arXiv subjects

Jan H. Thiede

Publications and source records attributed to Jan H. Thiede.

5 recordsLinked to original sources

arXiv2026

Restricted-Geometry Quantum Models Beyond Atoms: Application of the Eckhardt-Sacha approach to NSDI in Diatomic Systems

We present a (1+1)-dimensional quantum model designed to describe nonsequential double ionization (NSDI) in homonuclear diatomic molecules exposed to strong linearly polarized laser fields. Extending the restricted-geometry framework previously developed for atomic systems by Eckhardt and Sacha, our approach captures key features of NSDI, including the characteristic knee structure in double ionization yields. Despite its simplifying assumptions, the model shows good agreement with experimental data and proves particularly suitable for systems with $σ$-type orbital symmetry. It offers a computationally efficient tool for exploring multi-electron dynamics in molecular systems.

physics.atom-ph↗

arXiv2024

Frequency dependence of nonsequential double ionization of atoms in strong laser fields

The frequency dependence of (nonsequential) double ionization is studied in fully quantum mechanical calculations using a (1+1)-dimensional model atom. Other time-dependent effects such as the influence of the number of field cycles are also investigated. We present ionization yields and momentum distributions. The results are consistent with experimental and semi-classical data available in the literature, thus complementing them with a quantum mechanical description.

quant-ph↗

arXiv2020

Ab initio study of time-dependent dynamics in strong-field triple ionization

An ab initio analysis of strong-field three-electron ionization in a restricted-dimensionality model reveals the dynamics of the ionization process and the dominant channels for double (DI) and triple ionization (TI). Simulations using wave functions that respect the Pauli principle show that the most likely channel is a sequence of single ionization (SI) and DI, while direct TI has a much lower probability. The dominant DI process has the highest probability for a singlet of up- and down-spin electrons. The results demonstrate the significance of the Pauli principle for the selection of dominant pathways in ionization and possibly other many-electron processes in strong fields.

physics.atom-ph↗

arXiv2019

Double ionization of a three-electron atom: Spin correlation effects

We study the effects of spin degrees of freedom and wave function symmetries on double ionization in three-electron systems. Each electron is assigned one spatial degree of freedom. The resulting three-dimensional Schrödinger equation is integrated numerically using grid-based Fourier transforms. We reveal three-electron effects on the double ionization yield by comparing signals for different ionization channels. We explain our findings by the existence of fundamental differences between three-electronic and truly two-electronic spin-resolved ionization schemes. We find, for instance, that double ionization from a three-electron system is dominated by electrons that have the opposite spin.

physics.atom-ph↗

arXiv2018

Restricted space ab initio models for double ionization by strong laser pulses

Double electron ionisation process occurs when an intense laser pulse interacts with atoms or molecules. Exact {\it ab initio} numerical simulation of such a situation is extremely computer resources demanding, thus often one is forced to apply reduced dimensionality models to get insight into the physics of the process. The performance of several algorithms for simulating double electron ionization by strong femtosecond laser pulses are studied. The obtained ionization yields and the momentum distributions of the released electrons are compared, and the effects of the model dimensionality on the ionization dynamics discussed.

physics.atom-ph↗