Optical molasses and multilevel atoms: theory

作者：P. J. Ungar, David S. Weiss, Erling Riis, Steven Chu · 发表于：Journal of the Optical Society of America B · 年份：1989 · DOI：10.1364/josab.6.002058 · 被引用次数：362 · 研究领域：Cold Atom Physics and Bose-Einstein Condensates、Orbital Angular Momentum in Optics、Quantum Information and Cryptography

A theoretical analysis is given for laser cooling of a two-level atom with magnetic sublevels in the presence of polarization gradients. The optical Bloch equations for the multilevel system are solved numerically for four combinations of polarizations in one-dimensional optical molasses. The light-pressure force on the atom as given by a simple two-level theory is recovered in the absence of polarization gradients, whereas a spatial variation of the polarization is found to lead to a strong cooling force for slow atoms. The increased cooling force is responsible for the recent observations of atoms cooled in optical molasses to temperatures an order of magnitude below the Doppler limit.