Manipulating Vortices with Domain Walls in Superconductor-Ferromagnet Heterostructures

TL;DR

This paper reveals how Rashba spin-orbit coupling in superconductor-ferromagnet heterostructures influences vortex-domain wall interactions, enabling control over vortex motion based on domain wall helicity.

Contribution

It uncovers the role of spin-orbit coupling in vortex-domain wall interactions, demonstrating control of vortex behavior via domain wall helicity using numerical simulations and Ginzburg-Landau theory.

Findings

Spin-orbit coupling induces magnetoelectric interactions between vortices and domain walls.

Domain wall helicity determines whether vortices are pushed or dragged.

Vortex motion can be controlled by the type and helicity of domain walls.

Abstract

Vortices are point-like topological defects in superconductors whose motion dictates superconducting properties and controls device performance. In superconductor-ferromagnet heterostructures, vortices interact with topological defects in the ferromagnet such as line-like domain walls. While in previous heterostructure generations, vortex-domain wall interactions were mediated by stray fields; in new heterostructure families, more important become exchange fields and spin-orbit coupling. However, spin-orbit coupling's role in vortex-domain wall interactions remains unexplored. Here we uncover, via numerical simulations and Ginzburg-Landau theory, that Rashba spin-orbit coupling induces magnetoelectric interactions between vortices and domain walls that crucially depend on the wall's winding direction$-$its helicity. The wall's helicity controls whether vortices are pushed or dragged by N\'eel walls, and their gliding direction along Bloch walls. Our work capitalizes on interactions between topological defects from different order parameters and of different dimensionality to engineer enhanced functionality.