Topological chirality of dissipative limit cycles in an open Dicke model

RESUMO

In an open, $U(1)$-symmetric Dicke model with chiral atom-cavity couplings, we show that dissipation drives two limit-cycle phases of opposite chirality in the thermodynamic limit, obtaining exact analytical solutions. These phases are separated by a $U(1)$-broken superradiant state, lending the phase diagram a topological character, and persist under $U(1)$-preserving perturbations, making them candidates for chiral continuous time crystals. In addition to stable normal and inverted steady states, the model also exhibits multistability, where the long-time dynamics is set by the initial state. Our results establish dissipation as a resource for inducing chiral dynamical order in light-matter coupled systems.