Coupled quantum dots in single-wall carbon nanotubes

Electrical transport measurements have been carried out below View the MathML source on individual single-wall carbon nanotubes on which a narrow SiO2 layer was deposited between source and drain contacts. The current–voltage curves with different gate voltages showed modulation of the current-suppressed region near zero bias voltage (Coulomb gap), and a negative differential conductance at large biases. These results together with the bias dependence of Coulomb blockade oscillations suggest the formation of the coupled quantum dots in carbon nanotubes.