BOSONIC STIMULATION IN THE FORMATION OF A BOSE-EINSTEIN CONDENSATE

The formation of a Bose-Einstein condensate of a dilute atomic gas has been studied in situ with a nondestructive, time-resolved imaging tec hnique. Sodium atoms were evaporatively cooled close to the onset of B ose-Einstein condensation and then suddenly quenched to below the tran sition temperature. The subsequent equilibration and condensate format ion showed a slow onset distinctly different from simple relaxation. T his behavior provided evidence for the process of bosonic stimulation, or coherent matter-wave amplification, crucial to the concept of an a tom laser.