All-Optical Technique Creates Condensate

Researchers at Georgia Institute of Technology in Atlanta have developed an all-optical method to produce Bose-Einstein condensates. All other condensates produced to this point have required the use of magnetic confinement. The physicists are hopeful that the new technique can be extended to trap and cool mixtures of atoms as well as molecules.

The team employed two crossed beams from CO₂ lasers to confine atoms from a sub-Doppler laser-cooled gas of rubidium-87. Lowering the power of the beams for two seconds resulted in evaporative cooling and the formation of a condensate containing approximately 35,000 atoms. A description of the technique appears in the July 2 issue of Physical Review Letters