Time-resolved spectroscopy at surfaces and adsorbate dynamics: insights from a model-system approach

TL;DR

This paper presents a model for femtosecond laser-induced desorption at surfaces, combining exact numerical solutions and density functional theory to analyze surface-response mechanisms and the effects of pulse protocols.

Contribution

It introduces a finite-size model for surface desorption that enables detailed analysis of electronic and nuclear dynamics using numerical and DFT methods.

Findings

Coherent multiple-pulse protocols can significantly influence desorption outcomes.

Electronic correlations and surface response mechanisms compete during the desorption process.

The model provides insights into early dissociation stages and transient dynamics.

Abstract

We introduce a model description of femtosecond laser induced desorption at surfaces. The substrate part of the system is taken into account as a (possibly semi-infinite) linear chain. Here, being especially interested in the early stages of dissociation, we consider a finite-size implementation of the model (i.e., a finite substrate), for which an exact numerical solution is possible. By time-evolving the many-body wave function, and also using results from a time-dependent density functional theory description for electron-nuclear systems, we analyze the competition between several surface-response mechanisms and electronic correlations in the transient and longer time dynamics under the influence of dipole-coupled fields. Our model allows us to explore how coherent multiple-pulse protocols can impact desorption in a variety of prototypical experiments.