Dynamical mean-field driven spinor condensate physics beyond the single-mode approximation

TL;DR

This paper demonstrates experimentally that mean-field physics beyond the single-mode approximation significantly influences the non-equilibrium dynamics of spinor Bose-Einstein condensates, confirming theoretical predictions and highlighting implications for quantum technologies.

Contribution

It provides the first experimental evidence of beyond single-mode mean-field effects in spinor condensate dynamics, validating recent theoretical models.

Findings

Observed spin oscillation dynamics match theoretical predictions.

Detected dynamical spatial structure formation in the condensate.

Showed that spatial mean-field effects impact non-equilibrium behavior.

Abstract

$^{23}$Na spin-1 Bose-Einstein condensates are used to experimentally demonstrate that mean-field physics beyond the single-mode approximation can be relevant during the non-equilibrium dynamics. The experimentally observed spin oscillation dynamics and associated dynamical spatial structure formation confirm theoretical predictions that are derived by solving a set of coupled mean-field Gross-Pitaevskii equations [J. Jie et al., Phys. Rev. A 102, 023324 (2020)]. The experiments rely on microwave dressing of the $f=1$ hyperfine states, where $f$ denotes the total angular momentum of the $^{23}$Na atom. The fact that beyond single-mode approximation physics at the mean-field level, i.e., spatial mean-field dynamics that distinguishes the spatial density profiles associated with different Zeeman levels, can -- in certain parameter regimes -- have a pronounced effect on the dynamics when the spin healing length is comparable to or larger than the size of the Bose-Einstein condensate has implications for using Bose-Einstein condensates as models for quantum phase transitions and spin squeezing studies as well as for non-linear SU(1,1) interferometers.