Experimental indications for coherent coupling of two quantum dots

The coherent coupling of exciton states in single quantum dot molecules has been demonstrated by various experiments. Anti-crossings in the fine structure of excitons have been observed as well as diamagnetic shifts in Faraday- and Voigt-configuration which depend systematically on the width of the barrier between the two dots. Similar systematic dependences have been found for spin-splitting. Further indications have been obtained by comparison of excitation dependent studies of quantum dot molecules and single quantum dots