Quantum Turbulence

Abstract

The present article reviews the recent developments in the physics of quantum turbulence. Quantum turbulence (QT) was discovered in superfluid 4 He in the 1950s, and the research has tended toward a new direction since the mid 90s. The similarities and differences between quantum and classical turbulence have become an important area of research. QT is comprised of quantized vortices that are definite topological defects, being expected to yield a model of turbulence that is much simpler than the classical model. The general introduction of the issue and a brief review on classical turbulence are followed by a description of the dynamics of quantized vortices. Then, we discuss the energy spectrum of QT at very low temperatures. At low wavenumbers, the energy is transferred through the Richardson cascade of quantized vortices, and the spectrum obeys the Kolmogorov law, which is the most important statistical law in turbulence; this classical region shows the similarity to conventional turbulence. At higher wavenumbers, the energy is transferred by the Kelvin-wave cascade on each vortex. This quantum regime depends strongly on the nature of each quantized vortex. The possible dissipation mechanism is discussed. Finally, important new experimental studies, which include investigations into temperaturedependent transition to QT, dissipation at very low temperatures, QT created by vibrating structures, and visualization of QT, are reviewed. The present article concludes with a brief look at QT in atomic BoseEinstein condensates.

Quantum turbulence—from superfluid helium to atomic Bose–Einstein condensates

“…Thus, the investigation of QT may lead to a breakthrough in understanding a mystery of nature pondered since the era of da Vinci. There are many related topics not addressed in this article, regarding which we refer the readers to other review articles [15,16].…”

“…The present areas of study of QT are [15,16]: the energy spectra and the dissipation mechanism at zero temperature; QT created by vibrating structures; and visualization of QT.…”

Direct energy cascade in two-dimensional compressible quantum turbulence

“…quantum turbulence (QT). QT physics, comprising tangled quantized vortices, is an important research topic in lowtemperature physics [8,9]. Stimulated by recent experiments on both superfluid 3 He and superfluid 4 He, where a few similarities have been observed between quantum and classical turbulence [10][11][12][13][14][15][16][17], studies on QT have entered a new stage where one of the main motivations is to investigate the relationship between quantum and classical turbulence.…”

Spontaneous radiation and amplification of Kelvin waves on quantized vortices in Bose-Einstein condensates

“…Next, the DG instability is microscopically discussed in atomic BECs with the Gross-Pitaevskii (GP) and the Bogoliubov-de Gennes (BdG) models. Finally, it is shown that the DG instability can be applied to the observation of the dispersion relation of Kelvin waves, vortex reconnections [6], and quantum turbulence [7,8] in atomic BECs.…”