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 Karl Franzens University Graz

Graz University of Technology 

Attosecond electron dynamics in solids and layered systems
Prof. Reinhard Kienberger, Technical University of Munich
17:15 - 18:15 Tuesday 08 May 2018 TUG P2

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.

[1] R. Kienberger et al., Nature 427, 817 (2004).
[2] A. Cavalieri et al., Nature 449, 1029 (2009).
[3] S. Neppl et al., PRL 109 (8), 087401 (2012).
[4] S. Neppl et al., Nature 517, 342 (2015).