arXiv:1604.03374 · Physical Review A

Bimodal momentum distribution of laser-cooled atoms in optical lattices

Claude M. Dion, S. Jonsell, Anders Kastberg, Peder Sjölund

Published May 18, 2016• 6 citations

Abstract

We study, numerically and experimentally, the momentum distribution of atoms cooled in optical lattices. Using semiclassical simulations, we show that this distribution is bimodal, made up of a central feature corresponding to ``cold,'' trapped atoms, with tails of ``hot,'' untrapped atoms, and that this holds true also for very shallow potentials. Careful analysis of the distribution of high-momentum untrapped atoms, both from simulations and experiments, shows that the tails of the distribution do not follow a normal law, hinting at a power-law distribution and nonergodic behavior. We also revisit the phenomenon leading to the existence of an optimal cooling point, i.e., a potential depth below which the temperature of the atoms starts increasing.

DOI: 10.1103/physreva.93.053416

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