Giant Orbital Torque-driven Picosecond Switching in Magnetic Tunnel Junctions

TL;DR

This paper demonstrates a novel orbital Hall effect-driven magnetic tunnel junction that achieves ultrafast switching in 28.7 picoseconds with high efficiency, significantly advancing spintronics and orbitronics technologies.

Contribution

It introduces a new orbital Hall effect-based magnetic tunnel junction with high orbital-to-spin conversion efficiency and ultrafast switching capabilities.

Findings

Achieved 28.7 ps magnetic switching time.

Reduced driving voltages by five to eight times.

Demonstrated high orbital-to-spin conversion efficiency exceeding 90%.

Abstract

Orbital Hall effect was recently discovered as a novel pathway for driving magnetic moment. However, the integration of orbital Hall effect in magnetic memories suffers from low orbital-to-spin conversion efficiency and incompatibility with magnetic tunnel junctions. Here we demonstrate an orbital Hall effect-driven magnetic tunnel junction based on Ru/W bilayer, where the Ru layer possesses a strong orbital Hall conductivity and the {\alpha}-W layer features an orbital-to-spin conversion efficiency exceeding 90% because of the large orbit-spin diffusivity. By harnessing the giant orbital torque, we achieve a 28.7-picosecond switching and a five to eight-fold reduction in driving voltages over conventional spin-orbit torque magnetic memories. Our work bridges the critical gap between orbital effects and magnetic memory applications, significantly advancing the field of spintronics and orbitronics.