic occupations and radiate coherently, but the coupling alone is sufficient for stabilization. The system can have several stable states and switch between them. Moreover, the time reversal symmetry in this regime is, as a rule, broken. A number of existing experimental puzzles find natural interpretation in the framework of this theory.