Anisotropic magnetoresistance driven by surface spin orbit scattering

TL;DR

This paper theoretically explores how interfacial spin orbit scattering in insulator/ferromagnetic metal bilayers induces a unique anisotropic magnetoresistance with distinctive angular dependence, influenced by film thickness and spin polarization.

Contribution

It introduces a theoretical model for surface spin orbit scattering effects on magnetoresistance in bilayers, revealing a new angular dependence as a potential experimental signature.

Findings

Identifies a peculiar angular dependence of AMR due to surface spin orbit scattering.

Shows the AMR depends on film thickness and ferromagnet spin polarization.

Provides a theoretical framework for interpreting experimental AMR signatures.

Abstract

In a bilayer consisting of an insulator (I) and a ferromagnetic metal (FM), interfacial spin orbit scattering leads to spin mixing of the two conducting channels of the FM, which results in an unconventional anisotropic magnetoresistance (AMR). We theoretically investigate the magnetotransport in such bilayer structures by solving the spinor Boltzmann transport equation with generalized Fuchs-Sondheimer boundary condition that takes into account the effect of spin orbit scattering at the interface. We find that the new AMR exhibits a peculiar angular dependence which can serve as a genuine experimental signature. We also determine the dependence of the AMR on film thickness as well as spin polarization of the FM.