标题： 量子涡旋在正常流体中留下宏观的特征 显示英文标题

标题： Quantum vortices leave a macroscopic signature in the normal fluid

摘要： 最近的工作强调了超流体氦II中量子湍流的显著特性，这些特性由相互作用并在碰撞时重新连接的量子涡旋线的无序纠缠组成。 根据兰道的两流体理论，这些涡旋线在称为正常流体的热激发环境中运动。 到目前为止，正常流体通常被认为是一个被动背景，它只是为涡旋线提供了一种将动能耗散为热量的机制。 在这里，我们使用一个充分考虑涡旋线与正常流体之间双向相互作用的模型，表明每条涡旋线在正常流体中产生一个宏观尾流，这个尾流可能比涡旋线之间的平均距离更大；考虑到诱导这些尾流的超流体涡旋核心的微观尺寸，这令人惊讶。 我们表明，在热传导实验中，正常流体的流动因此可以描述为施加的均匀流动和由涡旋线产生的尾流的叠加，导致正常流体速度的非经典统计特性。 我们还认为，这种对兰道所假定的热激发中独立流体结构的首次证据可能是最近一些未被解释的实验发现的根本原因。 显示英文摘要

摘要： Recent work has highlighted the remarkable properties of quantum turbulence in superfluid helium II, consisting of a disordered tangle of quantised vortex lines which interact with each other and reconnect when they collide. According to Landau's two-fluid theory, these vortex lines move in a surrounding of thermal excitations called the normal fluid. Until now, the normal fluid has often been considered a passive background which simply provides the vortex lines with a mechanism for dissipating their kinetic energy into heat. Using a model which fully takes into account the two-way interaction between the vortex lines and the normal fluid, here we show that each vortex line creates a macroscopic wake in the normal fluid that can be larger than the average distance between vortex lines; this is surprising, given the microscopic size of the superfluid vortex cores which induce these wakes. We show that in heat transfer experiments, the flow of the normal fluid can therefore be described as the superposition of an imposed uniform flow and wakes generated by the vortex lines, leading to non-classical statistics of the normal fluid velocity. We also argue that this first evidence of independent fluid structures in the thermal excitations postulated by Landau may be at the root of recent, unaccounted for, experimental findings.