Evaporative cooling of cesium atoms in the gravito-optical surface trap

Abstract

We report on cooling of an atomic cesium gas closely above an evanescent-wave atom mirror. Our first evaporation experiments show a temperature reduction from 10 μK down to 300 nK along with a gain in phase-space density of almost two orders of magnitude. In a series of measurements of heating and spin depolarization an incoherent background of resonant photons in the evanescent-wave diode laser light was found to be the limiting factor at this stage.