Dynamic screening of a localized hole during photoemission from a metal cluster
1 Centro de Física de Materiales CFM/MPC (CSIC-UPV/EHU), Paseo Manuel de Lardizabal 5, San Sebastián, 20018, Spain
2 Donostia International Physics Center DIPC, Paseo Manuel de Lardizabal 4, San Sebastián, 20018, Spain
3 Institut des Sciences Moléculaires d’Orsay, ISMO, Unité de Recherches CNRS-Université Paris-Sud UMR 8214, Bâtiment 351, Université Paris-Sud, Orsay Cedex, 91405, France
Nanoscale Research Letters 2012, 7:447 doi:10.1186/1556-276X-7-447Published: 8 August 2012
Recent advances in attosecond spectroscopy techniques have fueled the interest in the theoretical description of electronic processes taking place in the subfemtosecond time scale. Here we study the coupled dynamic screening of a localized hole and a photoelectron emitted from a metal cluster using a semi-classical model. Electron density dynamics in the cluster is calculated with time-dependent density functional theory, and the motion of the photoemitted electron is described classically. We show that the dynamic screening of the hole by the cluster electrons affects the motion of the photoemitted electron. At the very beginning of its trajectory, the photoemitted electron interacts with the cluster electrons that pile up to screen the hole. Within our model, this gives rise to a significant reduction of the energy lost by the photoelectron. Thus, this is a velocity-dependent effect that should be accounted for when calculating the average losses suffered by photoemitted electrons in metals.