G. Schedelbeck et al., COUPLED QUANTUM DOTS FABRICATED BY CLEAVED EDGE OVERGROWTH - FROM ARTIFICIAL ATOMS TO MOLECULES, Science, 278(5344), 1997, pp. 1792-1795
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.