Role of transverse excitations in the instability of Bose-Einstein condensates moving in optical lattices
Role of transverse excitations in the instability of Bose-Einstein condensates moving in optical lattices
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DOI：
10.1103/physreva.70.043625
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发表时间：
2004-05
影响因子：
2.9
通讯作者：
Michele Modugno;C. Tozzo;F. Dalfovo
中科院分区：
文献类型：
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作者：
Michele Modugno;C. Tozzo;F. Dalfovo
利用Gross-Pitaevskii理论分析了一维光晶格中运动的玻色-爱因斯坦凝聚体的能量不稳定性和动力学不稳定性。全三维计算的结果进行了比较，一个有效的一维模型，非多项式薛定谔方程，指出横向自由度所发挥的作用。的不稳定阈值被证明是几乎不受横向激励，使他们可以准确地预测有效的一维模型。相反，横向激励原来是重要的特征的稳定性图和一个复杂的径向动力学的动态不稳定性的阈值以上的发生。这种分析提供了一个现实的框架，讨论在最近的实验中观察到的耗散动力学。
The occurrence of energetic and dynamical instabilities in a Bose-Einstein condensate moving in a one-dimensional (1D) optical lattice is analyzed by means of the Gross-Pitaevskii theory. Results of full 3D calculations are compared with those of an effective 1D model, the nonpolynomial Schr\"odinger equation, pointing out the role played by transverse degrees of freedom. The instability thresholds are shown to be scarcely affected by transverse excitations, so that they can be accurately predicted by effective 1D models. Conversely, transverse excitations turn out to be important in characterizing the stability diagram and the occurrence of a complex radial dynamics above the threshold for dynamical instability. This analysis provides a realistic framework to discuss the dissipative dynamics observed in recent experiments.