Magnetic Bloch-point hopping in multilayer skyrmions and associated emergent electromagnetic signatures

Abstract

Magnetic multilayers are promising tuneable systems for hosting magnetic skyrmions at/above room temperature. Revealing their intriguing switching mechanisms and associated inherent electrical responses are prerequisites for developing skyrmionic devices. In this work, we theoretically demonstrate the annihilation of single skyrmions occurring through a multilayer structure, which is mediated by hopping dynamics of topological hedgehog singularities known as Bloch points. The emerging intralayer dynamics of Bloch points are dominated by the Dzyaloshinskii-Moriya interaction, and their propagation can give rise to solenoidal emergent electric fields in the vicinity. Moreover, as the topology of spin textures can dominate their emergent magnetic properties, we show that the Bloch-point hopping through the multilayer will modulate the associated topological Hall response, with the magnitude proportional to the effective topological charge. We also investigate the thermodynamic stability of these states regarding the layer-dependent magnetic properties. This study casts light on the emergent electromagnetic signatures of skyrmion-based spintronics, rooted in magnetic-multilayer systems.

References in corpus (10)

• Advances in the Physics of Magnetic Skyrmions and Perspective for Technology
• Additive interfacial chiral interaction in multilayers for stabilization of small individual skyrmion at room temperature
• Spirit: Multifunctional Framework for Atomistic Spin Simulations
• Real-Space Berry Phases - Skyrmion Soccer
• Real-Space and Reciprocal-Space Berry Phases in the Hall Effect of Mn${}_{1-\mathrm{x}}$Fe${}_{\mathrm{x}}$Si
• Spin torque and force due to current for general spin textures
• Topological Hall and Spin Hall Effects in Disordered Skyrmionic Textures
• Mechanisms of skyrmion collapse revealed by sub-nm maps of the transition rate
• An accurate scheme to calculate the interatomic Dzyaloshinskii-Moriya interaction parameters
• Walker breakdown with a twist: Dynamics of multilayer domain walls and skyrmions driven by spin-orbit torque