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Low-energy peak structure in strong-field ionization by mid-infrared laser-pulses
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Stefanie Gräfe |
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Vienna Unversity of Technology |
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We analyze the formation of the low-energy structure (LES) in above-threshold ionization spectra first observed by Quan et al.(Phys. Rev. Lett. 2009) and Blaga et al. (Nature Phys. 2009) using both quasi-classical and quantum approaches. We show this structure to be largely classical in origin resulting from a two-dimensional focusing in the energy-angular momentum plane of the strong-field dynamics in the presence of the atomic potential. The peak at low energy is strongly correlated with high angular momenta of the photoelectron. Quantum simulations confirm this scenario. |