The procedure to realize two-dimensional quantum dot superlattices: From incoherently coupled to coherently coupled quantum dot arrays

We will describe, from both the theoretical and experimental points of view, a procedure leading to the realization of two-dimensional quantum dot superlattices (2D QDSLs). Two kinds of laterally coupled quantum dot arrays in which the exciton motions are coherent and incoherent: are studied by photoluminescence (PL) measurements. The formation of minibands with coherent exciton motion is demonstrated in the large red shift of the PL peak energy as well as the dramatic narrowing of the PL linewidth. Moreover, we indicate, using excitation-dependent PL spectra as an example, that the exciton coherence can be reduced by various scattering mechanisms.