近日，日本大阪公立大学的Kenta Asakawa&Makoto Tsubota及其研究团队取得一项新进展。他们对自引力玻色-爱因斯坦凝聚体中，两个量子化涡旋与集体模耦合的自旋进行了研究。相关研究成果已于2024年11月14日在国际知名学术期刊《物理评论A》上发表。

本文采用Gross-Pitaevskii-Poisson方程，对自引力玻色-爱因斯坦凝聚体（BEC）中两个平行量子化涡旋的共转进行了数值研究。长程引力吸引相互作用使得BEC能够在无需外部势的情况下实现自束缚，而引力势的密度依赖性则在量子化涡旋中引发了有趣的行为。

本研究旨在为了解引力相互作用影响下两个量子化涡旋的共转提供线索。两个量子化涡旋的共转与BEC的集体模式相耦合，这与外部势束缚下的典型BEC中观察到的行为显著不同。旋转周期随BEC中心初始位置的增加而线性增长。

这种与均匀BEC中观察到的二次增长偏差表明，引力相互作用对旋转的量子化涡旋产生了拖拽效应。两个紧密相邻的量子化涡旋沿着椭圆轨道旋转，并伴有径向波动。然而，当初始位置超出与涡旋核心尺寸相当的临界半径时，它们的轨迹会转变为向外螺旋，这暗示了有效耗散的开始。这项研究结果表明，量子化涡旋的径向波动与BEC的四极模式产生共振，从而产生一种耗散机制。

附：英文原文

Title: Corotation of two quantized vortices coupled with collective modes in self-gravitating Bose-Einstein condensates

Author: Kenta Asakawa, Makoto Tsubota

Issue&Volume: 2024/11/14

Abstract: We numerically examine the corotation of two parallel quantized vortices in a self-gravitating Bose-Einstein condensate (BEC) employing the Gross-Pitaevskii-Poisson equations. The long-range gravitationally attractive interaction allows the BEC to self-confine without the need for external potentials, while the density-dependence of the gravitational potential induces intriguing behaviors in the quantized vortices. The aim of this study is to provide a clue for understanding the corotation of two quantized vortices under the influence of gravitational interactions. The corotation of two quantized vortices is coupled with collective modes of the BEC, which markedly differs from the behavior observed in typical BECs confined by an external potential. The rotational period increases linearly with the initial position from the center of the BEC. This deviation from the quadratic increase observed in a uniform BEC suggests that the gravitational interaction exerts a drag effect on the rotating quantized vortices. The two closely positioned quantized vortices rotate along elliptical orbits with radial fluctuations. However, when the quantized vortices are initially positioned beyond a critical radius comparable to their core sizes, their trajectory transitions into an outward spiral, implying the onset of effective dissipation. Our findings demonstrate that the radial fluctuations of the quantized vortex resonate with the quadrupole mode of the BEC, giving rise to a dissipation mechanism.

DOI: 10.1103/PhysRevA.110.053310

Source: https://journals.aps.org/pra/abstract/10.1103/PhysRevA.110.053310