Analytical Study of Quantum Feedback Enhanced Rabi Oscillations

TL;DR

This paper provides an analytical solution for quantum feedback in a cavity QED system, showing how feedback can induce strong coupling oscillations from weak coupling conditions through interference effects.

Contribution

It introduces an exact analytical model for single photon quantum feedback in a structured continuum, revealing conditions to achieve strong coupling from weak coupling regimes.

Findings

Feedback-induced oscillations depend on delay time and coupling strength

Destructive interference prevents leakage into the continuum

System can be driven into strong coupling regime via feedback

Abstract

We present an analytical solution of the single photon quantum feedback in a cavity quantum electrodynamics system based on a half cavity set-up coupled to a structured continuum. The exact analytical expression we obtain allows us to discuss in detail under which conditions a single emitter-cavity system, which is initially in the weak coupling regime, can be driven into the strong coupling regime via the proposed quantum feedback mechanism [Carmele et al, Phys.Rev.Lett. 110, 013601]. Our results reveal that the feedback induced oscillations rely on a well-defined relationship between the delay time and the atom-light coupling strength of the emitter. At these specific values the leakage into the continuum is prevented by a destructive interference effect, which pushes the emitter to the strong coupling limit.