Non-chiral one-dimensional states propagating inside AB/BA domain walls in bilayer graphene

TL;DR

This paper investigates the electronic states within AB/BA domain walls in bilayer graphene, revealing the existence of non-chiral 1D states that depend on the boundary width and external conditions.

Contribution

It demonstrates that AB/BA domain walls can host non-chiral 1D states, expanding understanding beyond topologically protected chiral states.

Findings

Non-chiral 1D states exist in AB/BA domain walls.

The states depend on boundary width and interlayer bias.

Modeling shows these states can be confined or extend into the continuum.

Abstract

Boundaries between structural twins of bilayer graphene (so-called AB/BA domain walls) are often discussed in terms of the formation of topologically protected valley-polarised chiral states. Here, we show that, depending on the width of the AB/BA boundary, the latter can also support non-chiral one-dimensional (1D) states that are confined to the domain wall at low energies and take the form of quasi-bound states at higher energies, where the 1D bands cross into the two-dimensional spectral continuum. We present the results of modeling of electronic properties of AB/BA domain walls with and without magnetic field as a function of their width and interlayer bias.