Spectral Flow in Vortex Dynamics of 3He-B and Superconductors

TL;DR

This paper calculates the nondissipative force on vortices in superfluids and superconductors from spectral flow of fermion zero modes, revealing temperature-dependent mutual friction effects confirmed by experiments.

Contribution

It introduces a spectral flow-based calculation of nondissipative vortex forces and provides a comprehensive expression valid across all temperatures.

Findings

Reactive mutual friction parameter D' is negative in collisionless regime

D' becomes positive in hydrodynamic regime

Experimental data from 3He-B confirms spectral flow effects

Abstract

Nondissipative force acting on a vortex in Fermi superfluids and superconductors is calculated from the spectral flow of fermion zero modes in the vortex core. The spectral flow effect casts a new light on the problem of mutual friction in superfluids. We demonstrate that, for vortices in an isotropic system, the reactive mutual friction parameter D'(T) is negative in the collisionless regime and it is positive in the hydrodynamic regime. This agrees with 3He-B measurements [1] ( T.D.C. Bevan, et al, Phys. Rev. Lett., 74, 750 (1995)), which thus give the experimental verification of the spectral flow effect in the vortex dynamics. General expression for all 3 nondissipative forces (Magnus, Iordanskii and spectral flow) is presented in the whole temperature range.