Spin-resolved spectroscopy for the study of topological and correlated materials

Electron-based spectroscopy techniques have, for many decades, been playing an important role in the study of materials with novel electronic properties. Especially angle-resolved photoemission spectroscopy (ARPES) has provided important insights in the understanding of correlated materials. The addition of spin resolution (SARPES) has received much attention with the study of topological materials, but before these results it was already used to investigate ferromagnets and Rashba systems. After a short overview of results for systems with strong spin-orbit interaction, it will be shown how SARPES can be used to study hidden observables and to obtain additional information on correlated systems. To indicate how the use of spin-resolved spectroscopy can develop in the near future, examples of quantum time measurements, operando manipulation of multiferroics, and entanglement spectroscopy will be given.