Dynamical Instabilities of Strongly Interacting Ultracold Fermions in an Optical Cavity

TL;DR

This paper provides a theoretical analysis of dynamical instabilities in strongly interacting ultracold fermions within optical cavities, explaining experimental observations and predicting new behaviors due to long-range photon-mediated interactions.

Contribution

It introduces a quantitative framework for understanding the formation of superradiance and ordering dynamics in driven fermionic systems with long-range interactions, extending previous experimental insights.

Findings

Quantitative match with existing fermion experiments

Predictions for near-unitary Fermi gases in cavities

Identification of unique ordering dynamics due to non-local interactions

Abstract

Recent quench experiments on ultra cold fermions in optical cavities provide a clean platform for studying how long-range interactions between fermions structure their dynamics. Motivated by these experiments, we provide a theoretical analysis of the dynamical instabilities that lead to the formation of superradiance as the hybrid system is driven across the self-organization transition. We compute the rate at which order forms and quantify the fluctuations of the pre-quench state which seed the instability. Our results quantitatively match existing experiments on free fermions and make predictions for quench experiments involving near unitary fermi gases coupled to an optical cavity. Our work suggests that the non-local nature of the photon-mediated interactions between fermions generates ordering dynamics that are qualitatively different than those observed in short-range interacting systems.