一维光晶格中玻色凝聚气体的干涉

Interference of Bose-condensed gas in a 1D optical lattice

对捕限在三维轴对称谐振势阱叠加一维光晶格的组合势中的玻色凝聚气体,文章基于平均场G-P方程并运用传播子方法,求解玻色凝聚气体基态波函数及其随时间的演化,给出了物质波干涉图样的空间分布与光晶格势周期结构之间的关系.研究表明,运用这一方法得到的光晶格势中物质波干涉条纹与光学中的多光束干涉相类似,并且与Andrews和Peil等人的实验结果一致.物质波干涉图样随时间的演化也与Sadhan K.Adhikari通过直接数值求解G-P方程所得结果基本相同.

For the Bose-condensed gas in a combined potential consisting of an axially-symmetric harmonic magnetic trap and onedimensional （1D） optical lattice, using the mean-field Gross-Pitaevskii （G-P） equation and the propagator method, we study the formation of matter-wave interference upon releasing the condensate from the combined potential. The analytical result of the wave function for matter wave interference at any time t is given, and the relation between the interference fringe period and the optical lattice period is obtained. The interference pattern of Bose-condensed gas in the optical lattices is analogous to the multiple slit interference pattern in optics, and coincides with the results of experiment performed by Andrews et al. and Peil et al. and the numerical solution of the G-P equation by Sadhan K. Adhikari.