Surface trap for Cs atoms based on evanescent-wave cooling

We demonstrate a gravito-optical surface trap for Cs atoms which exploits cooling in an evanescent light wave. About 10(5) atoms were cooled down to 3 mu K and formed a sample with a mean height of similar to 20 mu m above the surface of a dielectric prism. The trap does not use a magnetic field and leads to very small atomic level perturbations. The excited-state population of the stored atoms is similar to 1.5 x 10(-6) and collisional losses are strongly suppressed.