[Todos] IAFE -COLOQUIOS: "Time-resolved photoionization on the attosecond scale"]]

["Area Difusión IAFE"]

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                       PRÓXIMO COLOQUIO DEL IAFE
                 Instituto de Astronomía y Física del Espacio
                           CONICET-UBA
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        "Time-resolved photoionization on the attosecond scale"

                               Stefan Nagele
  Institute for Theoretical Physics, Vienna University of Technology,
           Vienna, Austria, EU
               Miércoles 20 de noviembre de 2013 a las 14:00hs.
                          Aula del Edificio IAFE

The photoelectric effect, i.e. the emission of an electron after the
absorption of a photon, is one of the most fundamental processes in the
interaction of light with matter. The progress in the creation of
ultrashort light pulses during the last decade [1,2] has enabled the
time-resolved study of photoemission with attosecond precision (1as =
10-18s).
One of the most important experimental techniques is attosecond streaking
which is a pump-probe scheme that employs a phase-controlled (few-cycle)
infrared (IR) field and an extreme ultraviolet (XUV) attosecond pulse to
determine the arrival time of the photoelectrons in the continuum. The
challenge in interpreting the obtained time delays lies in disentangling
the intrinsic timing of the photoionization process, the so-called
Eisenbud-Wigner-Smith (EWS) delay, from additional measurement-induced
contributions caused by the probing IR field.
In this talk accurate quantum-mechanical simulations of attosecond
streaking for one- and two-electron systems, obtained by directly solving
the time-dependent Schrödinger equation, will be presented. Effects of the
probing IR field on the extracted streaking delays in the entrance
(initial state) and in the exit (continuum) channel for atomic
photoionization [5] will be identified and the effect of electronic
correlations on the time delays [6,7] will be investigated. As an outlook
streaking time shifts in more complex systems, e.g. endohedral fullerenes
where atoms are trapped in C60 cages, will be discussed.
References
[1] P. B. Corkum and F. Krausz, Nat. Phys. 3, 381 (2007).
[2] F. Krausz and M. Ivanov, Rev. Mod. Phys 81, 163 (2009).
[3] M. Schultze, M. Fiess, N. Karpowicz et al., Science 328, 1658 (2010).
[4] K. Klünder, J. M. Dahlström, M. Gisselbrecht et al., Phys. Rev. Lett.
106, 143002 (2011).
[5] S. Nagele, R. Pazourek, J. Feist, and J. Burgdörfer, Phys. Rev. A 85,
033401 (2012).
[6] S. Nagele, R. Pazourek, J. Feist, et al., J. Phys. B 44, 081001 (2011).
[7] R. Pazourek, J. Feist, S. Nagele, and J. Burgdörfer, Phys. Rev. Lett.
108, 163001 (2012).