A numerical study of two-photon ionization of helium using the Pyprop framework

Abstract

Few-photon induced breakup of helium is studied using a newly developed ab initio numerical framework for solving the six-dimensional time-dependent Schroedinger equation. We present details of the method and calculate (generalized) cross sections for the process of two-photon nonsequential (direct) double ionization at photon energies ranging from 39.4 to 54.4 eV, a process that has been very much debated in recent years and is not yet fully understood. In particular, we have studied the convergence property of the total cross section in the vicinity of the upper threshold (54.4 eV), versus the pulse duration of the applied laser field. We find that the cross section exhibits an increasing trend near the threshold, as has also been observed by others, and show that this rise cannot solely be attributed to an unintended inclusion of the sequential two-photon double ionization process, caused by the bandwidth of the applied field.

7 pages, 3 figures

References in corpus (5)

• Nonsequential two-photon double ionization of helium
• Separation and identification of dominant mechanisms in double photoionization
• Probing Electron Correlation via Attosecond XUV Pulses in the Two-Photon Double Ionization of Helium
• Two-photon double ionization of helium in the region of photon energies 42-50 eV
• Decoding sequential vs non-sequential two-photon double ionization of helium using nuclear recoil

Cited by in corpus (14)

• Time-dependent generalized-active-space configuration-interaction approach to photoionization dynamics of atoms and molecules
• Photoionization of helium by attosecond pulses: extraction of spectra from correlated wave functions
• Universal features in sequential and nonsequential two-photon double ionization of helium
• On the optimal basis set for electron dynamics in strong laser fields: The case of molecular ion H${}_2^{+}$
• Double photo-electron momentum spectra of Helium at infrared wavelength
• Time-dependent R-matrix theory applied to two-photon double ionization of He
• Nonsequential Two-Photon Double Ionization of Atoms: Identifying the Mechanism
• Dialogue on analytical and ab initio methods in attoscience
• Canonical symplectic structure and structure-preserving geometric algorithms for Schrödinger-Maxwell systems
• Correlation effects in strong-field ionization of heteronuclear diatomic molecules
• Multiphoton ionization and stabilization of helium in superintense xuv fields
• Two-photon double ionization with finite pulses: Application of the virtual sequential model to helium
• One-photon double ionization of helium: a heuristic formula for the cross section
• Coherent driving \emph{versus} decoherent dissipation in double inner-shell ionizations of neon atoms by attosecond pulses