Magnetic dipole-vortex interaction in a bilayer superconductor/soft-magnet heterostructure

TL;DR

This paper investigates how a magnetic dipole interacts with vortices in a superconductor/soft-magnet heterostructure, deriving interaction energies and critical dipole moments for vortex formation.

Contribution

It provides a theoretical analysis of dipole-vortex interactions in a bilayer heterostructure using the London approach, including critical dipole moments for vortex appearance.

Findings

Derived the energy of dipole-vortex interaction.

Calculated the critical dipole moment for vortex entry.

Analyzed effects of layer ordering on vortex formation.

Abstract

We study the penetration of the nonuniform magnetic field, created by a magnetic dipole with out-of-plane magnetization, into a film heterostructure composed of a type-II superconductor layer and a soft-magnet layer. In the framework of the London approach, the energy of the magnetic dipole-vortex interaction is derived and the critical value of the dipole moment for the first appearance of a vortex in the superconducting constituent is found for two cases of the layer ordering, namely when the dipole is located near the superconducting or, respectively, the magnetic constituent.