Related papers: Relativistic analytical R-matrix (ARM) theory for …
The probability of photoionization of a heavy hydrogen like ion is calculated within the relativistic perturbation theory. The Coulomb potential of a heavy nucleus is taken into account accurately by usage of the corresponding solutions of…
The effect of autoionizing resonances in atomic systems and processes is reviewed. Theoretical framework for treating resonances in the coupled channel approximation using the R-matrix method, as well as approximations related to plasma…
This review article deals with some case studies of relativistic and correlation effects in atomic systems. After a brief introduction to relativistic many-electron theory, a number of applications ranging from correlation energy to parity…
We consider the interaction of hydrogen-like atoms with a strong laser field and show that the strong field approximation and all its variants may be grouped into a set of families of approximation schemes. This is done by introducing an…
Extending the concepts of light-front field theory to quantum statistics provides a novel approach towards nuclear matter under extreme conditions. Such conditions exist, e.g., in neutron stars or in the early stage of our universe. They…
With increasing demand for accurate calculation of isotope shifts of atomic systems for fundamental and nuclear structure research, an analytic energy derivative approach is presented in the relativistic coupled-cluster theory framework to…
A theoretical framework for studying strong-field ionization of aligned molecules is presented, and alignment-dependent ionization yields are computed for CO2. Our calculations are in unprecedented agreement with recent experiments. We find…
The ionization of two-active-electron systems by intense laser fields is investigated theoretically. In comparison with time-dependent Hartree-Fock and exact two electron simulation, we show that the ionization rate is overestimated in SAE…
The role of relativistic corrections in Coulomb scattering of heavy ions at intermediate energy collisions ($E_{lab}\gtrsim 50$ MeV/n) is investigated by numerically solving a full set of coupled equations. We compare two methods, (a) one…
A new version of the R-matrix Floquet theory for laser-assisted electron-atom scattering is presented. The theory is non-perturbative and applicable to a non-relativistic many-electron atom or ion in a homogeneous linearly polarized field.…
Taking N2 and O2 as examples, we theoretically study the post-ionization dynamics of molecules in strong laser fields using a density matrix method for open systems, focusing on the effect of ionization-produced coherence on the dynamics of…
Despite its long standing usefulness for the analysis of various processes in intense laser fields, it is well-known that the so-called strong-field KFR or SFA ansatz does not account for the final-state Coulomb interaction. Due to its…
We present a detailed comparison of strong-field ionization of diatomic molecules and their companion atoms with nearly equal ionization potentials. We perform calculations in the length and velocity gauge formulations of the molecular…
The Bohr-Sommerfeld quantization rule and the Gamow formula for the width of quasistationary level are generalized by taking into account the relativistic effects, spin and Lorentz structure of interaction potentials. The relativistic…
The non-resonant two-photon ionization of hydrogen-like ions is studied in second-order perturbation theory, based on the Dirac equation. To carry out the summation over the complete Coulomb spectrum, a Green function approach has been…
The strong-coupling perturbation theory (SCPT) for correlated electron systems is extended to the case of full Coulomb interaction. The Coulomb mechanism of the orbital polarization is discussed and attention is paid to the importance of…
The strong-field approximation can be and has been applied in both length gauge and velocity gauge with quantitatively conflicting answers. For ionization of negative ions with a ground state of odd parity, the predictions of the two gauges…
We present a new convergent strong coupling expansion for two-level atoms in external periodic fields, free of secular terms. As a first application, we show that the coherent destruction of tunnelling is a third-order effect. We also…
The many-body theory of interacting electrons poses an intrinsically difficult problem that requires simplifying assumptions. For the determination of electronic screening properties of the Coulomb interaction, the Random Phase…
We present a density-matrix rate-equation approach to sequential tunneling through a metal particle weakly coupled to ferromagnetic leads. The density-matrix description is able to deal with correlations between degenerate many-electron…