Symmetry of Energy Bands in Crystals of Wurtzite Type II. Symmetry of Bands with Spin-Orbit Interaction Included

Abstract

Double-valued representations of the space group C4 6v (wurtzite lattice) have been constructed. A variant of perturbation theory is presented, allowing the investigation of the dispersion law in the vicinity of symmetry elements taking into consideration the spin-orbit interaction. The formulae obtained here differ from those available in the literature and lead to a qualitatively different dispersion law for a number of points. A group theoretical analysis of the structure of energy bands in a wurtzite type lattice was carried out taking the spin-orbit interaction into consideration. The possibility of energy surfaces E(k), where (in a proper approximation) the extremum is reached along an entire curve rather than in isolated points of k space, is demonstrated.