Related papers: Exact theory and numeric results for short pulse i…
The process of ionization of a hydrogen atom by a short infrared laser pulse is studied in the regime of very large pulse intensity, in the dipole approximation. Let $A$ denote the integral of the electric field of the pulse over time at…
Owing to its numerical simplicity, a two-dimensional two-electron model atom, with each electron moving in one direction, is an ideal system to study non-perturbatively a fully correlated atom exposed to a laser field. Frequently made…
We address the question of whether atomic bound states begin to stabilize in the short ultra-intense field limit. We provide a general theory of ionization probability and investigate its gauge invariance. For a wide range of potentials we…
We investigate dynamics of atomic and molecular systems exposed to intense, shaped chaotic fields and a weak femtosecond laser pulse theoretically. As a prototype example, the photoionization of a hydrogen atom is considered in detail. The…
We study $N$-electron atoms with nuclear charge $Z$. It is well known that, in the cationic ($Z > N$) high-$Z$ region, the atom behaves as a weakly interacting system. The anionic ($Z < N$) regime, on the other hand, is characterized by an…
A unitary model describing the electronic transitions in an atom subject to a strong high frequency laser pulse is proposed. The model fully accounts for the initial state coupling with the continuum spectrum. Continuum-continuum as well as…
We describe new exact results for a model of ionization of a bound state, induced by an oscillating potential. In particular we have obtained exact expressions, in the form of readily computable rapidly convergent sums, for the energy…
How fast can a laser pulse ionize an atom? We address this question by considering pulses that carry a fixed time-integrated energy per-area, and finding those that achieve the double requirement of maximizing the ionization that they…
The time-dependent Schr\"{o}dinger equation for the hydrogen atom and its interaction with coherent intense high-frequency short laser pulses is solved numerically exactly by propagating the single-electron wave packets. Thereby, the…
Modern laser systems are able to generate short and intense laser pulses ionizing matter in the poorly explored barrier-suppression regime. Field ionization in this regime is studied analytically and numerically. For analytical studies,…
We study the time evolution of the wave function of a particle bound by an attractive $\delta$-function potential when it is subjected to time dependent variations of the binding strength (parametric excitation). The simplicity of this…
The ionization of an atom by a high-frequency intense laser pulse, where the energy of a single-photon is sufficient to ionize the system, is investigated from first principles. It is shown that as a consequence of an AC Stark effect in the…
We revisit the stabilization of ionization of atoms subjected to a superintense laser pulse using nonlinear dynamics. We provide an explanation for the lack of complete ionization at high intensity and for the decrease of the ionization…
We theoretically analyze the quantum vortices - the zeros of electron wave function which are formed through atom ionization by ultrashort laser pulse. In 2D space we consider the case of above-threshold ionization of hydrogen atom and in…
We study numerically stabilization against ionization of a fully correlated two-electron model atom in an intense laser pulse. We concentrate on two frequency regimes: very high frequency, where the photon energy exceeds both, the…
In conditions where the interaction betweeen an atom and a short high-frequency extreme ultraviolet laser pulse is a perturbation, we show that a simple theoretical approach, based on Coulomb-Volkov-type states, can make reliable…
A theoretical comparison of the electronic excitation and ionisation behaviour of molecular hydrogen oriented either parallel or perpendicular to a linear polarised laser pulse is performed. The investigation is based on a non-perturbative…
Based on the favourable properties of previously used one-dimensional (1D) atomic model potentials, we introduce a novel 1D atomic model potential for the 1D simulation of the quantum dynamics of a single active electron atom driven by a…
If one-electron observables of a many-electron system are of interest, a many-electron dynamics can be represented exactly by a one-electron dynamics with effective potentials. The formalism for this reduction is provided by the Exact…
Based on a plausible requirement for the ground state density, we introduce a novel one-dimensional (1D) atomic model potential for the 1D simulation of the quantum dynamics of a single active electron atom driven by a strong, linearly…