Hannover 2010 – scientific programme

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A: Fachverband Atomphysik

A 8: Poster I

A 8.48: Poster

Tuesday, March 9, 2010, 16:30–19:00, Lichthof

Strong-field ionization of N₂, O₂, and CO₂ — •Simon Petretti¹, Yulian Vanne¹, Alejandro Saenz¹, Alberto Castro², and Piero Decleva³ — ¹Humboldt-Universität zu Berlin, Germany — ²Freie Universität Berlin, Germany — ³Universitá di Trieste, Italy

The availability of intense laser pulses with ultrashort pulse durations in the range of a few femtoseconds (or even attoseconds) offers a new way of exploring the behavior of molecules interacting with these intense laser fields. The femtosecond timescale should, e. g., be appropriate for time-resolved imaging of chemical reactions. Experimental progress towards this goal has been made by resolving molecular orbitals [1]. In order to check the assumption that molecular orbitals can be really imaged, we have set up a new theoretical model. The multiphoton ionization of molecules in intense laser fields is studied within the so-called single-active electron (SAE) approximation by solving the time-dependent Schrödinger equation (TDSE) numerically. Our code is designed in such a way that it can deal with in principle arbitrary molecules. The main focus of this presentation will be the alignment-dependent strong-field ionization of N₂, O₂, and CO₂ exposed to a short laser pulse (40 fs pulse duration) of a Ti:sapphire laser (800 nm) as recently investigated experimentally [2]. We do not only achieve qualitative agreement for N₂ and O₂, but provide also an explanation for the so far puzzling experimental CO₂ results.

[1] Itatani et al., Nature 432, 867 (2004).

[2] Pavičić et al., Phys. Rev. Lett. 98, 243001 (2007).