Karl Franzens University Graz | Graz University of Technology | |
Attosecond electron dynamics in solids and layered systems The generation of isolated attosecond pulses in the extreme ultraviolet (XUV) allowed to trace electronic processes on the attosecond time-scale [1]. Photoelectrons generated by laser based attosecond XUV-pulses are exposed to a synchronized field from infrared (IR) laser pulses. The energy shift experienced by the photoelectrons due to the IR field is dependent on the delay between the XUV pulse and the dressing field and allows to measure the respective delay in photoemission between electrons of different type (core electrons vs. conduction band electrons). The information gained in such experiments [2] triggered many theoretical activities leading to different explanations on the physical reason of the delay. Experiments have been performed on different solids [3] and at varying excitation photon energy. We show measurements of attosecond electron transport through defined numbers of adlayers on a bulk material [4] and through sub-monolayer structures, which allow to extract for the first time not only relative delays in electron emission but the absolute time an electron needs to travel through matter. |