Tunable spin and orbital torques in Cu-based magnetic heterostructures

TL;DR

This study investigates spin and orbital torques in copper-based magnetic heterostructures, revealing high efficiency and tunability through oxidation control, advancing low-cost spintronic device development.

Contribution

It provides the first comprehensive analysis of current-induced spin and orbital torques in Cu-based heterostructures, demonstrating tunable torque control via oxidation state manipulation.

Findings

High torque efficiencies in Ni80Fe20/Cu bilayers with oxidized Cu

Sign and amplitude control of damping-like torque through oxidation

Insights into charge, spin, and orbital transport interplay in Cu heterostructures

Abstract

Current-induced torques originating from earth-abundant 3d elements offer a promising avenue for low-cost and sustainable spintronic memory and logic applications. Recently, orbital currents -- transverse orbital angular momentum flow in response to an electric field -- have been in the spotlight since they allow current-induced torque generation from 3d transition metals. Here, we report a comprehensive study of the current-induced spin and orbital torques in Cu-based magnetic heterostructures. We show that high torque efficiencies can be achieved in engineered Ni80Fe20/Cu bilayers where Cu is naturally oxidized, exceeding the ones found in the archetypical Co/Pt. Furthermore, we demonstrate sign and amplitude control of the damping-like torque by manipulating the oxidation state of Cu via solid-state gating. Our findings provide insights into the interplay between charge, spin, and orbital transport in Cu-based heterostructures and open the door to the development of gate-tunable spin-orbitronic devices.