Spontaneous localization in InAs/GaAs self-assembled quantum-dot molecules

Spontaneous localization of hole states is predicted at all separations in vertically stacked InAs/GaAs self-assembled quantum dots. Eight-band k.p theory shows that valence band mixing enhanced by the unique three-dimensional strain distribution, subjects holes to very different environment than electrons. As a result, low energy holes are confined to their respective dots without forming bonding or antibonding states. This localization plays the same role as a vertically applied electric field in coupled quantum systems, and substantially decreases the exciton binding energy, which may be an impediment to the formation of entangled states in quantum-dot molecules. (C) 2002 American Institute of Physics.