近日，英国纽卡斯尔大学的教授Andrew W. Baggaley及其研究团队取得一项新进展。经过不懈努力，他们揭示三维均匀偶极超流体中的涡旋对动力学。相关研究成果已于2024年6月17日在国际知名学术期刊《物理评论A》上发表。

在均匀dBEC中，该研究团队分析了单涡旋的结构和涡旋对的动力学，他们研究了与非偶极范式的偏差。对于直线涡旋，研究人员发现，当偶极矩在涡旋线上具有非零正交投影时，诱导的偶极相互作用势会呈现轴向各向异性。这种特性导致涡旋核在投影方向上相应延长，形成各向异性超流体相，并在涡旋核附近增强了可压缩性。因此，具有相同符号的涡旋对的运动轨迹不再是熟悉的圆形轨道，而是呈现为一组椭圆和类椭圆曲线。

类似地，对于相反符号的涡旋对，它们沿双法线的平移速度被发现依赖于偶极子相互作用。研究人员期待这些发现能揭示dBECs中多种涡旋现象，如量子湍流、涡旋重连和涡旋晶格的潜在机制。

据悉，由于偶极-偶极相互作用的各向异性和长程性质，相对于非偶极凝聚体，偶极玻色-爱因斯坦凝聚体(dBECs)中涡旋的静态和动态特性可以得到很大的改变。

附：英文原文

Title: Vortex-pair dynamics in three-dimensional homogeneous dipolar superfluids

Author: Srivatsa B. Prasad, Nick G. Parker, Andrew W. Baggaley

Issue&Volume: 2024/06/17

Abstract: The static and dynamic properties of vortices in dipolar Bose-Einstein condensates (dBECs) can be considerably modified relative to their nondipolar counterparts by the anisotropic and long-ranged nature of the dipole-dipole interaction. Working in a uniform dBEC, we analyze the structure of single vortices and the dynamics of vortex pairs, investigating the deviations from the nondipolar paradigm. For a straight vortex line, we find that the induced dipolar interaction potential is axially anisotropic when the dipole moments have a nonzero projection orthogonal to the vortex line. This results in a corresponding elongation of the vortex core along this projection as well as an anisotropic superfluid phase and enhanced compressibility in the vicinity of the vortex core. Consequently, the trajectories of like-signed vortex pairs are described by a family of elliptical and oval-like curves rather than the familiar circular orbits. Similarly for opposite-signed vortex pairs their translation speeds along the binormal are found to be dipole-interaction dependent. We expect that these findings will shed light on the underlying mechanisms of many-vortex phenomena in dBECs such as quantum turbulence, vortex reconnections, and vortex lattices.

DOI: 10.1103/PhysRevA.109.063323

Source: https://journals.aps.org/pra/abstract/10.1103/PhysRevA.109.063323