Spin-orbit coupling and g-factor of X-valley in cubic GaN

We report our theoretical investigation on the spin-orbit coupling and g-factor of the X-valley in cubic GaN. We find that the spin-orbit coupling coefficient from sp 3d 5s ∗ tight-binding model is 0.029 eV Å, which is comparable with that in cubic GaAs. By employing the kṡp theory, we find that the g-factor in this case is only slightly different from the free electron g-factor. These results are expected to be important for the on-going study on spin dynamics far away from equilibrium in cubic GaN.