Vortex Dynamics in Ferromagnetic Superconductors: Vortex Clusters, Domain Walls and Enhanced Viscosity

TL;DR

This paper explores how vortex-vortex attraction and magnetic polarization in ferromagnetic superconductors lead to vortex clustering, dynamic instabilities, and enhanced viscosity, with implications for transport properties.

Contribution

It reveals the long-range vortex attraction and the formation of vortex clusters due to magnetic polarization, and describes vortex dynamics and instabilities in ferromagnetic superconductors.

Findings

Vortex-vortex attraction causes vortex clustering.

Vortex motion excites magnons and leads to instabilities.

Domain walls form at high vortex velocities.

Abstract

We demonstrate that there is a long-range vortex-vortex attraction in ferromagnetic superconductors due to polarization of the magnetic moments. Vortex clusters are then stabilized in the ground state for low vortex densities. The motion of vortex clusters driven by the Lorentz force excites magnons. This regime becomes unstable at a threshold velocity above which domain walls are generated for slow relaxation of the magnetic moments and the vortex configuration becomes modulated. This dynamics of vortices and magnetic moments can be probed by transport measurements.