DISCRIMINATIVE TEMPERATURE DEPENDENCIES OF DIFFERENTIAL LIGHT-SCATTERING CROSS-SECTIONS FROM AN ELECTRON-GAS IN SEMICONDUCTORS WITH A NONPARABOLIC DISPERSION OF ENERGY-BANDS

We present the results of a direct comparison between experiment and theory of the temperature dependencies of the integrated intensities and spectral linewidths in the quasielastic light-scattering spectra from the electron gas in III-V semiconductors. An explicit expression for the inelastic-electronic light-scattering cross sections in semiconductors with nonparabolic dispersion of energy bands is given for a realistic hydrodynamic free-electron-gas model. We find rather different effects of single-particle electronic excitations on polarized and depolarized scattering in n-InP in the temperature range 27300 K with near infrared excitation of the spectra. The results provide clear evidence for the existence of strong temperature-dependent free-electron-gas fluctuations and prove unambiguously the observation of light scattering from energy- and momentum-density fluctuations. © 1994 The American Physical Society.