Spontaneous symmetry breaking in nonlinear superradiance

TL;DR

This paper numerically explores how interaction with non-classical light states can induce spontaneous symmetry breaking in a modified superradiance system, leading to a collective, symmetry-broken state useful for quantum sensing.

Contribution

It introduces a novel approach leveraging symmetry-based selection rules to suppress single-photon emission, enabling a spontaneous transition to a collective symmetry-broken state in superradiance.

Findings

Demonstrates spontaneous symmetry breaking in a modified superradiance model.

Shows the system reaches a steady state after a spontaneous transition.

Reveals the setup can act as a quantum sensor reproducing quantum fluctuations.

Abstract

Creation and manipulation of non-classical states of light is rapidly becoming the focus of modern attosecond science. Here, we demonstrate numerically how interaction with such states can trigger the emergence of a many-body system with spontaneously broken symmetry by considering a modification of the well-known problem of superradiance encountered already by Dicke. Similarly to him, we investigate photon emission by ensembles of indistinguishable atoms. In contrast to him, however, we leverage symmetry-based selection rules to suppress emission of single photons by single atoms. A steady state is therefore only reached following a spontaneous transition into a collective symmetry-broken state of atoms and photonic modes. This transition permanently locks the atomic dipoles to the quantum field experienced by the system at a particular instant, transforming the entire setup into a potent quantum sensor reproducing the phase of the recorded quantum fluctuation.