We study the $^1$S$_0 - ^3$D$_2$ and $^1$S$_0 - ^3$D$_3$ transitions in Cu II and the $^1$S$_0 - ^3$P$^{rm o}_2$ transition in Yb III as possible candidates for the optical clock transitions. A recently developed version of the configuration (CI) met
hod, designed for a large number of electrons above closed-shell core, is used to carry out the calculation. We calculate excitation energies, transition rates, lifetimes, scalar static polarizabilities of the ground and clock states, and blackbody radiation shift. We demonstrate that the considered transitions have all features of the clock transition leading to prospects of highly accurate measurements. Search for new physics, such as time variation of the fine structure constant, is also investigated.
We perform atomic relativistic many-body calculations of the field isotope shifts and calculations of corresponding nuclear parameters for all stable even-even isotopes of Yb$^+$ ion. We demonstrate that if we take nuclear parameters of the Yb isotop
es from a range of the state-the-art nuclear models which all predict strong quadrupole nuclear deformation, then calculated non-linearity of the King plot, caused by the difference in the deformation in different isotopes, is consistent with the non-linearity observed in the experiment (Ian Counts {em et al}, Phys. Rev. Lett. {bf 125}, 123002 (2020)). The changes of nuclear RMS radius between isotopes extracted from experiment are consistent with those obtained in the nuclear calculations.
We study the prospects of using the electric quadrupole transitions from the ground states of Cu, Ag and Au to the metastable state $^2{rm D}_{5/2}$ as clock transitions in optical lattice clocks. We calculate lifetimes, transition rates, systematic
shifts, and demonstrate that the fractional uncertainty of the clocks can be similar to what is achieved in the best current optical clocks. The use of these proposed clocks for the search of new physics, such as time variation of the fine structure constant, search for low-mass scalar dark matter, violation of Local Position Invariance and violation of Lorenz Invariance is discussed.
We calculate field isotope shifts for nobelium atoms using nuclear charge distributions which come from different nuclear models. We demonstrate that comparing calculated isotope shifts with experiment can serve as a testing ground for nuclear theori
es. It also provides a way of extracting parameters of nuclear charge distribution beyond nuclear RMS radius, e.g. parameter of quadrupole deformation $beta$. We argue that previous interpretation of the isotope measurements in terms of $delta langle r^2 rangle$ between $^{252,254}$No isotopes should be amended when nuclear deformation is taken into account. We calculate isotope shifts for other known isotopes and for hypothetically metastable isotope $^{286}$No for which the predictions of nuclear models differ substantially.
We use a recently developed version of the configuration method for open shells to study electronic structure of erbium and fermium atoms. We calculate excitation energies of odd states connected to the even ground state by electric dipole transition
s, the corresponding transition rates, isotope shift, hyperfine structure, ionization potentials and static scalar polarizabilities. We argue that measuring isotope shift for several transitions can be used to study nuclear deformation in even-even nuclei. This is important for testing nuclear theory and for searching for the hypothetical island of stability. Since erbium and fermium have similar electronic structures, calculations for erbium serve as a guide to the accuracy of the calculations.
