Effect of Rashba spin-orbit coupling on the spin-dependent transport in magnetic tunnel junctions with semiconductor interlayers

摘要

Based on a mode match transfer matrix method and the quantum coherent transport theory of Mireles and Kirczenow, we investigate the coherent electron tunneling in FM/S1/I/S2/FM (FM represents the ferromagnetic metal layer, S1 and S2 represents the different semiconductor layer, respectively, I represents the insulator layer.) system. The effects of the thickness of the semiconductor layers and the Rashba spin-orbit coupling on the spin-dependent tunneling transmission coefficient and the properties of the tunnel magnetoresistance (TMR) are studied. It is found that the variations of tunneling transmission coefficients and the tunnel magnetoresistance TMR with Rashba spin-orbit coupling and the thickness of semiconductor layer, show typical resonant properties and the-TMR can be enhanced and its sign can switch from positive to negative by increasing the ratio of Rashba spin-orbit coupling strength between two semiconductor layers.