Vortex-lattice in a uniform Bose–Einstein condensate in a box trap
Vortex-lattice in a uniform Bose–Einstein condensate in a box trap
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盒式陷阱中均匀玻色-爱因斯坦凝聚体中的涡晶格
DOI：
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发表时间：
2019
期刊：
影响因子：
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通讯作者：
S. K. Adhikari
中科院分区：
文献类型：
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作者：
S. K. Adhikari
我们对盒式陷阱中快速旋转的均匀准二维玻色-爱因斯坦凝聚体（BEC）中涡旋晶格的形成进行了数值研究。我们考虑两种类型的盒子：方形和圆形。在方形二维盒式陷阱中，当产生的涡流数量是整数的平方时，发现涡流排列成完美的方格，但当产生的涡流数量是任意时，会发现中心附近存在偏差。对于圆形盒式疏水阀，快速旋转的 BEC 中产生的涡流位于同心闭合轨道上。在中心附近，这些轨道具有多边形形状，而在外围附近，轨道是圆形的。圆形箱式捕集器相当于早期液态 He II 实验中使用的旋转圆柱形桶。两种情况下产生的涡流数量与费曼的普遍估计在质量上一致。本研究的数值模拟是通过旋转坐标系中基本平均场 Gross-Pitaevskii (GP) 方程的解来进行的，其中生成的涡旋晶格的波函数是静止状态。因此，虚数时间传播方法可用于求解 GP 方程，已知该方程可得到精确的数值解。我们还使用收敛的虚时波函数作为初始状态，证明了旋转角频率发生微小变化时涡旋晶格在实时传播中的动态稳定性。
We study numerically the vortex-lattice formation in a rapidly rotating uniform quasi-two-dimensional Bose–Einstein condensate (BEC) in a box trap. We consider two types of boxes: square and circle. In a square-shaped 2D box trap, when the number of generated vortices is the square of an integer, the vortices are found to be arranged in a perfect square lattice, although deviations near the center are found when the number of generated vortices is arbitrary. In case of a circular box trap, the generated vortices in the rapidly rotating BEC lie on concentric closed orbits. Near the center, these orbits have the shape of polygons, whereas near the periphery the orbits are circles. The circular box trap is equivalent to the rotating cylindrical bucket used in early experiment(s) with liquid He II. The number of generated vortices in both cases is in qualitative agreement with Feynman’s universal estimate. The numerical simulation for this study is performed by a solution of the underlying mean-field Gross–Pitaevskii (GP) equation in the rotating frame, where the wave function for the generated vortex lattice is a stationary state. Consequently, the imaginary-time propagation method can be used for a solution of the GP equation, known to lead to an accurate numerical solution. We also demonstrated the dynamical stability of the vortex lattices in real-time propagation upon a small change of the angular frequency of rotation, using the converged imaginary-time wave function as the initial state.
影响因子：
8.6
作者：
Gaunt, Alexander L.;Schmidutz, Tobias F.;Hadzibabic, Zoran
通讯作者：
Hadzibabic, Zoran