Spin-transfer torque in magnetic multilayer nanopillars

TL;DR

This paper investigates how spin-polarized currents induce torque and correlation between magnetizations in a magnetic multilayer nanopillar structure, combining theoretical analysis with experimental parameter estimates.

Contribution

It extends the understanding of spin-transfer torque effects from single to coupled ferromagnets in multilayer nanopillars.

Findings

Correlation between magnetizations induced by spin-transfer torque

Dynamics of magnetization in coupled ferromagnets analyzed

Parameter estimates provided based on experimental data

Abstract

We consider a quasi one-dimensional configuration consisting of two small pieces of ferromagnetic material separated by a metallic one and contacted by two metallic leads. A spin-polarized current is injected from one lead. Our goal is to investigate the correlation induced between the magnetizations of the two ferromagnets by spin-transfer torque. This torque results from the interaction between the magnetizations and the spin polarization of the current. We discuss the dynamics of a single ferromagnet, the extension to the case of two ferromagnets, and give some estimates for the parameters based on experiments.