Dresden 2026 – scientific programme
Parts | Days | Selection | Search | Updates | Downloads | Help
TT: Fachverband Tiefe Temperaturen
TT 14: Superconductivity: Properties and Electronic Structure
TT 14.5: Talk
Monday, March 9, 2026, 16:00–16:15, HSZ/0103
On-site two-hole Coulomb energy in CuO and La2CuO4 from coincidence electron spectroscopy — •Danilo Kühn1, Swarnshikha Sinha1,2, Fredrik O. L. Johansson3, Katarzyna Siewirska1, Antonello Tebano4, Nils Mårtensson3, Andreas Lindblad3, Daniele Di Castro4, and Alexander Föhlisch1,2 — 1Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Berlin, Germany — 2Universität Potsdam, Potsdam, Germany — 3Uppsala University, Uppsala, Sweden — 4Universitá di Roma Tor Vergata, Roma, Italy
The high temperature superconductivity in layered cuprates is likely driven by strong electron correlations, though not fully understood. Here, Auger photoelectron coincidence spectroscopy (APECS) data of undoped La2CuO4 and CuO from the COESCA station at the BESSY II storage ring will be shown [1]. O 1s/ KVV and Cu 2p/ LVV coincidence measurements allow to disentangle the various structures in the Auger spectra and give detailed information of site specific multi-hole valence states.
The Auger spectra are analysed with Cini-Sawatzky and atomic multiplet models, in order to extract electronic parameters such as on-site Coulomb energy in O 2p and Cu 3d orbitals. Dynamics of the core excited states and delocalization of the multi-hole states are investigated. Our unique setup with ARTOF 2 time-of-flight spectrometers in combination with the tailored photon-pulse structure of a soft x-ray undulator beam line enables APECS with unprecedented information rate.
[1] D. Kühn et al., Nat. Commun. 16, 9748 (2025)
Keywords: electron coincidence spectroscopy; APECS; Coulomb energy; soft x-ray; cuprates