A gravito-optical surface trap (GOST). Cesium atoms are first cooled in a magneto-optic trap (MOT). Gravity pulls the atoms downward, where they are deflected upwards by "evanescent waves" (EW), the electromagnetic fields associated with a laser beam reflecting from beneath. On each bounce, however, the atoms lose some energy and therefore eventually collect in a chilled, essentially two-dimensional, cloud at the bottom of the trap. Horizontal focusing is provided by a hollow laser beam encircling the atoms. Researchers at the Max-Planck Institute in Heidelberg hope that the GOST approach will help in achieving a dense Bose-Einstein condensate of atoms.
This research is described in the 22 September 1997 issue of Physical Review Letters.
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