Aharonov-Bohm conductance oscillations and current equilibration in local n - p junctions in graphene

TL;DR

This paper investigates Aharonov-Bohm conductance oscillations and current equilibration in local n-p junctions within graphene nanoribbons under quantum Hall conditions, revealing how current interactions influence quantum interference patterns.

Contribution

It introduces a model for electrostatic potential and current equilibration in graphene n-p junctions, demonstrating the transition from conductance oscillations to fractional quantum Hall plateaus.

Findings

Persistent currents localized at the n-p junction support Aharonov-Bohm oscillations.

Current equilibration leads to the evolution of conductance from oscillations to fractional plateaus.

Electrostatic potential analysis near charge neutrality point explains the observed phenomena.

Abstract

We consider a small p-type island defined within n-type graphene nanoribbon induced by potential of a floating electrode. In the quantum Hall conditions the island supports persistent currents localized at the $n-p$ junction. When coupled to the graphene edge the island acts as an Aharonov-Bohm interferometer. We evaluate the electrostatic potential induced by the floating gate within the ribbon near the charge neutrality point and consider equilibration of the currents at both sides of the junction. The incoherent equilibration is introduced by the virtual probes technique. We describe the evolution of the coherent Aharonov-Bohm conductance oscillations to the quantum Hall fractional plateaus due to the current equilibration.