The Kondo resonance in a single InAs quantum dot probed by nanogap electrodes

We fabricated a pair of nano-gap electrodes to contact an uncapped single selfassembled InAs quantum dot and studied the single-electron transport properties. We observed clear signatures of the Kondo effect as the temperature was lowered, such as lifting of a Coulomb valley corresponding to an odd number of electrons in the dot and zero-bias anomaly in the differential conductance in the Coulomb valley. From the temperature dependence of these features, we estimated the Kondo temperature of about 2 K.