Damping of vortex waves in a superfluid

TL;DR

This paper investigates how vortex wave damping in superfluids is influenced by memory effects and the heat bath, revealing that friction remains largely unchanged while energetics show negligible memory corrections.

Contribution

It introduces a generalized quantum theory for vortex wave damping, highlighting the impact of memory corrections on vortex response and energetics in superfluids.

Findings

Friction coefficient remains essentially unchanged under vortex oscillations.

Memory corrections significantly affect vortex response but not energetics.

Vortex response exhibits Debye-type relaxation influenced by temperature and impurities.

Abstract

The damping of vortex cyclotron modes is investigated within a generalized quantum theory of vortex waves. Similarly to the case of Kelvin modes, the friction coefficient turns out to be essentially unchanged under such oscillations, but it is shown to be affected by appreciable memory corrections. On the other hand, the nonequilibrium energetics of the vortex, which is investigated within the framework of linear response theory, shows that its memory corrections are negligible. The vortex response is found to be of the Debye type, with a relaxation frequency whose dependence on temperature and impurity concentration reflects the complexity of the heat bath and its interaction with the vortex.