Double refraction of electron spin across a metal-semiconductor junction with Rashba and Dresselhaus spin-orbit interactions: A stronger spin-filtering effect

Abstract

The reflection and refraction of electrons across a two-dimensional metal-semiconductor tunnel junction are studied incorporating both Rashba and Dresselhaus spin-orbit interactions for the semiconductor region. The effects of incident electron energy, angle of incidence and spin-orbit interactions on the angles of refraction of the spin-up and spin-down electrons are calculated exactly. It is shown that the Dresselhaus interaction decreases the angle of refraction for the spin-down electrons more than the spin-up electrons causing a larger splitting between the spin-up and spin-down electrons. Also an increase in the incident energy is shown to increase the spin-filtering effect. The refraction coefficients, spin-up and spin-down current densities and tunnelling conductance are also studied with respect to spin-orbit interactions. Finally, the spin polarization current is determined in the semiconductor region in the presence of Rashba interaction alone and in the presence of both Rashba and Dresselhaus interactions.