Probing the Wannier function of Crystalline Solids with Angle‐Resolved Photoemission Spectroscopy

Angle‐resolved photoemission spectroscopy (ARPES) has been a widely adopted technique in the studies of quantum materials. The surface sensitivity of photoelectric effect also makes it a powerful tool to investigate surface and shallow interface phenomena. While an overwhelming majority of its use focuses on extracting the eigenenergy of the electron Bloch states in momentum space, attempts to extract information of the wave function via ARPES has been limited to molecular systems. In this perspective, it is proposed and advocated use ARPES to investigate and unravel wave function properties, as opposed to only the electron energy‐momentum dispersion relation, in crystalline solids and their interfaces. This can help enhance the rapidly growing development of material properties based on the spatial and geometric properties of the electronic wave functions.