Speaker: Jürg Osterwalder, Department of Physics, University of Zurich, Switzerland
Program Description
Two types of laser-based experiments will be discussed that can provide information on the attosecond response of conduction electrons upon excitation with light. An interferometric measurement using XUV attosecond pulse trains as pump and IR pulses as probe provides timing information about the photoemission process. Measurements on different noble metal surfaces will be presented. In the second type of experiment, few-cycle IR pulses interact with a sharp metal tip, and the energy spectra of the resulting laser-assisted electron emission are studied. At very high fluences, a massive new emission channel opens that shows the hallmarks of tunneling emission from the Fermi energy triggered by the strong field maxima of the laser pulse.