Controllable room-temperature metallic quantum dot

We demonstrate a technique for fabricating a controllable metallic dot coupled to metallic electrodes. This techniques enables one to explore the current-voltage characteristics while varying the distance between the dot and the leads. The fabrication technique combines atomic force microscope nanoscribing and nanomanipulation as well as electrochemical methods and enables very fine dot-lead coupling control. The measured current-voltage curves exhibit stable single-charge phenomena such as Coulomb blockade and Coulomb staircase which are clearly observed even at room temperature. This technique may provide an opportunity to study single electron charging effects in regimes that are currently unaccessible. (c) 2006 American Institute of Physics.