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

摘要

We study spin-dependent transport properties in magnetic tunneling junctions(MTJs) with semiconductor barriers, Fe/CuInSe$_2$/Fe(001) andFe/CuGaSe$_2$/Fe(001). By analyzing their transmittances at zero bias voltageon the basis of the first-principles calculations, we find that spin-dependentcoherent tunneling transport of $\Delta_1$ wave functions yields a relativelyhigh magnetoresistance (MR) ratio in both the MTJs. We carry out a detailedanalysis of the band-resolved transmittances in both the MTJs and find anabsence of the selective transmission of $\Delta_1$ wave functions in someenergy regions a few eV away from the Fermi level due to small band gaps inCuInSe$_2$ and CuGaSe$_2$.