A two-terminal spin valve device controlled by spin-orbit torques with enhanced giant magnetoresistance

TL;DR

This paper demonstrates a novel two-terminal spin valve device that combines spin-orbit torques and giant magnetoresistance, enabling electrical writing and reading of magnetization states with significantly improved GMR ratio.

Contribution

It introduces a new device architecture using TbCo and Co layers with a spacer to enhance GMR and achieve all-electrical control of magnetization states.

Findings

GMR ratio increased from 0.02% to 6% with Cu spacer.

Device allows electrical write/read of magnetization states.

Potential for simplified spintronic memory devices.

Abstract

We report on the combination of current-induced spin-orbit torques and giant magnetoresistance in a single device to achieve all-electrical write and read out of the magnetization. The device consists of perpendicularly magnetized TbCo and Co layers separated by a Pt or Cu spacer. Current injection through such layers exerts spin-orbit torques and switches the magnetization of the Co layer while the TbCo magnetization remains fixed. Subsequent current injection of lower amplitude senses the relative orientation of the magnetization of the Co and TbCo layers, which results in two distinct resistance levels for parallel and antiparallel alignment due to the current-in-plane giant magnetoresistance effect. We further show that the giant magnetoresistance of devices including a single TbCo/spacer/Co trilayer can be improved from 0.02% to 6% by using a Cu spacer instead of Pt. This type of devices offers an alternative route to a two terminal spintronic memory that can be fabricated with moderate effort.