Proposal of a robust measurement scheme for the non-adiabatic spin torque using the displacement of magnetic vortices

TL;DR

This paper introduces a robust measurement scheme to accurately determine the non-adiabatic spin torque strength by analyzing magnetic vortex displacement, addressing discrepancies in previous measurements and theoretical predictions.

Contribution

A new measurement method is proposed that isolates the non-adiabatic spin torque effect, improving accuracy and robustness over existing techniques.

Findings

The scheme effectively separates Oersted field effects from spin torque signals.

Analytical and numerical results confirm robustness against current direction uncertainties.

The method enhances measurement precision of non-adiabatic spin torque strength.

Abstract

The strength of the non-adiabatic spin torque is currently under strong debate, as its value differs by orders of magnitude as well in theoretical predictions as in measurements. Here, a measurement scheme is presented that allows to determine the strength of the non-adiabatic spin torque accurately and directly. Analytical and numerical calculations show that the scheme allows to separate the displacement due to the Oersted field and is robust against uncertainties of the exact current direction.