Theoretical Study of Momentum Matrix Elements of GaN

Abstract

The interaction between the conduction band and valence bands in wurtzite GaN is theoretically investigated by means of the first-principles calculation and the k\cdotpp theory. The momentum matrix elements are derived from the first-principles electronic band structure, calculated by a full-potential linearized augmented plane wave method. We also show analytical expressions of the momentum matrix elements, based on the 8×8 k\cdotpp theory for the wurtzite structure. The values estimated from the analytical expressions are in good agreement with those obtained from the first-principles calculation.