Application of the Complex Kohn Variational Method to Attosecond Spectroscopy
Abstract
The complex Kohn variational method is extended to compute light-driven electronic transitions between continuum wavefunctions in atomic and molecular systems. This development enables the study of multiphoton processes in the perturbative regime for arbitrary light polarization. As a proof of principle, we apply the method to compute the photoelectron spectrum arising from the pump-probe two-photon ionization of helium induced by a sequence of extreme ultraviolet and infrared-light pulses. We compare several two-photon ionization pump-probe spectra, resonant with the (2s2p)1P1o Feshbach resonance, with independent simulations based on the atomic B-spline close- coupling STOCK code, and find good agreement between the two approaches. This new finite-pulse perturbative approach is a step towards the ab initio study of weak-field attosecond processes in poly-electronic molecules.
Cite
@article{arxiv.1807.02183,
title = {Application of the Complex Kohn Variational Method to Attosecond Spectroscopy},
author = {Nicolas Douguet and Barry I. Schneider and Luca Argenti},
journal= {arXiv preprint arXiv:1807.02183},
year = {2018}
}