Skip to Main content Skip to Navigation
Theses

Ultrafast induced structural dynamics probed by time-resolved photoelectron spectroscopy

Abstract : This work aims to study the lattice structural dynamics of metals under laser femtosecond excitation using time-resolved photoelectron spectroscopy (Tr-PES). When irradiated by short infrared laser pulses, the thermal out-of-equilibrium state established between hot electrons and a cold lattice rises specific dynamics where the thermodynamic properties of matter are still subject to debate. The theoretical description of highly excited materials is difficult and appeals new experimental results to improve the understanding of these physical processes and material properties. Nonetheless, important challenges arise from the use of Tr-PES. When metals are irradiated with strong femtosecond infrared laser pulses, non-linear effects, like multiphoton ionization, can take place and produce photoelectrons with tenths of eV of kinetic energy. This pump photoelectron background can conceal the probe-induced photoelectron spectrum, and perturb the probe spectrum via Coulomb interactions (called space-charge effect). To overcome these challenges three actions were carried out. We designed and built a 100 eV beamline to avoid the superposition between the pump background and the probe photoelectron spectrum. The pump/probe space-charge effect was extensively studied theoretically and experimentally. Finally, the pump photoemission was greatly reduced in our experiments by carefully tuning the experimental parameters. This led us to perform Tr-PES measurements on copper samples of the lattice structural dynamics following the evolution of the photoelectron spectrum. The experiment constituted a proof-of-principle of the Tr-PES technique to study materials under strong excitation.
Complete list of metadatas

Cited literature [123 references]  Display  Hide  Download

https://tel.archives-ouvertes.fr/tel-02940555
Contributor : Abes Star :  Contact
Submitted on : Wednesday, September 16, 2020 - 1:18:08 PM
Last modification on : Tuesday, October 27, 2020 - 3:04:56 AM

File

DE_ANDA_VILLA_Manuel_2019.pdf
Version validated by the jury (STAR)

Identifiers

  • HAL Id : tel-02940555, version 1

Citation

Manuel de Anda Villa. Ultrafast induced structural dynamics probed by time-resolved photoelectron spectroscopy. Atomic Physics [physics.atom-ph]. Sorbonne Université, 2019. English. ⟨NNT : 2019SORUS193⟩. ⟨tel-02940555⟩

Share

Metrics

Record views

89

Files downloads

60