Influence of two-pair continuum correlations following resonant excitation of excitons.
The memory structure induced by coherent transitions to the exciton-exciton scattering continuum is shown to have significant influence on spectrally resolved four-wave-mixing signals even under selective excitation of 1s excitons. Comparisons between experiments and calculations that account nonperturbatively for these quantum kinetic Coulomb correlations demonstrate large compensations between mean-field contributions and transitions to the two-pair continuum. Experiments with different polarizations of the laser pulses show that two-pair continuum correlations are responsible for delay-time dependent shifts of the excitonic emission as well as for substantial deformations of the line shape.
Axt
V M
VM
Institut für Festkörpertheorie, Westfälische Wilhelms Universität Münster, Wilhelm-Klemm-Strasse 10, D-48149 Münster, Germany.
Haase
B
B
Neukirch
U
U