Observation of an Inverse Energy Cascade in Developed Acoustic Turbulence in Superfluid Helium

TL;DR

This paper reports the experimental observation of an inverse energy cascade in acoustic turbulence within superfluid helium, revealing giant rogue-like waves and supporting a developed theoretical framework.

Contribution

It presents the first experimental evidence of inverse energy cascade in superfluid helium's acoustic turbulence and develops a theory consistent with the observations.

Findings

Inverse energy cascade observed in superfluid helium

Giant rogue-like acoustic waves detected

Theory aligns well with experimental data

Abstract

We report observation of an inverse energy cascade in second sound acoustic turbulence in He II. Its onset occurs above a critical driving energy and it is accompanied by giant waves that constitute an acoustic analogue of the rogue waves that occasionally appear on the surface of the ocean. The theory of the phenomenon is developed and shown to be in good agreement with the experiments.