Vortex patterns in a superconducting-ferromagnetic rod

TL;DR

This paper investigates vortex patterns in a superconducting-ferromagnetic rod using 3D Ginzburg-Landau calculations, revealing how vortex configurations change with rod thickness and magnetic field inhomogeneity.

Contribution

It introduces a detailed 3D analysis of vortex patterns in superconducting-ferromagnetic rods, highlighting new vortex behaviors due to inhomogeneous magnetic fields and varying thickness.

Findings

Thin rods exhibit giant vortex states similar to homogeneous fields.

Thick rods show novel curved vortex lines exiting through the surface.

Vortex patterns depend strongly on rod thickness and field inhomogeneity.

Abstract

A superconducting rod with a magnetic moment on top develops vortices obtained here through 3D calculations of the Ginzburg-Landau theory. The inhomogeneity of the applied field brings new properties to the vortex patterns that vary according to the rod thickness. We find that for thin rods (disks) the vortex patterns are similar to those obtained in presence of a homogeneous magnetic field instead because they consist of giant vortex states. For thick rods novel patterns are obtained as vortices are curve lines in space that exit through the lateral surface.