Dynamics of interacting skyrmions in magnetic nano-track

TL;DR

This paper investigates the dynamic interactions of two skyrmions in magnetic nano-tracks, revealing how their behavior differs from single skyrmions and identifying collapse mechanisms under various current densities.

Contribution

It provides new insights into the behavior and stability of multiple skyrmions in confined geometries, crucial for their application in memory and neuromorphic devices.

Findings

Two skyrmions shrink near edges and follow helical paths.

The leading skyrmion collapses at lower current densities than a single skyrmion.

High current densities cause skyrmion annihilation via core and bubble-collapse mechanisms.

Abstract

Controlling multiple skyrmions in nanowires is important for their implementation in racetrack memory or neuromorphic computing. Here, we report on the dynamical behavior of two interacting skyrmions in confined devices with a comparison to a single skyrmion case. Although the two skyrmions shrink near the edges and follow a helical path, their behavior is different. Because the leading skyrmion is between the edge and the trailing one, its size is reduced further and collapses at a lower current density compared to the single skyrmion case. For higher current density, both skyrmions are annihilated with a core-collapse mechanism for the leading one followed by a bubble-collapse mechanism for the trailing one.