DIRECT OBSERVATION OF ATOMIC LOCALIZATION IN OPTICAL SUPERLATTICES

We present direct experimental evidence for the localization of atoms cooled and trapped in a three-dimensional optical superlattice. As in the case of solid-state superlattices, we are able to tailor the chara cteristics of the optical potential wells. In particular, we impose a long-range modulation to the depth of the potential wells whose size r emains in the optical wavelength range. The cooling mechanism in this configuration accumulates the atoms in the deepest wells. Images of th e resulting separated denser atomic planes (distance similar or equal to 70 mu m) have been obtained both by detecting the fluorescence and by observing the shadow of the cloud. [S1050-2947(98)50204-1].