Frequency-Resolved Purcell Effect for the Dissipative Generation of Steady-State Entanglement.

We report a driven-dissipative mechanism to generate stationary entangled W states among strongly interacting quantum emitters placed within a cavity. Driving the ensemble into the highest energy state-whether coherently or incoherently-enables a subsequent cavity-enhanced decay into an entangled steady state consisting of a single deexcitation shared coherently among all emitters, i.e., a W state, well known for its robustness against qubit loss. The nonharmonic energy structure of the interacting ensemble allows this transition to be resonantly selected by the cavity, while quenching subsequent off-resonant decays. Evidence of this purely dissipative mechanism should be observable in state-of-the-art cavity QED systems in the solid state, enabling new prospects for the scalable stabilization of quantum states in dissipative quantum platforms.