Lateral electron transport through single InAs quantum dots grown by molecular beam epitaxy

The transport properties of single InAs quantum dots (QDs) grown by molecular beam epitaxy have been investigated by metallic leads with nanogaps. It was found that the uncapped InAs QDs grown on the GaAs surfaces show metallic conductivities, indicating that even the exposed QDs are not depleted. On the contrary, it was found that no current flows through the exposed wetting layers. For the case of the QDs covered with GaAs capping layers, clear Coulomb gaps and Coulomb staircases have been observed at View the MathML source.