Effect of electron correlations on (001) Fe/MgO interfaces

TL;DR

This paper develops a reliable model for electron tunneling in Fe/MgO magnetic tunnel junctions, showing that many-body effects are crucial for accurately describing electron transport and matching experimental data.

Contribution

It introduces a new parametrization of transmission probability based on quasiparticle self-consistent GW calculations for Fe/MgO interfaces.

Findings

Transmission peak at +0.12 V matches experiments

Many-body effects are essential for accurate transport modeling

Intrinsic properties of well-defined Fe/MgO interfaces confirmed

Abstract

We developed a parametrization of transmission probability that reliably captures essential elements of the tunneling process in magnetic tunnel junctions. The electronic structure of Fe/MgO system is calculated within the quasiparticle self-consistent GW approximation and used to evaluate transmission probability across (001) Fe/MgO interface. The transmission has a peak at +0.12 V, in excellent agreement with recent differential conductance measurements for electrodes with antiparallel spin. These findings confirm that the observed current-voltage characteristics are intrinsic to well defined (001) Fe/MgO interfaces, in contrast to previous predictions based on the local spin-density approximation, and also that many-body effects are important to realistically describe electron transport across well defined metal-insulator interfaces.