Synopsis Atomic lanthanum anion La− is the best candidate for laser cooling of any atomic anions by far. The previous theoretical studies showed that La− has very a complicated electronic structure, which cannot be well resolved by the traditional photoelectron spectroscopy. In the present work, we used the slow-electron velocity-map imaging method in combination with an ion trap to measure the electronic structure of La−. The electron affinity of La is accurately determined to be 4496.97(20) cm−1 or 0.557553(25) eV.Synopsis Atomic lanthanum anion La− is the best candidate for laser cooling of any atomic anions by far. The previous theoretical studies showed that La− has very a complicated electronic structure, which cannot be well resolved by the traditional photoelectron spectroscopy. In the present work, we used the slow-electron velocity-map imaging method in combination with an ion trap to measure the electronic structure of La−. The electron affinity of La is accurately determined to be 4496.97(20) cm−1 or 0.557553(25) eV.

Journal of Physics Conference SeriesJan 1, 20200 citations

Towards trapping and laser cooling Ba and La ions

Jessie Hankes, Amanda Nelson, Patrick Banner +1 more

Bulletin of the American Physical SocietyJun 8, 20170 citations

Doubly ionized lanthanum as a qubit candidate for quantum networks

Steven Olmschenk

We propose doubly ionized lanthanum ( ${\mathrm{La}}^{2+}$ ) as a possible qubit candidate for quantum networks. Transitions between the lowest levels in the atom are in the infrared, enabling a direct matter-light interface amenable to long-distance quantum communication. These transitions could also be used to directly laser-cool trapped ${\mathrm{La}}^{2+}$ ions. The rich hyperfine structure of the ion may allow for a qubit stored in magnetic-field insensitive states as well as protocols for atom-photon entanglement.We propose doubly ionized lanthanum (${\mathrm{La}}^{2+}$) as a possible qubit candidate for quantum networks. Transitions between the lowest levels in the atom are in the infrared, enabling a direct matter-light interface amenable to long-distance quantum communication. These transitions could also be used to directly laser-cool trapped ${\mathrm{La}}^{2+}$ ions. The rich hyperfine structure of the ion may allow for a qubit stored in magnetic-field insensitive states as well as protocols for atom-photon entanglement.

arXiv:2109.01978Physical Review AApr 25, 20221 citation

Lifetimes of bound excited states of the lanthanum negative ion and implications for laser cooling: Experiment and theory

C. W. Walter, F. E. Vassallo, Julia Karls +12 more

The negative ion of lanthanum has one of the richest bound-state spectra observed for an atomic negative ion and it has been proposed as a promising candidate for laser cooling, which has not yet been achieved for any negatively charged system. In the present study, radiative decays of low-lying excited states of ${\mathrm{La}}^{\ensuremath{-}}$ were experimentally investigated at the DESIREE cryogenic electrostatic ion-beam storage ring facility using state-selective photodetachment over storage times of up to 800 s. Independently, the transition rates for the relevant states were calculated using a high-precision hybrid theoretical approach. The measured lifetime of the lowest excited state of ${\mathrm{La}}^{\ensuremath{-}}$ $({}^{3}{F}_{3}^{e})$ of 132(20) s agrees very well with the theoretical calculations and previous predictions. However, a puzzling discrepancy exists for the next-higher state ${}^{3}{F}_{4}^{e}$ , with the experiments yielding a lifetime $\ensuremath{\sim}4$ times shorter than calculated, highlighting the challenges for this complex ion. The results provide valuable insights into the prospects for laser cooling ${\mathrm{La}}^{\ensuremath{-}}$.The negative ion of lanthanum has one of the richest bound-state spectra observed for an atomic negative ion and it has been proposed as a promising candidate for laser cooling, which has not yet been achieved for any negatively charged system. In the present study, radiative decays of low-lying excited states of ${\mathrm{La}}^{\ensuremath{-}}$ were experimentally investigated at the DESIREE cryogenic electrostatic ion-beam storage ring facility using state-selective photodetachment over storage times of up to 800 s. Independently, the transition rates for the relevant states were calculated using a high-precision hybrid theoretical approach. The measured lifetime of the lowest excited state of ${\mathrm{La}}^{\ensuremath{-}}$ $({}^{3}{F}_{3}^{e})$ of 132(20) s agrees very well with the theoretical calculations and previous predictions. However, a puzzling discrepancy exists for the next-higher state ${}^{3}{F}_{4}^{e}$, with the experiments yielding a lifetime $\ensuremath{\sim}4$ times shorter than calculated, highlighting the challenges for this complex ion. The results provide valuable insights into the prospects for laser cooling ${\mathrm{La}}^{\ensuremath{-}}$.

Physical Review AOct 3, 20250 citations

Laser Cooling of Trapped Ions

Wayne M. Itano, Jonas Bergquist, J. J. Bollinger +1 more

Jan 1, 19915 citations

We propose doubly ionized lanthanum (

{\mathrm{La}}^{2+}

) as a possible qubit candidate for quantum networks. Transitions between the lowest levels in the atom are in the infrared, enabling a direct matter-light interface amenable to long-distance quantum communication. These transitions could also be used to directly laser-cool trapped

{\mathrm{La}}^{2+}

ions. The rich hyperfine structure of the ion may allow for a qubit stored in magnetic-field insensitive states as well as protocols for atom-photon entanglement.

({}^{3}{F}_{3}^{e})

of 132(20) s agrees very well with the theoretical calculations and previous predictions. However, a puzzling discrepancy exists for the next-higher state

{}^{3}{F}_{4}^{e}

, with the experiments yielding a lifetime $\ensuremath{\sim}4$ times shorter than calculated, highlighting the challenges for this complex ion. The results provide valuable insights into the prospects for laser cooling ${\mathrm{La}}^{\ensuremath{-}}$.