Electronic transport in locally gated graphene nanoconstrictions

TL;DR

This paper presents a novel fabrication method for locally gated graphene nanoconstrictions, demonstrating tunable electronic properties, enhanced gate efficiency, and conductance suppression due to quantum effects.

Contribution

The authors introduce a new etching and deposition technique for creating arbitrary graphene nanostructures with local gating capabilities.

Findings

Achieved an order of magnitude increase in gate efficiency.

Demonstrated complete device turn-off via local gate voltage.

Observed conductance suppression due to quantum confinement and Coulomb blockade.

Abstract

We have developed the combination of an etching and deposition technique that enables the fabrication of locally gated graphene nanostructures of arbitrary design. Employing this method, we have fabricated graphene nanoconstrictions with local tunable transmission and characterized their electronic properties. An order of magnitude enhanced gate efficiency is achieved adopting the local gate geometry with thin dielectric gate oxide. A complete turn off of the device is demonstrated as a function of the local gate voltage. Such strong suppression of device conductance was found to be due to both quantum confinement and Coulomb blockade effects in the constricted graphene nanostructures.