Ultra-short suspended single-wall carbon nanotube transistors

TL;DR

This paper presents a novel fabrication method for ultra-short suspended single-wall carbon nanotube transistors that host a single quantum dot, enabling studies of high-frequency oscillators with strong electron-vibron interactions.

Contribution

The authors develop a new technique combining gold bow-tie junctions and feedback-controlled electromigration to create ultra-short, clean, and tunable SWCNT transistors with quantum dots.

Findings

Devices exhibit clean electron transport at low temperatures.

Transistors function as tunable single-electron transistors.

Potential for THz oscillator applications with strong electron-vibron coupling.

Abstract

We describe a method to fabricate clean suspended single-wall carbon nanotube (SWCNT) transistors hosting a single quantum dot ranging in length from a few 10s of nm down to $\approx$ 3 nm. We first align narrow gold bow-tie junctions on top of individual SWCNTs and suspend the devices. We then use a feedback-controlled electromigration to break the gold junctions and expose nm-sized sections of SWCNTs. We measure electron transport in these devices at low temperature and show that they form clean and tunable single-electron transistors. These ultra-short suspended transistors offer the prospect of studying THz oscillators with strong electron-vibron coupling.