Surface states in zigzag and armchair graphene nanoribbons

TL;DR

This paper investigates the electronic surface states in zigzag and armchair graphene nanoribbons using a tight-binding model, revealing how edge geometries influence the energy gap and surface state classification.

Contribution

It provides a detailed analysis of surface states in graphene nanoribbons considering different edge geometries and surface perturbations, classifying states into Tamm and Shockley types.

Findings

Surface states can close the energy gap at the Dirac point in armchair nanoribbons.

Surface states are classified into Tamm and Shockley states based on their properties.

Edge geometry significantly affects the electronic spectra of nanoribbons.

Abstract

This paper presents electronic spectra of zigzag and armchair graphene nanoribbons calculated within the tight-binding model for pi-electrons. Zigzag and armchair nanoribbons of different edge geometries are considered, with surface perturbation taken into account. The properties of surface states are discussed on the basis of their classification into Tamm states and Shockley states. In armchair nanoribbons surface states are shown to close the energy gap at the Dirac point for certain edge geometries.