Creating a low-dimensional quantum gas using dark states in an inelastic evanescent-wave mirror

Abstract

We discuss an experimental scheme to create a low-dimensional gas of ultracold atoms, based on inelastic bouncing on an evanescent-wave mirror. Close to the turning point of the mirror, the atoms are transferred into an optical dipole trap. This scheme can compress the phase-space density and can ultimately yield an optically driven atom laser. An important issue is the suppression of photon scattering due to ``cross talk'' between the mirror potential and the trapping potential. We propose that for alkali-metal atoms the photon scattering rate can be suppressed by several orders of magnitude if the atoms are decoupled from the evanescent-wave light. We discuss how such dark states can be achieved by making use of circularly polarized evanescent waves.