Aharonov-Bohm interferences in polycrystalline graphene

TL;DR

This paper proposes defect scattering as a novel mechanism to induce Aharonov-Bohm interferences in polycrystalline graphene, enabling strong conductance oscillations in quantum Hall regimes through extended defect tunneling paths.

Contribution

It introduces defect scattering as an alternative to traditional methods for achieving AB interference in polycrystalline graphene and extends the approach to other 2D material systems.

Findings

Strong AB oscillations predicted in polycrystalline graphene with grain boundaries.

Defect scattering enables tunneling between edge channels, facilitating interference.

Applicable to systems with graphene barriers and potentially other 2D materials.

Abstract

Aharonov-Bohm (AB) interferences in the quantum Hall regime can be achieved, provided that electrons are able to transmit between two edge channels in nanostructures. Pioneering approaches include quantum point contacts in 2DEG systems, bipolar graphene p-n junctions, and magnetic field heterostructures. In this work, defect scattering is proposed as an alternative mechanism to achieve AB interferences in polycrystalline graphene. Indeed, due to such scattering, the extended defects across the sample can act as tunneling paths connecting quantum Hall edge channels. Consequently, strong AB oscillations in the conductance are predicted in polycrystalline graphene systems with two parallel grain boundaries. In addition, this general approach is demonstrated to be applicable to nano-systems containing two graphene barriers with functional impurities and perspectively, can also be extended to similar systems of 2D materials beyond graphene.