Ultrafast Quantum Kinetics of Time-Dependent RPA-Screened Coulomb Scattering

We study the Coulomb quantum kinetics of relaxation and dephasing of an electron-hole gas in asemiconductor excited by a coherent femtosecond laser pulse. Our theory employs the full two-time-dependent RPA-screened Coulomb potential. The self-consistently calculated potential evolves froma bare potential to the well-known dynamically screened RPA potential for long times. The timedependence of the particle distributions, the interband polarization, and the potential are calculated. Asa first application we study Rabi flopping with resonant femtosecond pulses. [S0031-9007(98)06707-6]