Optical Vibrational Modes and Electron-Phonon Interaction in GaAs Quantum Wells

Abstract
We have discovered phonons active in resonant Raman scattering from GaAs quantum-well heterostructures that are actually the optical vibrations of a thin ionic slab. These modes are revealed by selection rules for the polarizations of incident and scattered light that are different from those of bulk GaAs. Analysis of the Raman tensor indicates new deformation-potential electron-phonon scattering processes which are a direct consequence of the reduced symmetry of the layered system.