STSM by Johann Förster, Institut für Physik, Berlin (DE) with Piero Decleva, Universita’ di Trieste (IT)
On January 2, 2017 (89 days)

Molecules in short, intense elliptically polarized laser fields

Exposing molecules to intense, ultrashort laser fields is a promising tool to image and control (at this point small) molecules and possibly (in the future) chemical reactions. The orientation-dependence of ionization and elliptically polarized fields which are investigated theoretically within this STSM (for NH_3) directly reveal interesting structural information and dynamics caused by the field.

The method developed in collaboration between the groups of A. Saenz (Berlin) P. Decleva (Trieste) solving the time-dependent Schrödinger equation describing small molecules in intense laser fields (within the single-determinant approximation) is extended within this STSM. It is now possible to treat the orientation dependence of molecules belonging to symmetry groups containing degenerate irreducible representations (like the C_{2v} group of NH_3). Furthermore, time propagation using elliptically polarized laser fields is implemented.

The orientation-dependent ionization yields for linear polarization and propagation-direction-dependent ionization yields for elliptical/circular polarization (examples shown in the figure)  have been studied extensively. Ionization dominates for polarization directions parallel to the  inversion (x-)axis with a strong asymmetry visible for extremely short 2-cycle pulses. Obtained  results will be submitted for publication soon and the new code version allows for interesting future studies, e.g. ionization of chiral molecules exposed to elliptically polarized pulses.

As a result od this STSM a thesis project shall be defended at Humboldt-Univ., Berlin, under the supervision of Alejandro Saenz and with collaboration of P. Decleva (Univ. Trieste).

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