Hannover 2010 – wissenschaftliches Programm

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MO: Fachverband Molekülphysik

MO 24: Poster: Quantum Control

MO 24.6: Poster

Donnerstag, 11. März 2010, 16:00–18:30, Lichthof

Ultrafast Resonant Strong-Field Control on K₂ — •Tim Bayer, Matthias Wollenhaupt, Cristian Sarpe-Tudoran, and Thomas Baumert — University of Kassel, Institute of Physics and CINSaT, D-34132 Kassel, Germany

Selective Population of Dressed States (SPODS) is an elementary mechanism of resonant strong-field control. Recently, SPODS realizations based on chirped laser pulses, pulse sequences and combinations thereof were demonstrated experimentally on K atoms [1] and discussed in terms of control landscapes of coherent electronic excitation [2]. Moreover, the applicability of SPODS to the coherent control of chemical reactions was pointed out by wave packet calculations on K₂ [3]. The proposed pulse sequence scenario allows to switch quantum mechanical population transfer efficiently from a state of maximum electronic coherence among different electronic target states, with attosecond precision. In the experiment, we use phase shaped 30 fs, 800 nm laser pulses, e.g. multi-pulse sequences from sinusoidal phase modulation and double pulses from phase-step modulation, to excite K₂ in a supersonic beam. The final populations achieved in the various excited molecular states are probed by a time-delayed 570 nm laser pulse from an optical parametric amplifier. Employing energy resolved photoelectron spectroscopy, we investigate the switching capabilities of the molecular SPODS scheme in terms of efficiency and robustness.

[1] T. Bayer et al., Phys. Rev. Lett. 102, 023004 (2009)

[2] T. Bayer et al., J. Phys. B 41, 074007 (2008)

[3] M. Wollenhaupt et al., J. Photochem. Photobiol. A 180, 248 (2006)