Enhanced Nonadiabaticity in Vortex Cores due to the Emergent Hall Effect

Abstract

We present a combined theoretical and experimental study, investigating the origin of the enhanced nonadiabaticity of magnetic vortex cores. Scanning transmission x-ray microscopy is used to image the vortex core gyration dynamically to measure the nonadiabaticity with high precision, including a high confidence upper bound. We show theoretically, that the large nonadiabaticity parameter observed experimentally can be explained by the presence of local spin currents arising from a texture induced emergent Hall effect. This study demonstrates that the magnetic damping alpha and nonadiabaticity parameter beta are very sensitive to the topology of the magnetic textures, resulting in an enhanced ratio (beta/alpha>1) in magnetic vortex cores or Skyrmions.