Single electron tunnelling through high-Q single-wall carbon nanotube NEMS resonators

By first lithographically fabricating contact electrodes and then as last step growing carbon nanotubes with chemical vapour deposition across the ready-made chip, many potential contamination mechanisms for nanotube devices can be avoided. Combining this with pre-defined trenches on the chip, such that the nanotubes are freely suspended above the substrate, enables the formation of highly regular electronic systems. We show that, in addition, such suspended nanotubes provide excellent high-frequency and low-dissipation mechanical resonators. The motion detection mechanism of our experiment is discussed, and we measure the effect of Coulomb blockade and the back-action of single electron tunnelling on the mechanical motion. In addition data on the mechanical higher modes is presented.(a) Sketch of the basic experimental setup, with a nanotube nano-electromechanical resonator being driven contact-free via the electric field of a suspended radio-frequency antenna. (b) Gate voltage dependence of the observed mechanical resonance frequency for the fundamental bending mode of the nanotube resonator as well as higher modes.