We report our observation of the resonant fluorescence from highly charged uranium ions. Using the resonant coherent excitation (RCE) technique, the $2s$ - $2{p}_{3/2}$ transition in 191.68 MeV/u Li-like U ${}^{89+}$ ions was excited at 4.5 keV with a resonance width of 4.4 eV. The result demonstrated that the RCE can be applied to resonant fluorescence spectroscopy of high- $Z$ ions up to uranium with high efficiency and resolution.We report our observation of the resonant fluorescence from highly charged uranium ions. Using the resonant coherent excitation (RCE) technique, the $2s$-$2{p}_{3/2}$ transition in 191.68 MeV/u Li-like U${}^{89+}$ ions was excited at 4.5 keV with a resonance width of 4.4 eV. The result demonstrated that the RCE can be applied to resonant fluorescence spectroscopy of high-$Z$ ions up to uranium with high efficiency and resolution.

Physical Review AJun 7, 201323 citations

Cold interactions between an Yb+ ion and a Li atom: Prospects for sympathetic cooling, radiative association, and Feshbach resonances

Michał Tomza, Christiane P. Koch, Robert Moszyński

The electronic structure of the $(\mathrm{LiYb}{)}^{+}$ molecular ion is investigated with two variants of the coupled cluster method restricted to single, double, and noniterative or linear triple excitations. Potential-energy curves for the ground and excited states, permanent and transition electric dipole moments, and long-range interaction coefficients ${C}_{4}$ and ${C}_{6}$ are reported. The data are subsequently employed in scattering calculations and photoassociation studies. Feshbach resonances are shown to be measurable, despite the ion's micromotion in the Paul trap. Molecular ions can be formed in their singlet electronic ground state by one-photon photoassociation and in triplet states by two-photon photoassociation; and control of cold atom-ion chemistry based on Feshbach resonances should be feasible. Conditions for sympathetic cooling of an ${\mathrm{Yb}}^{+}$ ion by an ultracold gas of Li atoms are found to be favorable in the temperature range $10\phantom{\rule{0.28em}{0ex}}\mathrm{nK}--10\phantom{\rule{0.28em}{0ex}}\mathrm{mK}$ , and further improvements using Feshbach resonances should be possible. Overall, these results suggest excellent prospects for building a quantum simulator with ultracold ${\mathrm{Yb}}^{+}$ ions and Li atoms.The electronic structure of the $(\mathrm{LiYb}{)}^{+}$ molecular ion is investigated with two variants of the coupled cluster method restricted to single, double, and noniterative or linear triple excitations. Potential-energy curves for the ground and excited states, permanent and transition electric dipole moments, and long-range interaction coefficients ${C}_{4}$ and ${C}_{6}$ are reported. The data are subsequently employed in scattering calculations and photoassociation studies. Feshbach resonances are shown to be measurable, despite the ion's micromotion in the Paul trap. Molecular ions can be formed in their singlet electronic ground state by one-photon photoassociation and in triplet states by two-photon photoassociation; and control of cold atom-ion chemistry based on Feshbach resonances should be feasible. Conditions for sympathetic cooling of an ${\mathrm{Yb}}^{+}$ ion by an ultracold gas of Li atoms are found to be favorable in the temperature range $10\phantom{\rule{0.28em}{0ex}}\mathrm{nK}--10\phantom{\rule{0.28em}{0ex}}\mathrm{mK}$, and further improvements using Feshbach resonances should be possible. Overall, these results suggest excellent prospects for building a quantum simulator with ultracold ${\mathrm{Yb}}^{+}$ ions and Li atoms.

arXiv:1409.1192Physical Review AApr 17, 201568 citations

We report our observation of the resonant fluorescence from highly charged uranium ions. Using the resonant coherent excitation (RCE) technique, the

2s

2{p}_{3/2}

transition in 191.68 MeV/u Li-like U

{}^{89+}

ions was excited at 4.5 keV with a resonance width of 4.4 eV. The result demonstrated that the RCE can be applied to resonant fluorescence spectroscopy of high-

Z

ions up to uranium with high efficiency and resolution.

The electronic structure of the

(\mathrm{LiYb}{)}^{+}

molecular ion is investigated with two variants of the coupled cluster method restricted to single, double, and noniterative or linear triple excitations. Potential-energy curves for the ground and excited states, permanent and transition electric dipole moments, and long-range interaction coefficients

{C}_{4}

and

{C}_{6}

are reported. The data are subsequently employed in scattering calculations and photoassociation studies. Feshbach resonances are shown to be measurable, despite the ion's micromotion in the Paul trap. Molecular ions can be formed in their singlet electronic ground state by one-photon photoassociation and in triplet states by two-photon photoassociation; and control of cold atom-ion chemistry based on Feshbach resonances should be feasible. Conditions for sympathetic cooling of an

{\mathrm{Yb}}^{+}

ion by an ultracold gas of Li atoms are found to be favorable in the temperature range

10\phantom{\rule{0.28em}{0ex}}\mathrm{nK}--10\phantom{\rule{0.28em}{0ex}}\mathrm{mK}

, and further improvements using Feshbach resonances should be possible. Overall, these results suggest excellent prospects for building a quantum simulator with ultracold

{\mathrm{Yb}}^{+}

ions and Li atoms.