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Quantum-state selected cold molecular ions: preparation, properties, spectroscopy and chemistry

English title Quantum-state selected cold molecular ions: preparation, properties, spectroscopy and chemistry
Applicant Willitsch Stefan
Number 118921
Funding scheme SNSF Professorships
Research institution Physikalische Chemie Departement Chemie Universität Basel
Institution of higher education University of Basel - BS
Main discipline Physical Chemistry
Start/End 01.09.2008 - 31.08.2012
Approved amount 1'611'798.00
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Keywords (12)

cold molecules; state-selected molecular ions; Coulomb crystals; high-resolution spectroscopy; cold chemistry; ion traps; laser cooling; photoionisation; dissociative recombination; ion-molecule chemistry; quantum information processing; photoionization

Lay Summary (English)

Lead
Lay summary
The preparation and study of molecular matter at very low temperatures (T<1 K) is a new interdisciplinary field of research at the borderline between chemistry and physics. A particularly interesting variant of cold matter are cold molecular ions in ion traps which form ordered structures known as "Coulomb crystals". Molecular Coulomb crystals exhibit unusual properties: External perturbations are minimized in the cold environment, single ions can be observed, addressed and manipulated and the ordered samples of ions can be stored for hours in the ion trap. These features render molecular Coulomb crystals attractive systems for various novel applications in molecular physics and chemistry such as the study of fine quantum-mechanical details of chemical reactions at low temperatures, ultrahigh-resolution spectroscopy (frequency metrology) and quantum information processing. All of these applications, however, necessitate the generation of cold molecular ions in a well-defined rovibronic quantum state which has not been achieved up to date. In this proposal, a new experimental method is introduced to prepare cold (T<10 mK) quantum-state selected molecular ions in ion traps by combining state-selective threshold photoionization, molecular-beam and ion-cooling techniques. The properties of the cold state-selected ions will be characterized and thermalization mechanisms leading to a redistribution of the internal state populations will be studied. The state-selected molecular Coulomb crystals will be employed in novel experimental schemes to address both, long-standing but also new scientific problems in various areas of physical chemistry: the high-resolution spectroscopy of molecular cations, the measurement of fully state-selected dissociative-recombination cross sections and the study of ion-molecule reactions with fully state-selected reaction partners at ultra-low collision energies.
Direct link to Lay Summary Last update: 21.02.2013

Responsible applicant and co-applicants

Employees

Publications

Publication
Ion-Atom and Ion-Molecule Hybrid Systems: Ion-Neutral Chemistry at Ultra low Energies
Eberle Pascal, Doerfler Alexander D., von Planta Claudio, Ravi Krishnamurthy, Haas Dominik, Zhang Dong, de Meerakker Sebastiaan Y. T. van, Willitsch Stefan (2015), Ion-Atom and Ion-Molecule Hybrid Systems: Ion-Neutral Chemistry at Ultra low Energies, in XXIX INTERNATIONAL CONFERENCE ON PHOTONIC, ELECTRONIC, AND ATOMIC COLLISIONS (ICPEAC2015), PTS 1-12, 635, 012012.
Chemical reactions of conformationally selected 3-aminophenol molecules in a beam with Coulomb-crystallized Ca plus ions
Roesch Daniel, Willitsch Stefan, Chang Yuan-Pin, Kuepper Jochen (2014), Chemical reactions of conformationally selected 3-aminophenol molecules in a beam with Coulomb-crystallized Ca plus ions, in JOURNAL OF CHEMICAL PHYSICS, 140(12), 124202.
Ion-neutral chemistry at ultralow energies: dynamics of reactive collisions between laser-cooled Ca+ ions and Rb atoms in an ion-atom hybrid trap
Hall Felix H. J., Eberle Pascal, Hegi Gregor, Raoult Maurice, Aymar Mireille, Dulieu Olivier, Willitsch Stefan (2013), Ion-neutral chemistry at ultralow energies: dynamics of reactive collisions between laser-cooled Ca+ ions and Rb atoms in an ion-atom hybrid trap, in MOLECULAR PHYSICS, 111(14-15), 2020-2032.
Light-assisted cold chemical reactions of barium ions with rubidium atoms
Hall Felix H. J., Aymar Mireille, Raoult Maurice, Dulieu Olivier, Willitsch Stefan (2013), Light-assisted cold chemical reactions of barium ions with rubidium atoms, in MOLECULAR PHYSICS, 111(12-13), 1683-1690.
Specific Chemical Reactivities of Spatially Separated 3-Aminophenol Conformers with Cold Ca+ Ions
Chang Yuan-Pin, Dlugolecki Karol, Kuepper Jochen, Roesch Daniel, Wild Dieter, Willitsch Stefan (2013), Specific Chemical Reactivities of Spatially Separated 3-Aminophenol Conformers with Cold Ca+ Ions, in SCIENCE, 342(6154), 98-101.
Coulomb-crystallised molecular ions in traps: methods, applications, prospects
Willitsch S (2012), Coulomb-crystallised molecular ions in traps: methods, applications, prospects, in INTERNATIONAL REVIEWS IN PHYSICAL CHEMISTRY, 31(2), 175-199.
State-selected ion-molecule reactions with Coulomb-crystallized molecular ions in traps
Tong Xin, Nagy Tibor, Yosa Reyes Juvenal, Germann Matthias, Meuwly Markus, Willitsch Stefan (2012), State-selected ion-molecule reactions with Coulomb-crystallized molecular ions in traps, in Chem. Phys. Lett., 547, 1-7.
Temperature-independent quantum logic for molecular spectroscopy
Mur-Petit J, Garcia-Ripoll JJ, Perez-Rios J, Campos-Martinez J, Hernandez MI, Willitsch S (2012), Temperature-independent quantum logic for molecular spectroscopy, in PHYSICAL REVIEW A, 85(2), 022308-1-022308-8.
Collisional and radiative effects in the state-selective preparation of translationally cold molecular ions in ion traps
Tong X, Wild D, Willitsch S (2011), Collisional and radiative effects in the state-selective preparation of translationally cold molecular ions in ion traps, in PHYSICAL REVIEW A, 83(2), 023415-1-023415-10.
Experimental Methods in Cation Spectroscopy
Stefan Willitsch (2011), Experimental Methods in Cation Spectroscopy, in Martin Quack and Frederic Merkt (ed.), John Wiley & Sons, Ltd., Chichester, 1691-1712.
High-resolution Photoelectron Spectroscopy
Frederic Merkt Stefan Willitsch and Urs Hollenstein (2011), High-resolution Photoelectron Spectroscopy, in Martin Quack and Frederic Merkt (ed.), John Wiley & Sons, Ltd., Chichester, 1617-1654.
Light-Assisted Ion-Neutral Reactive Processes in the Cold Regime: Radiative Molecule Formation versus Charge Exchange
Hall FHJ, Aymar M, Bouloufa-Maafa N, Dulieu O, Willitsch S (2011), Light-Assisted Ion-Neutral Reactive Processes in the Cold Regime: Radiative Molecule Formation versus Charge Exchange, in PHYSICAL REVIEW LETTERS, 107(24), 243202-1-243202-5.
Physics and Chemistry of Cold Molecules
Dulieu O, Krems R, Weidemuller M, Willitsch S (2011), Physics and Chemistry of Cold Molecules, in PHYSICAL CHEMISTRY CHEMICAL PHYSICS, 13(42), 18703-18704.
Close to Zero
Willitsch S (2010), Close to Zero, in NACHRICHTEN AUS DER CHEMIE, 58(9), 872-875.
MOLECULAR PHYSICS Very cool molecular ions
Willitsch S (2010), MOLECULAR PHYSICS Very cool molecular ions, in NATURE PHYSICS, 6(4), 240-241.
Spectroscopy and Chemical Dynamics
Maier JP, Willitsch S (2010), Spectroscopy and Chemical Dynamics, in CHIMIA, 64(12), 855-858.
Sympathetic Cooling of Molecular Ions in Selected Rotational and Vibrational States Produced by Threshold Photoionization
Tong X, Winney AH, Willitsch S (2010), Sympathetic Cooling of Molecular Ions in Selected Rotational and Vibrational States Produced by Threshold Photoionization, in PHYSICAL REVIEW LETTERS, 105(14), 143001-1-143001-4.
Ion-molecule chemistry at very low temperatures: cold chemical reactions between Coulomb-crystallized ions and velocity-selected neutral molecules
Bell MT, Gingell AD, Oldham JM, Softley TP, Willitsch S (2009), Ion-molecule chemistry at very low temperatures: cold chemical reactions between Coulomb-crystallized ions and velocity-selected neutral molecules, in FARADAY DISCUSSIONS, 142, 73-91.
Molecules and Ions at Very Low Temperatures
Willitsch S (2009), Molecules and Ions at Very Low Temperatures, in CHIMIA, 63(1-2), 54-57.
Chemical applications of laser- and sympathetically-cooled ions in ion traps
Willitsch S, Bell MT, Gingell AD, Softley TP (2008), Chemical applications of laser- and sympathetically-cooled ions in ion traps, in PHYSICAL CHEMISTRY CHEMICAL PHYSICS, 10(48), 7200-7210.
Theoretical characterization of laser- and sympathetically-cooled ions in surface-electrode ion traps
I. M. Georgescu and S. Willitsch, Theoretical characterization of laser- and sympathetically-cooled ions in surface-electrode ion traps, in Phys. Chem. Chem. Phys..

Collaboration

Group / person Country
Types of collaboration
Laboratoire Aime-Cotton du CNRS, Paris France (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
Universität Hamburg Germany (Europe)
- in-depth/constructive exchanges on approaches, methods or results
CSIC Spain (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Publication

Scientific events

Active participation

Title Type of contribution Title of article or contribution Date Place Persons involved
19. European Conference on Dynamics of Molecular Systems (MOLEC) Talk given at a conference Cold and Controlled Chemistry with Coulomb-crystallised molecular ions in traps 09.09.2012 Oxford, UK, Great Britain and Northern Ireland Willitsch Stefan;
Quantum Science and Technology Poster Quantum control of cold molecular ions 18.06.2012 Monte Verita, CH, Switzerland Willitsch Stefan;
Chemical Sensing and Quantum Manipulation with Molecular Ions Workshop Talk given at a conference Quantum control and cold reactive collisions of laser- and sympathetically-cooled ions in traps 04.03.2012 Atlanta, USA, United States of America Willitsch Stefan;
12. Symposium on Atomic, Surface and Cluster Physics (SASP) Talk given at a conference Ion-neutral reactive collisions at sub-Kelvin temperatures 22.01.2012 Alpes d’Huez, F, France Willitsch Stefan;
Workshop on Coherence and Control at Ultracold Temperatures Poster Ion-neutral hybrid traps 06.09.2011 TU München, Germany Willitsch Stefan;
2. International Meeting on Atomic and Molecular Physics and Chemistry Talk given at a conference Cold molecular ions in traps: quantum-state control and chemistry 02.07.2011 Rennes, France, France Willitsch Stefan;
43. Conference of the European Group on Atomic Systems (EGAS) Poster Quantum state preparation of cold molecular ions 28.06.2011 Fribourg, CH, Switzerland Willitsch Stefan;
COST-IOTA Kick-Off Meeting Talk given at a conference Quantum-state-controlled cold molecular ions 23.03.2011 Heidelberg, Germany, Germany Willitsch Stefan;
Gordon Research Conference on Gaseous Ions Talk given at a conference Ion-neutral collision and reaction studies with state-selected, coulomb- crystallized ions in traps 27.02.2011 Galveston, USA, United States of America Willitsch Stefan;
Workshop on ”Cold and Controlled Molecular Collisions” Talk given at a conference Collisional Processes with laser- and sympathetically-cooled ions in ion traps”, Workshop on ”Cold and Controlled Molecular Collisions 02.02.2011 Schloss Ringerberg, Germany, Germany Willitsch Stefan;
NCCR QSIT kick-off meeting Talk given at a conference Quantum-state controlled, translationally cold molecular ions in ion trap: preparation and applica- tions 12.01.2011 Arosa, Switzerland, Switzerland Willitsch Stefan;
Annual Meeting of the RSC Spectroscopy and Dynamics Group Poster Quantum state preparation of cold molecular ions 05.01.2011 Edinburgh, UK, Great Britain and Northern Ireland Willitsch Stefan;
1. European Conference on Trapped Ions (ECTI) Talk given at a conference Quantum state controlled cold moelcular ions 20.09.2010 County Durham, UK, Great Britain and Northern Ireland Tong Xin;
nstitute of Physics, Division of Quantum Atomic, Molecular, and Plasma Physics (QuAMP) Summer School Talk given at a conference Generation, properties and applications of translationally cold ions in ion traps 30.08.2010 Imperial College London, UK, Great Britain and Northern Ireland Willitsch Stefan;
Workshop on Ion Traps and Guides Talk given at a conference Towards ultracold, state-selected ion-molecule chemistry using Coulomb-crystallised ions 23.07.2010 Telluride, USA, United States of America Willitsch Stefan;
10. European Conference on Atoms, Molecules and Photons (ECAMP) Poster Cold ion-neutral chemistry 05.07.2010 Salamanca, Spain, Spain Willitsch Stefan;
Annual Meeting of the Swiss Physical Society Poster Ion-neutral hybrid traps 21.06.2010 Basel, CH, Switzerland Hall Felix Henry Joynson;
Faraday Symposium of the Royal Society of Chemistry Talk given at a conference Internal and chemical dynamics of molecular ions: from high-resolution threshold-ionisation stud- ies to low-temperature reactive-collision experiments 27.03.2010 Oxford, UK, Great Britain and Northern Ireland Willitsch Stefan;
21. Colloquium on High-Resolution Molecular Spectroscopy (HRMS), Talk given at a conference Chemical reactions with translationally cold ions in ion traps 31.08.2009 Castellamare di Stabia, Italy, Italy Willitsch Stefan;
41. Conference of the European Group on Atomic Systems (EGAS), Talk given at a conference Chemical applications of laser- and sympathetically-cooled ions in ion traps 08.07.2009 Gdansk, Poland, Poland Willitsch Stefan;
Gordon Research Conference on Gaseous Ions Poster Cold ion-molecule reactions 01.03.2009 Galveston, USA, United States of America Willitsch Stefan;
Winter school ”Nanoscience in the Snow” Talk given at a conference Properties and applications of ion Coulomb crystals 14.01.2009 Jungfraujoch, CH, Switzerland Willitsch Stefan;
Latsis Symposium ”Intramolecular Dynamics, Symmetry and Spectroscopy” Poster Cold ion-molecule reactions 06.09.2008 Zurich, CH, Switzerland Willitsch Stefan;


Self-organised

Title Date Place
Faraday Discussion 150: Frontiers in Specrtoscopy 06.04.2011 Basel, Switzerland, Switzerland

Communication with the public

Communication Title Media Place Year
Talks/events/exhibitions Fest der Moleküle Western Switzerland 2011
Talks/events/exhibitions Markt und Fest des Wissens: 550 Jahre Universität Basel Western Switzerland 2010

Awards

Title Year
Ruzicka-Preis 2010
Marlow Medal and Prize 2009

Associated projects

Number Title Start Funding scheme
140834 Ion-neutral chemistry in the sub-Kelvin regime 01.09.2012 SNSF Professorships

Abstract

The preparation and study of molecular matter at very low temperatures (T<1 K) is a new interdisciplinary field of research at the borderline between chemistry and physics. A particularly interesting variant of cold matter are cold molecular ions in ion traps which form ordered structures known as Coulomb crystals. Molecular Coulomb crystals exhibit unusual properties: External perturbations are minimised in the cold environment, single ions can be observed, addressed and manipulated and the crystalline structures can be stored for hours in the ion trap. These features render molecular Coulomb crystals attractive systems for various novel applications in molecular physics and chemistry such as the study of fine quantum-mechanical details of chemical reactions at low temperatures, ultrahigh-resolution spectroscopy (frequency metrology) and quantum information processing. All of these applications, however, necessitate the generation of cold molecular ions in a well-defined rovibronic quantum state which has not been achieved up to date. In this proposal, a new experimental method is introduced to prepare cold (T<10 mK) quantum-state selected molecular ions in ion traps by combining state-selective threshold photoionisation, molecular-beam and ion-cooling techniques. The properties of the cold state-selected ions will be characterised and thermalisation mechanisms leading to a redistribution of the internal state populations will be studied. The state-selected molecular Coulomb crystals will be employed in novel experimental schemes to address both, long-standing but also new scientific problems in various areas of physical chemistry: the high-resolution spectroscopy of molecular cations, the measurement of fully state-selected dissociative-recombination cross sections and the study of ion-molecule reactions with fully state-selected reaction partners at ultra-low collision energies.
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