近日，英国纽卡斯尔大学Piotr Z. Stasiak团队研究了超流体涡旋重联普适性的实验和理论证据。相关论文于2025年5月22日发表在《美国科学院院刊》杂志上。

流体和超流体中重新连接的涡流之间的最小间距遵循关于时间的普遍标度律。这个标度律的预连接和后重连前导是不同的，这是一个与不可逆性和能量传递和耗散机制有关的性质。研究组通过实验和数值模型确定了超流氦中这些预制体的温度依赖性，该模型充分考虑了超流涡线和热法向流体分量的耦合动力学。 

在所有温度下，研究组观察到类似于在其他超流体和经典粘性流体中观察到的重联前后的不对称性，这表明涡旋重联显示出一种与小尺度正则化动力学无关的普遍行为。他们还用数值方法表明，每个涡旋重联事件都代表了正常流体中能量的突然注入。最后，研究组认为，在湍流中，只要超流体涡旋的密度足够大，这些间断的能量注入可以使正常流体保持扰动状态。

附：英文原文

Title: Experimental and theoretical evidence of universality in superfluid vortex reconnections

Author: Stasiak, Piotr Z., Xing, Yiming, Alihosseini, Yousef, Barenghi, Carlo F., Baggaley, Andrew, Guo, Wei, Galantucci, Luca, Krstulovic, Giorgio

Issue&Volume: 2025-5-22

Abstract: The minimum separation between reconnecting vortices in fluids and superfluids obeys a universal scaling law with respect to time. The prereconnection and the postreconnection prefactors of this scaling law are different, a property related to irreversibility and to energy transfer and dissipation mechanisms. In the present work, we determine the temperature dependence of these prefactors in superfluid helium from experiments and a numeric model which fully accounts for the coupled dynamics of the superfluid vortex lines and the thermal normal fluid component. At all temperatures, we observe a pre- and postreconnection asymmetry similar to that observed in other superfluids and in classical viscous fluids, indicating that vortex reconnections display a universal behavior independent of the small-scale regularizing dynamics. We also numerically show that each vortex reconnection event represents a sudden injection of energy in the normal fluid. Finally we argue that in a turbulent flow, these punctuated energy injections can sustain the normal fluid in a perturbed state, provided that the density of superfluid vortices is large enough.

DOI: 10.1073/pnas.2426064122

Source: https://www.pnas.org/doi/abs/10.1073/pnas.2426064122