Friction on a Quantized Vortex in a Superfluid

TL;DR

This paper derives an explicit expression for the friction experienced by a moving quantized vortex in a superfluid, revealing its dependence on system details and its independence from the transverse force, with special focus on quasiparticle contributions.

Contribution

It provides a new explicit formula for vortex friction based on Thouless, Ao, and Niu's formulation, and offers a thermodynamic interpretation of the force independence.

Findings

Friction depends on system details but not on the transverse force.

Friction exhibits a logarithmic divergence in a clean fermionic superfluid.

Transverse force remains unaffected by the friction.

Abstract

We obtain the explicit expression of the friction on a moving quantized vortex, following the formulation of Thouless, Ao and Niu. It is shown that the friction on a moving vortex is sensitive to details but does not change the transverse force. We provide a general thermodynamic interpretation for the mutual independence of the transverse force and the friction. The friction is evaluated for the case of quasiparticle contributions in a clean fermionic superfluid, showing a new feature of logarithmic divergence.