Abstract

Master thesis defense --

When driven by a spin-polarized current, the motion of magnetic skyrmions deviates from the direction of the applied current. This is known as the skyrmion Hall effect, which is caused by the emergent Lorentz force, with the skyrmion topological charge taking the place of the electric charge [1].
This work considers the influence of the magnetic film curvature on the skyrmion Hall effect. Using the previously developed methodology for curvilinear magnets [2], we generalize the Landau-Lifshitz-Gilbert-Zhang-Li equation for the case of curvilinear films. Next, we describe the translational dynamics of the skyrmions by means of collective coordinates. To this end, we adapt the Thiele equation accordingly.
As a case study, we consider skyrmion dynamics along a cylindrical surface. We found that the influence of the curvature on the Hall angle strongly depends on the type of skyrmion (Neel, Bloch, anti-skyrmion), as well as on the direction of the applied current with respect to the cylinder axis. For instance, the largest curvature effect on the Neel skyrmion is found for the azimuthally applied current, while for the Bloch skyrmion, this direction is intermediate between the azimuthal and longitudinal directions.
Moreover, we took into account the influence of the curvature-induced skyrmion deformation [3] on the skyrmion Hall effect. Considering curvature as a small perturbation, we computed skyrmion deformation in the first-order perturbation theory. The obtained results are verified by means of spin-lattice simulations.


[1] P. Bruno, V.K. Dugaev, and M. Taillefumier Phys. Rev. Lett. 93, 096806 (2004).
[2] Y. Gaididei, V.P. Kravchuk, D.D. Sheka, Phys. Rev. Lett. 112, 257203 (2014).
[3] K.V. Yershov, A. Kákay, V.P. Kravchuk, Phys. Rev. B 105, 054425 (2022).