Electronic structure of quantum-dot molecules and solids

We present an empirical tight-binding theory of nanocrystal nanosystems. We use our tight-binding theory to understand the electronic states of quantum-dot solids, the coupling between nanocrystals, and the hybridization of states in coupled structures. We consider coupled double-dot molecules. Results for epitaxial connections, with the dots lattice-matched across the interdot interface, show significant coupling when the connection is through more than a few atoms. The coupling strength depends on the spatial distribution and symmetry of the states involved, as in molecular hybridization.