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{sup 5} atoms were cooled down to 3{mu}K and formed a sample with a mean height of {approximately}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 {approximately}1.5{times}10{sup {minus}6} and collisional losses are strongly suppressed. {copyright} {ital 1997} {ital The American Physical Society}