Regensburg 2019 – wissenschaftliches Programm
O 64.8: Poster
Mittwoch, 3. April 2019, 17:45–20:00, Poster B1
Influence of cesium adsorption on plasmoemission from gold surfaces — •Jan-Henrik Herrig1,2, David Janoschka1,2, Pascal Dreher1,2, Michael Horn-von Hoegen1,2, and Frank-J. Meyer zu Heringdorf1,2 — 1Faculty of Physics & CENIDE, Lotharstraße 1, 47048 Duisburg — 2University of Duisburg-Essen, Duisburg, Germany
It is known that the superposition of a SPP-field and an incident light field leads to the non-linear emission of electrons. Recently, a photoemission electron microscopy (PEEM) experiment was used to show that the pump-probe contribution to the electron yield originates from the SPP's longitudinal component. Plasmoemisson, in which electrons are liberated from the metal surface by the SPP's electrical field alone, however, is dominated by the SPP's transverse component. To enable a second order emission process, the high work function of the used Au-surfaces is routinely decreased by the adsorption of sub-monolayer coverages of cesium. Until now, it was not known whether cesium adsorption changes which one of the field components dominates the plasmoemission yield. By careful analysis of the spatial modulation of the electron yield as function of cesium coverage in a plasmonic standing-wave experiment we can spatiotemporally separate the emission from different field components. Here we use light- and SPP-pulses to investigate whether there is a change in the spatial distribution of the electron yield induced by the cesium adsorption. We show evidence that sub-monolayer coverages of cesium do not have substantial influence on the character of the emission processes.