From coherently excited correlated states to incoherent relaxation processes in semiconductors

Summary form only given. We present a quantitative analysis of experiments measuring dephasing in quasi-2D GaAs quantum wells. Controlled amounts of incoherent carriers are introduced independently from the coherently driven e-h pairs that participate to the four-wave mixing. The two pulses excite the quantum-well sample at an energy slightly below the hh-exciton and have parallel polarizations allowing the formation of bound biexcitons. The incoherent carriers are generated by an independent cw laser exciting the sample in the continuum.