Pump-probe experiments are used as a controllable way to investigate the properties of photoexcited semi-conductors, in particular, the absorption saturation. We present an experiment-theory comparison for ZnSe quantum wells, investigating the energy renormalization and bleaching of the excitonic resonances. Experiments were performed with spin-selective excitation and above-bandgap pumping. The model, based on the semiconductor Bloch equations in the screened Hartree-Fock approximation, takes various scattering processes into account phenomenologically. Comparing numerical results with available experimental data, we explain the experimental results and find that the electron spin-flip occurs on a time scale of 30 ps.
|Number of pages||10|
|Journal||Journal of the Optical Society of America B: Optical Physics|
|Publication status||Published - Sep 2002|