Bias dependence in spin-polarized tunneling of ferromagnet ferromagnetic insulator (semiconductor)/ferromagnet junctions

Based on the nearly-free-eleceron approximation, the bias dependencies of electron transport properties of ferromagnet/ferromagnetic insulator (semiconductor)/ferromagnet junctions have been studied. Resonances appear in electron transmission probability. These resonances cause oscillations in the zero-temperature tunnel current and the resonances occur in tunnel conductance. Tunnel magnetoresistance (TMR) is an oscillatory function of bias. The TMR can reach a value as high as 100%. The bias dependencies of electron transport properties relate to the magnetic configurations of the junctions.