Resonance Measurement of Nonlocal Spin Torque in a Three-Terminal Magnetic Device

TL;DR

This paper reports a quantitative measurement of nonlocal spin torque in a three-terminal magnetic device using spin-torque-driven ferromagnetic resonance, confirming the effective circuit model and suggesting optimization strategies.

Contribution

It provides the first precise measurement of nonlocal spin torque and validates the effective circuit model for spin transport in such devices.

Findings

Measurement agrees with the circuit model predictions

Strategies for optimizing nonlocal torque are proposed

Enhancement of magnetic memory device design without large voltages

Abstract

A pure spin current generated within a nonlocal spin valve can exert a spin transfer torque on a nanomagnet. This nonlocal torque enables new design schemes for magnetic memory devices that do not require the application of large voltages across tunnel barriers that can suffer electrical breakdown. Here we report a quantitative measurement of this nonlocal spin torque using spin-torque-driven ferromagnetic resonance. Our measurement agrees well with the prediction of an effective circuit model for spin transport. Based on this model, we suggest strategies for optimizing the strength of nonlocal torque.