Quantum dot molecules and chains

A review of results from theoretical investigations of several systems composed of two or more coupled quantum dots (known as artificial molecules or quantum dot solids) is presented. All the calculations are performed within an empirical tight-binding theory. It is shown that coupling between nanocrystals can split and reorder energy levels and change state symmetries. The results help to understand and explain differences observed in optical spectra of arrays of quantum dots in comparison to the spectra obtained for non-interacting nanocrystals. We show also how an external electric field influences the properties of coupled quantum dots.