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

arXiv:quant-ph/0607055

Photoionization of strontium for trapped-ion quantum information processing

Kendra vant, John Chiaverini, Warren E. Lybarger, Dana J. Berkeland

Published Jul 7, 2006• 12 citations
arXivHTMLPDF

Abstract

We report a demonstration of simple and effective loading of strontium ions into a linear radio frequency Paul trap using photoionization. The ionization pathway is 5s2 1S0 -- 5s5p 1P1 -- 5p2 1D2, and the 5p2 1D2 final state is auto-ionizing. Both transitions are driven using diode lasers: a grating-stabilized 922 nm diode doubled in a single pass through potassium niobate to 461 nm and a bare diode at 405 nm. Using this technique, we have reduced the background pressure during the ion loading process by a factor of 2 compared to the conventional technique of electron bombardment. Initial ion temperatures are low enough that the ions immediately form crystals. It is also possible to observe the trapping region with a CCD camera during ion creation, allowing specific ion number loading with high probability.

DOI
10.48550/arxiv.quant-ph/0607055

Related papers

2-photon ionization and necessary laser and vacuum systems for experiments with trapped strontium ions

Emil Kirilov, Seth Putterman

We describe a efficient way to photoionize strontium atoms in a linear radio-frequency trap. We use a 2-photon second order process to excite the autoionization resonance (4d2 + 5p2) 1D2. A doubled pulsed Ti:Saphire laser system is used at 431nm to provide 100fsec pulses at 82Mhz. The fabrication of the laser systems for addressing the Sr+ transitions necessary for laser cooling and excitation of quantum jumps, vacuum system and ion trap structure are also described in detail. With the current setup a easy and repeatable trapping of linear ion chains is achieved at UHV pressures.

arXiv:0712.0222•Dec 3, 2007•0 citations

Trapping and cooling of Sr+ions: strings and large clouds

S. Removille, Romain Dubessy, B. Dubost +5 more

This paper reports on trapping and laser cooling of singly ionized strontium ions in a linear Paul trap. We describe the loading technique based on two-photon absorption of femtosecond pulses at a wavelength of 431 nm and we compare this technique to electron-bombardment ionization. We perform Doppler cooling of the ions in the few-ions regime as well as in the case of large clouds. The analysis of the fluorescence spectra and direct imaging of the cloud allows us to identify the Coulomb-crystal regime. These experiments open the way to the use of a large cold trapped-ion cloud as a medium for quantum optics and quantum information experiments.

Journal of Physics B Atomic Molecular and Optical Physics•Jul 15, 2009•19 citations

Efficient photoionization loading of trapped ions with ultrafast pulses

Louis Deslauriers, M. Acton, B. B. Blinov +16 more

Atomic cadmium ions are loaded into radiofrequency ion traps by photoionization of atoms in a cadmium vapor with ultrafast laser pulses. The photoionization is driven through an intermediate atomic resonance with a frequency-quadrupled mode-locked Ti:sapphire laser that produces pulses of either $100\text{\ensuremath{-}}\mathrm{fs}$ or $1\text{\ensuremath{-}}\mathrm{ps}$ duration at a central wavelength of $229\phantom{\rule{0.3em}{0ex}}\mathrm{nm}$. The large bandwidth of the pulses photoionizes all velocity classes of the Cd vapor, resulting in a high loading efficiency compared to previous ion trap loading techniques. Measured loading rates are compared with a simple theoretical model, and we conclude that this technique can potentially ionize every atom traversing the laser beam within the trapping volume. This may allow the operation of ion traps with lower levels of background pressures and less trap electrode surface contamination. The technique and laser system reported here should be applicable to loading most laser-cooled ion species.

arXiv:quant-ph/0608043•Physical Review A•Dec 29, 2006•26 citations

Nonselective Paul ion trap loading with a light-emitting diode

Ilia V. Zalivako, A. Borisenko, Ilya A. Semerikov +4 more

We demonstrate a simple nonisotope-selective method for ion trap loading, which is based on the irradiation of trap electrodes precoated with materials with a low work function by a light-emitting diode (LED). Photoelectrons emitted from the electrode surface and accelerated in the trap electric field ionize the atomic beam inside the trap, which results in the trap loading. We studied Y2O3 and Mg coatings for the trap electrodes and experimentally demonstrated trapping of single 24Mg+ ions as well as large ion crystals composed of up to 103 particles using a 400 nm LED. This method can be readily implemented in a variety of applications where simplicity, compactness, and robustness are critical, such as in portable ion frequency standards and commercial ion-based devices, for example. Possible modifications of this technique aimed for selective loading, reduction of induced electric stray fields, and getting rid of atomic oven are also discussed.

Applied Physics Letters•Sep 2, 2019•3 citations

Photoionization and photoelectric loading of barium ion traps

Andrew Steele, Layne Churchill, Paul F. Griffin +1 more

Simple and effective techniques for loading barium ions into linear Paul traps are demonstrated. Two-step photoionization of neutral barium is achieved using a weak intercombination line ($6{s}^{2}\phantom{\rule{0.2em}{0ex}}^{1}S_{0}\ensuremath{\leftrightarrow}6s6p\phantom{\rule{0.2em}{0ex}}^{3}P_{1}$, $\ensuremath{\lambda}=791\phantom{\rule{0.3em}{0ex}}\mathrm{nm}$) followed by excitation above the ionization threshold using a nitrogen gas laser $(\ensuremath{\lambda}=337\phantom{\rule{0.3em}{0ex}}\mathrm{nm})$. Isotopic selectivity is achieved by using a near Doppler-free geometry for excitation of the triplet $6s6p\phantom{\rule{0.2em}{0ex}}^{3}P_{1}$ state. Additionally, we report a particularly simple and efficient trap loading technique that employs an inexpensive uv epoxy curing lamp to generate photoelectrons.

arXiv:quant-ph/0702159•Physical Review A•May 8, 2007•41 citations

Addressing and Cooling of Single Ions in Paul Traps

Hanns‐Christoph Nägerl, Christian F. Roos, H. J. Rohde +4 more

The use of cold trapped ions for quantum information processing requires the preparation of linear strings of ions at low temperatures and the coherent manipulation by laser light of the quantum state of individual ions in the string. In our experiment, 40Ca+ ions are trapped in a linear Paul trap, forming crystallized linear strings when laser cooled. These strings are observed by fluorescence detection on the S1/2-P1/2 dipole transition at 397 nm using a photomultiplier and a CCD camera. The narrow S1/2-D5/2 quadrupole transition at 729 nm is used to investigate and manipulate the vibrational motion of the ion in the trap. The spectral resolution obtained up to now on this transition is 2 · 10—12, proving long coherence time of the two-level system. Addressing of individual ions in the string is achieved, using a tightly focused laser beam at 729 nm, and detected by the observation of quantum jumps from the S1/2 to the D5/2 level. These experimental techniques make ions in a superposition of their S1/2 and D5/2 states suitable as qubits for quantum information processing. The realization of a two-ion quantum gate furthermore requires ground-state cooling of the string. The status of current experiments is reviewed and techniques to achieve ground-state cooling of ion strings are discussed.

Fortschritte der Physik•May 1, 2000•18 citations
We report a demonstration of simple and effective loading of strontium ions into a linear radio frequency Paul trap using photoionization. The ionization pathway is 5s2 1S0 -- 5s5p 1P1 -- 5p2 1D2, and the 5p2 1D2 final state is auto-ionizing. Both transitions are driven using diode lasers: a grating-stabilized 922 nm diode doubled in a single pass through potassium niobate to 461 nm and a bare diode at 405 nm. Using this technique, we have reduced the background pressure during the ion loading process by a factor of 2 compared to the conventional technique of electron bombardment. Initial ion temperatures are low enough that the ions immediately form crystals. It is also possible to observe the trapping region with a CCD camera during ion creation, allowing specific ion number loading with high probability.
We describe a efficient way to photoionize strontium atoms in a linear radio-frequency trap. We use a 2-photon second order process to excite the autoionization resonance (4d2 + 5p2) 1D2. A doubled pulsed Ti:Saphire laser system is used at 431nm to provide 100fsec pulses at 82Mhz. The fabrication of the laser systems for addressing the Sr+ transitions necessary for laser cooling and excitation of quantum jumps, vacuum system and ion trap structure are also described in detail. With the current setup a easy and repeatable trapping of linear ion chains is achieved at UHV pressures.
This paper reports on trapping and laser cooling of singly ionized strontium ions in a linear Paul trap. We describe the loading technique based on two-photon absorption of femtosecond pulses at a wavelength of 431 nm and we compare this technique to electron-bombardment ionization. We perform Doppler cooling of the ions in the few-ions regime as well as in the case of large clouds. The analysis of the fluorescence spectra and direct imaging of the cloud allows us to identify the Coulomb-crystal regime. These experiments open the way to the use of a large cold trapped-ion cloud as a medium for quantum optics and quantum information experiments.
Atomic cadmium ions are loaded into radiofrequency ion traps by photoionization of atoms in a cadmium vapor with ultrafast laser pulses. The photoionization is driven through an intermediate atomic resonance with a frequency-quadrupled mode-locked Ti:sapphire laser that produces pulses of either $100\text{\ensuremath{-}}\mathrm{fs}$ or $1\text{\ensuremath{-}}\mathrm{ps}$ duration at a central wavelength of 229nm229\phantom{\rule{0.3em}{0ex}}\mathrm{nm}229nm. The large bandwidth of the pulses photoionizes all velocity classes of the Cd vapor, resulting in a high loading efficiency compared to previous ion trap loading techniques. Measured loading rates are compared with a simple theoretical model, and we conclude that this technique can potentially ionize every atom traversing the laser beam within the trapping volume. This may allow the operation of ion traps with lower levels of background pressures and less trap electrode surface contamination. The technique and laser system reported here should be applicable to loading most laser-cooled ion species.
We demonstrate a simple nonisotope-selective method for ion trap loading, which is based on the irradiation of trap electrodes precoated with materials with a low work function by a light-emitting diode (LED). Photoelectrons emitted from the electrode surface and accelerated in the trap electric field ionize the atomic beam inside the trap, which results in the trap loading. We studied Y2O3 and Mg coatings for the trap electrodes and experimentally demonstrated trapping of single 24Mg+ ions as well as large ion crystals composed of up to 103 particles using a 400 nm LED. This method can be readily implemented in a variety of applications where simplicity, compactness, and robustness are critical, such as in portable ion frequency standards and commercial ion-based devices, for example. Possible modifications of this technique aimed for selective loading, reduction of induced electric stray fields, and getting rid of atomic oven are also discussed.
Simple and effective techniques for loading barium ions into linear Paul traps are demonstrated. Two-step photoionization of neutral barium is achieved using a weak intercombination line ($6{s}^{2}\phantom{\rule{0.2em}{0ex}}^{1}S_{0}\ensuremath{\leftrightarrow}6s6p\phantom{\rule{0.2em}{0ex}}^{3}P_{1}$, $\ensuremath{\lambda}=791\phantom{\rule{0.3em}{0ex}}\mathrm{nm}$) followed by excitation above the ionization threshold using a nitrogen gas laser $(\ensuremath{\lambda}=337\phantom{\rule{0.3em}{0ex}}\mathrm{nm})$. Isotopic selectivity is achieved by using a near Doppler-free geometry for excitation of the triplet 6s6p3P16s6p\phantom{\rule{0.2em}{0ex}}^{3}P_{1}6s6p3P1​ state. Additionally, we report a particularly simple and efficient trap loading technique that employs an inexpensive uv epoxy curing lamp to generate photoelectrons.
The use of cold trapped ions for quantum information processing requires the preparation of linear strings of ions at low temperatures and the coherent manipulation by laser light of the quantum state of individual ions in the string. In our experiment, 40Ca+ ions are trapped in a linear Paul trap, forming crystallized linear strings when laser cooled. These strings are observed by fluorescence detection on the S1/2-P1/2 dipole transition at 397 nm using a photomultiplier and a CCD camera. The narrow S1/2-D5/2 quadrupole transition at 729 nm is used to investigate and manipulate the vibrational motion of the ion in the trap. The spectral resolution obtained up to now on this transition is 2 · 10—12, proving long coherence time of the two-level system. Addressing of individual ions in the string is achieved, using a tightly focused laser beam at 729 nm, and detected by the observation of quantum jumps from the S1/2 to the D5/2 level. These experimental techniques make ions in a superposition of their S1/2 and D5/2 states suitable as qubits for quantum information processing. The realization of a two-ion quantum gate furthermore requires ground-state cooling of the string. The status of current experiments is reviewed and techniques to achieve ground-state cooling of ion strings are discussed.