Evidence of Klein tunneling in graphene p-n junctions

TL;DR

This paper demonstrates that in graphene p-n junctions, the resistance behavior aligns with Klein tunneling predictions for Dirac fermions when potential steps are steep, supported by magnetoresistance measurements.

Contribution

It provides experimental evidence of Klein tunneling in graphene p-n junctions using gate-controlled potential barriers and magnetoresistance analysis.

Findings

Resistance matches Klein tunneling predictions

Disorder effects diminish with steep potential steps

Magnetoresistance measurements support theoretical models

Abstract

Transport through potential barriers in graphene is investigated using a set of metallic gates capacitively coupled to graphene to modulate the potential landscape. When a gate-induced potential step is steep enough, disorder becomes less important and the resistance across the step is in quantitative agreement with predictions of Klein tunneling of Dirac fermions up to a small correction. We also perform magnetoresistance measurements at low magnetic fields and compare them to recent predictions.