Miscible-Immiscible Transition and Nonequilibrium Scaling in Two-Component Driven Open Condensate Wires

We investigate the steady state phase diagram of two-component driven open condensates in one dimension. We identify a miscible-immiscible transition which is predominantly driven by gapped density fluctuations and occurs upon increasing the inter-component inelastic coupling. Below the transition in the miscible phase, we find the effective long wavelength dynamics to be described by a two-component Kardar-Parisi-Zhang (KPZ) equation that belongs to the nonequilibrium universality class of the one-dimensional single-component KPZ equation at generic choices of parameters. Our results are relevant for different experimental realizations for two-component driven open condensates in exciton-polariton systems.