Topologically confined states at corrugations of gated bilayer graphene

TL;DR

This paper explores how corrugations in gated bilayer graphene create topologically protected states and conducting channels, with implications for designing robust electronic transport pathways.

Contribution

It demonstrates the emergence of topologically protected gap states at stacking boundaries and analyzes their transport properties in corrugated bilayer graphene.

Findings

Topologically protected gap states appear at stacking boundaries.

Corrugations create robust conducting channels.

Finite-size states exhibit a gap, unlike boundary states.

Abstract

We investigate the electronic and transport properties of gated bilayer graphene with one corrugated layer, which results in a stacking AB/BA boundary. When a gate voltage is applied to one layer, topologically protected gap states appear at the corrugation, which reveal as robust transport channels along the stacking boundary. With increasing size of the corrugation, more localized, quantum-well-like states emerge. These finite-size states are also conductive along the fold, but in contrast to the stacking boundary states, which are gapless, they present a gap. We have also studied periodic corrugations in bilayer graphene; our findings show that such corrugations between AB- and BA-stacked regions behave as conducting channels that can be easily identified by their shape.