Suppression and Enhancement of Collisions in Optical Lattices

Abstract

In a three-dimensional optical lattice for metastable xenon we observe the dynamical effects of the optical potential on Penning ionizing collisions between atoms. Enhancement of collisions over that for free atoms is observed at short times after the atoms are loaded into the lattice. After the atoms thermalize and localize into the potential wells, we observe a suppression of the collisions by as much as a factor of 2. From our measurements and a simple model we are able to extract an estimate of the rate at which atoms ``hop'' between wells.