Theoretical Study on Magnetic Tunneling Junctions with Semiconductor Barriers CuInSe 2 and CuGaSe 2 Including a Detailed Analysis of Band-Resolved Transmittances

Abstract

We study spin-dependent transport properties in magnetic tunneling junctions (MTJs) with semiconductor barriers, Fe/CuInSe2/Fe(001) and Fe/CuGaSe2/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 Δ1 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 Δ1 wave functions in some energy regions a few eV away from the Fermi level due to small band gaps in CuInSe2 and CuGaSe2.