Retardation-induced anomalous population trapping in a multiply-excited, multiple-emitter waveguide-QED system

Abstract

We study in a numerically-exact manner a multiple-emitter, multiple-excitation waveguide quantum-electrodynamic (waveguide-QED) system including propagation time delay. In particular, we demonstrate anomalous population trapping as a result of the retardation in the excitation exchange between the waveguide and three initially excited emitters. Allowing for local phases in the emitter-waveguide coupling,this population trapping cannot be recovered using a Markovian treatment, proving the essential role of non-Markovian dynamics in the process. Furthermore, this time-delayed excitation exchange allows for a novel steady state, in which one emitter decays entirely to its ground state while the other two remain partially excited.