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O: Fachverband Oberflächenphysik

O 42: Electron-driven Processes

O 42.1: Vortrag

Dienstag, 18. März 2025, 14:00–14:15, H11

A simple model of nonadiabatic energy loss during hydrogen scattering from a semiconductor — •Xuexun Lu, Nils Hertl, and Reinhard J. Maurer — University of Warwick, Coventry, UK

Experiments on hydrogen atom scattering from Ge(111) show bimodal energy loss distributions with two peaks. The first peak corresponds to low energy loss and can be quantitatively reproduced with classical molecular dynamics (MD) simulations. The second peak lies at energy losses equivalent to or above the band gap of Ge and arises from electronic transitions between the valence band and the conduction band. Here, we develop a simple and interpretable model for H/Ge(111) scattering to inform the development of new mixed quantum-classical dynamics simulation methods suitable for the description of such nonadiabatic effects in gas-surface scattering. Using density functional theory data and experimental quantities, we parametrize an effective one-dimensional analytical model based on the Newns-Anderson Hamiltonian. The model allows us to study the coupled electron-nuclear dynamics and their conjugate energy transfer using nonadiabatic molecular dynamics methods such as independent electron surface hopping (IESH), molecular dynamics with electronic friction (MDEF), and the Ehrenfest method. In particular, IESH dynamics qualitatively reproduce the nonadiabatic energy transfer channel observed in the experiment.