Berlin 2014 – wissenschaftliches Programm

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K: Fachverband Kurzzeitphysik

K 1: Optische Methoden und Verfahren

K 1.6: Vortrag

Montag, 17. März 2014, 15:30–15:45, SPA SR203

Time-resolved investigation of photoelectron dynamics by Attosecond Streaking Spectroscopy on solid surfaces. — •Michael Gerl¹, Stefan Neppl², Peter Feulner³, and Reinhard Kienberger¹ — ¹Physik-Department E11, Technische Universität München (TUM) — ²Lawrence Berkeley National Laboratory, Chemical Sciences Division — ³Physik-Department E20, TUM

In refined experimental studies on tungsten single crystals, photoelectron dynamics in condensed matter systems is investigated by attosecond streaking spectroscopy. A reliable data basis of streaking measurements on W(110) and well-defined adsorbate systems could be established for an excitation energy of 105 eV. The main result is an improved accuracy of the time delay measured between photoemission from the conduction band states and the 4f core levels in tungsten. The potential of attosecond streaking spectroscopy could be rated by investigating possible systematic experimental errors. In this way, the accessibility of a resolving power of 15 as is confirmed. The datasets acquired at ℏ ω =105 eV provide an important milestone in a systematic study of streaking measurements involving different excitation energies, which could help to clarify the physical origin of time delays in photoemission from solids. Further steps towards a better understanding of photoemission time delays could be made by realizing experiments on adsorbate systems (Neppl et al., PRL 109 (2012), 087401) which can be quantitatively compared to theoretically predicted effects in attosecond photoemission. Additionally, a novel experimental approach to access absolute photoemission time delays is demonstrated.