Three-terminal scanning tunneling spectroscopy of suspended carbon nanotubes

TL;DR

This paper reports three-terminal low-temperature scanning tunneling spectroscopy on suspended carbon nanotubes, revealing Coulomb diamonds and phonon-assisted tunneling side peaks that are excitations of the main states.

Contribution

It introduces a three-terminal spectroscopy method for suspended nanotubes and demonstrates phonon-assisted tunneling features with gate dependence.

Findings

Observation of well-defined Coulomb diamonds.

Detection of phonon-assisted tunneling side peaks.

Side peaks share gate dependence with Coulomb peaks.

Abstract

We have performed low-temperature scanning tunneling spectroscopy measurements on suspended single-wall carbon nanotubes with a gate electrode allowing three-terminal spectroscopy measurements. These measurements show well-defined Coulomb diamonds as well as side peaks from phonon-assisted tunneling. The side peaks have the same gate voltage dependence as the main Coulomb peaks, directly proving that they are excitations of these states.