Theory of Resonance Raman Scattering near Critical Points

Abstract

Abstract The resonance behaviour of the Raman scattering cross section for allowed one‐phonon scattering is investigated as a function of incident frequency. Both the cases of uncorrelated and of interacting electron‐hole pairs as intermediate states are considered. The scattering amplitude is calculated for uncorrelated pairs for all types of critical points of the interband electronic energy. The dispersion of the scattering cross section is shown to be independent of the type of the critical point. The effect of Coulomb electron‐hole interaction is studied for M 0 and M 3s critical points. As a result of this interaction the resonance enhancement is much more stronger and the scattering cross section as a function of incident frequency shows more pronounced structures as compared to the case of uncorrelated pairs.