FREE-CARRIER ABSORPTION IN N-TYPE GALLIUM-ARSENIDE IN QUANTIZING MAGNETIC-FIELDS

Abstract

Free-carrier absorption in n-type GaAs in quantizing magnetic fields has been investigated quantum mechanically. It is assumed that the energy gand of electrons in semiconductors is nonparabolic and the dominant scattering mechanism for electrons is acoustic-phonon scattering via deformation-potential coupling. When the radiation field is polarized parallel to the magnetic field, the free-carrier absorption coefficient assumes a complex value due to the ac radiation and phonon fields. Our results show that the real part of the absorption coefficient and the imaginary part of the absorption coefficient oscillate with the magnetic field. However, at very low temperatures, oscillations in the imaginary part are diminished and its value decreases rapidly with increasing magnetic field.