We report on the observation of spontaneously drifting coupled spin and quadrupolar density waves in the ground state of laser driven Rubidium atoms. These laser-cooled atomic ensembles exhibit spontaneous magnetism via light mediated interactions when submitted to optical feedback by a retro-reflecting mirror. Drift direction and chirality of the waves arise from spontaneous symmetry breaking. The observations demonstrate a novel transport process in out-of-equilibrium magnetic systems.
@article{arxiv.2310.17305,
title = {Spontaneously sliding multipole spin density waves in cold atoms},
author = {G. Labeyrie and J. G. M. Walker and G. R. M. Robb and R. Kaiser and T. Ackemann},
journal= {arXiv preprint arXiv:2310.17305},
year = {2024}
}