Energy Dissipation during Diffusion at Metal Surfaces: Disentangling the Role of Phonons vs. Electron-Hole Pairs

Abstract

Helium spin echo experiments combined with ab initio-based Langevin molecular dynamics simulations are used to quantify the adsorbate-substrate coupling during the thermal diffusion of Na atoms on Cu(111). An analysis of trajectories within the local density friction approximation allows the contribution from electron-hole pair excitations to be separated from the total energy dissipation. Despite the minimal electronic friction coefficient of Na and the relatively small mass mismatch to Cu promoting efficient phononic dissipation, about $(20\pm 5)\%$ of the total energy loss is attributable to electronic friction. The results suggest a significant role of electronic non-adiabaticity in the rapid thermalization generally relied upon in adiabatic diffusion theories.

online abstract: https://journals.aps.org/prl/accepted/d407dYecI5d1684758993a12fec0464ce50191245

References in corpus (5)

• Canonical sampling through velocity-rescaling
• Accurate sampling using Langevin dynamics
• Competition between electron and phonon excitations in the scattering of nitrogen atoms and molecules off tungsten and silver surfaces
• Electron-hole spectra created by adsorption on metals from density-functional theory
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Cited by in corpus (3)

• Non-Adiabatic Vibrational Damping of Molecular Adsorbates: Insights into Electronic Friction and the Role of Electronic Coherence
• Electronic friction coefficients from the atom-in-jellium model for $Z=1-92$
• Justification for the use of Markovian Langevin statistics in the modelling of activated surface diffusion