Optical and evaporative cooling of cesium atoms in the gravito-optical   surface trap
  We report on cooling of an atomic cesium gas closely above an evanescent-wave atom mirror. At high densitities, optical cooling based on inelastic reflections is found to be limited by a density-dependent excess temperature and trap loss due to ultracold collisions involving repulsive molecular states. Nevertheless, very good starting conditions for subsequent evaporative cooling are obtained. Our first evaporation experiments show a temperature reduction from 10muK down to 300nK along with a gain in phase-space density of almost two orders of magnitude. 
M. Hammes, D. Rychtarik, V. Druzhinina, U. Moslener, I.   Manek-H\"onninger, and R. Grimm (Max-Planck-Institut f\"ur Kernphy...