Regensburg 2022 – wissenschaftliches Programm

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O: Fachverband Oberflächenphysik

O 16: Poster Monday: Ultrafast Processes 1

O 16.5: Poster

Montag, 5. September 2022, 18:00–20:00, P4

Description for the electronic non-equilibrium after ultrashort laser excitation of metals — •Markus Uehlein, Sebastian T. Weber, and Baerbel Rethfeld — Department of Physics and Research Center OPTIMAS, TU Kaiserslautern, Germany

When a metal is excited by a femtosecond laser pulse in the visible range, electrons absorb the energy, resulting in a non-equilibrium energy distribution. This absorption behavior and the following thermalization to a hot Fermi distribution can be simulated using complex and numerically expensive Boltzmann collision integrals [1]. After the thermalization, the two-temperature model (TTM) can describe the relaxation of the heated electrons and the phonons in a simple way. It is, however, unable to trace non-thermal electrons.
We present an intermediate model, called extended TTM (eTTM). It was developed in Refs. [2, 3] and adds a system of non-equilibrium electrons to the TTM. Besides some improvements to the published versions, we compare the eTTM to the Boltzmann model as well as to the TTM [4]. In particular, we compare the spectral particle dynamics to a time-resolved two-photon photoemission measurement [5].
[1] B. Y. Mueller and B. Rethfeld; PRB 87, 035139 (2013)
[2] E. Carpene; PRB 74, 024301 (2006)
[3] G. D. Tsibidis; Appl. Phys. A 124, 311 (2018)
[4] M. Uehlein, S. T. Weber and B. Rethfeld;
[4] Nanomaterials 12, 1655 (2022)
[5] Y. Beyazit et al.; Phys. Rev. Lett. 125, 076803 (2020)