Etched graphene quantum dots on hexagonal boron nitride

TL;DR

This study demonstrates that graphene quantum dots on hexagonal boron nitride exhibit reduced disorder and increased stability compared to those on SiO2, with properties varying with quantum dot size.

Contribution

The paper provides a comparative analysis of graphene quantum dots on hBN and SiO2, highlighting substrate effects on disorder and stability, with a focus on size-dependent behavior.

Findings

Reduced disorder in QDs on hBN compared to SiO2

Size-dependent decrease in peak spacing variability on hBN

Enhanced magnetic stability of QDs on hBN

Abstract

We report on the fabrication and characterization of etched graphene quantum dots (QDs) on hexagonal boron nitride (hBN) and SiO2 with different island diameters. We perform a statistical analysis of Coulomb peak spacings over a wide energy range. For graphene QDs on hBN, the standard deviation of the normalized peak spacing distribution decreases with increasing QD diameter, whereas for QDs on SiO2 no diameter dependency is observed. In addition, QDs on hBN are more stable under the influence of perpendicular magnetic fields up to 9T. Both results indicate a substantially reduced substrate induced disorder potential in graphene QDs on hBN.