The Role of Tensorial Electronic Friction in Energy Transfer at Metal Surfaces

TL;DR

This paper calculates the full electronic friction tensor at metal surfaces using first-principles methods, revealing anisotropic and non-diagonal features that influence energy transfer and mode coupling in atom-surface interactions.

Contribution

It introduces a first-principles approach to compute the full electronic friction tensor, highlighting its anisotropic and non-diagonal nature and its impact on energy redistribution.

Findings

Friction tensor is generally anisotropic and non-diagonal.

Electron-hole pair coupling induces mode coupling.

Results agree with established methods and experimental data.

Abstract

An accurate description of nonadiabatic energy relaxation is crucial for modeling atomistic dynamics at metal surfaces. Interfacial energy transfer due to electron-hole pair excitations coupled to motion of molecular adsorbates is often simulated by Langevin molecular dynamics with electronic friction. Here, we present calculations of the full electronic friction tensor by using first order time-dependent perturbation theory (TDPT) at the density functional theory (DFT) level. We show that the friction tensor is generally anisotropic and non-diagonal, as found for hydrogen atom on Pd(100) and CO on a Cu(100) surfaces. This implies that electron-hole pair induced nonadiabatic coupling at metal surfaces leads to friction-induced mode coupling, therefore opening an additional channel for energy redistribution. We demonstrate the robustness and accuracy of our results by direct comparison to established methods and experimental data.