Local absorption spectra of artificial atoms and molecules

We investigate theoretically the spatial dependence of the linear absorptio n spectra of single and coupled semiconductor. quantum dots, where the stro ng three-dimensional quantum confinement leads to an overall enhancement of Coulomb interaction and, in turn, to a pronounced renormalization of the e xcitonic properties. We show that-because of such Coulomb,correlations and the spatial interference of the exciton wave functions-unexpected spectral features appear whose intensity; depends on spatial resolution in a highly nonmonotonic way when the spatial resolution is comparable with the exciton ic Bohr radius. We finally discuss how the optical near-field properties of double quantum dots, are affected by their coupling.