Acta Physica Sinica
Self-trapping and its periodic modulation of Bose-Einstein condensates in double-well trap
Guanfang Wang, Fu Li-Bin, Zhao Hong, Liu Jie, (1)北京应用物理与计算数学研究所,北京 100088; (2)兰州大学物理科学与技术学院理论物理研究所,兰州 730000; (3)兰州大学物理科学与技术学院理论物理研究所,兰州 730000;中国工程物理研究院北京研究生部,北京 100088
Abstract
Self-trapping of Bose-Einstein condensates (BEC) in double-well trap is investigated. Two kinds of self-trapping are discussed through phase space analysis in the mean-field approximation: 1) The number of atoms oscillates near an equilibrium point in the phase space, while relative phase increases monotonously with time (running-phase); 2) Both the number of particles and the relative phase oscillate near an equilibrium point in the phase space. In particular, we investigate how an external periodic filed influence the self-trapping. It is found that the external periodic field may dramatically modulate the critical points at which the transition to self-trapping occurs. With this, we can observe self-trapping phenomenon in a dilute Bose-Einstein condensate with a very weak interaction as well. Finally, the effect of many-body quantum fluctuation on self-trapping is also studied. We also discuss how to observe the self-trapping phenomenon with present experimental techniques.