Current-driven Dynamics of Skyrmion Bubbles in Achiral Uniaxial Magnets

TL;DR

This paper investigates the behavior of skyrmion bubbles driven by spin-transfer torque in achiral ferromagnetic nanostripes, revealing conditions for stable motion and potential applications in spintronic devices.

Contribution

It demonstrates how the dynamics of skyrmion bubbles depend on the magnetic quality factor, providing insights for designing skyrmion-based spintronic devices.

Findings

Skyrmion bubbles are confined at the center for low quality factors.

Stable coherent motion occurs at higher quality factors (~3.8).

Results inform future spintronic device design.

Abstract

We report dynamics of skyrmion bubbles driven by spin-transfer torque in achiral ferromagnetic nanostripes using micromagnetic simulations. In a three-dimensional uniaxial ferromagnet with a quality factor that is smaller than 1, the skyrmion bubble is forced to stay at the central nanostripe by a repulsive force from the geometry border. The coherent motion of skyrmion bubbles in the nanostripe can be realized by increasing the quality factor to ~3.8. Our results should propel the design for future spintronic devices such as artificial neural computing and racetrack memory based on dipole-stabilized skyrmion bubbles.