Member-Login
Modelling attosecond pulse generation, attosecond metrology, and electron correlation in atoms
- The spatial distribution of the photoelectron density around the atomic core 1500 attoseconds after the interaction of a 150-attosecond extreme ultraviolet pulse with a neon atom. The wave packets released from the 2s and 2p subshells become spatially separated due to their different velocities.
Attosecond light pulses offer opportunities to conduct the most direct and versatile measurements of fast electron dynamics in atoms, molecules, and solids. The interpretation of such measurements is often a challenging task. In order to gain new insights into attosecond-scale quantum dynamics, we make use of extensive simulations and different levels of approximation, often facing the need to advance known theoretical methods and develop new models.
Progress in attosecond science depends on advances in the generation of attosecond pulses: shorter and more intense pulses in the extreme-ultraviolet range enable measurements of effects that would otherwise remain unresolved, while the availability of sufficiently intense pulses in the soft X-ray range would enable many attosecond experiments that cannot be performed nowadays. This motivates us to investigate new regimes of attosecond pulse generation enabled by recent advances in laser technology [1,2], especially those achieved within 
C.1.1.
The comparison of experiment with theory is an essential part of research. To properly interpret attosecond measurements, we advance analysis techniques and study, in collaboration with other research groups, underlying many-electron dynamics. This includes modelling attosecond streaking measurements on atoms and molecules within or beyond the single-active electron approximation, supporting C.1.2 with theory, and developing advanced algorithms for the analysis of attosecond streaking measurements [3,4]. The outstanding question here is how the electron motion is affected by electron-electron interactions in systems of ever increasing complexity, since understanding these dynamics would allow us to control matter on the level of electrons.
Key collaborators
C. A. Nicolaides (National Hellenic Research Foundation, Athens, Greece)
J. Burgdörfer (Technische Universität Wien, Austria)
R. de Vivie-Riedle (Ludwig-Maximilians-Universität München, Germany)
A. Scrinzi (Ludwig-Maximilians-Universität München, Germany)
References
[1] V. S. Yakovlev, M. Ivanov, F. Krausz. Enhanced phase-matching for generation of soft X-ray harmonics and attosecond pulses in atomic gases. Optics Express 15, 153511-15364 (2007)
[2] E. Goulielmakis, M. Schultze, M. Hofstetter, V. S. Yakovlev, J. Gagnon, M. Uiberacker, A. L. Aquila, E. M. Gullikson, D. T. Attwood, R. Kienberger, F. Krausz, U. Kleineberg. Single-Cycle Nonlinear Optics. Science 320, 1614-1617 (2008)
[3] J. Gagnon, E. Goulielmakis, V. S. Yakovlev. The accurate FROG characterization of attosecond pulses from streaking measurements. Appl. Phys. B 92, 25-32 (2008)
[4] J. Gagnon, Vladislav S. Yakovlev, The robustness of attosecond streaking measurements. Optics Express 17, 17678-17693 (2009)