An Ideal Mean-Field Transition in a Modulated Cold Atom System

TL;DR

This paper demonstrates a mean-field symmetry-breaking transition in a periodically modulated cold atom system, driven by long-range interactions and nonequilibrium fluctuations, with a comprehensive microscopic theory explaining the critical dynamics.

Contribution

It introduces an ideal mean-field transition in a modulated cold atom system and provides a microscopic theory for its critical dynamics.

Findings

Observation of symmetry-breaking transition with respect to time translation

Anomalous fluctuations in the symmetry-broken phase

Theoretical description matching experimental critical dynamics

Abstract

We show that an atomic system in a periodically modulated optical trap displays an ideal mean-field symmetry-breaking transition. The symmetry is broken with respect to time translation by the modulation period. The transition is due to the interplay of the long-range interatomic interaction and nonequilibrium fluctuations. The observed critical dynamics, including anomalous fluctuations in the symmetry broken phase, are fully described by the proposed microscopic theory.