Ultracold magnetically tunable interactions without radiative-charge-transfer losses between ${\mathrm{Ca}}^{+}, {\mathrm{Sr}}^{+}, {\mathrm{Ba}}^{+}$, and ${\mathrm{Yb}}^{+}$ ions and Cr atoms

Ultracold magnetically tunable interactions without radiative-charge-transfer losses between ${Ca}^{+}, {Sr}^{+}, {Ba}^{+}$ , and ${Yb}^{+}$ ions and Cr atoms

Michał Tomza

Phys. Rev. A 92, 062701 – Published 1 December 2015

Abstract

The ${Ca}^{+}, {Sr}^{+}, {Ba}^{+}$ , and ${Yb}^{+}$ ions immersed in an ultracold gas of the Cr atoms are proposed as experimentally feasible heteronuclear systems in which ion-atom interactions at ultralow temperatures can be controlled with magnetically tunable Feshbach resonances without charge transfer and radiative losses. Ab initio techniques are applied to investigate electronic-ground-state properties of the (CaCr) $^{+}$ , (SrCr) $^{+}$ , (BaCr) $^{+}$ , and (YbCr) $^{+}$ molecular ions. The potential energy curves, permanent electric dipole moments, and static electric dipole polarizabilities are computed. The spin-restricted open-shell coupled-cluster method restricted to single, double, and noniterative triple excitations and the multireference configuration-interaction method restricted to single and double excitations are employed. The scalar relativistic effects are included within the small-core energy-consistent pseudopotentials. The leading long-range induction and dispersion interaction coefficients are also reported. Finally, magnetic Feshbach resonances between the ${Ca}^{+}, {Sr}^{+}, {Ba}^{+}$ , and ${Yb}^{+}$ ions interacting with the Cr atoms are analyzed. The present proposal opens the way towards robust quantum simulations and computations with ultracold ion-atom systems free of radiative charge-transfer losses.