SUPPRESSION AND ENHANCEMENT OF COLLISIONS IN OPTICAL LATTICES

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