First-principles study of ultrafast bandgap dynamics in laser-excited $$\alpha$$-quartz
Résumé
Femtosecond-laser-induced evolution of -quartz bandgap was calculated using rst principles. First,
Time-Dependent Density Functional Theory (TDDFT) was used to describe excited electron dynamics
during the laser pulse irradiation. Then the temperature of excited electrons was estimated using
Finite-Temperature DFT. Finally, the GW approximation was applied to calculate the electronic
structure modication driven by hot electrons. As a result, an ultrafast decrease of the bandgap is
observed during a 15-fs laser pulse with a drop of 35 % at laser intensities near the damage threshold.
Domaines
Physique [physics]Origine | Fichiers produits par l'(les) auteur(s) |
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