Raman sound scattering in normal metals and superconductors

Raman sound scattering (RSS) is considered in normal metals and in superconductors. The scattering amplitude, calculated by second order perturbation theory from the Fröhlich Hamiltonian, has a resonance nature, enabling the observation of RSS at low temperatures in pure samples. High-frequency sound is considered in the two regions: A – ω ⪡ T and B – ω ⪢