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.

References in corpus (11)

• Bright Coherent Ultrahigh Harmonics in the keV X-Ray Regime from Mid-Infrared Femtosecond Lasers
• Phase matching of high harmonic generation in the soft and hard X-ray regions of the spectrum
• Attosecond dynamics through a Fano resonance: Monitoring the birth of a photoelectron
• 0.5 keV soft X-ray attosecond continua
• Attosecond-resolved photoionization of chiral molecules
• Theory of Attosecond Transient Absorption Spectroscopy of Krypton for Overlapping Pump and Probe Pulses
• Modulation of attosecond beating in resonant two-photon ionization
• Time-frequency representations of autoionization dynamics in helium
• Probing autoionizing states of molecular oxygen with XUV transient absorption: Electronic symmetry dependent lineshapes and laser induced modification
• Quantum coherent control of the photo\-electron angular distribution in bichromatic ionization of atomic neon
• Interference stabilization of autoionizing states in molecular $N_2$ studied by time- and angular-resolved photoelectron spectroscopy

Cited by in corpus (3)

• Electron Correlation Effects in Attosecond Photoionization of CO${}_2$
• Circular holographic ionization-phase meter
• Resonant Anisotropic Emission in Two-Photon Interferometric Spectroscopy