Deterministic switching of perpendicularly magnetic layers by spin orbital torque through stray field engineering

TL;DR

This paper introduces a multilayer structure that enables deterministic switching of perpendicular magnetic layers via spin orbital torque, using stray field engineering without external magnetic fields, confirmed by simulations and theoretical analysis.

Contribution

The study presents a novel multilayer design that achieves deterministic switching through stray field engineering, tunable parameters, and no need for external magnetic fields.

Findings

Deterministic switching confirmed by micromagnetic simulations.

Stray field can be tuned by adjusting layer magnetization and dimensions.

Switching occurs above a critical spin current density.

Abstract

We proposed a novel multilayer structure to realize the deterministic switching of perpendicularly magnetized layers by spin orbital torque from the spin Hall effect through stray field engineering. In our design, a pinned magnetic layer is introduced under the heave metal separated by an insulator, generating an in-plane stray field in the perpendicularly magnetized layer. We have confirmed the deterministic switching of perpendicularly magnetized layers through micromagnetic simulation and theoretical analysis. The in-plane stray field accounts for the deterministic switching exhibited in the structure and the reversal ultimate state of the magnetic layer is predictable when the applied spin current density is above the critical spin current density. Moreover, the stray field is easily tunable in a wide range by adjusting the saturation magnetization and dimensions of the pinned layer, and can accommodate different perpendicularly magnetized materials without any external magnetic field.