Hannover 2013 – scientific programme

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A: Fachverband Atomphysik

A 22: Poster: Interaction with strong or short laser pulses

A 22.7: Poster

Tuesday, March 19, 2013, 16:00–18:30, Empore Lichthof

Comparison of atomic photoelectron spectra obtained using the strong field and Coulomb-Volkov approximations with ab initio TDSE results — •Mohammad Adel Almajid and Dieter Bauer — Institut für Physik, Universität Rostock, 18051 Rostock

We investigate the agreement between photoelectron spectra for intense laser-atom interaction obtained using the strong field approximation (SFA) with or without Coulomb-Volkov approximation (CVA) and the results from the ab initio solution of the time-dependent Schrödinger equation (TDSE). In particular, we calculate the electron momentum distributions following strong-field ionization of atomic hydrogen by few-cycle, linearly polarized laser pulses. Within the plain-SFA the Coulomb potential is neglected after the emission of the photoelectron. A good agreement with the TDSE results is obtained only for the most energetic, rescattered photoelectrons whereas the low-energy part of the electron spectra differs significantly. For instance, the SFA is not able to reproduce the bouquet-shape patterns in the low-energy part of the photoelectron spectra, clearly visible in the TDSE results. Within the CVA the influence of the Coulomb potential on the outgoing photoelectron is accounted for in an approximate manner. In the multiphoton regime, the low-energy part of the photoelectron spectra obtained in CVA is in good agreement with the TDSE results. However, the agreement deteriorates as the tunneling regime is approached.