1
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Le TD. Exploring secular variation of the gravitational constant from high-resolution quasar spectra. Sci Rep 2024; 14:15610. [PMID: 38971828 PMCID: PMC11227554 DOI: 10.1038/s41598-024-65484-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2024] [Accepted: 06/20/2024] [Indexed: 07/08/2024] Open
Abstract
The exploration of potential variations in fundamental physical constants is crucial for testing of Grand Unification Theories (GUTs), which aim to unify the fundamental forces of nature. This study utilizes direct observational tests to explore these variations, offering a deep-look into the universe's distant past. By analyzing high-resolution quasar spectra of HE 0515-4414* and comparing them with laboratory-calibrated Ritz wavelengths, we establish an upper limit on the possible cosmological deviation of the gravitational constant:G ˙ / G = ( 0.918 ± 2.830 ) × 10 - 15 yr - 1 over cosmic timescales. Our findings provide a novel tool for probing the physical implications of GUTs, contributing to our understanding of fundamental physics.
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Affiliation(s)
- T D Le
- Division of Applied Physics, Dong Nai Technology University, Bien Hoa City, Vietnam.
- Faculty of Engineering, Dong Nai Technology University, Bien Hoa City, Vietnam.
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2
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Zhang C, Rittenhouse ST, Tscherbul TV, Sadeghpour HR, Hutzler NR. Sympathetic Cooling and Slowing of Molecules with Rydberg Atoms. PHYSICAL REVIEW LETTERS 2024; 132:033001. [PMID: 38307061 DOI: 10.1103/physrevlett.132.033001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2023] [Accepted: 12/05/2023] [Indexed: 02/04/2024]
Abstract
We propose to sympathetically slow and cool polar molecules in a cold, low-density beam using laser-cooled Rydberg atoms. The elastic collision cross sections between molecules and Rydberg atoms are large enough to efficiently thermalize the molecules even in a low-density environment. Molecules traveling at 100 m/s can be stopped in under 30 collisions with little inelastic loss. Our method does not require photon scattering from the molecules and can be generically applied to complex species for applications in precision measurement, quantum information science, and controlled chemistry.
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Affiliation(s)
- Chi Zhang
- Division of Physics, Mathematics, and Astronomy, California Institute of Technology, Pasadena, California 91125, USA
| | - Seth T Rittenhouse
- Department of Physics, the United States Naval Academy, Annapolis, Maryland 21402, USA
- ITAMP, Center for Astrophysics | Harvard & Smithsonian Cambridge, Massachusetts 02138, USA
| | - Timur V Tscherbul
- Department of Physics, University of Nevada, Reno, Nevada 89557, USA
| | - H R Sadeghpour
- ITAMP, Center for Astrophysics | Harvard & Smithsonian Cambridge, Massachusetts 02138, USA
| | - Nicholas R Hutzler
- Division of Physics, Mathematics, and Astronomy, California Institute of Technology, Pasadena, California 91125, USA
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3
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Lao G, Zhu GZ, Dickerson CE, Augenbraun BL, Alexandrova AN, Caram JR, Hudson ER, Campbell WC. Laser Spectroscopy of Aromatic Molecules with Optical Cycling Centers: Strontium(I) Phenoxides. J Phys Chem Lett 2022; 13:11029-11035. [PMID: 36413655 PMCID: PMC9720742 DOI: 10.1021/acs.jpclett.2c03040] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Accepted: 11/15/2022] [Indexed: 06/16/2023]
Abstract
We report the production and spectroscopic characterization of strontium(I) phenoxide (SrOC6H5 or SrOPh) and variants featuring electron-withdrawing groups designed to suppress vibrational excitation during spontaneous emission from the electronically excited state. Optical cycling closure of these species, which is the decoupling of the vibrational state changes from spontaneous optical decay, is found by dispersed laser-induced fluorescence spectroscopy to be high, in accordance with theoretical predictions. A high-resolution, rotationally resolved laser excitation spectrum is recorded for SrOPh, allowing the estimation of spectroscopic constants and identification of candidate optical cycling transitions for future work. The results confirm the promise of strontium phenoxides for laser cooling and quantum state detection at the single-molecule level.
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Affiliation(s)
- Guanming Lao
- Department
of Physics & Astronomy, University of
California Los Angeles, Los Angeles, California90095, United States
| | - Guo-Zhu Zhu
- Department
of Physics & Astronomy, University of
California Los Angeles, Los Angeles, California90095, United States
| | - Claire E. Dickerson
- Department
of Chemistry & Biochemistry, University
of California Los Angeles, Los
Angeles, California90095, United States
| | - Benjamin L. Augenbraun
- Department
of Physics, Harvard University, Cambridge, Massachusetts02138, United States
- Harvard-MIT
Center for Ultracold Atoms, Cambridge, Massachusetts02138, United States
| | - Anastassia N. Alexandrova
- Department
of Chemistry & Biochemistry, University
of California Los Angeles, Los
Angeles, California90095, United States
- Center
for Quantum Science and Engineering, University
of California, Los Angeles, California90095, United States
| | - Justin R. Caram
- Department
of Chemistry & Biochemistry, University
of California Los Angeles, Los
Angeles, California90095, United States
- Center
for Quantum Science and Engineering, University
of California, Los Angeles, California90095, United States
| | - Eric R. Hudson
- Department
of Physics & Astronomy, University of
California Los Angeles, Los Angeles, California90095, United States
- Center
for Quantum Science and Engineering, University
of California, Los Angeles, California90095, United States
- Challenge
Institute for Quantum Computation, University
of California, Los Angeles, California90095, United States
| | - Wesley C. Campbell
- Department
of Physics & Astronomy, University of
California Los Angeles, Los Angeles, California90095, United States
- Center
for Quantum Science and Engineering, University
of California, Los Angeles, California90095, United States
- Challenge
Institute for Quantum Computation, University
of California, Los Angeles, California90095, United States
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4
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Furtenbacher T, Hegedus ST, Tennyson J, Császár AG. Analysis of measured high-resolution doublet rovibronic spectra and related line lists of CH and OH. Phys Chem Chem Phys 2022; 24:19287-19301. [PMID: 35929432 PMCID: PMC9382695 DOI: 10.1039/d2cp02240k] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Detailed understanding of the energy-level structure of the quantum states as well as of the rovibronic spectra of the ethylidyne (CH) and the hydroxyl (OH) radicals is mandatory for a...
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Affiliation(s)
- Tibor Furtenbacher
- MTA-ELTE Complex Chemical Systems Research Group, Pázmány Péter sétány 1/A, H-1117 Budapest, Hungary.
| | - Samuel T Hegedus
- Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT, UK.
| | - Jonathan Tennyson
- Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT, UK.
| | - Attila G Császár
- MTA-ELTE Complex Chemical Systems Research Group, Pázmány Péter sétány 1/A, H-1117 Budapest, Hungary.
- Laboratory of Molecular Structure and Dynamics, Institute of Chemistry, ELTE Eötvös Loránd University and MTA-ELTE Complex Chemical Systems Research Group, Pázmány Péter sétány 1/A, H-1117 Budapest, Hungary
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5
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Prehn A, Ibrügger M, Rempe G, Zeppenfeld M. High-Resolution "Magic"-Field Spectroscopy on Trapped Polyatomic Molecules. PHYSICAL REVIEW LETTERS 2021; 127:173602. [PMID: 34739278 DOI: 10.1103/physrevlett.127.173602] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Revised: 08/10/2021] [Accepted: 09/16/2021] [Indexed: 06/13/2023]
Abstract
Rapid progress in cooling and trapping of molecules has enabled first experiments on high-resolution spectroscopy of trapped diatomic molecules, promising unprecedented precision. Extending this work to polyatomic molecules provides unique opportunities due to more complex geometries and additional internal degrees of freedom. Here, this is achieved by combining a homogeneous-field microstructured electric trap, rotational transitions with minimal Stark broadening at a"magic" offset electric field, and optoelectrical Sisyphus cooling of molecules to the low millikelvin temperature regime. We thereby reduce Stark broadening on the J=5←4 (K=3) transition of formaldehyde at 364 GHz to well below 1 kHz, observe Doppler-limited linewidths down to 3.8 kHz, and determine the magic-field line position with an uncertainty below 100 Hz. Our approach opens a multitude of possibilities for investigating diverse polyatomic molecule species.
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Affiliation(s)
- Alexander Prehn
- Max-Planck-Institut für Quantenoptik, Hans-Kopfermann-Strasse 1, 85748 Garching, Germany
| | - Martin Ibrügger
- Max-Planck-Institut für Quantenoptik, Hans-Kopfermann-Strasse 1, 85748 Garching, Germany
| | - Gerhard Rempe
- Max-Planck-Institut für Quantenoptik, Hans-Kopfermann-Strasse 1, 85748 Garching, Germany
| | - Martin Zeppenfeld
- Max-Planck-Institut für Quantenoptik, Hans-Kopfermann-Strasse 1, 85748 Garching, Germany
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6
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Vicentini E, Gambetta A, Coluccelli N, Di Sarno V, Maddaloni P, De Natale P, Castrillo A, Gianfrani L, Laporta P, Galzerano G. Absolute frequency stabilization of a QCL at 8.6 µm by modulation transfer spectroscopy. OPTICS LETTERS 2020; 45:4948-4951. [PMID: 32870899 DOI: 10.1364/ol.401265] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Accepted: 08/03/2020] [Indexed: 06/11/2023]
Abstract
Modulation transfer spectroscopy is used to demonstrate absolute frequency stabilization of an 8.6-µm-wavelength quantum cascade laser against a sub-Doppler absorption of the CHF3 molecule. The obtained spectral emission properties are thoroughly characterized through a self-referenced optical frequency comb, stabilized against either a GPS-disciplined Rb clock or a 1.54-µm Er-fiber laser locked to a high-finesse ultra-low-expansion optical cavity. Fractional long-term stability and accuracy at a level of 4×10-12 (at 100 s) and 3×10-10, respectively, are demonstrated, along with an emission linewidth as narrow as 10 kHz for observation times of 0.1 s.
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7
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New Limit on Space-Time Variations in the Proton-to-Electron Mass Ratio from Analysis of Quasar J110325-264515 Spectra. Symmetry (Basel) 2020. [DOI: 10.3390/sym12030344] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Astrophysical tests of current values for dimensionless constants known on Earth, such as the fine-structure constant, α , and proton-to-electron mass ratio, μ = m p / m e , are communicated using data from high-resolution quasar spectra in different regions or epochs of the universe. The symmetry wavelengths of [Fe II] lines from redshifted quasar spectra of J110325-264515 and their corresponding values in the laboratory were combined to find a new limit on space-time variations in the proton-to-electron mass ratio, ∆ μ / μ = ( 0.096 ± 0.182 ) × 10 − 7 . The results show how the indicated astrophysical observations can further improve the accuracy and space-time variations of physics constants.
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8
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Syme AM, Mousley A, Cunningham M, McKemmish LK. Diatomic Rovibronic Transitions as Potential Probes for Proton-to-Electron Mass Ratio Across Cosmological Time. Aust J Chem 2020. [DOI: 10.1071/ch19448] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Astrophysical molecular spectroscopy is an important method of searching for new physics through probing the variation of the proton-to-electron mass ratio, μ, with existing constraints limiting variation to a fractional change of less than 10−17per year. To improve on this constraint and therefore provide better guidance to theories of new physics, new molecular probes will be useful. These probes must have spectral transitions that are observable astrophysically and have different sensitivities to variation in the proton-to-electron mass ratio. Here, we concisely detail how the set of potential molecular probes and promising sensitive transitions is constrained based on how the frequency and intensity of these transitions align with available telescopes. Our detailed investigation focuses on rovibronic transitions in astrophysical diatomic molecules, using the spectroscopic models of 11 diatomics to identify sensitive transitions and probe how they generally arise in real complex molecules with many electronic states and fine structure. While none of the 11 diatomics investigated have sensitive transitions likely to be astrophysically observable, we have found that at high temperatures (1000K) five of these diatomics have a significant number of low intensity sensitive transitions arising from an accidental near-degeneracy between vibrational levels in the ground and excited electronic states. This insight enables screening of all astrophysical diatomics as potential probes of proton-to-electron mass variation, with CN, CP, SiN and SiC being the most promising candidates for further investigation for sensitivity in rovibronic transitions.
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9
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Passagem HF, Colín-Rodríguez R, Tallant J, Ventura da Silva PC, Bouloufa-Maafa N, Dulieu O, Marcassa LG. Continuous Loading of Ultracold Ground-State ^{85}Rb_{2} Molecules in a Dipole Trap Using a Single Light Beam. PHYSICAL REVIEW LETTERS 2019; 122:123401. [PMID: 30978081 DOI: 10.1103/physrevlett.122.123401] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2018] [Revised: 02/10/2019] [Indexed: 06/09/2023]
Abstract
We have developed an approach to continuously load ultracold ^{85}Rb_{2} vibrational ground-state molecules into a crossed optical dipole trap from a magneto-optical trap. The technique relies on a single high-power light beam with a broad spectrum superimposed onto a narrow peak at an energy of about 9400 cm^{-1}. This single laser source performs all the required steps: the short-range photoassociation creating ground-state molecules after radiative emission, the cooling of the molecular vibrational population down to the lowest vibrational level v_{X}=0, and the optical trapping of these molecules. Furthermore, we probe by depletion spectroscopy and determine that 75% of the v_{X}=0 ground-state molecules are in the three lowest rotational levels J_{X}=0, 1, 2. The lifetime of the ultracold molecules in the optical dipole trap is limited to about 70 ms by off-resonant light scattering. The proposed technique opens perspectives for the formation of new molecular species in the ultracold domain, which are not yet accessible by well-established approaches.
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Affiliation(s)
- Henry Fernandes Passagem
- Instituto de Física de São Carlos, Universidade de São Paulo, Caixa Postal 369, 13560-970, São Carlos, São Paulo, Brazil
| | - Ricardo Colín-Rodríguez
- Instituto de Física de São Carlos, Universidade de São Paulo, Caixa Postal 369, 13560-970, São Carlos, São Paulo, Brazil
| | - Jonathan Tallant
- Instituto de Física de São Carlos, Universidade de São Paulo, Caixa Postal 369, 13560-970, São Carlos, São Paulo, Brazil
| | - Paulo Cesar Ventura da Silva
- Instituto de Física de São Carlos, Universidade de São Paulo, Caixa Postal 369, 13560-970, São Carlos, São Paulo, Brazil
| | - Nadia Bouloufa-Maafa
- Laboratoire Aimé Cotton, CNRS, Université Paris-Sud, ENS Cachan, Université Paris-Saclay, 91405 Orsay cedex, France
| | - Olivier Dulieu
- Laboratoire Aimé Cotton, CNRS, Université Paris-Sud, ENS Cachan, Université Paris-Saclay, 91405 Orsay cedex, France
| | - Luis Gustavo Marcassa
- Instituto de Física de São Carlos, Universidade de São Paulo, Caixa Postal 369, 13560-970, São Carlos, São Paulo, Brazil
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10
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Zanon-Willette T, Lefevre R, Metzdorff R, Sillitoe N, Almonacil S, Minissale M, de Clercq E, Taichenachev AV, Yudin VI, Arimondo E. Composite laser-pulses spectroscopy for high-accuracy optical clocks: a review of recent progress and perspectives. REPORTS ON PROGRESS IN PHYSICS. PHYSICAL SOCIETY (GREAT BRITAIN) 2018; 81:094401. [PMID: 29862989 DOI: 10.1088/1361-6633/aac9e9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Probing an atomic resonance without disturbing it is an ubiquitous issue in physics. This problem is critical in high-accuracy spectroscopy or for the next generation of atomic optical clocks. Ultra-high resolution frequency metrology requires sophisticated interrogation schemes and robust protocols handling pulse length errors and residual frequency detuning offsets. This review reports recent progress and perspective in such schemes, using sequences of composite laser-pulses tailored in pulse duration, frequency and phase, inspired by NMR techniques and quantum information processing. After a short presentation of Rabi technique and NMR-like composite pulses allowing efficient compensation of electromagnetic field perturbations to achieve robust population transfers, composite laser-pulses are investigated within Ramsey's method of separated oscillating fields in order to generate non-linear compensation of probe-induced frequency shifts. Laser-pulses protocols such as hyper-Ramsey, modified hyper-Ramsey, generalized hyper-Ramsey and hybrid schemes as auto-balanced Ramsey spectroscopy are reviewed. These techniques provide excellent protection against both probe induced light-shift perturbations and laser intensity variations. More sophisticated schemes generating synthetic frequency-shifts are presented. They allow to reduce or completely eliminate imperfect correction of probe-induced frequency-shifts even in presence of decoherence due to the laser line-width. Finally, two universal protocols are presented which provide complete elimination of probe-induced frequency shifts in the general case where both decoherence and relaxation dissipation effects are present by using exact analytic expressions for phase-shifts and the clock frequency detuning. These techniques might be applied to atomic, molecular and nuclear frequency metrology, Ramsey-type mass spectrometry as well as precision spectroscopy.
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Affiliation(s)
- Thomas Zanon-Willette
- Sorbonne Université, Observatoire de Paris, Université PSL, CNRS, LERMA, F-75005, Paris, France
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11
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Wu H, Reens D, Langen T, Shagam Y, Fontecha D, Ye J. Enhancing radical molecular beams by skimmer cooling. Phys Chem Chem Phys 2018; 20:11615-11621. [PMID: 29658040 DOI: 10.1039/c8cp00962g] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A high-intensity supersonic beam source has been a key component in studies of molecular collisions, molecule-surface interaction, chemical reactions, and precision spectroscopy. However, the molecular density available for experiments in a downstream science chamber is limited by skimmer clogging, which constrains the separation between a valve and a skimmer to at least several hundred nozzle diameters. A recent experiment (Sci. Adv., 2017, 3, e1602258) has introduced a new strategy to address this challenge: when a skimmer is cooled to a temperature below the freezing point of the carrier gas, skimmer clogging can be effectively suppressed. We go beyond this proof-of-principle work in several key ways. Firstly, we apply the skimmer cooling approach to discharge-produced radical and metastable beams entrained in a carrier gas. We also identify two different processes for skimmer clogging mitigation-shockwave suppression at temperatures around the carrier gas freezing point and diffusive clogging at even lower temperatures. With the carrier clogging removed, we now fully optimize the production of entrained species such as hydroxyl radicals, resulting in a gain of 30 in density over the best commercial devices. The gain arises from both clogging mitigation and favorable geometry with a much shorter valve-skimmer distance.
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Affiliation(s)
- Hao Wu
- JILA, National Institute of Standards and Technology and the University of Colorado, Department of Physics, University of Colorado, Boulder, Colorado 80309-0440, USA.
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12
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Lim J, Almond JR, Trigatzis MA, Devlin JA, Fitch NJ, Sauer BE, Tarbutt MR, Hinds EA. Laser Cooled YbF Molecules for Measuring the Electron's Electric Dipole Moment. PHYSICAL REVIEW LETTERS 2018; 120:123201. [PMID: 29694100 DOI: 10.1103/physrevlett.120.123201] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2017] [Indexed: 06/08/2023]
Abstract
We demonstrate one-dimensional sub-Doppler laser cooling of a beam of YbF molecules to 100 μK. This is a key step towards a measurement of the electron's electric dipole moment using ultracold molecules. We compare the effectiveness of magnetically assisted and polarization-gradient sub-Doppler cooling mechanisms. We model the experiment and find good agreement with our data.
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Affiliation(s)
- J Lim
- Centre for Cold Matter, Blackett Laboratory, Imperial College London, Prince Consort Road, London SW7 2AZ, United Kingdom
| | - J R Almond
- Centre for Cold Matter, Blackett Laboratory, Imperial College London, Prince Consort Road, London SW7 2AZ, United Kingdom
| | - M A Trigatzis
- Centre for Cold Matter, Blackett Laboratory, Imperial College London, Prince Consort Road, London SW7 2AZ, United Kingdom
| | - J A Devlin
- Centre for Cold Matter, Blackett Laboratory, Imperial College London, Prince Consort Road, London SW7 2AZ, United Kingdom
| | - N J Fitch
- Centre for Cold Matter, Blackett Laboratory, Imperial College London, Prince Consort Road, London SW7 2AZ, United Kingdom
| | - B E Sauer
- Centre for Cold Matter, Blackett Laboratory, Imperial College London, Prince Consort Road, London SW7 2AZ, United Kingdom
| | - M R Tarbutt
- Centre for Cold Matter, Blackett Laboratory, Imperial College London, Prince Consort Road, London SW7 2AZ, United Kingdom
| | - E A Hinds
- Centre for Cold Matter, Blackett Laboratory, Imperial College London, Prince Consort Road, London SW7 2AZ, United Kingdom
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13
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14
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Insero G, Borri S, Calonico D, Pastor PC, Clivati C, D'Ambrosio D, De Natale P, Inguscio M, Levi F, Santambrogio G. Measuring molecular frequencies in the 1-10 μm range at 11-digits accuracy. Sci Rep 2017; 7:12780. [PMID: 28986590 PMCID: PMC5630624 DOI: 10.1038/s41598-017-12891-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Accepted: 09/08/2017] [Indexed: 11/09/2022] Open
Abstract
High-resolution spectroscopy in the 1-10 μm region has never been fully tackled for the lack of widely-tunable and practical light sources. Indeed, all solutions proposed thus far suffer from at least one of three issues: they are feasible only in a narrow spectral range; the power available for spectroscopy is limited; the frequency accuracy is poor. Here, we present a setup for high-resolution spectroscopy, whose approach can be applied in the whole 1-10 μm range. It combines the power of quantum cascade lasers (QCLs) and the accuracy achievable by difference frequency generation using an orientation patterned GaP crystal. The frequency is measured against a primary frequency standard using the Italian metrological fibre link network. We demonstrate the performance of the setup by measuring a vibrational transition in a highly-excited metastable state of CO around 6 μm with 11 digits of precision.
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Affiliation(s)
- G Insero
- Istituto Nazionale di Ottica-CNR & Dipartimento di Fisica e Astronomia, Università di Firenze & European Laboratory for Non-Linear Spectroscopy LENS, Via Nello Carrara 1, 50019, Sesto Fiorentino, Italy.,INFN, Istituto Nazionale di Fisica Nucleare, Sez. di Firenze, Via Nello Carrara 1, 50019, Sesto Fiorentino, Italy
| | - S Borri
- Istituto Nazionale di Ottica-CNR & Dipartimento di Fisica e Astronomia, Università di Firenze & European Laboratory for Non-Linear Spectroscopy LENS, Via Nello Carrara 1, 50019, Sesto Fiorentino, Italy.,INFN, Istituto Nazionale di Fisica Nucleare, Sez. di Firenze, Via Nello Carrara 1, 50019, Sesto Fiorentino, Italy
| | - D Calonico
- Istituto Nazionale di Ricerca Metrologica INRIM, Strada delle Cacce 91, 10135, Torino, Italy
| | - P Cancio Pastor
- Istituto Nazionale di Ottica-CNR & Dipartimento di Fisica e Astronomia, Università di Firenze & European Laboratory for Non-Linear Spectroscopy LENS, Via Nello Carrara 1, 50019, Sesto Fiorentino, Italy
| | - C Clivati
- Istituto Nazionale di Ricerca Metrologica INRIM, Strada delle Cacce 91, 10135, Torino, Italy
| | - D D'Ambrosio
- Istituto Nazionale di Ottica-CNR & Dipartimento di Fisica e Astronomia, Università di Firenze & European Laboratory for Non-Linear Spectroscopy LENS, Via Nello Carrara 1, 50019, Sesto Fiorentino, Italy
| | - P De Natale
- Istituto Nazionale di Ottica-CNR & Dipartimento di Fisica e Astronomia, Università di Firenze & European Laboratory for Non-Linear Spectroscopy LENS, Via Nello Carrara 1, 50019, Sesto Fiorentino, Italy.,INFN, Istituto Nazionale di Fisica Nucleare, Sez. di Firenze, Via Nello Carrara 1, 50019, Sesto Fiorentino, Italy
| | - M Inguscio
- Istituto Nazionale di Ottica-CNR & Dipartimento di Fisica e Astronomia, Università di Firenze & European Laboratory for Non-Linear Spectroscopy LENS, Via Nello Carrara 1, 50019, Sesto Fiorentino, Italy
| | - F Levi
- Istituto Nazionale di Ricerca Metrologica INRIM, Strada delle Cacce 91, 10135, Torino, Italy
| | - G Santambrogio
- Istituto Nazionale di Ottica-CNR & Dipartimento di Fisica e Astronomia, Università di Firenze & European Laboratory for Non-Linear Spectroscopy LENS, Via Nello Carrara 1, 50019, Sesto Fiorentino, Italy. .,INFN, Istituto Nazionale di Fisica Nucleare, Sez. di Firenze, Via Nello Carrara 1, 50019, Sesto Fiorentino, Italy. .,Istituto Nazionale di Ricerca Metrologica INRIM, Strada delle Cacce 91, 10135, Torino, Italy.
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15
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Okada K, Takada Y, Kimura N, Wada M, Schuessler HA. Development of a wavy Stark velocity filter for studying interstellar chemistry. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2017; 88:083106. [PMID: 28863702 DOI: 10.1063/1.4997721] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Cold polar molecules are key to both the understanding of fundamental physics and the characterization of the chemical evolution of interstellar clouds. To facilitate such studies over a wide range of temperatures, we developed a new type of Stark velocity filter for changing the translational and rotational temperatures of velocity-selected polar molecules without changing the output beam position. The translational temperature of guided polar molecules can be significantly varied by exchanging the wavy deflection section with one having a different radius of the curvature and a different deflection angle. Combining in addition a temperature variable gas cell with the wavy Stark velocity filter enables to observe the translational and rotational temperature dependence of the reaction-rate constants of cold ion-polar molecule reactions over the interesting temperature range of 10-100 K.
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Affiliation(s)
- Kunihiro Okada
- Department of Physics, Sophia University, 7-1 Kioicho, Chiyoda, Tokyo 102-8554, Japan
| | - Yusuke Takada
- Department of Physics, Sophia University, 7-1 Kioicho, Chiyoda, Tokyo 102-8554, Japan
| | - Naoki Kimura
- Department of Physics, Sophia University, 7-1 Kioicho, Chiyoda, Tokyo 102-8554, Japan
| | - Michiharu Wada
- RIKEN Nishina Center for Accelerator-Based Science, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Hans A Schuessler
- Department of Physics and Astronomy, Texas A&M University, College Station, Texas 77843, USA
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16
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Asselin P, Berger Y, Huet TR, Margulès L, Motiyenko R, Hendricks RJ, Tarbutt MR, Tokunaga SK, Darquié B. Characterising molecules for fundamental physics: an accurate spectroscopic model of methyltrioxorhenium derived from new infrared and millimetre-wave measurements. Phys Chem Chem Phys 2017; 19:4576-4587. [PMID: 28124691 DOI: 10.1039/c6cp08724h] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Precise spectroscopic analysis of polyatomic molecules enables many striking advances in physical chemistry and fundamental physics. We use several new high-resolution spectroscopic devices to improve our understanding of the rotational and rovibrational structure of methyltrioxorhenium (MTO), the achiral parent of a family of large oxorhenium compounds that are ideal candidate species for a planned measurement of parity violation in chiral molecules. Using millimetre-wave and infrared spectroscopy in a pulsed supersonic jet, a cryogenic buffer gas cell, and room temperature absorption cells, we probe the ground state and the Re[double bond, length as m-dash]O antisymmetric and symmetric stretching excited states of both CH3187ReO3 and CH3185ReO3 isotopologues in the gas phase with unprecedented precision. By extending the rotational spectra to the 150-300 GHz range, we characterize the ground state rotational and hyperfine structure up to J = 43 and K = 41, resulting in refinements to the rotational, quartic and hyperfine parameters, and the determination of sextic parameters and a centrifugal distortion correction to the quadrupolar hyperfine constant. We obtain rovibrational data for temperatures between 6 and 300 K in the 970-1015 cm-1 range, at resolutions down to 8 MHz and accuracies of 30 MHz. We use these data to determine more precise excited-state rotational, Coriolis and quartic parameters, as well as the ground-state centrifugal distortion parameter DK of the 187Re isotopologue. We also account for hyperfine structure in the rovibrational transitions and hence determine the upper state rhenium atom quadrupole coupling constant eQq'.
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Affiliation(s)
- Pierre Asselin
- Sorbonne Universités, UPMC Univ Paris 06, UMR 8233, MONARIS, F-75005, Paris, France and CNRS, UMR 8233, MONARIS, F-75005, Paris, France.
| | - Yann Berger
- Sorbonne Universités, UPMC Univ Paris 06, UMR 8233, MONARIS, F-75005, Paris, France and CNRS, UMR 8233, MONARIS, F-75005, Paris, France.
| | - Thérèse R Huet
- Univ. Lille, CNRS, UMR 8523 - PhLAM - Physique des Lasers Atomes et Molécules, F-59000 Lille, France
| | - Laurent Margulès
- Univ. Lille, CNRS, UMR 8523 - PhLAM - Physique des Lasers Atomes et Molécules, F-59000 Lille, France
| | - Roman Motiyenko
- Univ. Lille, CNRS, UMR 8523 - PhLAM - Physique des Lasers Atomes et Molécules, F-59000 Lille, France
| | - Richard J Hendricks
- Centre for Cold Matter, Blackett Laboratory, Imperial College London, Prince Consort Road, London SW7 2AZ, UK
| | - Michael R Tarbutt
- Centre for Cold Matter, Blackett Laboratory, Imperial College London, Prince Consort Road, London SW7 2AZ, UK
| | - Sean K Tokunaga
- Université Paris 13, Sorbonne Paris Cité, Laboratoire de Physique des Lasers, F-93430 Villetaneuse, France and CNRS, UMR 7538, LPL, F-93430 Villetaneuse, France.
| | - Benoît Darquié
- CNRS, UMR 7538, LPL, F-93430 Villetaneuse, France. and Université Paris 13, Sorbonne Paris Cité, Laboratoire de Physique des Lasers, F-93430 Villetaneuse, France
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17
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Fitch NJ, Tarbutt MR. Principles and Design of a Zeeman-Sisyphus Decelerator for Molecular Beams. Chemphyschem 2016; 17:3609-3623. [PMID: 27629547 PMCID: PMC5132136 DOI: 10.1002/cphc.201600656] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2016] [Indexed: 11/10/2022]
Abstract
We explore a technique for decelerating molecules using a static magnetic field and optical pumping. Molecules travel through a spatially varying magnetic field and are repeatedly pumped into a weak‐field seeking state as they move towards each strong field region, and into a strong‐field seeking state as they move towards weak field. The method is time‐independent and so is suitable for decelerating both pulsed and continuous molecular beams. By using guiding magnets at each weak field region, the beam can be simultaneously guided and decelerated. By tapering the magnetic field strength in the strong field regions, and exploiting the Doppler shift, the velocity distribution can be compressed during deceleration. We develop the principles of this deceleration technique, provide a realistic design, use numerical simulations to evaluate its performance for a beam of CaF, and compare this performance to other deceleration methods.
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Affiliation(s)
- N J Fitch
- Centre for Cold Matter, Blackett Laboratory, Imperial College London, Prince Consort Road, London, SW7 2AZ, UK
| | - M R Tarbutt
- Centre for Cold Matter, Blackett Laboratory, Imperial College London, Prince Consort Road, London, SW7 2AZ, UK
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18
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Prehn A, Ibrügger M, Glöckner R, Rempe G, Zeppenfeld M. Optoelectrical Cooling of Polar Molecules to Submillikelvin Temperatures. PHYSICAL REVIEW LETTERS 2016; 116:063005. [PMID: 26918988 DOI: 10.1103/physrevlett.116.063005] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2015] [Indexed: 06/05/2023]
Abstract
We demonstrate direct cooling of gaseous formaldehyde (H2CO) to the microkelvin regime. Our approach, optoelectrical Sisyphus cooling, provides a simple dissipative cooling method applicable to electrically trapped dipolar molecules. By reducing the temperature by 3 orders of magnitude and increasing the phase-space density by a factor of ∼10(4), we generate an ensemble of 3×10(5) molecules with a temperature of about 420 μK, populating a single rotational state with more than 80% purity.
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Affiliation(s)
- Alexander Prehn
- Max-Planck-Institut für Quantenoptik, Hans-Kopfermann-Strasse 1, 85748 Garching, Germany
| | - Martin Ibrügger
- Max-Planck-Institut für Quantenoptik, Hans-Kopfermann-Strasse 1, 85748 Garching, Germany
| | - Rosa Glöckner
- Max-Planck-Institut für Quantenoptik, Hans-Kopfermann-Strasse 1, 85748 Garching, Germany
| | - Gerhard Rempe
- Max-Planck-Institut für Quantenoptik, Hans-Kopfermann-Strasse 1, 85748 Garching, Germany
| | - Martin Zeppenfeld
- Max-Planck-Institut für Quantenoptik, Hans-Kopfermann-Strasse 1, 85748 Garching, Germany
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19
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Bichsel BJ, Alexander J, Dahal P, Morrison MA, Shafer-Ray NE, Abraham ERI. Creation of cold nitric oxide by extraction of the cold fraction of a thermal distribution. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2015; 86:103102. [PMID: 26520935 DOI: 10.1063/1.4931756] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
We describe a device using the Stark effect to extract the cold fraction of nitric oxide molecules from a warmer thermal distribution. Room temperature NO is cryogenically cooled to 72-82 K and injected into a straight, hexapole guide that uses the Stark effect. By blocking line-of-sight trajectories from the input to the output, primarily the slowest molecules are guided around the obstruction and are transferred into a new chamber. We measure the temperature distribution using a field-stabilized Rydberg time-of-flight technique. A superposition of molecular Rydberg states is excited, sufficiently increasing the lifetime of the excited state for a time-of-flight measurement for cold molecular samples. We produce a continuous source of nitric oxide with temperatures ranging from 7 to 20 K in the lowest ro-vibrational state. The output temperature is controlled by the initial temperature distribution and the guide voltage.
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Affiliation(s)
- Bryan J Bichsel
- Homer L. Dodge Department of Physics and Astronomy, University of Oklahoma, Norman, Oklahoma 73019, USA
| | - Jason Alexander
- Homer L. Dodge Department of Physics and Astronomy, University of Oklahoma, Norman, Oklahoma 73019, USA
| | - Parshuram Dahal
- Homer L. Dodge Department of Physics and Astronomy, University of Oklahoma, Norman, Oklahoma 73019, USA
| | - Michael A Morrison
- Homer L. Dodge Department of Physics and Astronomy, University of Oklahoma, Norman, Oklahoma 73019, USA
| | - Neil E Shafer-Ray
- Homer L. Dodge Department of Physics and Astronomy, University of Oklahoma, Norman, Oklahoma 73019, USA
| | - E R I Abraham
- Homer L. Dodge Department of Physics and Astronomy, University of Oklahoma, Norman, Oklahoma 73019, USA
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20
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Abstract
A cold, continuous, high flux beam of benzonitrile has been created via buffer gas cooling.
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21
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Marinakis S, Dean IL, Kłos J, Lique F. Collisional excitation of CH(X2Π) by He: new ab initio potential energy surfaces and scattering calculations. Phys Chem Chem Phys 2015. [DOI: 10.1039/c5cp03696h] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We present a new CH(X)–He potential energy surface which is able to reproduce all the available experimental results.
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Affiliation(s)
- Sarantos Marinakis
- Department of Chemistry and Biochemistry
- School of Biological and Chemical Sciences
- Queen Mary University of London
- London E1 4NS
- UK
| | - Indigo Lily Dean
- Department of Chemistry and Biochemistry
- School of Biological and Chemical Sciences
- Queen Mary University of London
- London E1 4NS
- UK
| | - Jacek Kłos
- Department of Chemistry and Biochemistry
- University of Maryland
- College Park
- USA
| | - François Lique
- LOMC – UMR 6294
- CNRS-Université du Havre
- BP 1123 – 76 063 Le Havre cedex
- France
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22
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Jansen P, Bethlem HL, Ubachs W. Perspective: Tipping the scales: Search for drifting constants from molecular spectra. J Chem Phys 2014; 140:010901. [DOI: 10.1063/1.4853735] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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