Experimental Demonstration of Efficient Spin-Orbit Torque Switching of an MTJ with sub-100 ns Pulses

TL;DR

This paper demonstrates efficient, sub-100 nanosecond spin-orbit torque switching in magnetic tunnel junctions with scaled dimensions, showing potential for fast, scalable spintronic memory devices.

Contribution

It presents a scalable SOT-MTJ device with reduced critical current and demonstrates reliable nanosecond switching using spin-orbit torque.

Findings

Achieved sub-100 ns switching pulses in SOT-MTJ devices.

Estimated effective spin Hall angle of 0.15-0.20.

Demonstrated bidirectional transient switching with reliable readout.

Abstract

Efficient generation of spin currents from charge currents is of high importance for memory and logic applications of spintronics. In particular, generation of spin currents from charge currents in high spin-orbit coupling metals has the potential to provide a scalable solution for embedded memory. We demonstrate a net reduction in critical charge current for spin torque driven magnetization reversal via using spin-orbit mediated spin current generation. We scaled the dimensions of the spin-orbit electrode to 400 nm and the nanomagnet to 270 nm x 68 nm in a three terminal spin-orbit torque, magnetic tunnel junction (SOT-MTJ) geometry. Our estimated effective spin Hall angle is 0.15-0.20 using the ratio of zero temperature critical current from spin Hall switching and estimated spin current density for switching the magnet. We show bidirectional transient switching using spin-orbit generated spin torque at 100 ns switching pulses reliably followed by transient read operations. We finally compare the static and dynamic response of the SOT-MTJ with transient spin circuit modeling showing the performance of scaled SOT-MTJs to enable nanosecond class non-volatile MTJs.