Quantum stabilization of a single-photon emitter in a coupled microcavity--half-cavity system

TL;DR

This paper investigates how optical feedback from a distant mirror can stabilize a single-photon emitter within a microcavity, using quantum electrodynamics to identify conditions for stable quantum states.

Contribution

It introduces a quantum analysis of emitter stabilization via half-cavity feedback, revealing conditions for stability involving multiple feedback modes and analogies with laser feedback models.

Findings

Multiple feedback modes enhance stability of the emitter state.

Conditions for stable dark states depend on feedback parameters.

Analogies with Lang-Kobayashi equations provide insight into feedback effects.

Abstract

We analyze the quantum dynamics of a two-level emitter in a resonant microcavity with optical feedback provided by a distant mirror (i.e., a half-cavity) with a focus on stabilizing the emitter-microcavity subsystem. Our treatment is fully carried out in the framework of cavity quantum electrodynamics. Specifically, we focus on the dynamics of a perturbed dark state of the emitter to ascertain its stability (existence of time oscillatory solutions around the candidate state) or lack thereof. In particular, we find conditions under which multiple feedback modes of the half cavity contribute to the stability, showing certain analogies with the Lang-Kobayashi equations, which describe a laser diode subject to classical optical feedback.