Wave turbulence on the surface of a ferrofluid submitted to a magnetic field

TL;DR

This study observes wave turbulence on a ferrofluid surface under a magnetic field, revealing a magnetic wave turbulence regime involving 4-wave interactions and coexistence of gravity, magnetic, and capillary wave regimes.

Contribution

It experimentally demonstrates magnetic wave turbulence on ferrofluid surfaces and identifies the regimes and interactions involved, including a triple coexistence point.

Findings

Magnetic surface waves appear above a critical magnetic field.

The power spectrum follows a frequency-power law indicating turbulence.

A triple point of gravity, magnetic, and capillary wave regimes is observed.

Abstract

We report the observation of wave turbulence on the surface of a ferrofluid mechanically forced and submitted to a static normal magnetic field. We show that magnetic surface waves arise only above a critical field. The power spectrum of their amplitudes displays a frequency-power law leading to the observation of a magnetic wave turbulence regime which is experimentally shown to involve a 4-wave interaction process. The existence of the regimes of gravity, magnetic and capillary wave turbulence is reported in the phase space parameters as well as a triple point of coexistence of these three regimes. Most of these features are understood using dimensional analysis or the dispersion relation of the ferrohydrodynamics surface waves.