Interface states at the boundary between ABC and ABA multilayer graphene structures

TL;DR

This paper investigates the electronic interface states at boundaries between ABC and ABA multilayer graphene, revealing non-topological interface bands that become quantized in finite structures, with differences depending on interface orientation.

Contribution

It provides a detailed analysis of interface states in multilayer graphene, highlighting the effects of local compression and shear on the formation of interface bands for different edge types.

Findings

Interface bands form at ABC/ABA boundaries, especially in armchair configurations.

Interface states are not topologically protected.

Finite structures show quantized energy levels derived from these interface bands.

Abstract

We study the interfaces between ABC and ABA regions in multilayer graphene, in particular we consider regions in which the transition between the ABA and ABC structure arises due to the local compression in one of the graphene layers for a zigzag interface, and to a local shear of the atoms for the armchair interface. When we consider an infinite ribbon configuration we find that interface bands form in these regions, more pronouncedly for the armchair-type interfaces. We note that these states are not topological. For fully-finite-size structures the continuous interface bands transform into sets of quantized levels.