Effect of Rashba and Dresselhaus Spin–Orbit Couplings on Electron Spin Polarization in a Hybrid Magnetic–Electric Barrier Nanostructure

A theoretical study has been carried out on the spin-dependent electron transport in a hybrid magnetic–electric barrier nanostructure with both Rashba and Dresselhaus spin–orbit couplings, which can be experimentally realized by depositing a ferromagnetic strip and a Schottky metal strip on top of a semiconductor heterostructure. The spin–orbit coupling-dependent transmission coefficient, conductance, and spin polarization are calculated by solving the Schrödinger equation exactly with the help of the transfer-matrix method. We find that both the magnitude and sign of the electron spin polarization vary strongly with the spin–orbit coupling strength. Thus, the degree of electron spin polarization can be manipulated by properly adjusting the spin–orbit coupling strength, and such a nanosystem can be employed as a controllable spin filter for spintronics applications.