论文标题

旋转量子波湍流

Rotating quantum wave turbulence

论文作者

Mäkinen, J. T., Autti, S., Heikkinen, P. J., Hosio, J. J., Hänninen, R., L'vov, V. S., Walmsley, P. M., Zavjalov, V. V., Eltsov, V. B.

论文摘要

旋转的湍流本质上是普遍存在的。先前的作品表明,这种湍流可以描述为在宽范围内的相互作用惯性波的集合。对于宏观量子冷凝物中的湍流,大尺度上的准经典动力学与小尺度上相应的动力学之间的过渡性质,在小尺度上,涡度的量化是必不可少的,仍然是一个未解决的尚未解决的问题。在这里,我们将波驱动的湍流的范式扩展到旋转的量子流体,其中波的光谱在量化的涡旋上的开尔文波延伸至显微镜尺度。我们通过定期调节角速度的定期调节,以最大的量表激发惯性波,并观察到能量无关的转移到较小的尺度上,并且最终在最低温度下难以捉摸的kelvin-wave级联反应。我们进一步发现,能量通过与经典埃克曼层不同的边界层泵送到系统,并通过数值模拟支持我们的观察结果。我们的实验证明了量子流体中湍流运动的新制度,可以忽略涡旋重新连接的作用,从而将经典和湍流的量子与裸露的骨骼之间的过渡剥离。

Rotating turbulence is ubiquitous in nature. Previous works suggest that such turbulence could be described as an ensemble of interacting inertial waves across a wide range of length scales. For turbulence in macroscopic quantum condensates, the nature of the transition between the quasiclassical dynamics at large scales and the corresponding dynamics at small scales, where the quantization of vorticity is essential, remains an outstanding unresolved question. Here we expand the paradigm of wave-driven turbulence to rotating quantum fluids where the spectrum of waves extends to microscopic scales as Kelvin waves on quantized vortices. We excite inertial waves at the largest scale by periodic modulation of the angular velocity and observe dissipation-independent transfer of energy to smaller scales and the eventual onset of the elusive Kelvin-wave cascade at the lowest temperatures. We further find that energy is pumped to the system through a boundary layer distinct from the classical Ekman layer and support our observations with numerical simulations. Our experiments demonstrate a new regime of turbulent motion in quantum fluids where the role of vortex reconnections can be neglected, thus stripping the transition between the classical and the quantum regimes of turbulence down to its bare bones.

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