Merging trapped ions with cold atomic clouds offers intriguing prospects for quantum chemistry and many-body quantum simulations. Especially when going beyond the standard alkali atomic baths by using lanthanide atoms, opportunities arise to study the interplay between the intermediate-range atom-ion interaction and the tunable long-range dipolar atom-atom interactions. However, the high total angular momentum of the ground-state of open-shell lanthanides, e.g. $^{5}I_{8}$ for dysprosium, affects the atom-ion potential. Here, we discuss the implications for long- and short-range atom-ion interactions and present a novel apparatus which combines an ytterbium ion (Yb $^{+}$ ) with dipolar dysprosium (Dy) atoms. We highlight the consequences of this novel Dy-Yb $^{+}$ mixture for observing buffer gas cooling, (non-) radiative charge transfer, and three-body recombination. While the energy-averaged rates are dominated by radiative charge transfer, particularly radiative association, we find that three-body recombination can compete with molecular-ion formation at Dy densities $n\gtrsim 10^{12}$ cm $^{-3}$ . This competition is further enhanced by the expected non-thermal distribution of ion energies. These processes could be experimentally characterised through controlled variation of the atom-ion interaction parameters, providing a direct test of our theoretical predictions.Merging trapped ions with cold atomic clouds offers intriguing prospects for quantum chemistry and many-body quantum simulations. Especially when going beyond the standard alkali atomic baths by using lanthanide atoms, opportunities arise to study the interplay between the intermediate-range atom-ion interaction and the tunable long-range dipolar atom-atom interactions. However, the high total angular momentum of the ground-state of open-shell lanthanides, e.g. $^{5}I_{8}$ for dysprosium, affects the atom-ion potential. Here, we discuss the implications for long- and short-range atom-ion interactions and present a novel apparatus which combines an ytterbium ion (Yb$^{+}$) with dipolar dysprosium (Dy) atoms. We highlight the consequences of this novel Dy-Yb$^{+}$ mixture for observing buffer gas cooling, (non-) radiative charge transfer, and three-body recombination. While the energy-averaged rates are dominated by radiative charge transfer, particularly radiative association, we find that three-body recombination can compete with molecular-ion formation at Dy densities $n\gtrsim 10^{12}$ cm$^{-3}$. This competition is further enhanced by the expected non-thermal distribution of ion energies. These processes could be experimentally characterised through controlled variation of the atom-ion interaction parameters, providing a direct test of our theoretical predictions.

arXiv:2609.26859Sep 22, 20260 citations

Generation of monochromatic radiation by atomic ions in a magnetic field

Vladimir S. Melezhik

In the presence of a magnetic field atomic ions are shown to generate monochromatic radiation with the frequency $\ensuremath{\omega}=QB/M$, depending on the field strength B and the ion mass M and charge Q. The origin of the effect is the interaction of the bound electrons with the oscillating field of the Stark term coupling the center of mass and electronic motions of an ion due to the nonseparability of the collective and internal degrees of freedom in the system. The intensity of the radiation is defined by the velocities of the ions and the magnetic field strength.In the presence of a magnetic field atomic ions are shown to generate monochromatic radiation with the frequency $\ensuremath{\omega}=QB/M$, depending on the field strength B and the ion mass M and charge Q. The origin of the effect is the interaction of the bound electrons with the oscillating field of the Stark term coupling the center of mass and electronic motions of an ion due to the nonseparability of the collective and internal degrees of freedom in the system. The intensity of the radiation is defined by the velocities of the ions and the magnetic field strength.

Physical Review AJun 1, 19991 citation

Interaction of Radiation with Atoms

Daniel F. Walls, Gerard J Milburn

Springer eBooksJan 1, 19941 citation

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

Michał Tomza

The ${\mathrm{Ca}}^{+}, {\mathrm{Sr}}^{+}, {\mathrm{Ba}}^{+}$ , and ${\mathrm{Yb}}^{+}$ 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 ${\mathrm{Ca}}^{+}, {\mathrm{Sr}}^{+}, {\mathrm{Ba}}^{+}$ , and ${\mathrm{Yb}}^{+}$ 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.The ${\mathrm{Ca}}^{+}, {\mathrm{Sr}}^{+}, {\mathrm{Ba}}^{+}$, and ${\mathrm{Yb}}^{+}$ 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 ${\mathrm{Ca}}^{+}, {\mathrm{Sr}}^{+}, {\mathrm{Ba}}^{+}$, and ${\mathrm{Yb}}^{+}$ 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.

arXiv:1509.05390Physical Review ADec 1, 201520 citations

Interaction of Radiation with Atoms

Daniel F. Walls, Gerard J Milburn

Springer eBooksDec 6, 20070 citations

^{5}I_{8}

for dysprosium, affects the atom-ion potential. Here, we discuss the implications for long- and short-range atom-ion interactions and present a novel apparatus which combines an ytterbium ion (Yb

^{+}

) with dipolar dysprosium (Dy) atoms. We highlight the consequences of this novel Dy-Yb

^{+}

mixture for observing buffer gas cooling, (non-) radiative charge transfer, and three-body recombination. While the energy-averaged rates are dominated by radiative charge transfer, particularly radiative association, we find that three-body recombination can compete with molecular-ion formation at Dy densities

n\gtrsim 10^{12}

^{-3}

. This competition is further enhanced by the expected non-thermal distribution of ion energies. These processes could be experimentally characterised through controlled variation of the atom-ion interaction parameters, providing a direct test of our theoretical predictions.

The

{\mathrm{Ca}}^{+}, {\mathrm{Sr}}^{+}, {\mathrm{Ba}}^{+}

, and

{\mathrm{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

{\mathrm{Ca}}^{+}, {\mathrm{Sr}}^{+}, {\mathrm{Ba}}^{+}

, and

{\mathrm{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.