General theoretical description of angle-resolved photoemission spectroscopy of van der Waals structures

TL;DR

This paper presents a comprehensive theoretical framework for modeling angle-resolved photoemission spectroscopy (ARPES) in complex van der Waals structures, including twisted bilayers, by incorporating generalized umklapp processes within a tight-binding approach.

Contribution

It introduces a general theory for ARPES in incommensurate vdW structures that surpasses previous low-energy models, applicable to a wide range of layered materials with lattice mismatches or misalignments.

Findings

Successfully models ARPES bands in twisted bilayer graphene and MoS₂.

Provides a method to interpret experimental ARPES data in complex vdW systems.

Extends understanding of electronic structures in materials with competing periodicities.

Abstract

We develop a general theory to model the angle-resolved photoemission spectroscopy (ARPES) of commensurate and incommensurate van der Waals (vdW) structures, formed by lattice mismatched and/or misaligned stacked layers of two-dimensional materials. The present theory is based on a tight-binding description of the structure and the concept of generalized umklapp processes, going beyond previous descriptions of ARPES in incommensurate vdW structures, which are based on continuous, low-energy models, being limited to structures with small lattice mismatch/misalignment. As applications of the general formalism, we study the ARPES bands and constant energy maps for two structures: twisted bilayer graphene and twisted bilayer MoS$_{2}$. The present theory should be useful in correctly interpreting experimental results of ARPES of vdW structures and other systems displaying competition between different periodicities, such as two-dimensional materials weakly coupled to a substrate and materials with density wave phases.