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arXiv · 0901.2014

Chiral symmetry breaking of magnetic vortices by sample roughness

A. Vansteenkiste·M. Weigand·M. Curcic·H. Stoll·G. Schütz·B. Van Waeyenberge
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Abstract

Finite-element micromagnetic simulations are employed to study the chiral symmetry breaking of magnetic vortices, caused by the surface roughness of thin-film magnetic structures. An asymmetry between vortices with different core polarizations has been experimentally observed for square-shaped platelets. E.g., the threshold fields for vortex core switching were found to differ for core up and down. This asymmetry was however not expected for these symmetrically-shaped structures, where both core polarizations should behave symmetrically. Three-dimensional finite element simulations are employed to show that a small surface roughness can break the symmetry between vortex cores pointing up and down. A relatively small sample roughness is found sufficient to reproduce the experimentally observed asymmetries. It arises from the lack of mirror-symmetry of the rough thin-film structures, which causes vortices with different handedness to exhibit asymmetric dynamics.

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A. Vansteenkiste, M. Weigand, M. Curcic, H. Stoll, G. Schütz, B. Van Waeyenberge. 2009-04-21. Chiral symmetry breaking of magnetic vortices by sample roughness. https://doi.org/10.1088/1367-2630%2F11%2F6%2F063006

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