Signatures of Klein tunneling in disordered graphene p-n-p junctions

TL;DR

This paper introduces a quantum transport modeling method for disordered graphene p-n-p junctions, revealing how disorder affects Klein tunneling signatures like resistance and Fano factor resonances.

Contribution

It combines microscopic disorder treatment, quantum analysis, and realistic system sizes, providing new insights into disorder effects on Klein tunneling in graphene.

Findings

Resonance peaks in resistance and Fano factor are observed due to quasi bound states.

Disorder washes out resonance features when mean free path is comparable to junction length.

The method enables realistic modeling of quantum transport in disordered graphene devices.

Abstract

We present a method for obtaining quantum transport properties in graphene that uniquely combines three crucial features: microscopic treatment of charge disorder, fully quantum mechanical analysis of transport, and the ability to model experimentally relevant system sizes. As a pertinent application we study the disorder dependence of Klein tunneling dominated transport in p-n-p junctions. Both the resistance and the Fano factor show broad resonance peaks due to the presence of quasi bound states. This feature is washed out by the disorder when the mean free path becomes of the order of the distance between the two p-n interfaces.