ULTRAFAST DYNAMICS AND QUANTUM TRANSPORT OF ELECTRONS IN STRONGLY DISORDERED SEMICONDUCTORS

The new experiments on the response of electrons in semiconductors to femtosecond optical pulses call for developing adequate theoretical to ols. A promising approach has been found in using the non-equilibrium Green functions approximately factorized on the basis of the so-called generalized Kadanoff-Baym ansatz. The present work investigates the v alidity of such approach on an example of a semiconductor with an allo y scattering, where the coherent potential approximation allows to con struct the non-equilibrium Green functions directly, so that an explic it comparison with the ansatz decoupling is possible. The ansatz for t he electron distribution is in this case justified as far as the quasi particle picture for the individual electrons is appropriate.