Probing electronic properties of quantum dots and molecules by nanogap metallic electrodes

Recent progress in nanofabrication technologies allows us to access to quantum mechanically well-defined electronic systems, such as quantum dots (QDs) and molecules. Such nanojunctions are expected to open a new paradigm in future optoelectronic devices. We have investigated electron transport through single self-assembled InAs QDs and molecules, using metallic leads with nanogaps. InAs QDs exhibited clear shell filling and novel transport phenomena such as Kondo effect. Furthermore, we have observed current-voltage characteristics molecular junctions fabricated by precisely controlled electromigration technique.