Effect of spin-orbit coupling on the wave vector and spin dependent transmission probability for the GaN/AlGaN/GaN heterostructure

Abstract

The effect of the Rashba and Dresselhaus spin–orbit coupling (SOC) on the transmission of electrons through the GaN/AlGaN/GaN heterostructure is studied. It is found that the Dresselhaus SOC causes the evident dependence of the transmission probability on the spin polarization and the in-plane wave vector of electrons, and also induces evident spin splitting of the resonant peaks in the (Ez-k) plane. Because the magnitude of the Rashba SOC is relatively small, its effect on the transmission of electrons is much less. As k increases, the peaks of transmission probability for spin-up electrons (T+) shift to a higher energy region and increase in magnitude, while the peaks of transmission probability for spin-down electrons (T−) shift to a lower energy region and decrease in magnitude. The polarization efficiency (P) is found to peak at the resonant energies and increases with the in-plane wave vector. Moreover, the built-in electric field caused by the spontaneous and piezoelectric polarization can increase the amplitude of P. Results obtained here are helpful for the efficient spin injection into the III-nitride heterostructures by nonmagnetic means from the device point of view.