Topological confinement in bilayer graphene

TL;DR

This paper explores a novel type of one-dimensional chiral states in bilayer graphene created by electrostatic confinement, highlighting their topological nature and potential applications in valleytronics.

Contribution

It introduces a new class of topologically confined chiral states in bilayer graphene, linked to the topological vacuum charge and domain wall configurations.

Findings

Chiral states appear at domain walls in bilayer graphene.

The number of zero-mode branches is determined by topological charge.

Potential for experimental observation and valleytronics applications.

Abstract

We study a new type of one-dimensional chiral states that can be created in bilayer graphene (BLG) by electrostatic lateral confinement. These states appear on the domain walls separating insulating regions experiencing the opposite gating polarity. While the states are similar to conventional solitonic zero-modes, their properties are defined by the unusual chiral BLG quasiparticles, from which they derive. The number of zero-mode branches is fixed by the topological vacuum charge of the insulating BLG state. We discuss how these chiral states can manifest experimentally, and emphasize their relevance for valleytronics.