Electron-Phonon Coupling in Wurtzite Semiconductors: Intervalley Scattering Selection Rules for Hexagonal GaN

Selection rules are presented for electron-phonon scattering in GaN with the wurtzite crystal structure. The results are obtained for the interband scattering between the lowest conduction band ($\Gamma$-valley) and the second conduction band ($U$-valley). These selection rules are derived based on the original group-theoretical analysis of the crystal vibrations in GaN, which included detailed compatibility relations for all phonon modes.