Integration of a gate electrode into carbon nanotube devices for scanning tunneling microscopy

TL;DR

This paper presents a new fabrication process for integrating a gate electrode into suspended carbon nanotubes, enabling combined scanning tunneling microscopy and electron transport studies.

Contribution

The work introduces a novel method to incorporate gate electrodes into carbon nanotube devices for enhanced spectroscopic and transport analysis.

Findings

Successful fabrication of gated suspended nanotubes

Observation of Coulomb blockade diamonds

Enabling combined STM and electron transport studies

Abstract

We have developed a fabrication process for incorporating a gate electrode into suspended single-walled carbon nanotube structures for scanning tunneling spectroscopy studies. The nanotubes are synthesized by chemical vapor deposition directly on a metal surface. The high temperature ~800 C involved in the growth process poses challenging issues such as surface roughness and integrity of the structure which are addressed in this work. We demonstrate the effectiveness of the gate on the freestanding part of the nanotubes by performing tunneling spectroscopy that reveals Coulomb blockade diamonds. Our approach enables combined scanning tunneling microscopy and gated electron transport investigations of carbon nanotubes.