Dispersive hybrid states and bandgap in zigzag Graphene/BN heterostructures

TL;DR

This paper investigates edge states in zigzag graphene/BN heterostructures, revealing high-velocity dispersive states and a tunable bandgap, which could enable advanced control of graphene-based electronic transport.

Contribution

It demonstrates how BN/Graphene interfaces modify edge states, introducing dispersive hybrid states with high velocities and a significant bandgap in asymmetric heterostructures.

Findings

High group velocities up to 7.4x10^5 m/s at interfaces.

Opposite sign velocities for N/C and B/C hybrid states.

A bandgap of about 207 meV in asymmetric structures.

Abstract

We study the properties of edge states in in-plane heterostructures made of adjacent zigzag graphene and BN ribbons. While in pure zigzag graphene nanoribbons, gapless edge states are nearly flat and cannot contribute significantly to the conduction, at BN/Graphene interfaces the properties of these states are significantly modified. They are still strongly localized at the zigzag edges of graphene but they exhibit a high group velocity up to 4.3x10^5 m/s at the B/C interface and even 7.4x10^5 m/s at the N-C interface. For a given wave vector the velocities of N/C and B/C hybrid interface states have opposite signs. Additionally, in the case of asymmetric structure BN/Graphene/BN, a bandgap of about 207 meV is open for sub-ribbon widths of 5 nm. These specific properties suggest new ways to engineer and control the transport properties of graphene nanostructures.