Related papers: Isotope shift calculations for atoms with one vale…
We investigate the potential to probe physics beyond the Standard Model with isotope shift measurements of optical atomic clock transitions. We first derive the reach for generic new physics above the GeV scale at the effective field theory…
Accurate quantum mechanics based predictions of property trends are so important for materials design and discovery that even inexpensive approximate methods are valuable. We use the Alchemical Integral Transform (AIT) to study…
Within the lowest-order relativistic approximation ($\sim v^2/c^2$) and to first order in $m_e/M$, the tensorial form of the relativistic corrections of the nuclear recoil Hamiltonian is derived, opening interesting perspectives for…
We present relativistic many-body perturbation theory plus configuration interaction (MBPT+CI) calculations of the lowest four excited states of Ni$^{12+}$, a promising candidate for highly charged ion (HCI) optical clocks. By combining the…
Isotope shifts have emerged as a sensitive probe of new bosons that couple to electrons and neutrons, and of nuclear structure. The recent Hz- or even sub-Hz-level isotope shift measurements across different elements call for a global…
Relativistic multiconfiguration Dirac-Hartree-Fock (MCDHF) calculations with configuration interaction (CI) are carried out for the $^{1}S_{0}$ and $^{3}P_{0,1}^o$ states in neutral ytterbium by use of the available GRASP2018 package. From…
A brief review of the search for variation of the fine structure constant in quasar absorption spectra is presented. Special consideration is given to the role of atomic calculations in the analysis of the observed data. A range of methods…
We have developed a broadly-applicable approach that drastically increases the ability to accurately predict properties of complex atoms. We applied it to the case of Ir$^{17+}$, which is of particular interest for the development of novel…
The isotopic shifts are determined to high accuracy for a number of light two-electron ions. The field components of these isotopic shifts have been determined with the use of the exact Racah-Rosental-Breit formula.
Isotope shifts in the nuclear charge radius of even and odd calcium isotopes are calculated within the nuclear shell model. The model space includes all configurations of nucleons in the $2s, 1d_{3/2}, 1f_{7/2}, {\rm and} ~2p_{3/2}$ orbits.…
We have measured the isotope shift of the narrow quadrupole-allowed 5 2S1/2 - 4 2D5/2 transition in 86Sr+ relative to the most abundant isotope 88Sr+. This was accomplished using high-resolution laser spectroscopy of individual trapped…
The scattering of neutral particles by an atomic nucleus can lead to electronic ionisation and excitation through a process known as the Migdal effect. We revisit and improve upon previous calculations of the Migdal effect, using the…
We measured the isotope shift in the $^2$S$_{1/2}$-$^2$P$_{3/2}$ (D2) transition in singly-ionized calcium ions using photon recoil spectroscopy. The high accuracy of the technique enables us to resolve the difference between the isotope…
Theory of the isotope shift of the centroid energies of light few-electron atoms is reviewed. Numerical results are presented for the isotope shift of the $2^3P$-$2^3S$ and $2^1S$-$2^3S$ transition energies of $^3$He and $^4$He. By…
A highly effective approach to the search for hypothetical new interactions through isotope shift spectroscopy of hydrogen-like ions is presented. A weighted difference of the g factor and ground-state energy is shown to assist in the…
We demonstrate that the isotope shift in isotopomers of diatomic molecules, where the nucleus of one of its constituent atoms is replaced by another isotope, can be expressed as the sum of a field shift and a mass shift, similar to the…
A possibility for fundamental constants to vary in time is suggested by theories unifying gravity with other interactions. In this article we examine proposals to use optical transitions of Sr, Dy, YbII and YbIII for the search of the time…
The specific mass shift in the electron affinity between ^{35}Cl and ^{37}Cl has been determined by tunable laser photodetachment spectroscopy to be -0.51(14) GHz. The isotope shift was observed as a difference in the onset of the…
We propose a new ab initio method designed for the accurate calculation of effective exchange integrals between atoms with numerous open-shells. This method applies to ferromagnetic as well as antiferromagnetic exchange, direct or…
It was recently shown that dielectronic recombination measurements can be used for accurately inferring changes in the nuclear mean-square charge radii of highly-charged lithium-like neodymium [Brandau et al., Phys. Rev. Lett. 100 073201…