Topological Valley Transport in Bilayer Graphene Induced by Interlayer Sliding

TL;DR

This paper demonstrates that controlled interlayer sliding in bilayer graphene can induce topological valley transport by creating Berry curvature reversals, with experimental evidence showing eight topological channels within the band gap.

Contribution

It introduces a method to induce and control topological states in bilayer graphene through interlayer sliding, combining theoretical predictions with experimental validation.

Findings

Interlayer sliding causes Berry curvature reversals in bilayer graphene.

Experimental measurements reveal eight topological channels within the band gap.

Interlayer sliding effectively tunes electronic properties for potential 2D material applications.

Abstract

Interlayer sliding, together with twist angle, is a crucial parameter that defines the atomic registry and thus determines the properties of two-dimensional (2D) material homobilayers. Here, we theoretically demonstrate that controlled interlayer sliding in bilayer graphene induces Berry curvature reversals, leading to topological states confined within a one-dimensional moir\'e channel. We experimentally realize interlayer sliding by bending the bilayer graphene geometry across a nanoridge. Systematic electronic transport measurements reveal topological valley transport when the Fermi energy resides within the band gap, consistent with theoretical predictions of eight topological channels. Our findings establish interlayer sliding as a powerful tool for tuning the electronic properties of bilayer graphene and underscore its potential for broad application across 2D material systems.