Quantum vortex driven Kelvin wave in the thermal background of superfluid helium

TL;DR

This study provides numerical evidence that Kelvin waves on quantized vortices in superfluid helium can be observed in the normal fluid component at finite temperatures, revealing temperature-dependent dynamics mediated by mutual friction.

Contribution

It introduces the FOUCAULT model to analyze Kelvin waves in superfluid helium, demonstrating temperature-dependent behavior and coupling between superfluid and normal fluid components.

Findings

Normal fluid supports Kelvin wave-like responses with matching dispersion relations.

Kelvin wave frequency and damping depend on temperature, unlike previous models.

Results suggest potential for experimental visualization of Kelvin waves in the normal phase.

Abstract

We present numerical evidence that Kelvin waves (KWs) on quantized vortices in superfluid helium can be directly observed in the normal fluid component at finite temperatures. Using the Fully cOUpled loCAl model of sUperfLuid Turbulence (FOUCAULT) model, we analyze the propagation and temperature dependence of KWs by simultaneously measuring the dispersion of waves on the vortex displacement and the normal fluid velocity. The results demonstrate that the normal fluid supports a coherent KW-like response, with a dispersion relation matching that of the vortex filament (VF). Unlike the Schwarz model where there is almost no temperature dependence, in FOUCAULT KWs frequency and damping both depend on temperature, highlighting the role of mutual friction in mediating the coupling between the two fluids. These findings open a pathway for experimental observation of KWs in the normal phase using tracer based visualization.