Superradiance of cold atoms coupled to a superconducting circuit

TL;DR

This paper studies how inhomogeneous coupling affects superradiance in cold atoms linked to a superconducting circuit, revealing that coupling variations can alter relaxation dynamics and dark state formation.

Contribution

It introduces a combined perturbation and numerical approach to analyze inhomogeneous superradiance and generalizes the superradiance propagator to the full Hilbert space.

Findings

Inhomogeneous couplings can significantly change superradiant relaxation.

Dark states can form, leading to incomplete relaxation.

Relaxation speed varies with coupling distribution.

Abstract

We investigate superradiance of an ensemble of atoms coupled to an integrated superconducting LC-circuit. Particular attention is paid to the effect of inhomogeneous coupling constants. Combining perturbation theory in the inhomogeneity and numerical simulations we show that inhomogeneous coupling constants can significantly affect the superradiant relaxation process. Incomplete relaxation terminating in "dark states" can occur, from which the only escape is through individual spontaneous emission on a much longer time scale. The relaxation dynamics can be significantly accelerated or retarded, depending on the distribution of the coupling constants. On the technical side, we also generalize the previously known propagator of superradiance for identical couplings in the completely symmetric sector to the full exponentially large Hilbert space.