Thermal emission in the ultrastrong coupling regime

TL;DR

This paper investigates thermal emission in cavity QED systems operating in the ultrastrong coupling regime, where traditional models fail, by employing a dressed basis approach to accurately compute emission spectra across various coupling strengths.

Contribution

It introduces a method to calculate thermal emission spectra in the ultrastrong coupling regime using a dressed basis approach, extending analysis to arbitrary light-matter interaction strengths.

Findings

Thermal photoluminescence spectra vary significantly with coupling strength.

The approach is applicable to circuit QED parameters.

Standard photodetection models are inadequate in this regime.

Abstract

We study thermal emission of a cavity quantum electrodynamic system in the ultrastrong-coupling regime where the atom-cavity coupling rate becomes comparable the cavity resonance frequency. In this regime, the standard descriptions of photodetection and dissipation fail. Following an approach that was recently put forward by Ridolfo et al.[arXiv:1206.0944], we are able to calculate the emission of systems with arbitrary strength of light matter interaction, by expressing the electric field operator in the cavity-emitter dressed basis. Here we present thermal photoluminescence spectra, calculated for given temperatures and for different couplings in particular for available circuit QED parameters.