Electronic structure of 2D van der Waals crystals and heterostructures investigated by spatially- and angle-resolved photoemission

TL;DR

This paper reviews recent advances in angle-resolved photoemission spectroscopy applied to two-dimensional van der Waals heterostructures, highlighting new insights into their electronic structures and device behaviors.

Contribution

It provides a comprehensive overview of the state-of-the-art techniques and recent developments in studying 2D heterostructures with angle-resolved photoemission.

Findings

First application of ARPES to 2D heterostructures

Insights into electronic structures of twisted bilayer graphene

In-operando characterization of gate-tunable devices

Abstract

Angle-resolved photoemission is a direct probe of the momentum-resolved electronic structure and proved influential in the study of bulk crystals with novel electronic properties. Thanks to recent technical advances, this technique can now be applied for the first time for the study of van der Waals heterostructures built by stacking two-dimensional crystals. In this article we will present the current state of the art in angle-resolved photoemission measurements on two-dimensional materials and review this still young field. We will focus in particular on devices similar to those used in transport and optics experiments, including the latest developments on magic-angle twisted bilayer graphene and on the in-operando characterization of gate tunable devices.