Rotating quantum wave turbulence
Rotating quantum wave turbulence
复制标题
DOI：
10.1038/s41567-023-01966-z
复制
发表时间：
2023-03-02
期刊：
影响因子：
19.6
通讯作者：
Eltsov, V. B.
中科院分区：
文献类型：
--
作者：
Makinen, J. T.;Autti, S.;Eltsov, V. B.
旋转强烈影响下的湍流被描述为跨各种长度尺度相互作用的惯性波的集合。在宏观量子凝聚体中，大尺度的准经典湍流动力学在小尺度上发生改变，其中涡量的量子化至关重要。这种转变的性质仍然是一个悬而未决的问题。在这里，我们将波驱动湍流的概念扩展到旋转的量子流体，其中波谱延伸到微观尺度，如量子化涡旋上的开尔文波。我们通过角速度的周期性调制在最大尺度上激发惯性波，并观察到与耗散无关的能量向较小尺度的转移以及在最低温度下难以捉摸的开尔文波级联的最终开始。我们进一步发现能量通过与经典埃克曼层不同的边界层被泵送到系统，并通过数值模拟支持我们的观察。我们的实验证明了量子流体中的湍流运动状态，其中涡旋重新连接的作用可以忽略不计，从而将经典湍流状态和量子状态之间的过渡剥离到其组成部分。量子湍流通常需要重新连接量子流体中看到的量子化涡旋。现在，超流氦实验显示出湍流动力学，涡旋重联可忽略不计，这是一种以所有长度尺度上相互作用的涡旋波为主的状态。
Turbulence under strong influence of rotation is described as an ensemble of interacting inertial waves across a wide range of length scales. In macroscopic quantum condensates, the quasiclassical turbulent dynamics at large scales is altered at small scales, where the quantization of vorticity is essential. The nature of this transition remains an unanswered question. Here we expand the concept 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 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 constituent components.Quantum turbulence typically entails reconnecting quantized vortices as seen in quantum fluids. Experiments with superfluid helium now show turbulent dynamics with negligible vortex reconnection, a regime dominated by interacting vortex waves at all length scales.