Electronic properties of graphene nanoribbons under gate electric fields

TL;DR

This study uses density-functional theory to analyze how gate electric fields influence the electronic states of graphene nanoribbons, revealing localized quantum-dot-like states and estimating dielectric properties.

Contribution

It introduces a detailed computational approach to examine the effects of in-plane gate electric fields on GNR electronic states, including state development and localization.

Findings

Formation of localized quantum-dot-like states in GNRs under electric fields

Determination of a static dielectric constant of approximately 4 for armchair GNRs

Observation of state evolution with varying electric field strength

Abstract

Quantum-dot states in graphene nanoribbons (GNR) were calculated using density-functional theory, considering the effect of the electric field of gate electrodes. The field is parallel to the GNR plane and was generated by an inhomogeneous charge sheet placed atop the ribbon. Varying the electric field allowed to observe the development of the GNR states and the formation of localized, quantum-dot-like states in the band gap. The calculation has been performed for armchair GNRs and for armchair ribbons with a zigzag section. For the armchair GNR a static dielectric constant of {\epsilon} approx. 4 could be determined.