Electronic transport across linear defects in graphene

TL;DR

This paper studies how electrons move across linear defects in graphene, using computational methods to analyze transmission, charge density, and current flow in various defect configurations and geometries.

Contribution

It introduces an analytical approach for transport in infinite graphene flakes with specific extended grain boundaries where Dirac points overlap.

Findings

Transmission varies with defect angle and structure.

Charge density and current flow are affected by defect type.

Extended defect lines with periodicity 3 have unique transport properties.

Abstract

We investigate the low-energy electronic transport across grain boundaries in graphene ribbons and infinite flakes. Using the recursive Green's function method, we calculate the electronic transmission across different types of grain boundaries in graphene ribbons. We show results for the charge density distribution and the current flow along the ribbon. We study linear defects at various angles with the ribbon direction, as well as overlaps of two monolayer ribbon domains forming a bilayer region. For a class of extended defect lines with periodicity 3, an analytic approach is developed to study transport in infinite flakes. This class of extended grain boundaries is particularly interesting, since the $K$ and $K'$ Dirac points are superposed.