Influence of plasma modes on surface dynamical conductivity of polar semiconductors

The dynamical conductivity of the inversion surface layer in a polar semiconductor is investigated theoretically taking into account the dynamical screening of electronic interactions, the formation of coupled plasmon-phonon modes and the electron scattering on these modes. Frequency and concentration dependencies of the conductivity are calculated for GaAs and PbTe. It is stated that the dynamical screening determines a considerable variation of the latter.