Probing barrier transmission in ballistic graphene

TL;DR

This paper investigates how transport barriers in graphene influence local electronic states, revealing mesoscale undulations and charge density scaling that can be used to characterize defects and improve graphene-based devices.

Contribution

It introduces a method to probe barrier scattering properties via local density of states without lateral transport measurements, aiding defect assessment in graphene.

Findings

It predicts mesoscale undulations caused by itinerant states.

Barriers can show double minima in local density of states.

Charge density scales as x^{-2} away from barriers.

Abstract

We derive the local density of states from itinerant and boundary states around transport barriers and edges in graphene and show that the itinerant states lead to mesoscale undulations that could be used to probe their scattering properties in equilibrium without the need for lateral transport measurements. This finding will facilitate vetting of extended structural defects such as grain boundaries or line defects as transport barriers for switchable graphene resonant tunneling transistors. We also show that barriers could exhibit double minima and that the charge density away from highly reflective barriers and edges scales as $x^{-2}$.