First-principles study on magnetic tunneling junctions with semiconducting CuInSe2 and CuGaSe2 barriers

Abstract

We theoretically investigate two magnetic tunneling junctions (MTJs) with different semiconductor barriers, CuInSe2 (CIS) and CuGaSe2 (CGS), sandwiched between Fe electrodes. We find that Δ1 wave functions provide dominant contributions to spin-dependent tunneling transport in both CIS- and CGS-based MTJs. We also find that the CGS-based MTJ has a much higher magnetoresistive (MR) ratio than the CIS-based MTJ, which indicates that a higher MR ratio is expected for a higher Ga concentration x in the recently reported CuIn1−xGaxSe2-based MTJs. Furthermore, we show that the CIS- and CGS-based MTJs have much smaller resistance–area products (RA) than the conventional MgO-based MTJs.