近日，日本大阪公立大学的Akihiro Kanjo与Hiromitsu Takeuchi合作并取得一项新进展。他们提出了超流体中大质量点涡的通用描述及涡旋惯性的验证方法。相关研究成果已于2024年12月11日在国际知名学术期刊《物理评论A》上发表。

量子涡旋的惯性，即涡旋质量，在超流体中从未被观测到，这是低温物理中的一个长期未解问题。在典型的超流氦-4实验中，涡旋质量的影响被认为可忽略不计。近年来，操纵超流原子气体中量子涡旋的实验技术取得了进展，使人们能够更精确地检验这一问题。

通过将涡旋质量时间和长度作为大质量量子涡旋多体问题的通用尺度，该研究团队以最简洁的方式构建了理论描述，该描述普遍适用于不同的量子流体，包括费米子和多组分超流体。一对同号涡旋的圆周运动存在两个分支：回旋分支和无质量分支。找到涡旋运动的稳定回旋分支是涡旋质量存在的明确证据，而超流氦-3B就是能观察到这一现象的具体系统。

涡旋质量对无质量分支的影响虽小，但可以通过不同初始条件下点涡旋的两体动力学差异来增强。这项研究结果表明，涡旋质量是绝对零度下双量子化涡旋分裂不稳定性的直接原因，而涡旋质量长度则表征了不稳定后的最终状态。研究还表明，一对反向旋转的大质量涡旋之间存在一个由涡旋质量长度表征的临界距离，当距离小于该临界值时，它们会在没有热波动的情况下自发湮灭。

附：英文原文

Title: Universal description of massive point vortices and verification methods of vortex inertia in superfluids

Author: Akihiro Kanjo, Hiromitsu Takeuchi

Issue&Volume: 2024/12/11

Abstract: Vortex mass, which is the inertia of a quantum vortex, has never been observed in superfluids and is a long-standing problem in low-temperature physics. The impact of the mass is considered negligible in typical experiments with superfluid He4. Recent developments of experimental techniques for manipulating quantum vortices in superfluid atomic gases have enabled us to test this problem more accurately. By introducing the vortex mass time and length as universal scales to many-body problems of massive quantum vortices, the theoretical description is formulated in the simplest manner and is universally applicable to different quantum fluids, including fermionic and multicomponent superfluids. There are two branches, the cyclotron and massless branches, for the circular motion of a pair of like-sign vortices. Finding a stable cyclotron branch for the motion of vortices is a clear evidence of vortex mass and superfluid He3B is the specific example of a system where this phenomena could be observed. The impact of the mass on the massless branch is small but can be enhanced by taking the difference in the two-body dynamics of point vortices with different initial conditions. Our results imply that the vortex mass is a direct cause of the splitting instability of a doubly quantized vortex at absolute zero and that the vortex mass length characterizes the final state after the instability. It is also demonstrated that a pair of massive vortices with opposite circulations has a critical distance characterized by the vortex mass length, below which they are spontaneously annihilated without thermal fluctuations.

DOI: 10.1103/PhysRevA.110.063311

Source: https://journals.aps.org/pra/abstract/10.1103/PhysRevA.110.063311