Effects of rf Current on Spin Transfer Torque Induced Dynamics

TL;DR

This paper investigates how radiofrequency currents influence spin transfer torque-induced switching in nanoscale spin valves, revealing frequency-dependent effects that alter magnetization dynamics and switching thresholds.

Contribution

It demonstrates the significant impact of rf currents on dc-driven magnetization switching and explains these effects through macrospin simulations, highlighting a novel interaction mechanism.

Findings

rf currents significantly modify switching dynamics

frequency locking and pulling effects observed

critical switching current depends on rf frequency

Abstract

The impact of radiofrequency (rf) currents on the direct current (dc) driven switching dynamics in current-perpendicular-to-plane nanoscale spin valves is demonstrated. The rf currents dramatically alter the dc driven free layer magnetization reversal dynamics as well as the dc switching level. This occurs when the frequency of the rf current is tuned to a frequency range around the dc driven magnetization precession frequencies. For these frequencies, interactions between the dc driven precession and the injected rf induce frequency locking and frequency pulling effects that lead to a measurable dependence of the critical switching current on the frequency of the injected rf. Based on macrospin simulations, including dc as well as rf spin torque currents, we explain the origin of the observed effects.