Heidelberg 2015 – wissenschaftliches Programm
A 28.12: Poster
Mittwoch, 25. März 2015, 17:00–19:00, C/Foyer
Coulomb-THz-Field-Coupling Induced Time Shifts in Atomic Photoemission — •Georg Schmid1, Kirsten Schnorr1, Sven Augustin1, Jakob Kunz1, Arne Senftleben1,9, Shaofeng Zhang1, Artem Rudenko3, Matthias Kübel4, Lutz Foucar8, Michael Gensch5, Yuhai H. Jiang6, Joachim Ullrich7, Alaa Al-Shemmary2, Torsten Golz2, Nikola Stojanovic2, Claus-Dieter Schröter1, Thomas Pfeifer1, and Robert Moshammer1 — 1MPI für Kernphysik, Heidelberg — 2DESY, Hamburg — 3Kansas State University, Manhattan, KS — 4MPI für Quantenoptik, Garching — 5HZDR, Dresden — 6SARI, Shanghai — 7PTB, Braunschweig — 8MPI für medizinische Forschung, Heidelberg — 9Universität Kassel
XUV pump - THz probe experiments were carried out at the free-electron laser in Hamburg. At a photon energy of 59.4 eV, neon 2p, 2s and valence shake-up photoelectrons (PEs) were emitted into a THz probe field of 152 um. Using a reaction microscope, the 3-dim PE momentum vectors were measured as a function of the pump-probe delay. By tracing the delay-dependent streaking spectrograms, a relative time shift in the emission of valence shake-up PEs and direct 2p PEs was observed. In the framework of attosecond streaking, it was shown that so-called Coulomb-laser-coupling leads to measurement-induced time shifts in addtion to the quantum mechanical EWS time shift. It is predicted that low-energetic PEs are strongly effected by the combined action of Coulomb and long-wave THz field. By selecting shake-up PEs with energies < 1 eV, we experimentally confirm Coulomb-laser-coupling time shifts in the range of low PE energies.