Manipulating transient SOT-MRAM switching dynamics for efficiency improvement and probabilistic switching

Manipulating Transient SOT-MRAM Switching Dynamics for Efficiency Improvement and Probabilistic Switching

This study explores the transient dynamics in switching processes of spin-orbit torque magnetic random-access memory (SOT-MRAM) devices, which are stabilized by in-plane uniaxial magnetocrystalline anisotropy. The authors develop a theoretical framework to describe the interaction between spin torques and effective magnetic fields during the magnetization write trajectory.

Switching Regimes and Theoretical Insights

The framework identifies regions of both failed and successful switching. Special attention is given to a “quasi-stochastic” regime found between deterministic switching outcomes. This regime arises from the interplay between torque-driven and precession-driven magnetization dynamics during switching.

Device Optimization Through Transient Phenomena

Minor modifications in device geometry, material properties, and electrical inputs are shown to leverage transient effects to reduce the switching barrier. This enables SOT-MRAM switching with considerably lower currents and faster write speeds compared to conventional designs.

Temperature Effects and Probabilistic Operation

At elevated temperatures, the initially unpredictable stochastic regime transitions into a clearly defined probabilistic “transition band.” This band features monotonic and tunable regions enabling controlled probabilistic switching.

“Through this addition of control mechanisms through electrical inputs, our framework paves the way for the creation of a fast, efficient probabilistic bit (p-bit) for the field of probabilistic computing.”

Author’s Summary

This research advances SOT-MRAM technology by harnessing transient switching dynamics to improve efficiency and enable tunable probabilistic operation, crucial for future probabilistic computing applications.

Nature — 2025-11-01