Berlin 2018 – wissenschaftliches Programm

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O: Fachverband Oberflächenphysik

O 78: Poster: Surface Dynamics - Reactions, Elementary Processes and Phase Transitions

O 78.5: Poster

Mittwoch, 14. März 2018, 18:15–20:30, Poster A

Modeling Nonadiabatic Effects in Gas-Surface Dynamics by Means of Electronic Friction — •Simon P. Rittmeyer and Karsten Reuter — Technische Universität München

Energy transfer at and across the interface fundamentally governs the dynamics of surface chemical reactions, e.g., in heterogeneous catalysis. On frequently employed metal catalysts, likely dissipation channels are the adsorbate interaction with substrate phonons and the nonadiabatic excitation of electron-hole (eh)-pairs in the surface. Despite considerable effort spent in the past decades, however, a general assessment of the relative importance of these competing energy dissipation channels has still not been achieved. In parts, this is attributable to the uncertainty that comes with effective models for the nonadiabatic energy dissipation—such as the electronic friction approach—inevitable for large scale simulations.

In order to improve upon this situation, we demonstrate the validation of the popular local density friction approximation (LDFA) for electronic friction by comparing to experimentally measured vibrational lifetimes [1], scrutinize underlying assumptions using explicitly evaluated eh-pair excitation spectra [2], and ultimately invoke this effective model to disentangle the role of the competing energy dissipation mechanisms in the context of thermal adatom diffusion [3].
S.P. Rittmeyer et al., Phys. Rev. Lett. 115, 046102 (2015).
S.P. Rittmeyer et al., Phys. Rev. Lett. 119, 176808 (2017).
S.P. Rittmeyer et al., Phys. Rev. Lett. 117, 196001 (2016).