Polaron-Polariton Assisted Thermally Activated Superradiance

We predict an anomalous thermally activated superradiance in molecular aggregates within polaritonic environments. In contrast to free space, the collective emission is enhanced when either the exciton-phonon coupling or the temperature increases. This counterintuitive phenomenon is captured by a microscopic theory that combines macroscopic quantum electrodynamics with a modified polaron quantum master equation approach, revealing a nontrivial interplay among excitons, phonons, and polaritons.