Dark state

"Entanglement generated by dissipation and steady state entanglement of two macroscopic objects", Polzik Purely dissipative entanglement creation. Deterministic and uncondional, no light state(environment). Two ensembles are entangled via common environment, which is x-polarized vacuum modes. The Linbland terms in the Master equation (to which they arrive after tracing over the photonic modes) drives system into an EPR state. This scheme is not conditional, as the measurement is performed continuously by the environment.