Aharonov-Bohm effect in an electron-hole graphene ring system

TL;DR

This paper reports the observation of Aharonov-Bohm oscillations in a graphene quantum ring, demonstrating quantum interference between electrons and holes, and showing that these oscillations are unaffected by the gate voltage sign.

Contribution

It introduces a graphene ring system that enables the study of electron-hole quantum interference, highlighting the equivalence of unipolar and dipolar interference effects.

Findings

Aharonov-Bohm oscillations observed in graphene rings.

Oscillation period and amplitude are independent of gate voltage sign.

Demonstrates quantum interference between electrons and holes.

Abstract

Aharonov-Bohm oscillations are observed in a graphene quantum ring with a top gate covering one arm of the ring. As graphene is a gapless semiconductor this geometry allows to study not only the quantum interference of electrons with electrons or holes with holes but also the unique situation of quantum interference between electrons and holes. The period and amplitude of the observed Aharonov-Bohm oscillations are independent of the sign of the applied gate voltage showing the equivalence between unipolar and dipolar interference.