Stability and decay of subradiant patterns in a quantum gas with photon-mediated interactions

TL;DR

This paper investigates the stability and decay of subradiant patterns in a quantum gas with photon-mediated long-range interactions, revealing metastability mechanisms and decay dynamics through combined experimental and theoretical analysis.

Contribution

It demonstrates the existence of long-lived subradiant patterns stabilized by photon-mediated interactions and provides a comprehensive ab-initio theory explaining their metastability and decay.

Findings

Subradiant patterns exhibit lifetimes far exceeding typical system timescales.

Decay occurs via an abrupt transition to a superradiant phase.

Photon-mediated interactions stabilize metastable quantum states.

Abstract

Metastability and its relaxation mechanisms challenge our understanding of the stability of quantum many-body systems, revealing a gap between the microscopic dynamics of the individual components and the effective descriptions used for macroscopic observables. We observe excited self-ordered subradiant patterns in a quantum gas coupled to two optical cavities and report lifetimes far beyond the system's typical timescales. These patterns eventually decay through an abrupt transition reordering the atoms into a superradiant phase. Ab-initio theory fully captures this macroscopic behavior, revealing that the subradiant patterns are stabilized by photon-mediated long-range interactions, thereby manifesting universal features of metastability characteristic of long-range interacting systems, as in astrophysics and plasma physics. Our work sheds light on the microscopic mechanisms stabilizing quantum states of matter and highlights the potential of photon-mediated forces for engineering correlations in many-body quantum systems.