Tunable Coulomb blockade in nanostructured graphene

TL;DR

This paper demonstrates tunable Coulomb blockade effects in a graphene quantum dot device, showing how gate control influences charge transport and energy levels, with potential implications for quantum electronics.

Contribution

It presents the first detailed measurement of Coulomb blockade in a fully tunable, nanostructured graphene quantum dot with three lateral gates.

Findings

Coulomb blockade resonances observed in graphene quantum dot

Charging energy of approximately 3.5 meV measured

Temperature increases lead to peak broadening and higher transmission

Abstract

We report on Coulomb blockade and Coulomb diamond measurements on an etched, tunable single-layer graphene quantum dot. The device consisting of a graphene island connected via two narrow graphene constrictions is fully tunable by three lateral graphene gates. Coulomb blockade resonances are observed and from Coulomb diamond measurements a charging energy of ~3.5 meV is extracted. For increasing temperatures we detect a peak broadening and a transmission increase of the nanostructured graphene barriers.