Electrons and phonons in Raman scattering

摘要

The theory has been developed to the first, second and third order Raman scattering (FORS, SORS, TORS respectively) in an isotopically disordered anharmonic semiconductor crystal. The theory is based on the interaction of electron with harmonic, localized and anharmonic field. The double time temperature dependent electron Green's function reveals the electron phonon line-width and shifts using equation of motion technique of quantum dynamics. Raman tensor and differential cross-section show excitations of phonon, polaron and exciton together their dependence linearly as well as non- linearly on temperature via anharmonicity. This feature of theory is not found by earlier workers.