Formation of coupled quantum dots in single-wall carbon nanotubes

The triple-barrier coupled quantum dots have been fabricated in individual single-wall carbon nanotubes by depositing a narrow SiO2 layer in between metallic source-drain contacts. The current-voltage characteristics at 4.2 K with different gate voltages before the SiO2 deposition have indicated the formation of a single quantum dot. After the SiO2 deposition, the irregular Coulomb diamonds and the negative differential conductance have been observed, which suggests the formation of coupled quantum dots. (C) 2001 American Institute of Physics.