Spin-orbit induced anisotropy in the tunneling magnetoresistance of magnetic tunnel junctions

TL;DR

This paper models how spin-orbit interactions, specifically Dresselhaus and Rashba couplings, influence tunneling magnetoresistance in magnetic tunnel junctions, explaining experimental anisotropy and its bias-induced inversion.

Contribution

It introduces a theoretical model linking spin-orbit interference to TAMR anisotropy and bias effects, aligning well with experimental data.

Findings

Two-fold symmetry of TAMR explained by spin-orbit interference

Bias can invert TAMR due to changes in Rashba coupling

Model matches experimental observations in Fe/GaAs/Au junctions

Abstract

The effects of the spin-orbit interaction on the tunneling magnetoresistance of magnetic tunnel junctions are investigated. A model in which the experimentally observed two-fold symmetry of the anisotropic tunneling magnetoresistance (TAMR) originates from the interference between Dresselhaus and Bychkov-Rashba spin-orbit couplings is formulated. Bias induced changes of the Bychkov-Rashba spin-orbit coupling strength can result in an inversion of the TAMR. The theoretical calculations are in good agreement with the TAMR experimentally observed in epitaxial Fe/GaAs/Au tunnel junctions.