Vortex--Phonon Interaction

TL;DR

This paper derives a Hamiltonian for vortex-phonon interactions in superfluids, enabling calculation of sound radiation rates from Kelvin waves and estimating turbulence spectrum cutoffs at zero temperature.

Contribution

It introduces a formal Hamiltonian framework for vortex-phonon interactions, linking Kelvin wave dynamics with sound emission in superfluids.

Findings

Calculated sound radiation rates from superfluid turbulence.

Estimated the short-wavelength cutoff of the turbulence spectrum.

Provided a theoretical basis for vortex-phonon scattering analysis.

Abstract

Kelvin waves (kelvons)--helical waves on quantized vortex lines--are the normal modes of vortices in a superfluid. At zero temperature, the only dissipative channel of vortex dynamics is phonon emission. Starting with the hydrodynamic action, we derive the Hamiltonian of vortex-phonon interaction, thereby reducing the problem of the interaction of Kelvin waves with sound to inelastic elementary excitation scattering. On the basis of this formalism, we calculate the rate of sound radiation by superfluid turbulence at zero temperature and estimate the value of short-wavelength cutoff of the turbulence spectrum.