Friction Coefficient and Berry Phase for a Topological Singularity in a Superfluid

TL;DR

This paper investigates the interplay of universal transverse and non-universal friction forces on topological singularities in superfluids, revealing a logarithmic divergence in the friction coefficient through microscopic theory.

Contribution

It provides a microscopic evaluation of the friction coefficient for topological singularities in superfluids, highlighting a novel logarithmic divergence feature.

Findings

Universal transverse force coexists with non-universal friction force.

Friction coefficient exhibits logarithmic divergence in a clean fermionic superfluid.

Explicit quasiparticle contribution calculated using BCS theory.

Abstract

The coexistence of the universal transverse force and the non-universal friction force on a topological singularity in a superfluid is shown here. Based on the BCS type microscopic theory, we explicitly evaluate the quasiparticle contribution to the friction coefficient in a clean fermionic superfluid, showing a new feature of logarithmic divergence.