Reduction of back switching by large damping ferromagnetic material

TL;DR

This paper investigates how increasing the damping constant in ferromagnetic materials can effectively suppress back switching during spin-orbit torque-induced magnetization switching, providing new insights into magnetic device stability.

Contribution

It demonstrates through numerical and theoretical analyses that large damping constants significantly reduce back switching in ferromagnets with easy axis parallel to current.

Findings

Large damping suppresses back switching effectively.

Back switching is less likely with higher damping constants.

Theoretical models support numerical simulation results.

Abstract

Recent studies on magnetization dynamics induced by spin-orbit torque have revealed a weak dependence of the critical current for magnetization switching on the damping constant of a ferromagnetic free layer. This study, however, reveals that the damping constant nevertheless plays a key role in magnetization switching induced by spin-orbit torque. An undesirable switching, returning to an initial state, named as back switching, occurs in a ferromagnet with an easy axis parallel to the current direction. Numerical and theoretical analyses reveal that back switching is strongly suppressed when the damping constant of the ferromagnet is large.