Nanosecond-timescale low error switching of in-plane magnetic tunnel junctions through dynamic Oersted-field assisted spin-Hall effect

TL;DR

This study demonstrates the fastest reliable in-plane magnetic tunnel junction switching at 2 ns using spin-Hall effect and Oersted-field assistance, surpassing previous macrospin model predictions and highlighting potential for high-speed memory applications.

Contribution

It reveals that Oersted magnetic fields significantly enhance spin-Hall torque switching speed in in-plane MTJs, enabling reliable sub-3 ns switching.

Findings

Achieved 2 ns reliable switching with error rates of 10^-5.

Oersted fields modify magnetic dynamics, improving switching performance.

Potential for high-speed, low-energy magnetic memory applications.

Abstract

We investigate fast-pulse switching of in-plane-magnetized magnetic tunnel junctions (MTJs) within 3-terminal devices in which spin-transfer torque is applied to the MTJ by the giant spin Hall effect. We measure reliable switching, with write error rates down to $10^{-5}$, using current pulses as short as just 2 ns in duration. This represents the fastest reliable switching reported to date for any spin-torque-driven magnetic memory geometry, and corresponds to a characteristic time scale that is significantly shorter than predicted possible within a macrospin model for in-plane MTJs subject to thermal fluctuations at room temperature. Using micromagnetic simulations, we show that in the 3-terminal spin-Hall devices the Oersted magnetic field generated by the pulse current strongly modifies the magnetic dynamics excited by the spin-Hall torque, enabling this unanticipated performance improvement. Our results suggest that in-plane MTJs controlled by Oersted-field-assisted spin-Hall torque are a promising candidate for both cache memory applications requiring high speed and for cryogenic memories requiring low write energies.