Nonzero Skyrmion Hall Effect in Topologically Trivial Structures

TL;DR

This paper reveals that the skyrmion Hall effect persists in topologically trivial structures when driven by spin-orbit torques, challenging previous assumptions and impacting future racetrack memory designs.

Contribution

It demonstrates that the skyrmion Hall angle depends on helicity in trivial structures under spin-orbit torque, contrary to prior beliefs that it vanishes.

Findings

Skyrmion Hall effect exists in trivial structures with spin-orbit torque.

The Hall angle is directly related to skyrmion helicity.

This effect presents a challenge for racetrack memory development.

Abstract

It is widely believed that the skyrmion Hall effect, often disruptive for device applications, vanishes for overall topologically trivial structures such as (synthetic) antiferromagnetic skyrmions and skyrmioniums due to a compensation of Magnus forces. In this manuscript, however, we report that in contrast to the case of spin-transfer torque driven skyrmion motion, this notion is generally false for spin-orbit torque driven objects. We show that the skyrmion Hall angle is directly related to their helicity and imposes an unexpected roadblock for developing faster and lower input racetrack memories based on spin-orbit torques.