Controlled creation and stability of kπ-skyrmions on a discrete lattice

Abstract

We determine sizes and activation energies of kπ-skyrmions on a discrete lattice using the Landau- Lifshitz-Gilbert equation and the geodesic nudged elastic band method. The employed atomic material parameters are based on the skyrmionic material system Pd/Fe/Ir(111). We find that the critical magnetic fields for collapse of the 2π-skyrmion and 3π-skyrmion are very close to each other and considerably lower than the critical field of the 1π-skyrmion. The activation energy protecting the structures does not strictly decrease with increasing k as it can be larger for the 3π-skyrmion than for the 2π-skyrmion depending on the applied magnetic field. Furthermore, we propose a method of switching the skyrmion order k by a reversion of the magnetic field direction in samples of finite size.

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