Giant Skyrmions Stabilized by Dipole-Dipole Interactions in Thin Ferromagnetic Films

Motohiko Ezawa

doi:10.1103/physrevlett.105.197202

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arXiv · 1007.4048

Giant Skyrmions Stabilized by Dipole-Dipole Interactions in Thin Ferromagnetic Films

Motohiko Ezawa

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Abstract

Motivated by a recent magnetization reversal experiment on a TbFeCo thin film, we study a topological excitation in the anisotropic nonlinear sigma model together with the Zeeman and magnetic dipole-dipole interactions. Dipole-dipole interactions turn a ferromagnet into a frustrated spin system, which allows a nontrivial spin texture such as a giant skyrmion. We derive an analytic formula for the skyrmion radius. The radius is controllable by the external magnetic field. It is intriguing that a skyrmion may have already been observed as a magnetic domain. A salient feature is that a single skyrmion can be created or destroyed experimentally. An analysis is made also on skyrmions in chiral magnets.

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Motohiko Ezawa. 2010-11-03. Giant Skyrmions Stabilized by Dipole-Dipole Interactions in Thin Ferromagnetic Films. https://doi.org/10.1103/physrevlett.105.197202

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