Controlled switching of N\'eel caps in flux-closure magnetic dots

TL;DR

This paper demonstrates controlled switching of Nél caps in flux-closure magnetic dots through magnetic field-induced propagation of surface vortices, advancing understanding of magnetic vortex core dynamics.

Contribution

It introduces a method to selectively switch Nél caps in flux-closure states of micron-sized magnetic dots using magnetic fields.

Findings

Controlled switching of Nél caps achieved

Switching occurs via surface vortex propagation

Selective manipulation of magnetic domain structures

Abstract

While magnetic hysteresis usually considers magnetic domains, the switching of the core of magnetic vortices has recently become an active topic. We considered Bloch domain walls, which are known to display at the surface of thin films flux-closure features called N\'eel caps. We demonstrated the controlled switching of these caps under a magnetic field, occurring via the propagation of a surface vortex. For this we considered flux-closure states in elongated micron-sized dots, so that only the central domain wall can be addressed, while domains remain unaffected.