Polarization dependence of semiconductor exciton and biexciton   contributions to phase-resolved optical two-dimensional Fourier-transform   spectra
  We study the coherent light-matter interactions of GaAs quantum wells associated with excitons, biexcitons and many-body effects. For most polarization configurations, excitonic features dominate the phase-resolved two-dimensional Fourier-transform (2DFT) spectra and have dispersive lineshapes, indicating the presence of many-body interactions. For cross-linear excitation, excitonic features become weak and absorptive due to the strong suppression of many-body effects; a result that can not be directly determined in transient four-wave mixing experiments. The biexcitonic features do not weaken for cross-polarized excitation and thus are more important. 
Alan D. Bristow, Denis Karaiskaj, Xingcan Dai, Richard. P. Mirin, and   Steven T. Cundiff