Strongly coupling a cavity to inhomogeneous ensembles of emitters : potential for long lived solid-state quantum memories

TL;DR

This paper theoretically explores how coupling a cavity to inhomogeneous emitter ensembles can enhance quantum memory coherence, with potential for long-lived solid-state quantum storage through cavity protection and collective dark states.

Contribution

It demonstrates that the shape of the emitter distribution influences coherence and shows cavity coupling can protect polaritonic states, enabling improved quantum memory performance.

Findings

Cavity coupling can mitigate inhomogeneous broadening effects.

The shape of the emitter distribution affects coherence properties.

Coupled ensembles support a collective dark state useful for quantum storage.

Abstract

We investigate theoretically the coupling of a cavity mode to a continuous distribution of emitters. We discuss the influence of the emitters inhomogeneous broadening on the existence and on the coherence properties of the polaritonic peaks. We find that their coherence depends crucially on the shape of the distribution and not only on its width. Under certain conditions the coupling to the cavity protects the polaritonic states from inhomogeneous broadening, resulting in a longer storage time for a quantum memory based on emitters ensembles. When two different ensembles of emitters are coupled to the resonator, they support a peculiar collective dark state, also very attractive for the storage of quantum information.