Controllable Bistability and Turbulent Behavior of Large Atom Number Magneto-Optical Traps

Atomic cloud instabilities in Magneto-Optical Traps (MOT) are often caused by variations from ideal trapping conditions, such as misaligned trapping beams. These instabilities are commonly observed, and there have been several attempts to describe the underlying features of these unstable states. Efforts to understand these states have included descriptions of the cloud center of mass in time as well as attempts to classify trapped atom clouds into different instability regimes from still images, but these lack a comprehensive understanding of the dynamics of the entire cloud over time. A more complete grasp of these dynamics will serve to further understanding of cold atom clouds, which have properties that are less understood than their colder (BEC) and warmer (thermal vapor) counterparts. In working toward this understanding, we report on experimentally observed unstable states induced in a sodium-23 MOT. We can repeatably vary the dynamics of these states by controlling the location of the magnetic field zero along a single direction. We classify these unstable states using a high time resolution camera, and reveal bistable states among these dynamics.