Spin-filtering effects of double-barrier magnetic tunnel junctions with an indium phosphide (InP) spacer

Highlights: • Spin-polarized currents in symmetric (asymmetric) double-barrier MTJs are investigated. • There is an InP semiconductor as a spacer. • A spin-diode behavior is observed for asymmetric double-barrier MTJs. • A nearly 100% spin-filtering is found at a certain range of bias voltage. Spin-polarized currents in double-barrier magnetic tunnel junctions (MTJs) as CoFeB/MgO/InP/MgO/CoFeB (MTJs-InP) are investigated by non-equilibrium Green's function formalism. The asymmetric structures with a half-metal LSMO contact are studied and a spin-diode behavior is found compared to the MTJs-InP. Charge and spin currents as well as spin polarization as a function of bias voltage, angle between magnetizations and quantum-well thickness are also described. A nearly 100% spin polarization is observed at a certain range of bias voltage. Therefore, one can design excellent spin-filter devices based on new MTJs-InP.