Nonequilibrium steady state in a large magneto-optical trap

TL;DR

This paper demonstrates the existence of a nonequilibrium steady state in large magneto-optical traps, characterized by anisotropic velocity distributions, and explores its properties through a 3D model considering long-range light-mediated interactions.

Contribution

It provides numerical evidence of a nonequilibrium steady state in large MOTs and analyzes its characteristics using a detailed 3D model with nonlocal interactions.

Findings

Identification of anisotropic velocity distribution in NESS

Dependence of NESS on MOT parameters

Comparison of model predictions with experimental thresholds

Abstract

Considering light-mediated long-range interactions between cold atoms in a magneto-optical trap (MOT), we present numerical evidence of a nonequilibrium steady state (NESS) for sufficiently large number of atoms (> 10^8). This state manifests itself as the appearance of an anisotropic distribution of velocity when a MOT approaches the threshold beyond which self-oscillating instabilities occur. Our three-dimensional (3D) spatiotemporal model with nonlocal spatial dependencies stemming from the interatomic interactions has recently been compared successfully to predict different instability thresholds and regimes in experiments with rubidium atoms. The behavior of the NESS is studied as a function of the main MOT parameters, including its spatiotemporal characteristics.