Adjustable spin torque in magnetic tunnel junctions with two fixed layers
arXiv:cond-mat/0503376 · doi:10.1063/1.1899764
Abstract
We have fabricated nanoscale magnetic tunnel junctions (MTJs) with an additional fixed magnetic layer added above the magnetic free layer of a standard MTJ structure. This acts as a second source of spin-polarized electrons that, depending on the relative alignment of the two fixed layers, either augments or diminishes the net spin-torque exerted on the free layer. The compound structure allows a quantitative comparison of spin-torque from tunneling electrons and from electrons passing through metallic spacer layers, as well as analysis of Joule selfheating effects. This has significance for current-switched magnetic random access memory (MRAM), where spin torque is exploited, and for magnetic sensing, where spin torque is detrimental.
3 pages, 2 figures, to appear in Appl. Phys. Lett