Spin-orbit torque (SOT) enables ultra-fast, energy-efficient magnetization switching, making it a promising mechanism for introducing MRAMs for cache memory applications. However, current SOT-MRAM devices face write efficiency limitations, with charge-to-spin conversion (ξDL) reaching ∼ 45\%, far below the projected ∼ 80\% needed to comply with the current delivery of advanced transistor nodes. Recent advances in orbital current physics, evidenced in a wide class of materials, offer a path to enhance ξDL. Here, we study the Ta(3-30 nm)\slash W(1-4 nm) system, revealing a large additional spin-orbit torque contribution arising from Ta, a four-fold increase compared to the spin Hall effect in Ta alone, attributed to the orbital Hall contribution. This system exhibits larger ξDL than W-based SOT systems with more robust perpendicular magnetic anisotropy and compatibility with 400∘C annealing. Leveraging these advantages, we integrate the Ta/W system into 3-terminal SOT-MTJ devices, showing a level of performance similar to that of W-based systems. Our results show that orbital physics can be easily integrated into SOT-MTJ systems, offering a viable strategy to enhance SOT-MRAM efficiency. In addition, we propose and demonstrate a proof-of-concept for vertical non-local switching of SOT-MTJ using orbital torques, simplifying bottom-pinned SOT-MRAM fabrication.
@article{arxiv.2605.27215,
title = {Orbital and Spin-Orbit Torque Interplay in Ta/W-based Magnetic Tunnel Junctions with Vertical Non-local Switching},
author = {Marco Biagi and Corrado C. M. Capriata and K. Subham Senapati and Ioannis Trikoilis Koll and Corentin Bouchard and Ricardo C. Sousa and Louis Hutin and Bernard Viala and Kevin Garello},
journal= {arXiv preprint arXiv:2605.27215},
year = {2026}
}