Effect of Image Potential on Spin Polarized Transport through Magnetic Tunnel Junctions

TL;DR

This paper investigates how image potential influences spin-polarized electron transport in Fe/MgO/Fe magnetic tunnel junctions, revealing its impact on current densities and tunnel magnetoresistance at different biases.

Contribution

It introduces a combined model using Simmons' approach and non-equilibrium Green's functions to analyze the role of image potential in spin transport.

Findings

Image potential increases current densities for specific symmetry bands at higher bias.

The tunnel magnetoresistance ratio is more affected at lower bias.

Effects vary with barrier thickness.

Abstract

We study the effect of image potential on spin polarized transport through Fe/MgO/Fe magnetic tunnel junctions in the presence of symmetry filtering. The image potential is included within the Simmon's model coupled with the non-equilibrium Green's function formalism to calculate the quantum transport. The increase in the current densities for the $\Delta_1$ symmetry and the $\Delta_5$ symmetry bands due to the image potential is more pronounced at higher bias, whereas, the increase in the magnitude of the tunnel magnetoresistance ratio is more prominent at lower bias for various barrier thicknesses.