Tight Binding Approach for Conduction Subband Spin-Splitting of GaAs/Al0.3Ga0.7As and In0.7Ga0.3As/In0.7Al0.3As Superlattices

In this work, we used tight-binding approach for the subject of zero-field spin-splitting in semiconductor heterojunction. We constructed two dimensional electron gas (2DEG) systems that include both spin-orbit interaction parameters and an effect of symmetric potential by adding electric field to the tight-binding Hamiltonian. This model was applied to GaAs/AlGaAs and InGaAs/InAlAs (001) superlattice and the results were compared with each other. As we had expected, the large spin-orbit interaction was obtained in the narrow gap InGaAs/InAlAs heterostructure. And conduction subband spin-splitting from showed k-direction anisotropy, and obtained spin-splitting energy of InGaAs/InAlAs superlattice was almost five times larger than that in the GaAs/Al_0.3Ga_0.7As.