Expansion dynamics of a spherical Bose–Einstein condensate

作     者：Rui-Zong Li Tian-You Gao Dong-Fang Zhang Shi-Guo Peng Ling-Ran Kong Xing Shen Kai-Jun Jiang 李睿宗;高天佑;张东方;彭世国;孔令冉;沈星;江开军

作者机构：State Key Laboratory of Magnetic Resonance and Atomic and Molecular PhysicsWuhan Institute of Physics and MathematicsChinese Academy of SciencesWuhan 430071China Center for Cold Atom PhysicsChinese Academy of SciencesWuhan 430071China School of PhysicsUniversity of Chinese Academy of SciencesBeijing 100049China 

出 版 物：《Chinese Physics B》 (中国物理B（英文版）)

年 卷 期：2019年第28卷第10期

页      面：478-482页

核心收录：

学科分类：07[理学] 0805[工学-材料科学与工程（可授工学、理学学位）] 0704[理学-天文学] 0702[理学-物理学] 

基　　金：Project supported by the National Key Research and Development Program of China(Grant No.2016YFA0301503) the National Natural Science Foundation of China(Grant Nos.11674358,11434015,and 11474315) Chinese Academy of Sciences(Grant No.YJKYYQ20170025) 

主　　题：Bose-Einstein condensate spherical trap free expansion 

摘      要：We experimentally and theoretically observe the expansion behaviors of a spherical Bose-Einstein condensate. A rubidium condensate is produced in an isotropic optical dipole trap with an asphericity of 0.037. We measure the variation of the condensate size in the expansion process after switching off the trap. The free expansion of the condensate is isotropic,which is different from that of the condensate usually produced in the anisotropic trap. We derive an analytic solution of the expansion behavior based on the spherical symmetry, allowing a quantitative comparison with the experimental measurement. The interaction energy of the condensate is gradually converted into the kinetic energy during the expansion and after a long time the kinetic energy saturates at a constant value. We obtain the interaction energy of the condensate in the trap by probing the long-time expansion velocity, which agrees with the theoretical calculation. This work paves a way to explore novel quantum states of ultracold gases with the spherical symmetry.