用SSCN方法研究二维光晶格中玻色凝聚气体的干涉演化  

Research on interference evolution for bose-condensed gas in 2-D optical lattice with SSCN method

作　　者：何芳[1] 刘夏吟[1] 徐志君[1] 

机构地区：[1]浙江工业大学理学院,浙江杭州310032

出　　处：《浙江工业大学学报》2011年第3期351-354,共4页Journal of Zhejiang University of Technology

基　　金：浙江省自然科学基金资助项目(Y6090620)

摘　　要：采用分步克兰克尼科尔森(Split-step Crank-Nicholson,SSCN)方法,数值求解含时Gross-Pitaevskii(G-P)方程,研究二维光晶格中玻色凝聚气体宏观量子性质随时间的演化,给出非线性项系数C=1和C=5两种情形下,取消组合势后玻色凝聚气体密度在自由空间的演化图样,可以看出光晶格中各子原子云与相邻光晶格中的原子云在自由空间膨胀、然后叠加、干涉,由于相位相干性,从而形成九个清晰的干涉峰;而且在相同的时刻,C=5的干涉演化图样中的亮斑比C=1的要大.数值研究结果与现有实验结果和理论分析一致.The Split-step Crank-Nicholson method is applied to solve numerically the two-dimensional（2D） time dependent GP equation.The evolution of macroscopic quantum interference property for bose-condensed gas trapped in 2D optical lattice is investigated.The interference patterns of C=1 and C=5 are given when both the optical lattice and magnetic trap are switched off at time t=0,then nine bright spots are formed because the atom cloud released from one lattice site expands,overlaps and interferes with atom clouds from neighboring sites due to favorable interference,and the spots of C=5 are larger than those of C=1.The result is consistent with the present experimental and theoretical analysis.

关 键 词：分步克兰克尼科尔森方法 光晶格 玻色凝聚气体 干涉 

分 类 号：O431.2[机械工程—光学工程]