Angular dependence of the tunneling anisotropic magnetoresistance

TL;DR

This paper explores how the tunneling anisotropic magnetoresistance (TAMR) varies with magnetization direction, influenced by spin-orbit coupling, across different crystal orientations and strain conditions in magnetic tunnel junctions.

Contribution

It extends a phenomenological model to provide a unified description of TAMR's angular dependence in various MTJ orientations and strain effects.

Findings

Predicted TAMR angular dependence for (001), (110), and (111) MTJs.

Identified the influence of structure and bulk inversion asymmetry on TAMR.

Analyzed the impact of in-plane uniaxial strain on TAMR.

Abstract

Based on general symmetry considerations we investigate how the dependence of the tunneling anisotropic magnetoresistance (TAMR) on the magnetization direction is determined by the specific form of the spin-orbit coupling field. By extending a phenomenological model, previously proposed for explaining the main trends of the TAMR in (001) ferromagnet/semiconductor/normal-metal magnetic tunnel junctions (MTJs) [J. Moser {\it et al.}, Phys. Rev. Lett. 99, 056601 (2007)], we provide a unified qualitative description of the TAMR in MTJs with different growth directions. In particular, we predict the forms of the angular dependence of the TAMR in (001),(110), and (111) MTJs with structure inversion asymmetry and/or bulk inversion asymmetry. The effects of in-plane uniaxial strain on the TAMR are also investigated.