Orbital and Spin–Orbit Torque Interplay in Ta/W-Based Magnetic Tunnel Junctions with Vertical Nonlocal Switching
Abstract
Spin–orbit torque (SOT) enables ultrafast, energy-efficient magnetization switching, making it promising for MRAM cache applications. However, current SOT-MRAM devices face write efficiency limitations, with charge-to-spin conversion (ξDL) reaching only ∼ 45%, well below the projected ∼80% required for advanced transistor nodes. Recent advances in orbital current physics offer a route to enhance ξDL. Here, we study the Ta(3–30 nm)/W(1–4 nm) system, revealing a large additional torque contribution from Ta, a 4-fold increase over the spin Hall effect in Ta alone, attributed to the orbital physics. This system exhibits larger ξDL than W-based SOT systems, while maintaining robust perpendicular magnetic anisotropy and 400 °C annealing compatibility. We integrate the Ta/W system into 3-terminal SOT-MTJ devices, demonstrating performance comparable to W-based systems. Our results show that orbital physics offers a viable strategy to enhance SOT-MRAM efficiency. We further propose and demonstrate proof-of-concept vertical nonlocal switching using orbital torques, simplifying bottom-pinned SOT-MRAM fabrication.
Related
- Giant orbital torque-driven picosecond switching in magnetic tunnel junctions
- Robustness of Skyrmion-Mediated Magnetization Switching in Perpendicular Magnetic Tunnel Junctions (p-MTJs) to Material Disorder and Elevated Temperature
- Cooperative STT and SOT switching in perpendicular magnetic tunnel junctions: Role of the pulse-end magnetization state
- Analysis of Josephson junctions switching time distributions for the detection of single microwave photons
- Eddy currents and current reversal in curved magnetic thin-film Josephson junctions
BibTeX
@article{biagi2026orbital,
title = {{Orbital and Spin–Orbit Torque Interplay in Ta/W-Based Magnetic Tunnel Junctions with Vertical Nonlocal Switching}},
author = {Marco Biagi and Corrado Capriata and Corentin Bouchard and Subham Kintali Senapati and Ioannis Trikoilis Koll and Ricardo Sousa and Louis Hutin and Bernard Viala and Kevin Garello},
journal = {Nano Letters},
year = {2026},
month = sep,
doi = {10.1021/acs.nanolett.6c02672},
eprint = {2605.27215},
archivePrefix = {arXiv},
url = {https://hal.science/hal-05763702v1},
note = {CC BY-NC-SA 4.0},
}
RIS
TY - JOUR
TI - Orbital and Spin–Orbit Torque Interplay in Ta/W-Based Magnetic Tunnel Junctions with Vertical Nonlocal Switching
AU - Marco Biagi
AU - Corrado Capriata
AU - Corentin Bouchard
AU - Subham Kintali Senapati
AU - Ioannis Trikoilis Koll
AU - Ricardo Sousa
AU - Louis Hutin
AU - Bernard Viala
AU - Kevin Garello
PY - 2026
DA - 2026/09/21
JO - Nano Letters
DO - 10.1021/acs.nanolett.6c02672
UR - https://hal.science/hal-05763702v1
AB - Spin–orbit torque (SOT) enables ultrafast, energy-efficient magnetization switching, making it promising for MRAM cache applications. However, current SOT-MRAM devices face write efficiency limitations, with charge-to-spin conversion (ξDL) reaching only ∼ 45%, well below the projected ∼80% required for advanced transistor nodes. Recent advances in orbital current physics offer a route to enhance ξDL. Here, we study the Ta(3–30 nm)/W(1–4 nm) system, revealing a large additional torque contribution from Ta, a 4-fold increase over the spin Hall effect in Ta alone, attributed to the orbital physics. This system exhibits larger ξDL than W-based SOT systems, while maintaining robust perpendicular magnetic anisotropy and 400 °C annealing compatibility. We integrate the Ta/W system into 3-terminal SOT-MTJ devices, demonstrating performance comparable to W-based systems. Our results show that orbital physics offers a viable strategy to enhance SOT-MRAM efficiency. We further propose and demonstrate proof-of-concept vertical nonlocal switching using orbital torques, simplifying bottom-pinned SOT-MRAM fabrication.
SN - 1530-6984
SN - 1530-6992
ER -