Manipulation of hybrid skyrmion dynamics by step Dzyaloshinskii–Moriya interaction approach

Abstract

The topological protected magnetic state, which plays a pivotal role against any continuous deformation of a magnetic skyrmion, comes with an unwanted skyrmion Hall effect (SkHE) that poses a significant challenge in practical applications. Here, we present a detailed micromagnetic simulation study that delves into the controlled manipulation of skyrmion dynamics through subtle engineering of the Dzyaloshinskii–Moriya interaction (DMI) in a hybrid skyrmion-based racetrack. In particular, we introduce a gradient variation of bulk and interfacial DMIs, which results in a parabolic trajectory of the skyrmion motion, thereby allowing us to find a critical DMI ratio with almost zero SkHE. Most importantly, we present a novel approach involving the engineering of a racetrack with strategically placed step DMI regions that gives us meticulous control over the size and speed of the hybrid skyrmions. The present study gives a new direction for the simultaneous realization of stable skyrmions without SkHE and an increased skyrmion speed with optimized DMI engineering.