Single wall carbon nanotube double quantum dot

The authors report on two top-gate defined, coupled quantum dots in a semiconducting single wall carbon nanotube, constituting a tunable double quantum dot system. The single wall carbon nanotubes are contacted by titanium electrodes and gated by three narrow top-gate electrodes as well as a back gate. The authors show that a bias spectroscopy plot on just one of the two quantum dots can be used to extract the addition energy of both quantum dots. Furthermore, honeycomb charge stability diagrams are analyzed by an electrostatic capacitor model that includes cross capacitances, and they extract the coupling energy of the double quantum dot. (c) 2006 American Institute of Physics.