SKM 2023 – wissenschaftliches Programm
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HL: Fachverband Halbleiterphysik
HL 40: Focus Session: Frontiers of Electronic-Structure Theory VI (joint session O/HL)
HL 40.7: Vortrag
Donnerstag, 30. März 2023, 12:30–12:45, TRE Ma
A first-principles Newns-Anderson chemisorption function applied to ultrafast electron transfer — •Simiam Ghan1, Elias Diesen1, Christian Kunkel1, Karsten Reuter1, and Harald Oberhofer2 — 1Fritz-Haber-Institut der MPG, Berlin, Germany. — 2University of Bayreuth, Bayreuth, Germany
We offer a method to calculate the electronic couplings Had between an adsorbate and substrate in an ab-initio fashion. The couplings are acquired by projection of the Kohn-Sham Hamiltonian onto a diabatic basis[1]. By averaging over the Brillouin Zone, it becomes possible to calculate a convergent chemisorption function of Newns and Anderson[2], which gives the energetic broadening of an adsorbate frontier orbital upon adsorption. This broadening corresponds to the experimentally-observable lifetime of an electron in the state, which we confirm for the case of core-excited Ar*(2p3/2−14s) atoms on a number of transition metal surfaces[3].
We find that the (tunneling) model captures and elucidates aspects of energy-dependence, spin, phase cancellation and k-space in the electron transfer process, in particular suggesting a significant role played by the surface d-bands. Given the prevalence of electronic couplings - and the chemisorption function - in theoretical models, we discuss potential for further applications.
[1] S. Ghan et al., J. Chem. Theory Comput. 16, 7431 (2020).
[2] D. Newns, Phys. Rev. 178, 3, 1123 (1969).
[3] F. Blobner et al., Phys. Rev. Lett. 112, 086801 (2014).