Femtosecond coherent dynamics of free carriers in semiconductors

Abstract

Using two-color femtosecond pump-probe spectroscopy, we study quantum coherent effects in the dynamics of nonthermal carrier distributions in semiconductors. At very low excitation densities, energy non-conserving transitions and memory effects are observed during the spontanous emission of LO phonons in GaAs. For strong excitation, we present the first experiment demonstating Rabi-oscillations of the carrier density in the absorption continuum of InP.