近日，比利时安特卫普大学的J. Tempere及其研究小组与日本大阪公立大学的H. Takeuchi合作并取得一项新进展。经过不懈努力，他们揭示超流体费米气体中双量子化涡旋的分裂不稳定性。相关研究成果已于2024年4月22日在国际知名学术期刊《物理评论A》上发表。

该研究团队利用低能有效场论研究了超流体费米气体在BEC-BCS交叉中双量子化涡旋的分裂不稳定性。研究人员通过线性稳定性分析和非平衡态数值模拟表明，在交叉处，不稳定性的特征发生了显著变化。在BEC极限条件下，涡旋会分裂成两个单量子化的涡旋，这一过程伴随着声子的发射；然而，在BCS极限下，声子的发射现象则完全消失。

在交叉区，双量子化涡旋的不稳定性和声子发射增强，导致双量子化涡旋的寿命减小。由于旋转超辐射效应，发射出的声子呈现螺旋状放大，这实际上是一种从旋转黑洞中带走能量和角动量的机制。此外，研究人员还研究了温度、布居不平衡以及三维效应对这一过程的影响。

附：英文原文

Title: Splitting instability of a doubly quantized vortex in superfluid Fermi gases

Author: W. Van Alphen, H. Takeuchi, J. Tempere

Issue&Volume: 2024/04/22

Abstract: The splitting instability of a doubly quantized vortex in the BEC-BCS crossover of a superfluid Fermi gas is investigated by means of a low-energy effective field theory. Our linear stability analysis and nonequilibrium numerical simulations reveal that the character of the instability drastically changes across the crossover. In the BEC limit, the splitting of the vortex into two singly quantized vortices occurs through the emission of phonons, while such an emission is completely absent in the BCS limit. In the crossover regime, the instability and phonon emission are enhanced and the lifetime of a doubly quantized vortex becomes minimal. The emitted phonon can be observed as a spiraling pattern amplified due to the rotational superradiance, known as a mechanism to carry away energy and angular momentum from a spinning black hole. We also investigate the influence of temperature, population imbalance, and three-dimensional effects.

DOI: 10.1103/PhysRevA.109.043317

Source: https://journals.aps.org/pra/abstract/10.1103/PhysRevA.109.043317