The structure and hyperfine magnetic properties of epitaxial Fe ultrathin films on a vicinal Pds110d surface have been investigated by means of low-energy electron diffraction sLEEDd, reflection high-energy electron diffraction sRHEEDd and Fe conversion electron Mössbauer spectroscopy sCEMSd. LEED and RHEED provide evidence for initial pseudomorphic film growth. The RHEED determination of the i...

The hyperfine structure of highly charged 238 92 U ions with rotationally excited nuclei Abstract The hyperfine structure (hfs) of electron levels of 238 92 U ions with the nucleus excited in the low-lying rotational 2 + state with an energy E 2 + = 44.91 keV is investigated. In hydrogenlike uranium, the hfs splitting for the 1s 1/2-ground state of the electron constitutes 1.8 eV. The hyperfine...

He-droplet-induced changes of the hyperfine structure constants of alkali-metal atoms are investigated by a combination of relativistically corrected ab initio methods with a simulation of the helium density distribution based on He density functional theory. Starting from an accurate description of the variation of the hyperfine structure constant in the M-He diatomic systems (M=Li, Na, K, Rb)...

The electronic structure and the location of muonium centers (Mu) in single-crystalline ZnO were determined for the first time. Two species of Mu centers with extremely small hyperfine parameters have been observed below 40 K. Both Mu centers have an axial-symmetric hyperfine structure along with a <0001> axis, indicating that they are located at the antibonding (AB(O, parallel )) and bond-cent...

Hyperfine interactions, magnetic interactions between the spins of electrons and nuclei, in graphene and related carbon nanostructures are studied. By using a combination of accurate first principles calculations on graphene fragments and statistical analysis, I show that both isotropic and dipolar hyperfine interactions in sp2 carbon nanostructures can be accurately described in terms of the l...

Theoretical investigations of the hyperfine structure of the hydrogen molecular ion (one electron and two protons) are discussed. The nuclear spin-rotation interaction has been found to be of the same sign as in the hydrogen molecule and the hyperfine transition frequencies can be accurately predicted. With measurements of the hyperfine structure of the deuterium molecular ion (or of HD) it sho...

The determination of hyperfine structure resolved excitation cross sections and rate coefficients due to H2 collisions is required to interpret astronomical spectra. In this paper, we present several theoretical approaches to compute these data. An almost exact recoupling approach and approximate sudden methods are presented. We apply these different approaches to the HCl-H2 collisional system ...

We demonstrate a new technique for measuring the absolute frequencies of atomic transitions. The technique uses a ring-cavity resonator whose length is calibrated using a reference laser locked to the D2 line in Rb. The frequency of this line is known to be 384 230 484.468(10) MHz. Using a second laser locked to the D1 line of Rb, we measure the frequencies of various hyperfine transitions in t...

The magnetic hyperfine structure of the non-rigid methanol molecule is investigated experimentally and theoretically. 12 hyperfine patterns are recorded using molecular beam microwave spectrometers. These patterns, along with previously recorded ones, are analyzed in an attempt to evidence the effects of the magnetic spin-torsion coupling due to the large amplitude internal rotation of the meth...

The radical pair model has been successful in explaining behavioral characteristics of the geomagnetic compass believed to underlie the navigation capability of certain avian species. In this study, the spin dynamics of the radical pair model and decoherence therein are interpreted from a microscopic state transition point of view. This helps to elucidate the interplay between the hyperfine and...