The theoretical study of Bose-Einstein condensation in confined system

Zhen Ya Xu, Shuyu Zhou, Qu Qiu-Zhi +4 more

By evaporative cooling in QUIC trap, Bose-Einstein condensate (BEC) was achieved with 2×105 87Rb atoms in |F=2, mF=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.

Adelchi Fabrocini

S. Stringari

Bose-Einstein condensates confined in traps exhibit unique features which have been the object of extensive experimental and theoretical studies in the last few years. In this paper I will discuss some issues concerning the behaviour of the order parameter and the dynamic and superfluid effects exhibited by such systems.

G. GNANAPRAGASAM

Kunal K. Das

Tomoya Isoshima, Mikio Nakahara, Tetsuo Ohmi +1 more

It is shown theoretically that a persistent current can be continuously created in a Bose-Einstein condensate (BEC) of alkali-metal atoms confined in a multiply connected region by making use of a spin degree of freedom of the order parameter of a BEC. We demonstrate that this persistent current is easily transformed into a vortex. Relaxation processes of these BEC after the confining field is turned off are also studied, so that our analyses are compared with time-of-flight experiments. The results are shown to clearly reflect the existence of a persistent current.