  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 de-excitation shared coherently among all
emitters, i.e., a $W$ state, well known for its robustness against qubit loss.
The non-harmonic 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.
