Direct observation of Bose-Einstein condensation transition in 87 Rb atomic gases in tightly confinement QUIC trap

By evaporative cooling in QUIC trap, Bose-Einstein condensate (BEC) was achieved with 2 x 10(587) Rb atoms in \ F = 2, M-F = 2] state. We have demonstrated the criterion of BEC transition by the variation of the axial size of the atoms in tight confinement, and observed phase transition from thermal atomic gases to Bose-Einstein condensate, and measured the shift of aspect ratio of BEC during free expansion, which compared with theoretical prediction