Precursor Phenomena of Nucleations of Quantized Vortices in the Presence of a Uniformly Moving Obstacle in Bose-Einstein Condensates
Precursor Phenomena of Nucleations of Quantized Vortices in the Presence of a Uniformly Moving Obstacle in Bose-Einstein Condensates
复制标题
玻色-爱因斯坦凝聚中存在均匀移动障碍物时量子化涡旋成核的前驱现象
DOI：
10.1007/s10909-013-0964-9
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发表时间：
2014
期刊：
影响因子：
--
通讯作者：
Masaya Kunimi and Yusuke Kato
中科院分区：
文献类型：
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作者：
A.Arita;Y.Igarashi;T.Morisaku;H.Yui;Masaya Kunimi and Yusuke Kato
通过求解Gross-Pitaevskii方程和Bogoliubov方程，研究了具有均匀运动高斯势的二维环面中玻色-爱因斯坦凝聚体的激发和涨落.当电势的移动速度v接近临界速度（>0）时，电流亚稳态（对于足够慢的移动电势，亚稳态会降低到基态）和第一激发态之间的能隙Δ为零。我们发现了一个标度律，这意味着一个特征时间尺度向临界速度发散。在临界速度附近，我们发现，低能量的局部密度波动增强。这些行为可以看作是涡旋形核的前兆现象。
We investigate excitations and fluctuations of Bose-Einstein condensates in a two-dimensional torus with a uniformly moving Gaussian potential by solving the Gross-Pitaevskii equation and the Bogoliubov equation. The energy gap Δ between the current-flowing metastable state (that reduces to the ground state for sufficiently slowly-moving potential) and the first excited state vanishes when the moving velocityvof the potential approaches a critical velocity(>0). We find a scaling law, which implies that a characteristic time scale diverges toward the critical velocity. Near the critical velocity, we show that low-energy local density fluctuations are enhanced. These behaviors can be regarded as precursor phenomena of the vortex nucleation.