  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.
