SELF-ORGANIZATION OF ATOMIC SAMPLES IN RESONATORS AND COLLECTIVE LIGHT FORCES

We report on a novel type of collective friction force acting on the center-of-mass motion of a self-organizing atomic sample inside a resonator. The force substantially exceeds the sum of the light forces acting on isolated atoms. We also observe spontaneous symmetry breaking between two equivalent, but spatially offset, self-organization patterns in the standing wave resonator, as predicted by Domokos and Ritsch. We identify and experimentally verify the dependencies of the threshold for the self-organization process on incident-light and atomic sample properties.