Magnetization reversal of ferromagnetic nanodisc placed above a superconductor

TL;DR

This study uses numerical simulations to explore how a superconductor influences the magnetization reversal process in nanoscale ferromagnetic disks, revealing significant effects on vortex stability fields with potential practical applications.

Contribution

It introduces a detailed simulation approach to analyze the impact of superconductors on nanomagnet magnetization reversal, highlighting changes in vortex stability fields.

Findings

Vortex nucleation and annihilation fields are significantly affected by the superconductor.

The stable vortex field interval enlarges by 100-200 Oe due to the superconductor.

Ground state magnetization remains mostly unchanged by the superconductor.

Abstract

Using numerical simulation we have studied a magnetization distribution and a process of magnetization reversal in nanoscale magnets placed above a superconductor plane. In order to consider an influence of superconductor on magnetization distribution in the nanomagnet we have used London approximation. We have found that for usual values of London penetration depth the ground state magnetization is mostly unchanged. But at the same time the fields of vortex nucleation and annihilation change significantly: the interval where vortex is stable enlarges on 100-200 Oe for the particle above the superconductor. Such fields are experimentally observable so there is a possibility of some practical applications of this effect.