The physics of quantum materials is dictated by many-body interactions and mathematical
concepts such as symmetry and topology that have transformed our understanding of matter …

The recent development of double photoemission (DPE) spectroscopy at surfaces using
laser-based high-order harmonic generation in combination with time-of-flight electron …

Coincidence spectroscopy is a powerful spectroscopic method addressing the recording of
more than one particle involved in an ionization process simultaneously. In the current …

Correlated valence electrons in Ag and Cu are investigated using double photoemission
spectroscopy driven by a high-order harmonic light source. Electron pairs consisting of two d …

The physics of quantum materials is dictated by many-body interactions and mathematical
concepts such as symmetry and topology that have transformed our understanding of matter …

In time-resolved photoemission experiments, more than one electron can be emitted from
the solid by a single ultrashort pulse. We theoretically demonstrate how correlations …

We present a new experimental setup to study electron-electron coincidences from
superconducting surfaces. In our approach, electrons emitted from a surface are projected …

The emission of an electron pair upon single-photon absorption requires a finite electron-
electron interaction. Therefore, double photoemission is a particularly sensitive tool to study …

We present a joint experimental and theoretical study of correlated electron pair emission
from a ferromagnetic Fe (001) surface induced by spin-polarized low-energy electrons. Spin …

Metal oxides like NiO are usually termed'highly correlated', because the material properties
are decisively determined by the electron–electron interaction. This makes them interesting …