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:2308.03935 · Physical Review Letters

Trapping and Sympathetic Cooling of Conformationally Selected Molecular Ions

Lei Xu, Jutta Toscano, Stefan Willitsch

Published Feb 21, 2024• 9 citations
arXivHTMLPDF

Abstract

We report the generation, trapping, and sympathetic cooling of individual conformers of molecular ions with the example of cis- and trans- meta-aminostyrene. Following conformationally selective photoionization, the incorporation of the conformers into a Coulomb crystal of laser-cooled calcium ions was confirmed by fluorescence imaging, mass spectrometry, and molecular dynamics simulations. We deduce the molecules to be stable in the trap environment for more than ten minutes. The present results pave the way for the spectroscopy and controlled chemistry of distinct ionic conformers in traps.

DOI
10.1103/physrevlett.132.083001

Related papers

Sympathetic cooling of rovibrationally state-selected molecular ions

Tong, Xin, Alexander H. Winney, Stefan Willitsch

We present a new method for the generation of rotationally and vibrationally state-selected, translationally cold molecular ions in ion traps. Our technique is based on the state-selective threshold photoionization of neutral molecules followed by sympathetic cooling of the resulting ions with laser-cooled calcium ions. Using N$_2^+$ ions as a test system, we achieve > 90 % selectivity in the preparation of the ground rovibrational level and state lifetimes on the order of 15 minutes limited by collisions with background-gas molecules. The technique can be employed to produce a wide range of apolar and polar molecular ions in the ground and excited rovibrational states. Our approach opens up new perspectives for cold quantum-controlled ion-molecule-collision studies, frequency-metrology experiments with state-selected molecular ions and molecular-ion qubits.

arXiv:1006.5642•Jun 29, 2010•0 citations

Sympathetic cooling of molecular ions in a surface-electrode ion trap

Arezoo Mokhberi, Stefan Willitsch

We report the sympathetic cooling and Coulomb crystallization of molecular ions above the surface of an ion-trap chip. ${\mathrm{N}}_{2}^{+}$ and ${\mathrm{CaH}}^{+}$ ions were confined in a surface-electrode radio-frequency (rf) ion trap and cooled by the interaction with laser-cooled ${\mathrm{Ca}}^{+}$ ions to secular translational temperatures in the millikelvin range. The configuration of trapping potentials generated by the surface electrodes enabled the formation of planar bicomponent Coulomb crystals and the spatial separation of the molecular from the atomic ions on the chip. The structural and thermal properties of the Coulomb crystals were characterized using molecular dynamics simulations. The present study extends chip-based trapping techniques to cold molecular ions with potential applications in mass spectrometry, chemistry, quantum information science, and spectroscopy.

arXiv:1404.4292•Physical Review A•Aug 4, 2014•10 citations

Sympathetic Cooling of Molecular Ions in Selected Rotational and Vibrational States Produced by Threshold Photoionization

Xin Tong, Alexander H. Winney, Stefan Willitsch

We present a new method for the generation of rotationally and vibrationally state-selected, translationally cold molecular ions in ion traps. Our technique is based on the state-selective threshold photoionization of neutral molecules followed by sympathetic cooling of the resulting ions with laser-cooled calcium ions. Using N₂(+) ions as a test system, we achieve >90% selectivity in the preparation of the ground rovibrational level and state lifetimes on the order of 15 minutes limited by collisions with background-gas molecules. The technique can be employed to produce a wide range of apolar and polar molecular ions in the ground and excited rovibrational states. Our approach opens up new perspectives for cold quantum-controlled ion-molecule-collision studies, frequency-metrology experiments with state-selected molecular ions and molecular-ion qubits.

Physical Review Letters•Sep 27, 2010•137 citations

Chemical applications of laser- and sympathetically-cooled ions in ion traps

Stefan Willitsch, Martin T. Bell, Alexander D. Gingell +1 more

Ensembles of cold atomic and molecular ions in ion traps prepared at millikelvin temperatures by laser and sympathetic cooling have recently found considerable interest in both physics and chemistry. At very low temperatures the ions form ordered structures in the trap also known as "Coulomb crystals". Ion Coulomb crystals exhibit a range of intriguing properties which render them attractive systems for novel experiments in chemical dynamics, ultrahigh-resolution spectroscopy and quantum-information processing. In this article we review the methods used to prepare atomic and molecular ion Coulomb crystals and discuss some recent studies in mass spectrometry, low-temperature chemistry and precision spectroscopy to illustrate their scientific potential for chemical applications. Finally, we conclude with an outlook on outstanding challenges and prospective further developments in the field.

Physical Chemistry Chemical Physics•Jan 1, 2008•146 citations

Coulomb-crystallised molecular ions in traps: methods, applications, prospects

Stefan Willitsch

Translationally cold, spatially localised molecular ions prepared by sympathetic cooling with laser-cooled atomic ions in ion traps have recently found a wide range of applications in both chemistry and physics. The very low temperatures of the ions (down to millikelvins), their tight localisation in the trap and the ability to control and manipulate single isolated molecules on the quantum level offer intriguing possibilities for new experiments in the realms of cold chemistry, precision molecular spectroscopy, mass spectrometry and quantum technology. The present article gives an overview of the basic experimental methods, current topics and recent developments in this field.

International Reviews in Physical Chemistry•Mar 27, 2012•127 citations

Scalable microchip ion traps and guides for cold molecular ions

Arezoo Mokhberi

Sympathetic cooling and Coulomb crystallisation of molecular ions above the \nsurface of an ion-trap chip were demonstrated. N2+ and CaH+ ions were confined \nin a surface-electrode radiofrequency ion trap and cooled by the interaction \nwith laser-cooled Ca+ ions to secular translational temperatures in the \nmilliKelvin range. The configuration of trapping potentials generated by the surface \nelectrodes enabled the formation of planar bicomponent Coulomb crystals \nand the spatial separation of the molecular from the atomic ions. The structural \nand thermal properties of the crystals were characterized using molecular \ndynamics simulations. The effects of trap anharmoncities on the shape and \nenergy of bicomponent crystals were theoretically investigated. It was shown \nthat the trapping potentials can also deliberately be engineered to spatially \nseparate ion species in bicomponent crystals. Furthermore, a multi-functional \nsurface-electrode radiofrequency ion-trap chip has been developed to enable experiments \nwith cold molecular ions using a monolithic device. The chip was \ndesigned to combine various tasks such as loading and preparation of ions, mass \nspectrometry, spectroscopy, reaction studies, and manipulation of ion crystals \nin a miniaturised device. This chip features carefully engineered ion channel \nintersections that enable transporting sympathetically cooled molecular ions in \nthe form of bicomponent crystals. A detailed description of the fabrication and \nsimulation of the two chips are presented. The present study extends chipbased \ntrapping techniques to Coulomb-crystallised molecular ions with potential \napplications in mass spectrometry, cold chemistry, quantum technology, and \nspectroscopy.

•Jan 1, 2016•1 citation
We report the generation, trapping, and sympathetic cooling of individual conformers of molecular ions with the example of cis- and trans- meta-aminostyrene. Following conformationally selective photoionization, the incorporation of the conformers into a Coulomb crystal of laser-cooled calcium ions was confirmed by fluorescence imaging, mass spectrometry, and molecular dynamics simulations. We deduce the molecules to be stable in the trap environment for more than ten minutes. The present results pave the way for the spectroscopy and controlled chemistry of distinct ionic conformers in traps.
We present a new method for the generation of rotationally and vibrationally state-selected, translationally cold molecular ions in ion traps. Our technique is based on the state-selective threshold photoionization of neutral molecules followed by sympathetic cooling of the resulting ions with laser-cooled calcium ions. Using N2+_2^+2+​ ions as a test system, we achieve > 90 % selectivity in the preparation of the ground rovibrational level and state lifetimes on the order of 15 minutes limited by collisions with background-gas molecules. The technique can be employed to produce a wide range of apolar and polar molecular ions in the ground and excited rovibrational states. Our approach opens up new perspectives for cold quantum-controlled ion-molecule-collision studies, frequency-metrology experiments with state-selected molecular ions and molecular-ion qubits.
We report the sympathetic cooling and Coulomb crystallization of molecular ions above the surface of an ion-trap chip. N2+{\mathrm{N}}_{2}^{+}N2+​ and CaH+{\mathrm{CaH}}^{+}CaH+ ions were confined in a surface-electrode radio-frequency (rf) ion trap and cooled by the interaction with laser-cooled Ca+{\mathrm{Ca}}^{+}Ca+ ions to secular translational temperatures in the millikelvin range. The configuration of trapping potentials generated by the surface electrodes enabled the formation of planar bicomponent Coulomb crystals and the spatial separation of the molecular from the atomic ions on the chip. The structural and thermal properties of the Coulomb crystals were characterized using molecular dynamics simulations. The present study extends chip-based trapping techniques to cold molecular ions with potential applications in mass spectrometry, chemistry, quantum information science, and spectroscopy.
We present a new method for the generation of rotationally and vibrationally state-selected, translationally cold molecular ions in ion traps. Our technique is based on the state-selective threshold photoionization of neutral molecules followed by sympathetic cooling of the resulting ions with laser-cooled calcium ions. Using N₂(+) ions as a test system, we achieve >90% selectivity in the preparation of the ground rovibrational level and state lifetimes on the order of 15 minutes limited by collisions with background-gas molecules. The technique can be employed to produce a wide range of apolar and polar molecular ions in the ground and excited rovibrational states. Our approach opens up new perspectives for cold quantum-controlled ion-molecule-collision studies, frequency-metrology experiments with state-selected molecular ions and molecular-ion qubits.
Ensembles of cold atomic and molecular ions in ion traps prepared at millikelvin temperatures by laser and sympathetic cooling have recently found considerable interest in both physics and chemistry. At very low temperatures the ions form ordered structures in the trap also known as "Coulomb crystals". Ion Coulomb crystals exhibit a range of intriguing properties which render them attractive systems for novel experiments in chemical dynamics, ultrahigh-resolution spectroscopy and quantum-information processing. In this article we review the methods used to prepare atomic and molecular ion Coulomb crystals and discuss some recent studies in mass spectrometry, low-temperature chemistry and precision spectroscopy to illustrate their scientific potential for chemical applications. Finally, we conclude with an outlook on outstanding challenges and prospective further developments in the field.
Translationally cold, spatially localised molecular ions prepared by sympathetic cooling with laser-cooled atomic ions in ion traps have recently found a wide range of applications in both chemistry and physics. The very low temperatures of the ions (down to millikelvins), their tight localisation in the trap and the ability to control and manipulate single isolated molecules on the quantum level offer intriguing possibilities for new experiments in the realms of cold chemistry, precision molecular spectroscopy, mass spectrometry and quantum technology. The present article gives an overview of the basic experimental methods, current topics and recent developments in this field.
Sympathetic cooling and Coulomb crystallisation of molecular ions above the \nsurface of an ion-trap chip were demonstrated. N2+ and CaH+ ions were confined \nin a surface-electrode radiofrequency ion trap and cooled by the interaction \nwith laser-cooled Ca+ ions to secular translational temperatures in the \nmilliKelvin range. The configuration of trapping potentials generated by the surface \nelectrodes enabled the formation of planar bicomponent Coulomb crystals \nand the spatial separation of the molecular from the atomic ions. The structural \nand thermal properties of the crystals were characterized using molecular \ndynamics simulations. The effects of trap anharmoncities on the shape and \nenergy of bicomponent crystals were theoretically investigated. It was shown \nthat the trapping potentials can also deliberately be engineered to spatially \nseparate ion species in bicomponent crystals. Furthermore, a multi-functional \nsurface-electrode radiofrequency ion-trap chip has been developed to enable experiments \nwith cold molecular ions using a monolithic device. The chip was \ndesigned to combine various tasks such as loading and preparation of ions, mass \nspectrometry, spectroscopy, reaction studies, and manipulation of ion crystals \nin a miniaturised device. This chip features carefully engineered ion channel \nintersections that enable transporting sympathetically cooled molecular ions in \nthe form of bicomponent crystals. A detailed description of the fabrication and \nsimulation of the two chips are presented. The present study extends chipbased \ntrapping techniques to Coulomb-crystallised molecular ions with potential \napplications in mass spectrometry, cold chemistry, quantum technology, and \nspectroscopy.