Determination of interatomic coupling between two-dimensional crystals using angle-resolved photoemission spectroscopy

TL;DR

This paper presents a method using angle-resolved photoemission spectroscopy to determine interatomic coupling in two-dimensional crystal heterostructures, revealing how stacking and twisting affect their electronic properties.

Contribution

The study introduces a novel spectroscopic approach to quantify interlayer coupling in 2D materials, applicable across various stacking configurations and layer numbers.

Findings

Interatomic coupling can be extracted from ARPES spectra of trilayer structures.

The method is validated on twisted trilayer graphene.

Results are applicable to diverse van der Waals heterostructures.

Abstract

Lack of directional bonding between two-dimensional crystals like graphene or monolayer transition metal dichalcogenides provides unusual freedom in selection of components for vertical van der Waals heterostructures. However, even for identical layers, their stacking, in particular the relative angle between their crystallographic directions, modifies properties of the structure. We demonstrate that the interatomic coupling between two two-dimensional crystals can be determined from angle-resolved photoemission spectra of a trilayer structure with one aligned and one twisted interface. Each of the interfaces provides complementary information and together they enable self-consistent determination of the coupling. We parametrize interatomic coupling for carbon atoms by studying twisted trilayer graphene and show that the result can be applied to structures with different twists and number of layers. Our approach demonstrates how to extract fundamental information about interlayer coupling in a stack of two-dimensional crystals and can be applied to many other van der Waals interfaces.