  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.
