Resonant electron scattering by graphene antidot

TL;DR

This paper investigates resonant electron scattering caused by edge states on graphene nanoholes, revealing how these states influence conductivity and local density of states, with implications for graphene-based electronic devices.

Contribution

It provides a detailed calculation of the scattering cross section and analyzes the effects of edge imperfections and Coulomb interactions on resonant scattering phenomena.

Findings

Resonant peaks in conductivity depend on edge state localization and lifetime.

Edge rippling and inhomogeneity modify resonance characteristics but not their existence.

Local density of states shows a resonant dependence on gate voltage.

Abstract

The edge states which were observed on a linear edge of graphene may also persist on a curved edge. We calculate the elastic transport scattering cross section on a graphene nanohole supporting the edge states. Resonant peaks in the gate voltage dependence of conductivity of graphene with such nanoholes are obtained. Position and height of the resonances are determined by the localization depth of the quasibound edge states, and width -- by their lifetime. The scattering amplitude near the resonant energies has a strong valley asymmetry. We evaluate the effect of moderate edge rippling, inhomogeneity of boundary parameter along the edge, and Coulomb effects (charged nanohole) on the edge states and show that they do not affect the presence of the resonances, but can substantially influence their position, height and width. The local density of states near the nanohole also demonstrates a resonant dependence on gate voltage.