An adaptive model for the optical properties of excited gold

Fuente: arXiv
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Autori principali: Ndione, P. D., Weber, S. T., Gericke, D. O., Rethfeld, B.
Natura: Preprint
Pubblicazione: 2023
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author Ndione, P. D.
Weber, S. T.
Gericke, D. O.
Rethfeld, B.
author_facet Ndione, P. D.
Weber, S. T.
Gericke, D. O.
Rethfeld, B.
contents We study the temperature-dependent optical properties of gold over a broad energy spectrum covering photon energies below and above the interband threshold. We apply a semi-analytical Drude-Lorentz model with temperature-dependent oscillator parameters. Our approximations are based on the distribution of electrons over the active bands with a density of states provided by density functional theory. This model can be easily adapted to other materials with similar band structures and can also be applied to the case of occupational nonequilibrium. Our calculations show a strong enhancement of the intraband response with increasing electron temperature while the interband component decreases. Moreover, our model compares well with density functional theory-based calculations for the reflectivity of highly excited gold and reproduces many of its key features. Applying our methods to thin films shows a sensitive nonlinear dependence of the reflection and absorption on the electron temperature. These features are more prominent at small photon energies and can be highlighted with polarized light. Our findings offer valuable insights for modeling ultrafast processes, in particular, the pathways of energy deposition in laser-excited samples.
format Preprint
id arxiv_https___arxiv_org_abs_2307_11874
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle An adaptive model for the optical properties of excited gold
Ndione, P. D.
Weber, S. T.
Gericke, D. O.
Rethfeld, B.
Materials Science
We study the temperature-dependent optical properties of gold over a broad energy spectrum covering photon energies below and above the interband threshold. We apply a semi-analytical Drude-Lorentz model with temperature-dependent oscillator parameters. Our approximations are based on the distribution of electrons over the active bands with a density of states provided by density functional theory. This model can be easily adapted to other materials with similar band structures and can also be applied to the case of occupational nonequilibrium. Our calculations show a strong enhancement of the intraband response with increasing electron temperature while the interband component decreases. Moreover, our model compares well with density functional theory-based calculations for the reflectivity of highly excited gold and reproduces many of its key features. Applying our methods to thin films shows a sensitive nonlinear dependence of the reflection and absorption on the electron temperature. These features are more prominent at small photon energies and can be highlighted with polarized light. Our findings offer valuable insights for modeling ultrafast processes, in particular, the pathways of energy deposition in laser-excited samples.
title An adaptive model for the optical properties of excited gold
topic Materials Science
url https://arxiv.org/abs/2307.11874