Dynamics of chiral solitons driven by polarized currents in monoaxial helimagnets

TL;DR

This paper demonstrates how chiral solitons in monoaxial helimagnets can be stabilized with magnetic fields and driven by polarized currents, revealing their dynamics and stability limits in spintronics applications.

Contribution

It introduces a method to create and control single chiral solitons in monoaxial helimagnets using external magnetic fields and polarized currents, highlighting their steady motion and stability conditions.

Findings

Chiral solitons can be stabilized with external magnetic fields.

Steady soliton motion occurs under polarized currents with nonadiabatic torque.

A critical current density exists beyond which solitons become unstable.

Abstract

Chiral solitons are one dimensional localized magnetic structures that are metastable in some ferromagnetic systems with Dzyaloshinskii-Moriya interactions and/or uniaxial magnetic anisotropy. Though topological textures in general provide a very interesting playground for new spintronics phenomena, how to properly create and control single chiral solitons is still unclear. We show here that chiral solitons in monoaxial helimagnets, characterized by a uniaxial Dzyaloshinskii-Moriya interaction, can be stabilized with external magnetic fields. Once created, the soliton moves steadily in response to a polarized electric current, provided the induced spin-transfer torque has a dissipative (nonadiabatic) component. The structure of the soliton depends on the applied current density in such a way that steady motion exists only if the applied current density is lower than a critical value, beyond which the soliton is no longer stable.