Exciton-polariton condensate
= Exciton-polariton condensate
An <exciton-polariton condensate> has coherent macroscopic occupation of an <exciton>–<photon> hybrid mode. Finite <photon> lifetime makes it an open system: pumping a noncondensed reservoir can replenish condensate losses. A condensate equation coupled to a reservoir-rate equation describes gain saturation, interaction shifts and reservoir feedback; it need not possess a conserved <Hamiltonian>.