Chiral properties of graphene h-BN hybrid systems

TL;DR

This paper investigates the chiral properties of hybrid graphene-h-BN systems, revealing how they can be decomposed into effective subsystems with specific electronic features relevant for applications.

Contribution

It introduces a chiral decomposition method for hybrid graphene-h-BN systems and identifies the conditions for characteristic electronic phenomena like Fabry-Pérot resonances and magic angles.

Findings

Identification of subsystem types depending on hybrid composition

Parameter ranges for observing spectral features

Analysis of hybrid stacking effects on electronic properties

Abstract

The application of the chiral decomposition procedure to hybrid graphene h-BN systems revealed rules for the partition of the system into effective subsystems being bilayers plus monolayer in case the number of layers is odd. Three types of subsystems have been detected namely purely graphene bilayers and monolayers, mixed bilayers and pure h-BN monolayers depending on the hybrid composition. The effective parameters characterizing these chiral subsystems consist of the interlayer couplings and on-site potentials which shows the mechanism of compensation of the asymmetry introduced into the system by h-BN layers. For illustration, we provide a pedagogical overview about chiral tunneling in graphene subsystems (MLG, BLG) present in hybrid with one h-BN layer. We have established the parameter ranges for which the characteristic features in the spectrum are observed, such as Fabry-P\'erot resonances in the case of MLG and "magic angles" in the case of effective BLG. We also consider different hybrid stacking in order to indicate effective systems with the desired properties required in the electronic and spintronic applications.