Berlin 2024 – scientific programme
Parts | Days | Selection | Search | Updates | Downloads | Help
O: Fachverband Oberflächenphysik
O 95: Electronic Structure of Surfaces II: Spectroscopy, Surface States
O 95.5: Talk
Thursday, March 21, 2024, 16:00–16:15, MA 144
Double Photoemission of C60 on SrTiO3(001) with pulsed laser radiation — •Kathrin Plass1, Robin Kamrla1, Frank O. Schumann2, and Wolf Widdra1 — 1Institute of Physics, Martin-Luther-Universität Halle-Wittenberg, Halle (Saale), Germany — 2Max Planck Institute of Microstructure Physics, Halle (Saale), Germany
Via photoelectron spectroscopy, important insights into the electronic structure of solids were obtained. However, correlation effects can only be addressed indirectly. With double photoemission spectroscopy (DPE), such phenomena can be observed directly by detecting pairs of correlated photoelectrons emitted upon absorption of a single photon [1]. C60 is classified as a strongly correlated material with a highly structured valence band. In this contribution we present DPE data for C60 thin films on SrTiO3(001), obtained by a laboratory high-order harmonic (HHG) light source, operating at MHz repetition rates [2]. For different photon energies, we analyze the 2D energy maps of correlated electron pairs and compare the resulting sum energy spectra to simulations using a two-electron density of states [3,4]. This allows us to determine orbital-resolved two-electron binding energy shifts in C60 for the first time.
[1] J. Berakdar et al., Phys. Rev. Lett. 81, 3535 (1998)
[2] A. Trützschler et al., Phys. Rev. Lett. 118, 136401 (2017)
[3] M. Cini, Solid State Communications 24, 681 (1977)
[4] G. A. Sawatzky, Phys. Rev. Lett. 39, 504 (1977)
Keywords: C60; correlation; spectroscopy; photoemission; high harmonic generation