Boosting spin-orbit torque efficiency in spin-current generator/magnet/oxide superlattices

TL;DR

This paper introduces a novel 3D superlattice structure that significantly enhances spin-orbit torque efficiency in spintronic devices by leveraging inversion symmetry breaking through oxide layers.

Contribution

It demonstrates that stacking spin-current generator/magnet/oxide layers boosts torque efficiency, advancing spintronics with high energy efficiency and durability.

Findings

Boosted spin torque efficiency in superlattices with oxide layers.

Inversion symmetry breaking enhances spin-orbit effects.

Potential for high-density, energy-efficient spintronic memory.

Abstract

Efficient manipulation of magnetic materials is essential for spintronics. In spin-current generator/magnet bilayers, the efficiency of spin-orbit torques per magnetic layer thickness scales inversely with the magnetic layer thickness, leading to considerable power increase in applications with large magnetic layer thickness. Here, we develop a 3D spin-orbit material scheme in which the spin torque efficiency can be remarkably boosted up by stacking [spin-current generator/magnet/oxide]n superlattices, with the oxide layers breaking the inversion symmetry. In contrast, the spin torque diminishes in [spin-current generator/magnet]n superlattices lacking inversion symmetry breaking. These results advances the understanding of spin-orbit torques in magnetic multilayers and establishes spin-current generator/magnet/oxide superlattices as advantageous bricks for development of high energy-efficiency, high-endurance, and high-density spintronic memory and computing.