Berlin 2024 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
O: Fachverband Oberflächenphysik
O 108: Electronic Structure Theory II
O 108.4: Vortrag
Freitag, 22. März 2024, 11:15–11:30, MA 043
Interpreting ultrafast electron transfer on surfaces with first-principles electronic couplings — •Simiam Ghan1, Elias Diesen1, Christian Kunkel1, Karsten Reuter1, and Harald Oberhofer2 — 1Fritz-Haber Institute of the Max-Planck Society, Berlin — 2Department of Physics, University of Bayreuth
The electronic coupling between adsorbates and surfaces is invoked in models of e.g. charge transfer, chemisorption, and quantum impurities (Kondo physics). While the coupling matrix element Had is usually approximated, we demonstrate here that it can be calculated directly from first principles Density Functional Theory. This is achieved through a projection of the Kohn-Sham Hamiltonian upon a basis of diabatic states localized on either the adsorbate or surface systems. An appropriate integration of couplings over the Brillouin zone allows for calculation of the Newns-Anderson chemisorption function, a coupling-weighted density of states which gives the line broadening of an adsorbate frontier state upon adsorption. This broadening corresponds to the experimentally-observed lifetime of an electron in the state, which we confirm for core-excited Ar*(2p3/2−14s) atoms on a number of transition metal surfaces. The use of explicit coupling matrix elements is found to be highly advantageous, elucidating the ultrafast electron transfer process in terms of coupling to the various bands of the surface[1]. The suitability of the scheme for treating fully chemisorbed systems is discussed.
[1] S. Ghan et al. J. Chem. Phys. 158, 234103 (2023).
Keywords: Density Functional Theory; Electronic Coupling; Ultrafast Electron Transfer