Düsseldorf 2007 – wissenschaftliches Programm

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A: Fachverband Atomphysik

A 9: Interaction with strong laser pulses II

A 9.2: Vortrag

Dienstag, 20. März 2007, 14:30–14:45, 5M

Molecular tomography: test of accuracy and improvements using time-dependent calculations — •Elmar van der Zwan¹ and Manfred Lein² — ¹Max-Planck-Institut für Kernphysik, Heidelberg, Deutschland — ²Institut für Physik, Universität Kassel, Deutschland

Recently a method to perform tomographic imaging of molecular orbitals using High Harmonic Generation (HHG) has been proposed [1]. The method is based on the simplification that the returning electron in the three-step model can be modeled as a plane wave. We investigate the effect of this assumption in a time-dependent calculation by numerically comparing results for the final reconstructed orbital using two different methods which, without the plane-wave assumption, should lead to identical results; namely the reconstruction based on dipole matrix elements or on momentum matrix elements. An error reduction scheme is developed to post-process the results. Using a priori constraints like compactness and realness of the orbital, and knowledge about the type of error introduced, we can remove a large part of the error. We present results for molecules with both anti-symmetric and asymmetric valence orbitals, as they cause problems in the original scheme.

[1] J. Itatani, J. Levesque, D. Zeidler, H. Niikura, H. Pépin, J.C. Kieffer, P.B. Corkum and D.M. Villeneuve. Tomographic imaging of molecular orbitals. Nature 432, 867-871 (2004)