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:physics/0406088 · Physical Review Letters

Nondestructive Identification of Cold and Extremely Localized Single Molecular Ions

Michael Drewsen, A. Mortensen, R. Martinussen, Peter Frøhlich Staanum, Jens Lykke Sørensen

Published Dec 8, 2004• 137 citations
arXivHTMLPDF

Abstract

We demonstrate a simple and nondestructive method for identification of a single molecular ion sympathetically cooled by a single laser cooled atomic ion in a linear Paul trap. The technique is based on a precise nondestructive determination of the molecular ion mass through a measurement of the eigenfrequency of a common motional mode of the two ions. The demonstrated mass resolution is sufficiently high that molecular ion mass doublets can potentially be distinguished from each other. The obtained results represent an important step towards single molecule gas phase chemical physics.

DOI
10.1103/physrevlett.93.243201

Related papers

Experiments with single cold molecular ions

Klaus Højbjerre, Peter Frøhlich Staanum, David Offenberg +3 more

In this paper we present ongoing work on single cold molecular ion experiments in a linear Paul trap. In particular, we discuss the properties and prospects of using a non‐destructive identification technique. Measuring the resonance frequency of a common motional mode of a laser cooled atomic ion and a molecular ion the harmonic trap potential, the mass of the latter can be determined. We report recent results using this technique for the cases of 40Ca18O+ and C3H3+.

AIP conference proceedings•Jan 1, 2006•1 citation

Motional resonance coupling in cold multispecies Coulomb crystals

Bernhard Roth, P. Blythe, Stephan Schiller

We investigate the coupling between motional resonances of translationally cold ($10\phantom{\rule{0.3em}{0ex}}\mathrm{mK}$ range) atomic and molecular ions in multispecies Coulomb crystals, stored in a linear Paul trap. The atomic and molecular ions were sympathetically cooled by laser-cooled ${\mathrm{Be}}^{+}$ ions. The motional resonances of the different ion species were determined nondestructively with high mass-to-charge resolution upon excitation with an oscillating electric field. The experimental results show good agreement with results from molecular dynamics simulations and allow for a precise identification of sympathetically cooled particles in multispecies ion crystals.

Physical Review A•Feb 1, 2007•50 citations

Cooling and Mass-Analysis of Molecules Using Laser-Cooled Atoms

Takashi Baba, Izumi Waki

This paper presents the first sympathetic cooling of molecular ions using laser-cooled atomic ions. To this end, we developed a novel combination of sympathetic cooling and in situ mass spectroscopy that allows the use of laser-cooled atomic ions to detect sympathetically-cooled molecular ions non-destructively. We demonstrate this technique by cooling and mass-analysing ions of ultra-high-vacuum residual gas and externally introduced air in situ with less than 80 ions each, confined in a radio-frequency quadrupole (RFQ). This capability to detect and identify sympathetically-cooled molecules with potentially-high sensitivity in situ in an RFQ should be useful for molecular spectroscopy, chemical analysis and study of cold molecules and clusters.

Japanese Journal of Applied Physics•Sep 1, 1996•83 citations

Molecular-dynamics simulations of cold single-species and multispecies ion ensembles in a linear Paul trap

C. B. Zhang, David Offenberg, Bernhard Roth +2 more

The properties of cold ion plasmas with large numbers $(>200)$ of laser- and sympathetically cooled species are modeled in detail using molecular dynamics simulations. We describe how to extract temperatures and ion numbers from CCD images. The identification of the ion species by excitation of their oscillation modes is discussed. The sympathetic cooling efficiency, effects of the rf micromotion and of collision heating by a neutral background gas are analyzed, in part experimentally.

Physical Review A•Jul 30, 2007•105 citations

An ion trap time-of-flight mass spectrometer with high mass resolution for cold trapped ion experiments

Philipp Christoph Schmid, J. M. Greenberg, Mikhail I. Miller +2 more

Trapping molecular ions that have been sympathetically cooled with laser-cooled atomic ions is a useful platform for exploring cold ion chemistry. We designed and characterized a new experimental apparatus for probing chemical reaction dynamics between molecular cations and neutral radicals at temperatures below 1 K. The ions are trapped in a linear quadrupole radio-frequency trap and sympathetically cooled by co-trapped, laser-cooled, atomic ions. The ion trap is coupled to a time-of-flight mass spectrometer to readily identify product ion species and to accurately determine trapped ion numbers. We discuss, and present in detail, the design of this ion trap time-of-flight mass spectrometer and the electronics required for driving the trap and mass spectrometer. Furthermore, we measure the performance of this system, which yields mass resolutions of m/Δm ≥ 1100 over a wide mass range, and discuss its relevance for future measurements in chemical reaction kinetics and dynamics.

arXiv:1707.07036•Review of Scientific Instruments•Dec 1, 2017•48 citations

Experimental techniques for cold chemistry and molecular spectroscopy in an ion trap

Kevin Sheridan

A range of experimental techniques for application in reaction studies between ionic and neutral atoms/molecules and high resolution spectroscopy experiments with sympathetically cooled molecular ions are presented. A novel ion trap loading scheme using the photo-ionisation of atoms generated by the pulsed laser ablation of a solid calcium target has been characterised. We have identified the range of ablation laser fluences that must be used in order to produce a flux of neutral calcium atoms, which is a prerequisite for isotope selective ion trap loading. Calcium ions are trapped and laser cooled in a linear radio-frequency ion trap. We have developed a spectroscopy scheme that allows the entire fluorescence spectrum of trapped ions to be rapidly collected with high precision while maintaining a low ion temperature and good ion localisation throughout interrogation. The scheme has been demonstrated by measuring the saturation intensity of the calcium ion 4S1/2?4P1/2 transition. We have developed a novel scheme to measure the secular motion of trapped ions and demonstrated the application of the technique to ion-neutral collision reaction experiments. Employing pulsed excitation and Doppler velocimetry, we have measured the centre-of-mass mode frequency of single ions as well as large ion crystals with a frequency precision better than 2x10-3 within an interrogation time on the order of seconds. This method has been used to measure the mass of ions and observe charge exchange collisions between trapped calcium isotopes. In particular, we have measured the 44Ca++40Ca!40Ca++44Ca reaction cross section and demonstrated the single-event resolution of the technique. Finally, we have developed a novel all-optical broadband scheme for exciting, amplifying and measuring the secular motion of ions in the trap. Oscillation induced by optical excitation has been coherently amplified to control and measure the ion's secular motion. Requiring only a single interrogation laser, the ion's oscillation amplitude can be precisely controlled. The application of this technique to non-destructive spectroscopy of trapped molecular ions is discussed.

•Oct 3, 2013•0 citations
We demonstrate a simple and nondestructive method for identification of a single molecular ion sympathetically cooled by a single laser cooled atomic ion in a linear Paul trap. The technique is based on a precise nondestructive determination of the molecular ion mass through a measurement of the eigenfrequency of a common motional mode of the two ions. The demonstrated mass resolution is sufficiently high that molecular ion mass doublets can potentially be distinguished from each other. The obtained results represent an important step towards single molecule gas phase chemical physics.
We investigate the coupling between motional resonances of translationally cold (10mK10\phantom{\rule{0.3em}{0ex}}\mathrm{mK}10mK range) atomic and molecular ions in multispecies Coulomb crystals, stored in a linear Paul trap. The atomic and molecular ions were sympathetically cooled by laser-cooled Be+{\mathrm{Be}}^{+}Be+ ions. The motional resonances of the different ion species were determined nondestructively with high mass-to-charge resolution upon excitation with an oscillating electric field. The experimental results show good agreement with results from molecular dynamics simulations and allow for a precise identification of sympathetically cooled particles in multispecies ion crystals.
This paper presents the first sympathetic cooling of molecular ions using laser-cooled atomic ions. To this end, we developed a novel combination of sympathetic cooling and in situ mass spectroscopy that allows the use of laser-cooled atomic ions to detect sympathetically-cooled molecular ions non-destructively. We demonstrate this technique by cooling and mass-analysing ions of ultra-high-vacuum residual gas and externally introduced air in situ with less than 80 ions each, confined in a radio-frequency quadrupole (RFQ). This capability to detect and identify sympathetically-cooled molecules with potentially-high sensitivity in situ in an RFQ should be useful for molecular spectroscopy, chemical analysis and study of cold molecules and clusters.
The properties of cold ion plasmas with large numbers (>200)(>200)(>200) of laser- and sympathetically cooled species are modeled in detail using molecular dynamics simulations. We describe how to extract temperatures and ion numbers from CCD images. The identification of the ion species by excitation of their oscillation modes is discussed. The sympathetic cooling efficiency, effects of the rf micromotion and of collision heating by a neutral background gas are analyzed, in part experimentally.
Trapping molecular ions that have been sympathetically cooled with laser-cooled atomic ions is a useful platform for exploring cold ion chemistry. We designed and characterized a new experimental apparatus for probing chemical reaction dynamics between molecular cations and neutral radicals at temperatures below 1 K. The ions are trapped in a linear quadrupole radio-frequency trap and sympathetically cooled by co-trapped, laser-cooled, atomic ions. The ion trap is coupled to a time-of-flight mass spectrometer to readily identify product ion species and to accurately determine trapped ion numbers. We discuss, and present in detail, the design of this ion trap time-of-flight mass spectrometer and the electronics required for driving the trap and mass spectrometer. Furthermore, we measure the performance of this system, which yields mass resolutions of m/Δm ≥ 1100 over a wide mass range, and discuss its relevance for future measurements in chemical reaction kinetics and dynamics.
A range of experimental techniques for application in reaction studies between ionic and neutral atoms/molecules and high resolution spectroscopy experiments with sympathetically cooled molecular ions are presented. A novel ion trap loading scheme using the photo-ionisation of atoms generated by the pulsed laser ablation of a solid calcium target has been characterised. We have identified the range of ablation laser fluences that must be used in order to produce a flux of neutral calcium atoms, which is a prerequisite for isotope selective ion trap loading. Calcium ions are trapped and laser cooled in a linear radio-frequency ion trap. We have developed a spectroscopy scheme that allows the entire fluorescence spectrum of trapped ions to be rapidly collected with high precision while maintaining a low ion temperature and good ion localisation throughout interrogation. The scheme has been demonstrated by measuring the saturation intensity of the calcium ion 4S1/2?4P1/2 transition. We have developed a novel scheme to measure the secular motion of trapped ions and demonstrated the application of the technique to ion-neutral collision reaction experiments. Employing pulsed excitation and Doppler velocimetry, we have measured the centre-of-mass mode frequency of single ions as well as large ion crystals with a frequency precision better than 2x10-3 within an interrogation time on the order of seconds. This method has been used to measure the mass of ions and observe charge exchange collisions between trapped calcium isotopes. In particular, we have measured the 44Ca++40Ca!40Ca++44Ca reaction cross section and demonstrated the single-event resolution of the technique. Finally, we have developed a novel all-optical broadband scheme for exciting, amplifying and measuring the secular motion of ions in the trap. Oscillation induced by optical excitation has been coherently amplified to control and measure the ion's secular motion. Requiring only a single interrogation laser, the ion's oscillation amplitude can be precisely controlled. The application of this technique to non-destructive spectroscopy of trapped molecular ions is discussed.