Visualizing electronic structures of quantum materials by angle-resolved photoemission spectroscopy

Electronic structures are critical characteristics that determine the electrical, magnetic and optical properties of materials. With the capability of directly visualizing band dispersions and Fermi surfaces, angle-resolved photoemission spectroscopy (ARPES) has emerged as a powerful experimental tool to extract the electronic structures of materials and the coupling of these electronic structures to different degrees of freedom in crystal lattices. In the past three decades, advances in instrumentation and light sources have significantly improved the accuracy and efficiency of ARPES experiments. These advances have enabled the application of ARPES in novel material systems to aid our understanding of their physical properties and behaviours. In this Review, we give a brief introduction to the principles of ARPES and outline its applications in different material systems, with a focus on topological quantum materials and transition metal dichalcogenides.