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arXiv · 1902.09846

Spin eigen-excitations of an antiferromagnetic skyrmion

Volodymyr P. Kravchuk·Olena Gomonay·Denis D. Sheka·Davi R. Rodrigues·Karin Everschor-Sitte·Jairo Sinova·Jeroen van den Brink·Yuri Gaididei
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Abstract

We theoretically predict and classify the localized modes of a skyrmion in a collinear uniaxial antiferromagnet and discuss how they can be excited. As a central result, we find two branches of skyrmion eigenmodes with distinct physical properties characterized by being low or high energy excitations. The frequency dependence of the low-energy modes scales as $R_0^{-2}$ for skyrmions with large radius $R_0$. Furthermore, we predict localized high-energy eigenmodes, which have no direct ferromagnetic counterpart. Except for the breathing mode, we find that all localized antiferromagnet skyrmion modes, both in the low and high-energy branch, are doubly degenerated in the absence of a magnetic field and split otherwise. We explain our numerical results for the low-energy modes within a string model representing the skyrmion boundary.

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Volodymyr P. Kravchuk, Olena Gomonay, Denis D. Sheka, Davi R. Rodrigues, Karin Everschor-Sitte, Jairo Sinova, Jeroen van den Brink, Yuri Gaididei. 2019-02-26. Spin eigen-excitations of an antiferromagnetic skyrmion. https://doi.org/10.1103/physrevb.99.184429

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