Formation of coupled quantum dots in single-wall carbon nanotubes

Abstract

The triple-barrier coupled quantum dots have been fabricated in individual single-wall carbon nanotubes by depositing a narrow ${\mathrm{SiO}}_{\mathrm{2}}$ layer in between metallic source–drain contacts. The current–voltage characteristics at 4.2 K with different gate voltages before the ${\mathrm{SiO}}_{\mathrm{2}}$ deposition have indicated the formation of a single quantum dot. After the ${\mathrm{SiO}}_{\mathrm{2}}$ deposition, the irregular Coulomb diamonds and the negative differential conductance have been observed, which suggests the formation of coupled quantum dots.