Semiclassical Theory of Collision-Induced Loss from Optical Traps

Frank Rebentrost, Selina Klose, Joachim Großer

Andrew M. Smith II, Keith R. Burnett, Paul S. Julienne

A semiclassical analysis of the losses in an optical trap due to radiative collisions is presented. We use WKB theory to calculate the overlap between the ground- and excited-state wave functions. The results may be written as an absorption line shape and a survival on the excited state, with an excited-state velocity determined by energy conservation. In the region around resonance for the transition, the results reduce to those presented in previous analyses.

Thad G Walker, D. W. Seskdo, Christopher R. Monroe +1 more

Paul S. Julienne, S. H . Pan, H. R. Thorsheim +1 more

Quantal and semiclassical calculations have been carried out for the rate coefficient of the collision‐induced emission process in which a ground and excited state sodium atom collide, emit a red‐shifted photon, and separate with enough kinetic energy to escape the trap. The large rate coefficient implies that this process will limit the densities which can be achieved in optical traps.

Y. B. Band, Paul S. Julienne

We develop an optical-Bloch-equation approach for modeling ultracold-atom collisions in optical traps. The method incorporates a molecular picture of the atomic collision, laser-field dressing of the molecular states participating in the dynamics, and decay of the population and polarization due to spontaneous emission of excited states. The last is important to incorporate because the duration of the cold collisions is longer than the excited-state lifetimes. The relative motion of the atoms during the course of the collision is treated semiclassically with corrections for the time-dependent relative motion of the atoms in the various channels. An application of the method to Cs trap loss due to fine-structure-changing collisions is presented. Good agreement with experiment is obtained.

David W. Sesko, Thad G Walker, Christopher R. Monroe +2 more