Excitonic and biexcitonic effects in the coherent optical response of semiconductor quantum dots

Few particle effects in the coherent optical spectra of semiconductor quantum dots are analyzed using a density-matrix approach that explicitly accounts for exciton-exciton interactions. Few-particle interactions are shown to play an important role in the appearance of additional lines with increasing pumping density. The nature of these interactions is examined within the framework of biexcitonic interactions. A consistent description of additional peaks appearing at high photoexcitation density is given.