Dresden 2003 – wissenschaftliches Programm

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O: Oberflächenphysik

O 29: Zeitaufgelöste Spektroskopie II

O 29.6: Vortrag

Donnerstag, 27. März 2003, 12:30–12:45, FOE/ORG

Collective and single particle dynamics in Ag nanoparticles studied by time-resolved two-photon photoemission — •Walter Pfeiffer, Matthias Merschdorf, and Claudia Kennerknecht — Physikalisches Insitut, Universität Wüerzburg, Am Hubland, 97074 Wüerzburg

For metal nanoparticles, the collective response is dominated by the surface plasmon excitation. For an excitation energy close to this surface plasmon resonance the induced polarization modifies the incident field. In general, this is important for the analysis of any kind of photoemission spectra including two-photon photoemission. Here we demonstrate how the collective response influences time-resolved two-photon photoemission from Ag nanoparticles supported on graphite. The combination of Fourier-spectroscopy and interferometrically resolved two-photon photoemission spectroscopy allows to disentangle collective and single particle dynamics, yielding the energy dependent single particle lifetimes of electrons in the nanoparticles.