Probing the linear and nonlinear excitations of Bose-condensed neutral atoms in a trap.
Probing the linear and nonlinear excitations of Bose-condensed neutral atoms in a trap.
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DOI：
10.1103/physreva.54.4178
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发表时间：
1996-11
期刊：
影响因子：
--
通讯作者：
Ruprecht;Edwards;Burnett;Clark
中科院分区：
文献类型：
--
作者：
Ruprecht;Edwards;Burnett;Clark
通过求解Bogoliubov方程和直接积分依赖于时间的Ginzburg-Pitaevskii-Gross方程，研究了被囚禁的中性原子的玻色-爱因斯坦凝聚体对囚禁势的弱和强正弦扰动的响应.我们发现，当扰动的频率等于凝聚体的激发光谱的模式位置之一时，凝聚体的畸变是最大的。在共振时，凝聚体表现出很强的非线性响应，可以作为一个明确的签名的模式频率在实验中的陷阱势弱扰动。对于强驱动，我们发现了一系列的非线性效应，如谐波产生和频率混合的证据。这些现象是传统非线性光学的物质波类似物，应该可以直接在碱金属原子的蒸发冷却样品中进行研究。
We investigate the response of a Bose-Einstein condensate of trapped, neutral atoms to weak and strong sinusoidal perturbation of the trapping potential both by solving the Bogoliubov equations and by direct integration of the time-dependent, driven Ginzburg-Pitaevskii-Gross equation. We find that the distortion of the condensate is maximal when the frequency of the perturbation equals one of the mode positions of the condensate’s excitation spectrum. On resonance, the condensate exhibits a strong nonlinear response that can be used as a clear signature of the mode frequency in an experiment where the trap potential is weakly perturbed. For strong driving, we find evidence for an array of nonlinear effects such as harmonic generation and frequency mixing. These phenomena are the matter-wave analogs of conventional nonlinear optics and should be straightforward to study in evaporatively cooled samples of alkali-metal atoms.© 1996 The American Physical Society.