All optical local cooling and trapping in 3D

Institut für Theoretische Physik, Universität Innsbruck, Technikerstr. 25, A-6020 Innsbruck, Austria

Received: 11 April 1997
Accepted: 21 July 1997

Abstract

We propose a scheme for three-dimensional trapping and cooling of atoms in a bichromatic standing wave formed by two different longitudinal modes of an optical cavity. The atoms are cooled through an efficient Sisyphus mechanism and trapped at those anti-nodes (maxima) of the stronger field where the second weaker field has a node, this leading to a large effective atom-field coupling. Contrary to the case of a single strong standing wave, the final width of the momentum distribution is considerably less than the depth of the optical potential implying long storage times. The scheme offers the possibility of capturing atoms out of the background and achieving high local densities modulated with the beat frequency of the two involved modes. The results from a three-dimensional semi-classical calculation are confirmed by a full QMCWF simulation as well as by a quantum rate equation model in the one-dimensional case in the proper limits.