Competing mechanisms for light-induced magnetic self-organization in cold atoms: ground-state coherence vs orientation

Josh Walker

We investigated the interplay between two mechanisms for magnetic self-organization in a cloud of cold atoms subjected to a retro-reflected laser beam. The transition between two different phases, one linked to a spontaneous spatial modulation of the Δm = 2 ground-state coherence and the other to that of the magnetic orientation (spin), can be induced by tuning either a weak magnetic field or the laser intensity. We have investigated numerical simulations of the coexistence of the two phases and the laser intensity transition both of which are compared with experimental observations.