In the Dirac operator framework we characterize and estimate the ground state energy of relativistic hydrogenic atoms in a constant magnetic field and describe the asymptotic regime corresponding to a large field strength using relativistic Landau levels. We also define and estimate a critical magnetic field beyond which stability is lost.

The model microfield method has been applied to the broadening of spectral lines emitted by multiply charged hydrogenic ions in pure and binary mixtures. Special attention is paid to the calculation of the ionic microfield distribution function. Extensive comparisons with other theoretical results are performed. Fine structure effects are shortly discussed. This

Possibilities of precision weak-interaction measurements in relativistic hydrogenic ions are considered. It is shown that using high-energy ion storage rings (RHIC, SPS, LHC), and utilizing relativistic Doppler tuning and laser cooling, it is possible to achieve sensitivity necessary for testing physics beyond the Standard Model.

Time evolution of wave packets built from the eigenstates of the Dirac equation for a hydrogenic system is considered. We investigate the space and spin motion of wave packets which, in the non-relativistic limit, are stationary states with a probability density distributed uniformly along the classical, elliptical orbit (elliptic WP). We show that the precession of such a WP, due to relativist...

We investigate the behavior of impurity fields immersed in a larger condensate field in various dimensions. We discuss the localization of a single impurity field within a condensate and note the effects of surface energy. We derive the functional form of the attractive condensate-mediated interaction between two impurities. Generalizing the analysis to N impurity fields, we show that within va...

We study an Anderson impurity in a semiconducting host using the density matrix renormalization group technique. We use the U = 0 one–dimensional Anderson Hamiltonian at half filling as the semiconducting host since it has a hybridization gap. By varying the hybridization of the host, we can control the size of the semiconducting gap. We consider chains with 25 sites and we place the Anderson i...

This paper presents an analysis of the motion of an neutral impurity species in a nanometer scale 4He cluster, extending a previous study of the dynamics of an ionic impurity. It is shown that for realistic neutral impurity–He potentials, such as those of SF6 and OCS, the impurity is kept well away of the the surface of the cluster by long range induction and dispersion interactions with He, bu...

This paper presents an analysis of the motion of an neutral impurity species in a nanometer scale 4He cluster, extending a previous study of the dynamics of an ionic impurity. It is shown that for realistic neutral impurity–He potentials, such as those of SF6 and OCS, the impurity is kept well away of the the surface of the cluster by long range induction and dispersion interactions with He, bu...

This paper presents an analysis of the motion of a neutral impurity species in a nanometre scale He cluster, extending a previous study of the dynamics of an ionic impurity. It is shown that for realistic neutral impurity± He potentials, such as those of SF6 and OCS, the impurity is kept well away from the surface of the cluster by long range induction and dispersion interactions with He, but t...

Exact relations are derived between scaling to the high-density limit of density functional theory and taking Z to infinity for nondegenerate atoms. Gorling-Levy perturbation results are deduced for hydrogenic densities. The kinetic contribution to the correlation energy is also studied, and estimates given for its value for neutral atoms. Popular approximate functionals are tested against thes...