COUPLED QUANTUM DOTS FABRICATED BY CLEAVED EDGE OVERGROWTH - FROM ARTIFICIAL ATOMS TO MOLECULES

Atomically precise quantum dots of mesoscopic size have been fabricate d in the gallium arsenide-aluminum gallium arsenide material system by cleaved edge overgrowth, with a high degree of control over shape, co mposition, and position. The formation of bonding and antibonding stat es between two such ''artificial atoms'' was studied as a function of quantum dot separation by microscopic photoluminescence (PL) spectrosc opy. The coupling strength within these ''artificial molecules'' is ch aracterized by a systematic dependence, of the separation of the bondi ng and antibonding levels, and of the PL linewidth, on the ''interatom ic'' distance. This model system opens new insights into the physics o f coupled quantum objects.