Instability of Overlapped Vortices Rotating in Opposite Directions in Binary Bose–Einstein Condensates
Instability of Overlapped Vortices Rotating in Opposite Directions in Binary Bose–Einstein Condensates
复制标题
二元玻色-爱因斯坦凝聚态中相反方向旋转的重叠涡旋的不稳定性
DOI：
10.1007/s10909-012-0798-x
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发表时间：
2012
影响因子：
2
通讯作者：
H. Takeuchi
中科院分区：
文献类型：
--
作者：
S. Ishino;M. Tsubota;H. Takeuchi
本文从理论上研究了饼状玻色-爱因斯坦凝聚体中涡旋的不稳定性。我们考虑一个量子化的涡旋位于每个凝聚体的中心，两个凝聚体以相反的方向旋转。在具有重叠涡旋的BEC中，总环流为零，因为存在相对旋转，这是一个分量相对于另一个分量的旋转，但没有总旋转，这是两个分量的旋转之和。我们认为，零量子涡旋是不稳定的，因为这个系统是局部反超流，两个反向传播的可混溶超流。在均匀系统中，当两个凝结体之间的相对速度超过临界值时，逆流是不稳定的。我们通过数值求解Gross-Pitaevskii方程来研究零量子涡旋的动力学。为了理解数值计算的结果，我们将逆流不稳定性应用到我们目前的系统中。
We theoretically study the instability of vortices in pancake-shaped trapped binary Bose–Einstein condensates. We consider that a quantized vortex is at the center of each condensate and two condensates rotate in the opposite directions. The total circulation is zero in BECs having the overlapped vortices because there is relative rotation, which is the rotation of one component in relation to the rotation of the other, but no total rotation, which is the sum of the rotation in both components. We think that the zero-quantum vortices are unstable because this system is locally countersuperflow, two counterpropagating miscible superflows. In a uniform system, the countersuperflow is unstable when the relative velocity between the two condensates exceeds a critical value. We investigate the dynamics of the zero-quantum vortices by numerically solving the Gross–Pitaevskii equations. To understand the results of the numerical calculations, we apply the countersuperflow instability to our present system.