A comprehensive time-resolved electronic Raman scattering theory for nonequilibrium carrier excitations in semiconductors is presented. The following are simultaneously taken into account: (i) the effects of the ultrashort laser pulse for probing the excited carrier distribution function; (ii) the fact that the fluctuation-dissipation theorem is not valid under conditions of nonequilibrium carrier distributions; (iii) the effects of quasiparticle life time via a finite collision time in the Raman scattering cross section; and (iv) the effect of the time-dependent resonant enhancement factor due to the band structure. The single-particle scattering spectra for spin-density fluctuation contribution is found to be significantly broadened by an ultrashort laser pulse, but is substantially narrowed by the finite collision time. The effect of the time-dependent resonant enhancement factor has been demonstrated to broaden the line shape of single-particle scattering spectra for the spin-density fluctuation contribution as the probe photon energy increases.
|Original language||English (US)|
|Number of pages||11|
|Journal||Journal of Applied Physics|
|State||Published - 1992|
ASJC Scopus subject areas
- Physics and Astronomy(all)