Superconducting vortices manipulated by magnetic domain walls in superconductor-ferromagnet heterostructures. A do- main wall in the ferromagnetic thin film (FM) that is proximity coupled to a superconducting layer (SC) interacts with vortices (blue tubes) via the magnetoelectric effect induced by spin-orbit coupling. The winding of the domain wall (helicity) and the vortices (vorticity) control whether vortices glide along the domain wall, get dragged, or (as depicted) pushed.

Manipulating vortices with domain walls in superconductor-ferromagnet heterostructures

Vortices are pointlike 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 linelike 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 Néel 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.

S. A. Díaz, J. Nothhelfer, K. M. D. Hals, and K. Everschor-Sitte
Phys. Rev. B 109, 20 (2024)