Theoretical study on magnetic tunneling junctions with semiconductor barriers CuInSe$_2$ and CuGaSe$_2$ including a detailed analysis of band-resolved transmittances

TL;DR

This study uses first-principles calculations to analyze spin-dependent tunneling in magnetic junctions with semiconductor barriers, revealing high magnetoresistance linked to coherent $$ wave transmission and band structure effects.

Contribution

It provides a detailed theoretical analysis of band-resolved transmittances in MTJs with CuInSe$_2$ and CuGaSe$_2$ barriers, highlighting the role of band gaps in transmission properties.

Findings

High magnetoresistance due to $$ wave tunneling

Absence of selective $$ wave transmission in certain energy regions

Band gap effects influence tunneling behavior

Abstract

We study spin-dependent transport properties in magnetic tunneling junctions (MTJs) with semiconductor barriers, Fe/CuInSe$_2$/Fe(001) and Fe/CuGaSe$_2$/Fe(001). By analyzing their transmittances at zero bias voltage on the basis of the first-principles calculations, we find that spin-dependent coherent tunneling transport of $\Delta_1$ wave functions yields a relatively high magnetoresistance (MR) ratio in both the MTJs. We carry out a detailed analysis of the band-resolved transmittances in both the MTJs and find an absence of the selective transmission of $\Delta_1$ wave functions in some energy regions a few eV away from the Fermi level due to small band gaps in CuInSe$_2$ and CuGaSe$_2$.