标题： 超流体中的湍流扩散和分散 显示英文标题

标题： Turbulent diffusion and dispersion in a superfluid

摘要： 单体扩散和双体分散是经典湍流中的基本过程，控制着粒子的混合与输运。然而，它们在超流体湍流中的行为仍未被充分探索。在这项研究中，我们数值研究了在 0 K 极限下两种不同湍流状态中量子化涡旋和超流体团簇的扩散和相对分散：一种是由随机涡旋缠结表征的超量子湍流，另一种是准经典湍流，在其中局部极化的涡旋产生类似于经典湍流的大尺度流动。我们的结果显示，虽然在两种湍流状态下涡旋段在短时间内的超扩散行为相似，但超流体团簇的行为却有所不同：在超量子湍流中遵循相同的超扩散标度，在准经典湍流中则显著偏离。这种对比为短时间超扩散之谜提供了关键线索。此外，我们还表明涡旋段和超流体团簇的双体分散在超量子和准经典湍流中表现出不同的标度行为，突显了这两种湍流状态之间的根本差异。我们的发现填补了超流体湍流研究中的一个关键空白，为无粘量子流体中的湍流传质提供了新的见解。 显示英文摘要

摘要： Single-body diffusion and two-body dispersion are fundamental processes in classical turbulence, governing particle mixing and transport. However, their behaviors in superfluid turbulence remain largely unexplored. In this study, we numerically investigate the diffusion and relative dispersion of quantized vortices and superfluid parcels in the 0 K limit in two distinct turbulence regimes: ultra-quantum turbulence, characterized by a randomized vortex tangle, and quasiclassical turbulence, in which locally polarized vortices create large-scale flows resembling classical turbulence. Our results reveal that while vortex segments exhibit similar superdiffusion behavior at short times in both regimes, superfluid parcels behave differently: following the same superdiffusion scaling in ultra-quantum turbulence but deviating significantly in quasiclassical turbulence. This contrast provides a key clue to the origin of short-time superdiffusion, a puzzle since its recent discovery. Additionally, we show that two-body dispersion of both vortex segments and superfluid parcels exhibits distinct scaling behaviors in ultra-quantum and quasiclassical turbulence, highlighting fundamental differences in these two turbulence regimes. Our findings bridge a critical gap in superfluid turbulence research, offering new insights into turbulent transport in inviscid quantum fluids.