Characterization of Spin-Transfer-Torque effect induced magnetization dynamics driven by short current pulses

TL;DR

This study investigates the magnetization dynamics driven by spin-transfer torque in a microstructured waveguide using short current pulses, introducing a novel method to accurately determine the threshold current for damping compensation.

Contribution

A new, robust method based on magnon density evolution is developed to determine the threshold current in spin-transfer-torque experiments, independent of signal-to-noise ratio.

Findings

Identified the threshold current for damping compensation.

Developed a noise-insensitive method for threshold determination.

Provided insights into spin-wave dynamics under short current pulses.

Abstract

We present a time-resolved study of the magnetization dynamics in a microstructured Cr$|$Heusler$|$Pt waveguide driven by the Spin-Hall-Effect and the Spin-Transfer-Torque effect via short current pulses. In particular, we focus on the determination of the threshold current at which the spin-wave damping is compensated. We have developed a novel method based on the temporal evolution of the magnon density at the beginning of an applied current pulse at which the magnon density deviates from the thermal level. Since this method does not depend on the signal-to-noise ratio, it allows for a robust and reliable determination of the threshold current which is important for the characterization of any future application based on the Spin-Transfer-Torque effect.