Collective effects between multiple nuclear ensembles in an x-ray cavity-QED setup

TL;DR

This paper extends the theoretical model of x-ray cavity-QED with Moessbauer nuclei to include multiple nuclear ensembles and cavity modes, revealing cooperative effects and spectral signatures, and successfully modeling related experiments.

Contribution

The paper introduces a comprehensive quantum mechanical model for multiple nuclear ensembles and modes in x-ray cavity-QED, capturing cooperative effects and spectral features.

Findings

Reproduces experimental spectral signatures

Reveals cooperative effects between nuclear ensembles

Provides a microscopic understanding of the system

Abstract

The setting of Moessbauer nuclei embedded in thin-film cavities has facilitated an aspiring platform for x-ray quantum optics as shown in several recent experiments. Here, we generalize the theoretical model of this platform that we developed earlier [Phys. Rev. A 88, 043828 (2013)]. The theory description is extended to cover multiple nuclear ensembles and multiple modes in the cavity. While the extensions separately do not lead to qualitatively new features, their combination gives rise to cooperative effects between the different nuclear ensembles and distinct spectral signatures in the observables. A related experiment by Roehlsberger et al. [Nature 482, 199 (2012)] is successfully modeled, the scalings derived with semiclassical methods are reproduced, and a microscopic understanding of the setting is obtained with our quantum mechanical description.