Interaction between soft magnetic and superconducting films

TL;DR

This paper provides a theoretical analysis of how soft magnetic and superconducting films interact, revealing effects like vortex-induced magnetization and potential control of vortex-wall interactions, with implications for magnetic imaging.

Contribution

It introduces a theoretical model describing the interaction between magnetic and superconducting films, highlighting vortex-induced magnetization effects and tunable interactions.

Findings

Vortex induces a magnetization distribution in the magnetic film.

The magnetic field near the vortex core can change sign due to magnetization.

Tuning the anisotropy field enhances vortex and Bloch wall interactions.

Abstract

We study theoretically the interaction between soft magnetic and superconducting films. It is shown that the vortex induces a magnetization distribution in the magnetic film, thus modifying the magnetic field as well as the interactions with e.g. Bloch walls. In particular, the field from the vortex may change sign close to the core as a result of the vortex-induced magnetization, thus resulting in a crossover from attraction to repulsion between vortices and Bloch walls. Moreover, we show that by tuning the anisotropy field of the magnetic film, one may enhance the interaction between Bloch walls and vortices. Finally, we discuss how the structure of a Bloch wall in presence of the thin film superconductor can be revealed by magneto-optic imaging using an additional magneto-optic indicator.