  On the basis of a microscopic theory, the signatures of many-particle
correlations in Two-Dimensional Fourier-Transform Spectra (2D-FTS) of
semiconductor nanostructures are identified and compared to experimental data.
Spectra in the photon energy range of the heavy-hole and light-hole excitonic
resonances show characteristic features due to correlations, which depend on
the relative polarization directions of the excitation pulses.
