Enhanced Non-Adiabaticity in Vortex Cores due to the Emergent Hall Effect

TL;DR

This paper combines theory and experiments to explain the high non-adiabaticity in magnetic vortex cores, attributing it to an emergent Hall effect that generates local spin currents in complex magnetic textures.

Contribution

It demonstrates that the enhanced non-adiabaticity in vortex cores is due to an emergent Hall effect, supported by both experimental measurements and theoretical analysis.

Findings

High non-adiabaticity observed in vortex cores

Emergent Hall effect explains local spin currents

Enhanced non-adiabaticity absent in 1D domain walls

Abstract

We present a combined theoretical and experimental study, investigating the origin of the enhanced non-adiabaticity of magnetic vortex cores. Scanning transmission X-ray microscopy is used to image the vortex core gyration dynamically to measure the non-adiabaticity with high precision, including a high confidence upper bound. Using both numerical computations and analytical derivations, we show that the large non-adiabaticity parameter observed experimentally can be explained by the presence of local spin currents arising from a texture-induced emergent Hall effect. This enhanced non-adiabaticity is only present in two- and three-dimensional magnetic textures such as vortices and skyrmions and absent in one-dimensional domain walls, in agreement with experimental observations.