Ionizing Collisions in the Optical Lattice of Metastable Krypton and Argon Atoms

Abstract

Ionizing collisional loss rate of the metastable argon and krypton atoms inan optical lattice is compared with the rate of atoms in free space as afunction of lattice laser detuning.Contrary to a simple picture of the isolation of atoms by the latticepotential, our experimental result shows that the collision rate in opticallattice is always larger than that in free space except at a large laserdetuning of -- 10³ transition linewidth.Comparing the experimental result with the theoretical values that arederived from the classical trajectory calculation of the atom, we foundthat the optical pumping to non-trapped adiabatic potential surfaceprevents the collision suppression because it keeps the number ofnon-trapped atoms to a finite value even at low excitation rate.