Topological Zero-Line Modes in Folded Bilayer Graphene

TL;DR

This paper proposes a practical method to create tunable topological zero-line modes in folded bilayer graphene, combining theoretical analysis and experimental fabrication, with potential applications in low-power electronics.

Contribution

It introduces a feasible folded bilayer graphene design for topological channels, simplifying previous complex setups and demonstrating controllable fabrication methods.

Findings

Tunable topological conducting channels can be formed in folded bilayer graphene.

External magnetic fields enhance conductance in the presence of impurities.

The proposed structure can be fabricated controllably and easily.

Abstract

We theoretically investigate a folded bilayer graphene structure as an experimentally realizable platform to produce the one-dimensional topological zero-line modes. We demonstrate that the folded bilayer graphene under an external gate potential enables tunable topologically conducting channels to be formed in the folded region, and that a perpendicular magnetic field can be used to enhance the conducting when external impurities are present. We also show experimentally that our proposed folded bilayer graphene structure can be fabricated in a controllable manner. Our proposed system greatly simplifies the technical difficulty in the original proposal by considering a planar bilayer graphene (i.e., precisely manipulating the alignment between vertical and lateral gates on bilayer graphene), laying out a new strategy in designing practical low-power electronics by utilizing the gate induced topological conducting channels.