Angle-resolved photoemission spectroscopy

TL;DR

ARPEs is a versatile technique that provides detailed energy and momentum information about electronic structures in quantum materials, enabling significant scientific discoveries and ongoing advancements.

Contribution

This paper reviews the principles, instrumentation, and scientific applications of ARPES, highlighting recent technological improvements and future challenges.

Findings

ARPEs has advanced with improved resolution and new observables.

ARPEs has been successfully applied to various quantum materials.

Future developments face technical and analytical challenges.

Abstract

For solid-state materials, the electronic structure, E(k), is critical in determining a crystal's physical properties. By experimentally detecting the electronic structure, the fundamental physics can be revealed. Angle-resolved photoemission spectroscopy (ARPES) is a powerful technique for directly observing the electronic structure with energy- and momentum-resolved information. Over the past decades, major improvements in the energy and momentum resolution, alongside the extension of ARPES observables to spin (SpinARPES), micrometer or nanometer lateral dimensions (MicroARPES/NanoARPES), and femtosecond timescales (TrARPES), have led to major scientific advances. These advantages have been achieved across a wide range of quantum materials, such as high-temperature superconductors, topological materials, two-dimensional materials and heterostructures. This primer introduces key aspects of ARPES principles, instrumentation, data analysis, and representative scientific cases to demonstrate the power of the method. Perspectives and challenges on future developments are also discussed.