Radio-frequency assisted switching in perpendicular magnetic tunnel junctions

TL;DR

This paper demonstrates that applying a small RF pulse before a DC pulse enhances switching efficiency in perpendicular STT-MRAM, enabling shorter pulses and improved device endurance.

Contribution

It presents the first experimental study of RF-assisted switching in perpendicular STT-MRAM, showing efficiency gains and endurance improvements.

Findings

RF+DC scheme increases switching probability

Shorter DC pulses are possible with RF assistance

Modeling qualitatively matches experimental trends

Abstract

Spin-transfer torque magnetic random-access memory (STT-MRAM) relies on nanoscale magnetic tunnel junctions (MTJs) as its fundamental building blocks. Next-generation STT-MRAM requires strategies that simultaneously improve switching energy efficiency and device endurance. Here, we present the first study of perpendicular STT-MRAM writing assisted by radio-frequency (RF) spin torque. We show that applying a small-amplitude RF pulse prior to a direct-current (DC) writing pulse enhances the MTJ switching probability, with the efficiency gain increasing at lower RF frequencies. This RF+DC writing scheme enables shorter DC pulses, thereby improving device endurance. Analytical and numerical modeling qualitatively reproduces the experimental trends, while quantitative discrepancies indicate that realistic MTJ properties beyond idealized models play an important role in RF-assisted switching.