Quantum Interference in Graphene Nanoconstrictions

TL;DR

This paper investigates quantum interference effects in graphene nanoconstrictions, revealing Fabry-Perot and Fano resonances caused by internal reflections and localized states, advancing understanding of quantum phenomena in graphene devices.

Contribution

It demonstrates the coexistence of Fabry-Perot and Fano interferences in graphene nanoconstrictions and provides a theoretical explanation for their origin.

Findings

Observation of multimode Fabry-Perot interference patterns.

Detection of sharp Fano antiresonances in conductance.

Theoretical model linking localized states to Fano resonances.

Abstract

We report quantum interference effects in the electrical conductance of chemical vapor deposited graphene nanoconstrictions fabricated using feedback controlled electroburning. The observed multimode Fabry-Perot interferences can be attributed to reflections at potential steps inside the channel. Sharp antiresonance features with a Fano line shape are observed. Theoretical modeling reveals that these Fano resonances are due to localized states inside the constriction, which couple to the delocalized states that also give rise to the Fabry-Perot interference patterns. This study provides new insight into the interplay between two fundamental forms of quantum interference in graphene nanoconstrictions.