相关论文: Multi-photon above threshold ionization of multi-e…
We present a theory illuminating the cross-over from strong-field tunnelling ionization to weak-field multiphoton ionization in the interaction of a classical laser field with a hydrogen atom. A simple formula is derived in which the…
We consider tunnel ionization of an atom or molecule in a strong field within an analytical treatment of the R-matrix method, in which an imaginary boundary is set up inside the classically forbidden region that acts as a source of ionized…
The multiphoton ionization rate of molecules depends on the alignment of the molecular axis with respect to the ionizing laser polarization. By studying molecular frame photo-electron angular distributions from N$_2$, O$_2$ and benzene, we…
In the nonrelativistic many-electron approximation of the theory of photoionization of the atom in the formalism of secondary quantization and the theory of irreducible tensor operators, analytical structures for the quadrupole transition…
The present study presents a comprehensive theoretical investigation of atom and asymmetric top molecule inelastic scattering based on the R-matrix formalism. The proposed methodology establishes a rigorous framework for treating inelastic…
Using the eigenchannel R-matrix method we calculate partial photoionization cross sections from the ground state of the helium atom for incident photon energies up to the N=9 manifold. The wide energy range covered by our calculations…
Multiple scattering theory is applied to low-energy electron collisions with a complex target formed of two molecular scatterers. The total T-matrix is expressed in terms of the T-matrix for each isolated molecule. We apply the approach to…
A simple analytical solution for the problem of multiphoton detachment from negative ions by a linearly polarized laser field is found. It is valid in the wide range of intensities and frequencies of the field, from the perturbation theory…
Many nonlinear quantum phenomena of intense laser-atom physics can be intuitively explained with the concept of trajectory. In this paper, Bohmian mechanics (BM) is introduced to study a multiphoton process of atoms interacting with the…
We calculate the photo-ionization cross-section from the ground state of the helium atom, using the complex rotation method and diagonalization of sparse matrices. This produces directly the positions and widths of the doubly excited 1Po…
Techniques for producing cold and ultracold molecules are enabling the study of chemical reactions and scattering at the quantum scattering limit, with only a few partial waves contributing to the incident channel, leading to the…
We present ground state photoionization cross sections of atoms and ions averaged over resonance structures for photoionization modeling of astrophysical sources. The detailed cross sections calculated in the close-coupling approximation…
A new general formalism for determining the electric multipole polarizabilities of quantum (atomic and nuclear) bound systems based on the use of the transition matrix in momentum space has been developed. As distinct from the conventional…
We employ the time-dependent R-Matrix (TDRM) method to calculate anisotropy parameters for positive and negative sidebands of selected harmonics generated by two-color two-photon above threshold ionization of argon. We consider odd…
Photoelectron angular distributions (PADs) obtained from ionization of potassium atoms using moderately intense femtosecond IR fields ($\sim$10$^{12}$Wcm$^{-2}$) of various polarization states are shown to provide a route to "complete"…
The absolute generalized cross sections and angular distribution parameters of photoelectrons for the two-photon above threshold $3p$-ionization of Ar were calculated in the exciting photon energy range from 15.76 to 36 eV. The correlation…
We report a numerical calculation of the two-photon absorption coefficient of electrons in a binding potential using the real-time real-space higher-order difference method. By introducing random vector averaging for the intermediate state,…
The ionization by photon or electron impact of the inner (2a1) and outer (1t2) valence orbitals of the CH4 molecule is investigated theoretically. In spite of a number of approximations, including a monocentric approach and a rather simple…
A theoretical investigation of photoabsorption and photoionization of Fe^{14+} extending beyond an earlier frame transformation R-matrix implementation is performed using a fully-correlated, Breit-Pauli R-matrix formulation including both…
The previously applied independent atom model (IAM) for highly charged ion-molecule collisions which implemented the suppression of multiple ionization and capture on the basis of geometric overlaps of cross-sectional areas representing…