Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

Physical Review A

High-resolution ultraviolet spectra of sympathetically-laser-cooled Cd+ ions

Hidetsuka Imajo, Kazuhiro Hayasaka, R. Ohmukai, U. Tanaka, Masayoshi Watanabe, Shinji Urabe

Published Jan 1, 1996• 30 citations
Publisher

Abstract

Cadmium ions (${\mathrm{Cd}}^{+}$) have been cooled sympathetically below 1 K by means of Coulomb interactions with laser-cooled ${\mathrm{Be}}^{+}$ ions that are trapped simultaneously in a Penning trap. The ultraviolet resonance lines (5${\mathit{s}}^{\mathrm{}2}$${\mathit{S}}_{1/2}$\ensuremath{\leftrightarrows}5${\mathit{p}}^{\mathrm{}2}$${\mathit{P}}_{3/2}$, \ensuremath{\lambda}=214.5 nm) of the cooled ${\mathrm{Cd}}^{+}$ ions were observed using a frequency-doubled cw dye laser. This radiation is based on efficient frequency doubling in a nonlinear crystal [\ensuremath{\beta}-${\mathrm{BaB}}_{2}$${\mathrm{O}}_{4}$ (BBO)] with an external enhancement cavity. The spectra of the six isotopes (A=110--114, and 116) were obtained using a natural isotope mixture, and the reliability of the measured isotope shifts is discussed. \textcopyright{} 1996 The American Physical Society.

DOI
10.1103/physreva.53.122

Related papers

Laser cooling and isotope separation of Cd^+ ions confined in a linear Paul trap

U. Tanaka, Hidetsuka Imajo, Kazuhiro Hayasaka +3 more

Cadmium ions in a natural isotope mixture have been trapped in a linear Paul trap and laser cooled. The fluorescence spectra from all even isotopes, including the (108)Cd(+) isotopes with a natural abundance of 0.89%, were observed. Additionally, we eliminated the heavier isotopes from the trapping region by adjusting the tuning of the laser frequency and by changing the dc voltage applied to the end electrodes.

Optics Letters•Sep 1, 1997•11 citations

Spatial separation of ion clouds between sympathetically laser-cooled Cd + -ion isotopes in a Penning trap

Hidetsuka Imajo, Kazuhiro Hayasaka, R. Ohmukai +3 more

Natural ${\mathrm{Cd}}^{+}$ ions in a Penning trap are cooled sympathetically below 1 K by a Coulomb interaction with directly laser-cooled ${\mathrm{Be}}^{+}$ ions. Spatial separation of the ${\mathrm{Be}}^{+}$ and ${\mathrm{Cd}}^{+}$ ion clouds due to centrifugal force is observed directly. When the frequency of rotation of the ion clouds is accelerated, the separation between ${\mathrm{Cd}}^{+}$ -ion isotopes (A=110 and 116) can be clearly observed, though their mass difference is very small. The equations of motion for 100 ${\mathrm{Be}}^{+}$ ions and 50 ${\mathrm{Cd}}^{+}$ ions are solved to simulate the experiments, and the result shows the spatial separation between the two ion species. The separation between the ${\mathrm{Cd}}^{+}$ -ion isotopes is investigated by comparing the experimental results with numerical calculations.

Physical Review A•Feb 1, 1997•25 citations

Laser-cooling Cadmium Bosons and Fermions with Near Ultraviolet Triplet Excitations

Kurt Gibble

Abstract Cadmium is laser-cooled and trapped with excitations to triplet states with UVA light, first using only the 67 kHz wide 326 nm intercombination line and subsequently, for large loading rates, the 25 MHz wide 361 nm 3 P 2 → 3 D 3 transition. Eschewing the hard UV 229 nm 1 S 0 → 1 P 1 transition, only small magnetic fields gradients, less than 6 G cm−1, are required enabling a 100% transfer of atoms from the 361 nm trap to the 326 nm narrow-line trap. All 8 stable cadmium isotopes are straightforwardly trapped, including two nuclear-spin- 1 2 fermions that require no additional repumping. We observe evidence of 3 P 2 collisions limiting the number of trapped metastable atoms, report isotope shifts for 111Cd and 113Cd of the 326 nm 1 S 0 → 3 P 1, 480nm 3 P 1 → 3 S 1, and 361 nm 3 P 2 → 3 D 3 transitions, and measure the 114Cd 5s5p 3 P 2 → 5s5d 3 D 3 transition frequency to be 830 096 573(15) MHz.

arXiv:2408.08424•Journal of Physics Conference Series•Nov 1, 2024•1 citation

Isotope shifts of natural Sr+ measured by laser fluorescence in a sympathetically cooled Coulomb crystal

B. Dubost, Romain Dubessy, Benjamin Szymanski +3 more

We measured by laser spectroscopy the isotope shifts between naturally occurring even isotopes of strontium ions for both the $5s\phantom{\rule{0.16em}{0ex}}{\phantom{\rule{0.16em}{0ex}}}^{2}{S}_{1/2}\ensuremath{\rightarrow}5p\phantom{\rule{0.16em}{0ex}}{\phantom{\rule{0.16em}{0ex}}}^{2}{P}_{1/2}$ (violet) and the $4d\phantom{\rule{0.16em}{0ex}}{\phantom{\rule{0.16em}{0ex}}}^{2}{D}_{3/2}\ensuremath{\rightarrow}5p\phantom{\rule{0.16em}{0ex}}{\phantom{\rule{0.16em}{0ex}}}^{2}{P}_{1/2}$ (infrared) dipole-allowed optical transitions. Fluorescence spectra were taken by simultaneous measurements on a two-component Coulomb crystal in a linear Paul trap containing ${10}^{3}$--${10}^{4}$ laser-cooled ${\mathrm{Sr}}^{+}$ ions. The isotope shifts are extracted from the experimental spectra by fitting the data with the analytical solution of the optical Bloch equations describing a three-level atom interacting with two laser beams. This technique allowed us to increase the precision with respect to previously reported data obtained by optogalvanic spectroscopy or fast atomic-beam techniques. The results for the $5s\phantom{\rule{0.16em}{0ex}}{\phantom{\rule{0.16em}{0ex}}}^{2}{S}_{1/2}\ensuremath{\rightarrow}5p\phantom{\rule{0.16em}{0ex}}{\phantom{\rule{0.16em}{0ex}}}^{2}{P}_{1/2}$ transition are ${\ensuremath{\nu}}_{88}\ensuremath{-}{\ensuremath{\nu}}_{84}=+378(4)$ MHz and ${\ensuremath{\nu}}_{88}\ensuremath{-}{\ensuremath{\nu}}_{86}=+170(3)$ MHz, in agreement with previously reported measurements. In the case of the previously unexplored $4d\phantom{\rule{0.16em}{0ex}}{\phantom{\rule{0.16em}{0ex}}}^{2}{D}_{3/2}\ensuremath{\rightarrow}5p\phantom{\rule{0.16em}{0ex}}{\phantom{\rule{0.16em}{0ex}}}^{2}{P}_{1/2}$ transition we find ${\ensuremath{\nu}}_{88}\ensuremath{-}{\ensuremath{\nu}}_{84}=\ensuremath{-}828(4)$ MHz and ${\ensuremath{\nu}}_{88}\ensuremath{-}{\ensuremath{\nu}}_{86}=\ensuremath{-}402(2)$ MHz. These results provide more data for stringent tests of theoretical calculations of the isotope shifts of alkali-metal-like atoms. Moreover, they simplify the identification and the addressing of ${\mathrm{Sr}}^{+}$ isotopes for ion frequency standards or quantum-information-processing applications in the case of multi-isotope ion strings.

arXiv:1402.3390•Physical Review A•Mar 7, 2014•12 citations

Sympathetic cooling in two-species ion crystals in a Penning trap

S. Schmidt, T. Murböck, Zoran Andelkovic +5 more

We have studied the formation and properties of two-species ion Coulomb crystals in the Penning trap of the SpecTrap experiment. These crystals have been formed by injection of admixture ions from an external source into a previously confined and laser-cooled cloud of magnesium ions. This kind of study, performed over a range of the admixture ions’ charge-to-mass ratios, indicates the conditions for their sympathetic cooling and the formation of two-species ion crystals. This mechanism allows efficient cooling of the admixed species such as highly charged ions which do not feature suitable laser-cooling transitions, and thus make them accessible to high-resolution laser spectroscopy.

Journal of Modern Optics•Jul 16, 2017•15 citations

Spectroscopy of Single Trapped Ions and Application to Frequency Standards

HERBERT WALTHER

Single ions trapped and laser cooled provide ideal objects for high resolution spectroscopy and frequency standards. For the latter purpose we are investigating the 5s2 1S0 → 5s5p 3P0 transition of In+. With a natural linewidth of only 1.1 Hz this resonance offers very high resolution and is highly immune to frequency shifts due to external electromagnetic fields, because it connects two levels with vanishing electronic magnetic momenta [1]. The wavelength of this clock transition is 236.5 nm and is technically very convenient, since it coincides with the fourth harmonic of the 946 nm Nd:YAG laser line. So this intrinsically frequency stable solid-state laser can be used to excite the transition [2]. For laser cooling and fluorescence detection of the indium ion the 5s2 1So -> 5s5p 3P1 transition at 230.6 nm can be employed. The use of the relatively narrow intercombination line for laser cooling allows us to study optical sideband cooling in the strong binding regime, where the oscillation frequencies of the ion in the trap (around 1 MHz) are larger than the optical linewidth of 360 kHz. In this parameter range laser cooling is possible to the quantum ground state of the vibrational motion in the trap corresponding to a temperature of roughly 100 μK. The same low temperature was obtained with sideband cooling of a small Coulomb crystal consisting of two ions, creating an interesting new quantum few-particle system.

Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC)•Jan 1, 1998•0 citations
Cadmium ions (Cd+{\mathrm{Cd}}^{+}Cd+) have been cooled sympathetically below 1 K by means of Coulomb interactions with laser-cooled Be+{\mathrm{Be}}^{+}Be+ ions that are trapped simultaneously in a Penning trap. The ultraviolet resonance lines (5{\mathit{s}}^{\mathrm{}2}$${\mathit{S}}_{1/2}\ensuremath{\leftrightarrows}5{\mathit{p}}^{\mathrm{}2}$${\mathit{P}}_{3/2}, \ensuremath{\lambda}=214.5 nm) of the cooled Cd+{\mathrm{Cd}}^{+}Cd+ ions were observed using a frequency-doubled cw dye laser. This radiation is based on efficient frequency doubling in a nonlinear crystal [\ensuremath{\beta}-{\mathrm{BaB}}_{2}$${\mathrm{O}}_{4} (BBO)] with an external enhancement cavity. The spectra of the six isotopes (A=110--114, and 116) were obtained using a natural isotope mixture, and the reliability of the measured isotope shifts is discussed. \textcopyright{} 1996 The American Physical Society.
Natural Cd+{\mathrm{Cd}}^{+}Cd+ ions in a Penning trap are cooled sympathetically below 1 K by a Coulomb interaction with directly laser-cooled Be+{\mathrm{Be}}^{+}Be+ ions. Spatial separation of the Be+{\mathrm{Be}}^{+}Be+ and Cd+{\mathrm{Cd}}^{+}Cd+ ion clouds due to centrifugal force is observed directly. When the frequency of rotation of the ion clouds is accelerated, the separation between Cd+{\mathrm{Cd}}^{+}Cd+ -ion isotopes (A=110 and 116) can be clearly observed, though their mass difference is very small. The equations of motion for 100 Be+{\mathrm{Be}}^{+}Be+ ions and 50 Cd+{\mathrm{Cd}}^{+}Cd+ ions are solved to simulate the experiments, and the result shows the spatial separation between the two ion species. The separation between the Cd+{\mathrm{Cd}}^{+}Cd+ -ion isotopes is investigated by comparing the experimental results with numerical calculations.
Abstract Cadmium is laser-cooled and trapped with excitations to triplet states with UVA light, first using only the 67 kHz wide 326 nm intercombination line and subsequently, for large loading rates, the 25 MHz wide 361 nm 3 P 2 → 3 D 3 transition. Eschewing the hard UV 229 nm 1 S 0 → 1 P 1 transition, only small magnetic fields gradients, less than 6 G cm−1, are required enabling a 100% transfer of atoms from the 361 nm trap to the 326 nm narrow-line trap. All 8 stable cadmium isotopes are straightforwardly trapped, including two nuclear-spin- 1 2 fermions that require no additional repumping. We observe evidence of 3 P 2 collisions limiting the number of trapped metastable atoms, report isotope shifts for 111Cd and 113Cd of the 326 nm 1 S 0 → 3 P 1, 480nm 3 P 1 → 3 S 1, and 361 nm 3 P 2 → 3 D 3 transitions, and measure the 114Cd 5s5p 3 P 2 → 5s5d 3 D 3 transition frequency to be 830 096 573(15) MHz.
We measured by laser spectroscopy the isotope shifts between naturally occurring even isotopes of strontium ions for both the $5s\phantom{\rule{0.16em}{0ex}}{\phantom{\rule{0.16em}{0ex}}}^{2}{S}_{1/2}\ensuremath{\rightarrow}5p\phantom{\rule{0.16em}{0ex}}{\phantom{\rule{0.16em}{0ex}}}^{2}{P}_{1/2}$ (violet) and the $4d\phantom{\rule{0.16em}{0ex}}{\phantom{\rule{0.16em}{0ex}}}^{2}{D}_{3/2}\ensuremath{\rightarrow}5p\phantom{\rule{0.16em}{0ex}}{\phantom{\rule{0.16em}{0ex}}}^{2}{P}_{1/2}$ (infrared) dipole-allowed optical transitions. Fluorescence spectra were taken by simultaneous measurements on a two-component Coulomb crystal in a linear Paul trap containing 103{10}^{3}103--104{10}^{4}104 laser-cooled Sr+{\mathrm{Sr}}^{+}Sr+ ions. The isotope shifts are extracted from the experimental spectra by fitting the data with the analytical solution of the optical Bloch equations describing a three-level atom interacting with two laser beams. This technique allowed us to increase the precision with respect to previously reported data obtained by optogalvanic spectroscopy or fast atomic-beam techniques. The results for the $5s\phantom{\rule{0.16em}{0ex}}{\phantom{\rule{0.16em}{0ex}}}^{2}{S}_{1/2}\ensuremath{\rightarrow}5p\phantom{\rule{0.16em}{0ex}}{\phantom{\rule{0.16em}{0ex}}}^{2}{P}_{1/2}$ transition are ${\ensuremath{\nu}}_{88}\ensuremath{-}{\ensuremath{\nu}}_{84}=+378(4)$ MHz and ${\ensuremath{\nu}}_{88}\ensuremath{-}{\ensuremath{\nu}}_{86}=+170(3)$ MHz, in agreement with previously reported measurements. In the case of the previously unexplored $4d\phantom{\rule{0.16em}{0ex}}{\phantom{\rule{0.16em}{0ex}}}^{2}{D}_{3/2}\ensuremath{\rightarrow}5p\phantom{\rule{0.16em}{0ex}}{\phantom{\rule{0.16em}{0ex}}}^{2}{P}_{1/2}$ transition we find ${\ensuremath{\nu}}_{88}\ensuremath{-}{\ensuremath{\nu}}_{84}=\ensuremath{-}828(4)$ MHz and ${\ensuremath{\nu}}_{88}\ensuremath{-}{\ensuremath{\nu}}_{86}=\ensuremath{-}402(2)$ MHz. These results provide more data for stringent tests of theoretical calculations of the isotope shifts of alkali-metal-like atoms. Moreover, they simplify the identification and the addressing of Sr+{\mathrm{Sr}}^{+}Sr+ isotopes for ion frequency standards or quantum-information-processing applications in the case of multi-isotope ion strings.
We have studied the formation and properties of two-species ion Coulomb crystals in the Penning trap of the SpecTrap experiment. These crystals have been formed by injection of admixture ions from an external source into a previously confined and laser-cooled cloud of magnesium ions. This kind of study, performed over a range of the admixture ions’ charge-to-mass ratios, indicates the conditions for their sympathetic cooling and the formation of two-species ion crystals. This mechanism allows efficient cooling of the admixed species such as highly charged ions which do not feature suitable laser-cooling transitions, and thus make them accessible to high-resolution laser spectroscopy.
Single ions trapped and laser cooled provide ideal objects for high resolution spectroscopy and frequency standards. For the latter purpose we are investigating the 5s2 1S0 → 5s5p 3P0 transition of In+. With a natural linewidth of only 1.1 Hz this resonance offers very high resolution and is highly immune to frequency shifts due to external electromagnetic fields, because it connects two levels with vanishing electronic magnetic momenta [1]. The wavelength of this clock transition is 236.5 nm and is technically very convenient, since it coincides with the fourth harmonic of the 946 nm Nd:YAG laser line. So this intrinsically frequency stable solid-state laser can be used to excite the transition [2]. For laser cooling and fluorescence detection of the indium ion the 5s2 1So -> 5s5p 3P1 transition at 230.6 nm can be employed. The use of the relatively narrow intercombination line for laser cooling allows us to study optical sideband cooling in the strong binding regime, where the oscillation frequencies of the ion in the trap (around 1 MHz) are larger than the optical linewidth of 360 kHz. In this parameter range laser cooling is possible to the quantum ground state of the vibrational motion in the trap corresponding to a temperature of roughly 100 μK. The same low temperature was obtained with sideband cooling of a small Coulomb crystal consisting of two ions, creating an interesting new quantum few-particle system.