COOLING AND LOCALIZATION DYNAMICS IN OPTICAL LATTICES

Using Bragg scattering as a sensitive probe, we study how atoms are co oled and localized after the sudden turn-on of 1D and 3D optical latti ces. We measure the time evolution of the mean-square position spread of the atoms in the lattice potential wells, a quantity proportional t o their effective temperature. The rate of exponential approach to equ ilibrium is proportional to the photon scattering rate and about 6 tim es faster in 1D than in 3D. This simple proportionality was unexpected , based on the usual model of Sisyphus cooling, but is in agreement wi th our 1D Monte Carlo simulations.