Tailoring 10 nm Scale Suspended Graphene Junctions and Quantum Dots

TL;DR

This paper introduces a versatile electromigration-based method to fabricate low-disorder, 10 nm scale suspended graphene junctions and quantum dots, enabling advanced quantum electronic and optical studies.

Contribution

It presents a novel fabrication technique for precise, low-disorder suspended graphene nanostructures with controllable dimensions and shapes.

Findings

Successfully fabricated 6-55 nm graphene junctions and quantum dots.

Achieved controlled tearing of graphene channels down to 27 nm.

Demonstrated high-quality suspended quantum dots.

Abstract

The possibility to make 10 nm scale, and low-disorder, suspended graphene devices would open up many possibilities to study and make use of strongly coupled quantum electronics, quantum mechanics, and optics. We present a versatile method, based on the electromigration of gold-on-graphene bow-tie bridges, to fabricate low-disorder suspended graphene junctions and quantum dots with lengths ranging from 6 nm up to 55 nm. We control the length of the junctions, and shape of their gold contacts by adjusting the power at which the electromigration process is allowed to avalanche. Using carefully engineered gold contacts and a nonuniform downward electrostatic force, we can controllably tear the width of suspended graphene channels from over 100 nm down to 27 nm. We demonstrate that this lateral confinement creates high-quality suspended quantum dots. This fabrication method could be extended to other two-dimensional materials.