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

TL;DR

This paper theoretically investigates the spin-orbit coupling and g-factor of the X-valley in cubic GaN, providing key parameters for understanding spin dynamics in this material.

Contribution

It presents the first detailed calculations of spin-orbit coupling and g-factor in cubic GaN's X-valley using tight-binding and k·p models.

Findings

Spin-orbit coupling coefficient is 0.029 eV·Å, comparable to cubic GaAs.

g-factor is close to the free electron g-factor.

Results are relevant for spin dynamics studies in cubic GaN.

Abstract

We report our theoretically 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 $sp^3d^5s^\ast$ tight-binding model is 0.029\,eV$\cdot${\AA}, which is comparable with that in cubic GaAs. By employing the ${\bf k}\cdot{\bf p}$ 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.