Skyrmion soliton motion on periodic substrates by atomistic and particle-based simulations

¹ POSMAT - Programa de Pós-Graduação em Ciência e Tecnologia de Materiais, São Paulo State University (UNESP), School of Sciences - Bauru 17033-360, SP, Brazil
² Theoretical Division and Center for Nonlinear Studies, Los Alamos National Laboratory Los Alamos, NM 87545, USA
³ Department of Physics, São Paulo State University (UNESP), School of Sciences - Bauru 17033-360, SP, Brazil

Received: 5 September 2024
Accepted: 13 November 2024

Abstract

We compare the dynamical behavior of magnetic skyrmions interacting with square and triangular defect arrays just above commensuration using both atomistic and particle-based models. Under applied drives, the initial motion is a kink traveling through the pinned skyrmion lattice. For the square defect array, both models agree well and show a regime in which the soliton motion is locked along 45°. The atomistic model also produces locking of a soliton along 30°, which is absent in the particle-based model. For the triangular defect array, the atomistic model exhibits 30° soliton motion over a wide region of external current values. In contrast, the particle-based model gives 45° soliton motion over a small range of external driving force values. The difference arises because the nondeforming particle model facilitates meandering skyrmion orbits while the deformable atomistic model enables stronger skyrmion-skyrmion interactions that reduce the meandering. Our results indicate that soliton motion through pinned skyrmion lattices on a periodic substrate is a robust effect.