Superradiance in a structured radiation reservoir

Abstract

An atomic Dicke system is coupled to a photonic band-gap continuum, which we model by a Fano-profile density of states. By introduction of two pseudomodes, a Markovian master equation can be derived governing only the degrees of freedom of the atoms plus the two pseudomodes. One of the modes can be adiabatically eliminated, and effectively we then have an atomic Dicke system coupled to a harmonic oscillator and both systems coupled to the same flat continuum. We find that following the superradiant regime, a metastable state is reached for the atomic system. The decay of the metastable state is nonexponential, and we derive an analytical expression for the decay based on perturbation theory and trapping states identified by the Monte Carlo wave-function method. Further, we investigate mean-value equations of motion for the operators of the system and discuss different decorrelation approximations of the operator expectation values.