Mean-field dynamics of a Bose-Einstein condensate in a time-dependent triple-well trap: Nonlinear eigenstates, Landau-Zener models and STIRAP
Mean-field dynamics of a Bose-Einstein condensate in a time-dependent triple-well trap: Nonlinear eigenstates, Landau-Zener models and STIRAP
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DOI：
10.1103/physreva.73.013617
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发表时间：
2005-07
影响因子：
2.9
通讯作者：
E. Graefe;H. Korsch;D. Witthaut
中科院分区：
文献类型：
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作者：
E. Graefe;H. Korsch;D. Witthaut
在三能级近似下，研究了三阱阱中玻色-爱因斯坦凝聚态（BEC）的动力学行为。在平均场近似（Gross-Pitaevskii方程）中考虑了原子间的相互作用，得到非线性三能级模型。Neweigenstatesemantics由于非线性，取决于系统参数。当参数变化时，如果这种非线性本征态消失，绝热性就失效了。对两种重要的特殊情况：三能级Landau-Zener模型和STIRAP方案，分析了绝热性损失的动力学含义。我们讨论了等斜率Landau-Zener模型中环状能级的出现。在绝热极限下，Zener隧穿几率不趋于零，并且随着参数变化速度的变化而出现明显的振荡，进一步将绝热相干粒子数转移的STIRAP方案推广到非线性情形.结果表明，如果非线性超过失调，STIRAP就会崩溃。
Technische Universit¨at Kaiserslautern, FB Physik, D-67653 Kaiserslautern, Ger many(Dated: February 1, 2008)We investigate the dynamics of a Bose–Einstein condensate (BEC) in a triple-well trap in athree-level approximation. The inter-atomic interactions are taken into account in a mean-fieldapproximation (Gross-Pitaevskii equation), leading toanonlinear three-levelmodel. Neweigenstatesemerge due to the nonlinearity, depending on the system parameters. Adiabaticity breaks down ifsuch a nonlinear eigenstate disappears when the parameters are varied. The dynamical implicationsof this loss of adiabaticity are analyzed for two important special cases: A three level Landau-Zener model and the STIRAP scheme. We discuss the emergence of looped levels for an equal-slope Landau-Zener model. The Zener tunneling probability does not tend to zero in the adiabaticlimit and shows pronounced oscillations as a function of the velocity of the parameter variation.Furthermore we generalize the STIRAP scheme for adiabatic coherent population transfer betweenatomic states to the nonlinear case. It is shown that STIRAPbreaks down if the nonlinearity exceedsthe detuning.