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Time-dependent calculation of ionization in Potassium at mid-infrared wavelengths

P. Maragakis·E. Cormier·P. Lambropoulos
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Abstract

We study the dynamics of the Potassium atom in the mid-infrared, high intensity, short laser pulse regime. We ascertain numerical convergence by comparing the results obtained by the direct expansion of the time-dependent Schroedinger equation onto B-Splines, to those obtained by the eigenbasis expansion method. We present ionization curves in the 12-, 13-, and 14-photon ionization range for Potassium. The ionization curve of a scaled system, namely Hydrogen starting from the 2s, is compared to the 12-photon results. In the 13-photon regime, a dynamic resonance is found and analyzed in some detail. The results for all wavelengths and intensities, including Hydrogen, display a clear plateau in the peak-heights of the low energy part of the Above Threshold Ionization (ATI) spectrum, which scales with the ponderomotive energy Up, and extends to 2.8 +- 0.5 Up.

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P. Maragakis, E. Cormier, P. Lambropoulos. 1999-07-13. Time-dependent calculation of ionization in Potassium at mid-infrared wavelengths. https://doi.org/10.1103/physreva.60.4718

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