Pump-probe experiments are used as a controllable way to investigate the properties of photoexcited semiconductors, 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.
@article{arxiv.0807.3092,
title = {Ultrafast pump-probe dynamics in ZnSe-based semiconductor quantum-wells},
author = {Henni Ouerdane and George Papageorgiou and Ian Galbraith and Ajoy K. Kar and Brian S. Wherrett},
journal= {arXiv preprint arXiv:0807.3092},
year = {2008}
}
Comments
10 pages, 9 figures. Key words: nonlinear and ultrafast optics, modeling of femtosecond pump-probe experiments, electron spin-flip time