Emergent electromagnetism induced by topological defects created during magnetization reversal in nanowires

TL;DR

This paper reveals that topological point-defects formed during magnetization reversal in nanowires lead to emergent electromagnetism, with defects rapidly separating and generating significant electric fields.

Contribution

It introduces the role of hedgehog-antihedgehog pairs in magnetization switching and their impact on emergent electric fields in ferromagnetic nanoparticles.

Findings

Topological defects govern magnetization reversal.

Defects generate substantial emergent electric fields.

Defects separate at speeds exceeding domain wall velocities.

Abstract

We report that the irreversible magnetization switching process in ferromagnetic nanoparticles is governed by the formation and dynamics of topological point-defects in the form of hedgehog-antihedgehog pairs. After nucleation, these pairs rapidly separate with speeds exceeding domain wall velocities, and they generate an emergent electric field of solenoidal character and substantial magnitude.