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基于Gross-Pitaevskii方程,运用有效化学势概念,研究了囚禁在组合势(由磁阱和三维光 晶格组成)中玻色凝聚气体在三维光晶格中的分布规律,并由此得到玻色凝聚气体的归 一化基态波函数.在取消组合势和仅取消光晶格而保留磁阱的两种情况下,运用传播子方 法求解出玻色凝聚气体密度分布的解析表达式.取消组合势后,理论计算所得到的玻色凝聚 气体聚随时间的演化规律与Greiner等的实验结果相一致.仅取消光晶格而保留磁阱时,研 究表明玻色凝聚气体的干涉模式呈现周期性的振荡行为.此外,在磁阱为各向异性的情况下 ,
关键词:
玻色凝聚气体
磁阱
光晶格
干涉模式 相似文献
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评估学习行为,改革教学模式 总被引:1,自引:0,他引:1
本文从调查研究着手,分析了当前大学生物理存在的问题,提出了具体的教学对策,并对一年来教改革实践效果用调查数据作了对比分析,得了有意义的教学启示,取得了有益经验。 相似文献
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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.
关键词:
玻色凝聚气体
子凝聚原子云
光晶格势
干涉 相似文献
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For a Bose-condensed gas in a combined potential consisting of an axially-symmetric harmonic magnetic trap and one-dimensional (1D) optical lattice, using the mean-field Gross-Pitaevskii (G-P) equation and the propagator method, we obtain the analytical result of the order parameter for matter wave interference at any time. The evolution of the interference pattern under a variation of the relative phase △Ф between successive subcondensates trapped on an optical lattices is also studied. For △Ф=π, the interference pattern is symmetric with two sharp peaks, which are symmetrically located on a straight line on both sides of a vacant central peak and moving apart from each other. This work is in agreement with available experimental results. 相似文献
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The evolution and collision of Bose-condensed gases in one-dimensional optical lattices are investigated in the presence of an infinitely deep square well created by two far-off resonant laser beams.The two far-off resonant laser beams are superimposed on the combined potential consisting of a magnetic trap and one-dimensional optical lattices.After the combined potential is switched off,the analytical result of the evolution of the density distribution of the Bose-condensed gas is given by using the propagator method.The collisions between the condensate and the infinitely deep square well are shown in the present work. 相似文献
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Adiabatic tunneling of Bose–Einstein condensates with modulated atom interaction in a double-well potential 下载免费PDF全文
We study the adiabatic tunneling of Bose–Einstein condensates in a symmetric double-well potential when the interaction strength between the atoms is modulated linearly or in a cosine periodic form. It is shown that the system evolves along a nonlinear eigenstate path. In the case of linear modulation under the adiabatic approximation conditions, the tunneling probability of the condensate atoms to the other potential well is half. However, when the system is periodically scanned in the adiabatic process, we find an interesting phenomenon. A small change in the cycle period can lead to the condensate atoms returning to the right well or tunneling to the left well. The system comes from a linear eigenstate back to a nonlinear one, which is completely different from the linear eigenstate evolution. We explain the results by using the energy level and the phase diagram. 相似文献