NETWORKS OF QUANTUM NANODOTS - THE ROLE OF DISORDER IN MODIFYING ELECTRONIC AND OPTICAL-PROPERTIES

Disorder is shown to induce qualitative changes in the electronic spec trum and hence in the response of assemblies of quantum dots. Lattices of quantum dots have one unique source of disorder: the dots themselv es can be prepared with a narrow distribution of properties but they a re never quite identical. This is unlike a lattice of atoms or molecul es. In addition, lattices of quantum dots have a configurational disor der and can also be prepared with compositional disorder. The relaxati on of selection rules and the splittings of degeneracies due to symmet ry breaking induced by these fluctuations can be probed by optical mea ns. Special attention is given to the enhancement and to the variation of the second harmonic response as a function of the spacing between the dots.