Optical excitonic absorption spectrum in coupled quantum dots due to dipole-dipole interactions

We investigate the excitonic absorption spectrum induced by dipole-dipole interactions in two coupled quantum dots. The dipoles excited in neighboring quantum dots lead to constructive and destructive interference in excitonic polarizations. We find that the excitonic absorption peaks oscillate with the Rabi oscillation of the population and that two new peaks appear around the region where the bright excitonic state transfers to a dark state. The peaks result from a competition between the two types of interference. Therefore, the excitonic absorption spectrum in the coupled quantum dot system can be controlled by using the dipoles generated in neighboring quantum dots.