Effects of size quantization in the spectra and Γ - M transitions in (GaAs)m(AlAs)n(001) superlattices

Based on the pseudopotential method and the phenomenological model of coupling forces, electron scattering by short-wavelength phonons in the conduction band of superlattices (GaAs)(m)(AlAs)(n) with thin layers (n, m <= 10) is studied. Intervalley deformation potentials for transitions between the lower states of the Gamma and M valleys of superlattices, which are analogs of the sphalerite transitions of Gamma - X and X - X, are calculated. The intensity of the Gamma - M transitions is determined mainly by the longitudinal optical vibrations of the Al atoms and depends strongly on the mixing of the states T and X. The capture of phonons and electrons in AlAs layers leads to an increase in the deformation potentials of X - X transitions.