Dissipative phase locking of exciton-polariton condensates

We demonstrate, both experimentally and theoretically, a new phenomenon: the presence of dissipative coupling in the system of driven bosons. This is evidenced for a particular case of externally excited spots of exciton-polariton condensates in semiconductor microcavities. We observe that for two spatially separated condensates the dissipative coupling leads to the phase locking, either in-phase or out-of-phase, between the condensates. The effect depends on the distance between the condensates. For several excited spots, we observe the appearance of spontaneous vorticity in the system.