Influence of higher Coulomb correlations on optical coherent-control signals from a ZnSe quantum well

The manipulation of the coherent optical polarization in a quantum well with a pair of phase-locked laser pulses is investigated by using wave-mixing signals. The measurements are performed in four- and six-wave-mixing geometries with different polarization states of the excitation pulses. Even at moderate excitation densities, the signals are modulated by higher harmonics that correspond to high-order optical nonlinearities. A significant effect of higher Coulomb correlations on the coherent-control signals is demonstrated by comparing the experiments with calculations based on a microscopic density-matrix theory. The theoretical approach makes use of the dynamics-controlled truncation scheme. The corresponding numerical results are in good agreement with the experiment. (C) 2003 Optical Society of America.