Related Experiment Video
Updated: May 7, 2025

Magnetic Tweezers for the Measurement of Twist and Torque
Published on: May 19, 2014
Harnessing orbital Hall effect in spin-orbit torque MRAM
Rahul Gupta1, Chloé Bouard2, Fabian Kammerbauer3
1Institute of Physics, Johannes Gutenberg University Mainz, 55099, Mainz, Germany. rahul.gupta.phy@outlook.com.
Abstract:
Spin-Orbit Torque (SOT) Magnetic Random-Access Memory (MRAM) devices offer improved power efficiency, nonvolatility, and performance compared to static RAM, making them ideal, for instance, for cache memory applications. Efficient magnetization switching, long data retention, and high-density integration in SOT MRAM require ferromagnets (FM) with perpendicular magnetic anisotropy (PMA) combined with large torques enhanced by Orbital Hall Effect (OHE). We have engineered a PMA [Co/Ni]3 FM on selected OHE layers (Ru, Nb, Cr) and investigated the potential of theoretically predicted larger orbital Hall conductivity (OHC) to quantify the torque and switching current in OHE/[Co/Ni]3 stacks. Our results demonstrate a ~30% enhancement in damping-like torque efficiency with a positive sign for the Ru OHE layer compared to a pure Pt layer, accompanied by a ~20% reduction in switching current for Ru compared to pure Pt across more than 250 devices, leading to more than a 60% reduction in switching power. These findings validate the application of Ru in devices relevant to industrial contexts, supporting theoretical predictions regarding its superior OHC. This investigation highlights the potential of enhanced orbital torques to improve the performance of orbital-assisted SOT-MRAM, paving the way for next-generation memory technology.
Related Concept Videos
Torque On A Current Loop In A Magnetic Field
Consider a rectangular current-carrying loop containing N turns of wire, placed in a uniform magnetic field. The net force on a current-carrying loop...
Atomic Nuclei: Magnetic Resonance
The Hall Effect
MOSFET: Enhancement Mode
In their basic form, enhancement-mode MOSFETs are typically non-conductive when the gate-source voltage (Vgs) is zero. This default 'off' state means no...
Atomic Nuclei: Nuclear Relaxation Processes
Magnetic Moment of an Electron

