Soliton motion induced along ferromagnetic skyrmion chains in chiral thin nanotracks

TL;DR

This study uses atomistic simulations to demonstrate stable soliton motion along ferromagnetic skyrmion chains in chiral nanotracks, revealing phases like pinned, soliton, and quasi-free motion, with potential technological implications.

Contribution

It introduces the first detailed analysis of soliton dynamics along skyrmion chains in nanotracks, highlighting stable motion without skyrmion Hall effect and effects of pinning strength.

Findings

Stable soliton motion observed without skyrmion Hall effect.

Velocity-current curves show distinct phases including pinned, soliton, and quasi-free motion.

Pinning strength influences the onset and characteristics of soliton motion.

Abstract

Using atomistic magnetic simulations we investigate the soliton motion along a pinned skyrmion chain containing an interstitial skyrmion. We find that the soliton can exhibit stable motion along the chain without a skyrmion Hall effect for an extended range of drives. Under a constant drive the solitons have a constant velocity. We also measure the skyrmion velocity-current curves and identify the signatures of different phases including a pinned phase, stable soliton motion, and quasi-free motion at higher drives where all of the skyrmions depin from the pinning centers and move along the rigid wall. In the quasi-free motion regime, the velocity is oscillatory due to the motion of the skyrmions over the pinning sites. For increasing pinning strength, the onset of soliton motion shifts to higher values of current density. We also find that for stronger pinning, the characteristic velocity-current shape is affected by the annihilation of single or multiple skyrmions in the drive interval over which the soliton motion occurs. Our results indicate that stable skyrmion soliton motion is possible and could be useful for technological applications.