Graphene based quantum dots

TL;DR

This paper reports the discovery of quantum dot arrays in graphene on ruthenium, where localized electronic states form a regular pattern with potential applications in single-electron physics.

Contribution

It introduces a novel nanostructure of graphene quantum dots on ruthenium, demonstrating controlled localization of electronic states and quantum well resonances.

Findings

Localized electronic states separated by 3 nm

Quantum well resonances modulated by graphene corrugation

Strong resonances on decoupled 'hill' regions

Abstract

Laterally localized electronic states are identified on a single layer of graphene on ruthenium. The individual states are separated by 3 nm and comprise regions of about 90 carbon atoms. This constitutes a quantum dot array, evidenced by quantum well resonances that are modulated by the corrugation of the graphene layer. The quantum well resonances are strongest on the isolated "hill" regions where the graphene is decoupled from the surface. This peculiar nanostructure is expected to become important for single electron physics where it bridges zero-dimensional molecule-like and two-dimensional graphene on a highly regular lattice.