Title: Ultrafast control of electron dynamics: atoms, diatomics and chiral molecules Speaker: Matthias Wollenhaupt Department of Physics, Kassel University Time: Thursday, February 23th, 15.15 Place: Phys. Aud. Abstract: The ability to generate ultrashort laser pulses of controllable shape [1] with sub-attosecond precision [2] has made it possible to precisely manipulate the dynamics of quantum systems. In the first experiment, three-dimensional control of light-matter interaction is exemplified on free electron wave packets from REMPI of potassium atoms with polarization-shaped laser pulses [3]. An experimental technique for accurate three-dimensional tomographic reconstruction of those shaped free electron wave packets based on measurements of Photoelectron Angular Distributions (PADs) is presented [4]. The designer wave packets resulting from this complex light-matter interaction show the enormous potential of polarization-shaping as a tool for three-dimensional coherent control. In the second experiment we demonstrate strong-field control of the bound electron dynamics on potassium dimers. In our two-color energy resolved photoelectron spectroscopy experiment an intense IR-pulse, the phase of which is tailored to the electronic wave packet oscillation [5], guides the system towards a preselected target channel. The unshaped VIS pulse probes the population of the electronic target states. Finally, a femtosecond laser based approach to chiral recognition of randomly oriented molecules in the gas phase enabling implementations in analytics is presented. PAD resulting from REMPI of camphor and fenchone molecules are studied in order to investigate the Circular Dichroism in the photo-ionization of chiral molecules. The observed circular dichroism effect using left- and right-handed circularly polarized femtosecond laser pulses is in the ± ten percent regime [6]. [1] M. Wollenhaupt et al., Springer Handbook of Lasers and Optics, (2007), Chap. 12. [2] J. Köhler et al., Optics Express 19, 11368 (2011). [3] M. Wollenhaupt et al., Appl Phys B 95, 245 (2009). [4] M. Wollenhaupt et al., Appl Phys B 95, 647 (2009). [5] T. Bayer et al., Phys.Rev.Lett. 102, 023004-1 (2009). [6] C. Lux et al., Angewandte Chemie, in print (2012). Jacob Sherson and Aurélien Dantan Coffee, tea and cake will be served at 11.05 ----------------------------------- Aurelien Dantan Ion Trap Group Department of Physics and Astronomy University of Aarhus Ny Munkegade, bygn. 1520 8000 Aarhus Denmark +4589423602