Current-induced dynamics in non-collinear dual spin-valves

TL;DR

This paper theoretically investigates how non-collinear magnetic configurations in dual spin-valves influence spin-transfer torque and dynamics, revealing potential for reduced critical currents and unique magnetic behaviors.

Contribution

It introduces a theoretical analysis of spin-transfer torque in non-collinear dual spin-valves, including a formula for critical current and macrospin simulation predictions.

Findings

Non-collinear configurations significantly affect spin torque and dynamics.

Critical current can be reduced by several times compared to single spin valves.

Macrospin simulations predict unique free layer behaviors in various magnetic layer arrangements.

Abstract

Spin-transfer torque and current induced spin dynamics in spin-valve nanopillars with the free magnetic layer located between two magnetic films of fixed magnetic moments is considered theoretically. The spin-transfer torque in the limit of diffusive spin transport is calculated as a function of magnetic configuration. It is shown that non-collinear magnetic configuration of the outermost magnetic layers has a strong influence on the spin torque and spin dynamics of the central free layer. Employing macrospin simulations we make some predictions on the free layer spin dynamics in spin valves composed of various magnetic layers. We also present a formula for critical current in non-collinear magnetic configurations, which shows that the magnitude of critical current can be several times smaller than that in typical single spin valves.