ELFT HÍRADÓ

[Szeminárium koordinátor <sem-admin AT szfki.hu>]

SZFI SeminarPápa ZsuzsannaWigner FK SZFI, ELI-ALPSUltrafast Probing of 
Electron Occupancies of Nanoplasmonic SystemsTuesday, 1 December 2020, 10:00, 
video conference, https://letsmeet.wigner.hu/szeminariumPlasmonic systems are 
of great interest due to the nanometric volumes and ultrafast timescales 
involved during their excitation and decay. Upon the absorption of a photon, 
energy is transferred to the electrons in the metal, thus driving the 
electron distribution out of equilibrium. As time evolves on fs scale, a 
series of energy redistributions occur where energetic electrons first 
scatter among themselves and redistribute their energy until a high 
temperature Fermi–Dirac distribution is reached on the scale of hundreds of 
femtoseconds. Electron–phonon interactions then lead to a gradual reduction 
of this electronic temperature on a picosecond time scale. Due to the 
surface-bound nature of plasmons, these light-matter interaction processes 
are also worth examining from a new perspective. As the electron occupancies 
change during the various processes described above so does the dielectric 
function. This means that it is possible to retrieve electron occupancies and 
electron energy levels at different stages of plasmon excitation and decay by 
measuring the dielectric function of the plasmonic system in a highly 
sensitive way. In this presentation, I will report on a new tool for 
ultrasensitive probing of plasmonic hot electron occupancies in gold, 
applying ultrafast pump-probe spectroscopic ellipsometry.  Minden 
érdeklődőt szívesen látunk! - Everyone is welcome to attend.Róbert 
Juhászsem-admin AT szfki.hu