Spontaneous ordering in a cold atomic cloud

A description in terms of a Fokker-Planck equation (FPe) for the single-atom probability distribution was developed, allowing for the investigation of the combined action of the cavity fields, momentum cooling and spatial diffusion. The FPe is coupled to the cavity modes via the Maxwell equations. The structure of the resulting equations closely resembles that of the Kuramoto model. This analogy open the door to new and exciting perspectives and potential applications in sampled of coherently pumped cold atoms. The atomic position and momentum are normalized to the photon wave vector and momentum, respectively. The spontaneous ordering in a cold atomic cloud was demonstrated.