1
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Chen TY, Steinmetz SA, Patterson BD, Jasper AW, Kliewer CJ. Direct observation of coherence transfer and rotational-to-vibrational energy exchange in optically centrifuged CO 2 super-rotors. Nat Commun 2023; 14:3227. [PMID: 37270647 DOI: 10.1038/s41467-023-38873-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2023] [Accepted: 05/18/2023] [Indexed: 06/05/2023] Open
Abstract
Optical centrifuges are laser-based molecular traps that can rotationally accelerate molecules to energies rivalling or exceeding molecular bond energies. Here we report time and frequency-resolved ultrafast coherent Raman measurements of optically centrifuged CO2 at 380 Torr spun to energies beyond its bond dissociation energy of 5.5 eV (Jmax = 364, Erot = 6.14 eV, Erot/kB = 71, 200 K). The entire rotational ladder from J = 24 to J = 364 was resolved simultaneously which enabled a more accurate measurement of the centrifugal distortion constants for CO2. Remarkably, coherence transfer was directly observed, and time-resolved, during the field-free relaxation of the trap as rotational energy flowed into bending-mode vibrational excitation. Vibrationally excited CO2 (ν2 > 3) was observed in the time-resolved spectra to populate after 3 mean collision times as a result of rotational-to-vibrational (R-V) energy transfer. Trajectory simulations show an optimal range of J for R-V energy transfer. Dephasing rates for molecules rotating up to 5.5 times during one collision were quantified. Very slow decays of the vibrational hot band rotational coherences suggest that they are sustained by coherence transfer and line mixing.
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Affiliation(s)
- Timothy Y Chen
- Sandia National Laboratories, Livermore, 94550, CA, USA
- Applied Materials, Inc., Santa Clara, 95051, CA, USA
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2
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Kallush S, Dann R, Kosloff R. Controlling the uncontrollable: Quantum control of open-system dynamics. SCIENCE ADVANCES 2022; 8:eadd0828. [PMID: 36322661 PMCID: PMC9629718 DOI: 10.1126/sciadv.add0828] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Accepted: 09/14/2022] [Indexed: 06/16/2023]
Abstract
Control of open quantum systems is essential for the realization of contemporary quantum science and technology. We demonstrate such control using a thermodynamically consistent framework, taking into account the fact that the drive can modify the system's interaction with the environment. Such an effect is incorporated within the dynamical equation, leading to control-dependent dissipation. This relation serves as the key element for open-system control. The control paradigm is displayed by analyzing entropy-changing state-to-state transformations, such as heating and cooling. The difficult task of controlling quantum gates is achieved for nonunitary reset maps with complete memory loss. In addition, we identify a mechanism for controlling unitary gates by actively removing entropy from the system to the environment. We demonstrate a universal set of single- and double-qubit unitary gates under dissipation.
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Affiliation(s)
- Shimshon Kallush
- Sciences Department, Holon Academic Institute of Technology, 52 Golomb Street, Holon 58102, Israel
- The Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem 9190401, Israel
| | - Roie Dann
- The Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem 9190401, Israel
| | - Ronnie Kosloff
- The Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem 9190401, Israel
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3
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Zhao B, Pan JW. Quantum control of reactions and collisions at ultralow temperatures. Chem Soc Rev 2022; 51:1685-1701. [PMID: 35169822 DOI: 10.1039/d1cs01040a] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
At temperatures close to absolute zero, the molecular reactions and collisions are dominantly governed by quantum mechanics. Remarkable quantum phenomena such as quantum tunneling, quantum threshold behavior, quantum resonances, quantum interference, and quantum statistics are expected to be the main features in ultracold reactions and collisions. Ultracold molecules offer great opportunities and challenges in the study of these intriguing quantum phenomena in molecular processes. In this article, we review the recent progress in the preparation of ultracold molecules and the study of ultracold reactions and collisions using ultracold molecules. We focus on the controlled ultracold chemistry and the scattering resonances at ultralow temperatures. The challenges in understanding the complex ultracold reactions and collisions are also discussed.
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Affiliation(s)
- Bo Zhao
- Hefei National Laboratory for Physical Sciences at the Microscale and Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026, China. .,Shanghai Branch, CAS Center for Excellence and Synergetic Innovation Center in Quantum Information and Quantum Physics, University of Science and Technology of China, Shanghai 201315, China.,Shanghai Research Center for Quantum Sciences, Shanghai 201315, China
| | - Jian-Wei Pan
- Hefei National Laboratory for Physical Sciences at the Microscale and Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026, China. .,Shanghai Branch, CAS Center for Excellence and Synergetic Innovation Center in Quantum Information and Quantum Physics, University of Science and Technology of China, Shanghai 201315, China.,Shanghai Research Center for Quantum Sciences, Shanghai 201315, China
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4
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Abstract
Polar radioactive molecules have been suggested to be exceptionally sensitive systems in the search for signatures of symmetry-violating effects in their structure. Radium monofluoride (RaF) possesses an especially attractive electronic structure for such searches, as the diagonality of its Franck-Condon matrix enables the implementation of direct laser cooling for precision experiments. To maximize the sensitivity of experiments with short-lived RaF isotopologues, the molecular beam needs to be cooled to the rovibrational ground state. Due to the high kinetic energies and internal temperature of extracted beams at radioactive ion beam (RIB) facilities, in-flight rovibrational cooling would be restricted by a limited interaction timescale. Instead, cooling techniques implemented on ions trapped within a radiofrequency quadrupole cooler-buncher can be highly efficient due to the much longer interaction times (up to seconds). In this work, the feasibility of rovibrationally cooling trapped RaF+ and RaH+ cations with repeated laser excitation is investigated. Due to the highly diagonal nature between the ionic ground state and states in the neutral system, any reduction of the internal temperature of the molecular ions would largely persist through charge-exchange without requiring the use of cryogenic buffer gas cooling. Quasirelativistic X2C and scalar-relativistic ECP calculations were performed to calculate the transition energies to excited electronic states and to study the nature of chemical bonding for both RaF+ and RaH+. The results indicate that optical manipulation of the rovibrational distribution of trapped RaF+ and RaH+ is unfeasible due to the high electronic transition energies, which lie beyond the capabilities of modern laser technology. However, more detailed calculations of the structure of RaH+ might reveal possible laser-cooling pathways.
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5
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Onate CA, Okon IB, Onyeaju MC, Ebomwonyi O. Vibrational energies of some diatomic molecules for a modified and deformed potential. Sci Rep 2021; 11:22498. [PMID: 34795376 PMCID: PMC8602305 DOI: 10.1038/s41598-021-01998-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2021] [Accepted: 10/29/2021] [Indexed: 11/21/2022] Open
Abstract
A molecular potential model is proposed and the solutions of the radial Schrӧdinger equation in the presence of the proposed potential is obtained. The energy equation and its corresponding radial wave function are calculated using the powerful parametric Nikiforov–Uvarov method. The energies of cesium dimer for different quantum states were numerically obtained for both negative and positive values of the deformed and adjustable parameters. The results for sodium dimer and lithium dimer were calculated numerically using their respective spectroscopic parameters. The calculated values for the three molecules are in excellent agreement with the observed values. Finally, we calculated different expectation values and examined the effects of the deformed and adjustable parameters on the expectation values.
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Affiliation(s)
- C A Onate
- Physics Programme, Department of Physical Sciences, Landmark University, Omu-Aran, Nigeria. .,Landmark University SDG 4 (Quality Education), Omu-Aran, Nigeria.
| | - I B Okon
- Theoretical Physics Group, Department of Physics, University of Uyo, Uyo, Nigeria
| | - M C Onyeaju
- Theoretical Physics Group, Department of Physics, University of Port Harcourt, P.M.B. 5323 Choba, Port Harcourt, Nigeria
| | - O Ebomwonyi
- Department of Physics, University of Benin, Benin City, Nigeria
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6
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Antonov IO, Stollenwerk PR, Venkataramanababu S, de Lima Batista AP, de Oliveira-Filho AGS, Odom BC. Precisely spun super rotors. Nat Commun 2021; 12:2201. [PMID: 33850116 PMCID: PMC8044131 DOI: 10.1038/s41467-021-22342-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Accepted: 03/03/2021] [Indexed: 11/09/2022] Open
Abstract
Improved optical control of molecular quantum states promises new applications including chemistry in the quantum regime, precision tests of fundamental physics, and quantum information processing. While much work has sought to prepare ground state molecules, excited states are also of interest. Here, we demonstrate a broadband optical approach to pump trapped SiO+ molecules into pure super rotor ensembles maintained for many minutes. Super rotor ensembles pumped up to rotational state N = 67, corresponding to the peak of a 9400 K distribution, had a narrow N spread comparable to that of a few-kelvin sample, and were used for spectroscopy of the previously unobserved C2Π state. Significant centrifugal distortion of super rotors pumped up to N = 230 allowed probing electronic structure of SiO+ stretched far from its equilibrium bond length. Optical pulses can be useful to create and control molecules in higher quantum states. Here the authors use optical pumping to create rotationally excited states of SiO+ molecular ion into super rotor ensemble.
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Affiliation(s)
- Ivan O Antonov
- Department of Physics and Astronomy, Northwestern University, Evanston, IL, USA
| | | | | | - Ana P de Lima Batista
- Departamento de Química, Laboratório Computacional de Espectroscopia e Cinética, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto-SP, Brazil
| | - Antonio G S de Oliveira-Filho
- Departamento de Química, Laboratório Computacional de Espectroscopia e Cinética, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto-SP, Brazil
| | - Brian C Odom
- Department of Physics and Astronomy, Northwestern University, Evanston, IL, USA. .,Applied Physics program, Northwestern University, Evanston, IL, USA.
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7
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Wellnitz D, Schütz S, Whitlock S, Schachenmayer J, Pupillo G. Collective Dissipative Molecule Formation in a Cavity. PHYSICAL REVIEW LETTERS 2020; 125:193201. [PMID: 33216580 DOI: 10.1103/physrevlett.125.193201] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Accepted: 09/24/2020] [Indexed: 06/11/2023]
Abstract
We propose a mechanism to realize high-yield molecular formation from ultracold atoms. Atom pairs are continuously excited by a laser, and a collective decay into the molecular ground state is induced by a coupling to a lossy cavity mode. Using a combination of analytical and numerical techniques, we demonstrate that the molecular yield can be improved by simply increasing the number of atoms, and can overcome efficiencies of state-of-the-art association schemes. We discuss realistic experimental setups for diatomic polar and nonpolar molecules, opening up collective light matter interactions as a tool for quantum state engineering, enhanced molecule formation, collective dynamics, and cavity mediated chemistry.
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Affiliation(s)
- David Wellnitz
- ISIS (UMR 7006) and icFRC, University of Strasbourg and CNRS, 67000 Strasbourg, France
- IPCMS (UMR 7504), University of Strasbourg and CNRS, 67000 Strasbourg, France
| | - Stefan Schütz
- ISIS (UMR 7006) and icFRC, University of Strasbourg and CNRS, 67000 Strasbourg, France
- IPCMS (UMR 7504), University of Strasbourg and CNRS, 67000 Strasbourg, France
| | - Shannon Whitlock
- ISIS (UMR 7006) and icFRC, University of Strasbourg and CNRS, 67000 Strasbourg, France
| | - Johannes Schachenmayer
- ISIS (UMR 7006) and icFRC, University of Strasbourg and CNRS, 67000 Strasbourg, France
- IPCMS (UMR 7504), University of Strasbourg and CNRS, 67000 Strasbourg, France
| | - Guido Pupillo
- ISIS (UMR 7006) and icFRC, University of Strasbourg and CNRS, 67000 Strasbourg, France
- Institut Universitaire de France (IUF), 75000 Paris, France
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8
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Stollenwerk PR, Antonov IO, Venkataramanababu S, Lin YW, Odom BC. Cooling of a Zero-Nuclear-Spin Molecular Ion to a Selected Rotational State. PHYSICAL REVIEW LETTERS 2020; 125:113201. [PMID: 32975973 DOI: 10.1103/physrevlett.125.113201] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Accepted: 08/10/2020] [Indexed: 06/11/2023]
Abstract
We demonstrate rotational cooling of the silicon monoxide cation via optical pumping by a spectrally filtered broadband laser. Compared with diatomic hydrides, SiO^{+} is more challenging to cool because of its smaller rotational interval. However, the rotational level spacing and the large dipole moment of SiO^{+} allows for direct manipulation by microwaves, and the absence of hyperfine structure in its dominant isotopologue greatly reduces demands for pure quantum state preparation. These features make ^{28}Si^{16}O^{+} a good candidate for future applications such as quantum information processing. Cooling to the ground rotational state is achieved on a 100 ms timescale and attains a population of 94(3)%, with an equivalent temperature T=0.53(6) K. We also describe a novel spectral-filtering approach to cool into arbitrary rotational states and use it to demonstrate a narrow rotational population distribution (N±1) around a selected state.
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Affiliation(s)
| | - Ivan O Antonov
- Department of Physics and Astronomy, Northwestern University, Evanston, Illinois 60208, USA
| | | | - Yen-Wei Lin
- Department of Physics and Astronomy, Northwestern University, Evanston, Illinois 60208, USA
| | - Brian C Odom
- Department of Physics and Astronomy, Northwestern University, Evanston, Illinois 60208, USA
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9
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Fernandes GFS, Pontes MAP, Faria UJ, Machado FBC, Ferrão LFA. Multireference study of ionic/covalent electronic states of MF (M = Be, Mg and Ca). SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2020; 233:118210. [PMID: 32163875 DOI: 10.1016/j.saa.2020.118210] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Revised: 02/19/2020] [Accepted: 02/29/2020] [Indexed: 06/10/2023]
Abstract
Ultracold environments composed by atoms or molecules offer an opportunity to study chemical reactions at the quantum-state level, for simulation of solid-state systems, as qubits in quantum computing, and for test fundamental symmetries. Those ultracold conditions formed by molecules can be obtained from cryogenic buffer gas, via supersonic expansion, followed by deceleration or from the laser cooling process. Diatomic alkaline earth monofluoride molecules have been shown as great candidates for the laser cooling process. In this sense, the present work focuses on the characterization of the low-lying doublet electronic states correlated to the first dissociation channel of the alkaline earth monofluorides diatomic molecules MF (M = Be, Mg and Ca). The developed state-of-the-art methodology was based on a qualitative analysis of the diatomic electronic structure, employing a hypothetical potential energy curve or by a simple molecular orbital diagram combined with bond order analysis. The potential energy curves, excitation and dissociation energies, and various sets of spectroscopic parameters were calculated by the MRCI/cc-pV5Z methodology. Transition probabilities for emission and radiative lifetimes among the characterized electronic states were also calculated for the (A)2Π ⟶ (X)2Σ+ electronic transition. Comparing the spectroscopy properties, we were able to indicate the CaF molecule as the best candidate molecule for laser cooling devices among the studied molecules.
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Affiliation(s)
| | - Marcelo A P Pontes
- Instituto Tecnológico de Aeronáutica, São José dos Campos, SP 12228-900, Brazil
| | - Ulisses J Faria
- Instituto Tecnológico de Aeronáutica, São José dos Campos, SP 12228-900, Brazil
| | | | - Luiz F A Ferrão
- Instituto Tecnológico de Aeronáutica, São José dos Campos, SP 12228-900, Brazil.
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10
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Bai S, Han X, Bai J, Jiao Y, Wang H, Zhao J, Jia S. Observation of photoassociation spectroscopy of ultralong 37D 5/2 + 6S 1/2Cs 2 Rydberg molecules. J Chem Phys 2020; 152:084302. [PMID: 32113370 DOI: 10.1063/1.5132993] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
We present an experimental observation of 37D5/2 + 6S1/2Cs2 Rydberg-ground molecules by employing a two-photon photoassociation method. Two distinct Rydberg-ground molecular signals, deep and shallow bound molecules, are observed at the red detuning of atomic line. In theory, the model of scattering interaction between the Rydberg electron and ground-state atom is used to simulate the experiments. Two potential energy curves with energy minimum, deep pure triplet 3Σ and shallow hyperfine-mixed singlet-triplet 1,3Σ potentials, refer to the attained Rydberg-ground molecular signals, respectively. Calculations of the binding energy of triplet 3Σ and mixed 1,3Σv = 0 states are compared with the measurements. The agreement between the calculated and measured values of the binding energy yields zero-energy scattering lengths as T(0) = -19.2a0 and as S(0) = -1.3a0, respectively.
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Affiliation(s)
- Suying Bai
- State Key Laboratory of Quantum Optics and Quantum Optics Devices, Institute of Laser Spectroscopy, Shanxi University, Taiyuan 030006, China
| | - Xiaoxuan Han
- State Key Laboratory of Quantum Optics and Quantum Optics Devices, Institute of Laser Spectroscopy, Shanxi University, Taiyuan 030006, China
| | - Jingxu Bai
- State Key Laboratory of Quantum Optics and Quantum Optics Devices, Institute of Laser Spectroscopy, Shanxi University, Taiyuan 030006, China
| | - Yuechun Jiao
- State Key Laboratory of Quantum Optics and Quantum Optics Devices, Institute of Laser Spectroscopy, Shanxi University, Taiyuan 030006, China
| | - Huihui Wang
- State Key Laboratory of Quantum Optics and Quantum Optics Devices, Institute of Laser Spectroscopy, Shanxi University, Taiyuan 030006, China
| | - Jianming Zhao
- State Key Laboratory of Quantum Optics and Quantum Optics Devices, Institute of Laser Spectroscopy, Shanxi University, Taiyuan 030006, China
| | - Suotang Jia
- State Key Laboratory of Quantum Optics and Quantum Optics Devices, Institute of Laser Spectroscopy, Shanxi University, Taiyuan 030006, China
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11
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Urbańczyk T, Koperski J. Ro-vibrational cooling of diatomic molecules Cd2 and Yb2: rotational energy structure included. Mol Phys 2019. [DOI: 10.1080/00268976.2019.1694712] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Affiliation(s)
- Tomasz Urbańczyk
- Smoluchowski Institute of Physcics, Jagiellonian University, Kraków, Poland
| | - Jarosław Koperski
- Smoluchowski Institute of Physcics, Jagiellonian University, Kraków, Poland
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12
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Abstract
A comprehensive approach to modeling open quantum systems consistent with thermodynamics is presented. The theory of open quantum systems is employed to define system bath partitions. The Markovian master equation defines an isothermal partition between the system and bath. Two methods to derive the quantum master equation are described: the weak coupling limit and the repeated collision model. The role of the eigenoperators of the free system dynamics is highlighted, in particular, for driven systems. The thermodynamical relations are pointed out. Models that lead to loss of coherence, i.e., dephasing are described. The implication of the laws of thermodynamics to simulating transport and spectroscopy is described. The indications for self-averaging in large quantum systems and thus its importance in modeling are described. Basic modeling by the surrogate Hamiltonian is described, as well as thermal boundary conditions using the repeated collision model and their use in the stochastic surrogate Hamiltonian. The problem of modeling with explicitly time dependent driving is analyzed. Finally, the use of the stochastic surrogate Hamiltonian for modeling ultrafast spectroscopy and quantum control is reviewed.
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Affiliation(s)
- Ronnie Kosloff
- The Institute of Chemistry and The Fritz Haber Centre for Theoretical Chemistry, The Hebrew University of Jerusalem, Jerusalem 9190401, Israel
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13
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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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14
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Abstract
Molecular overtone transitions provide optical frequency transitions sensitive to variation in the proton-to-electron mass ratio ( μ ≡ m p / m e ). However, robust molecular state preparation presents a challenge critical for achieving high precision. Here, we characterize infrared and optical-frequency broadband laser cooling schemes for TeH + , a species with multiple electronic transitions amenable to sustained laser control. Using rate equations to simulate laser cooling population dynamics, we estimate the fractional sensitivity to μ attainable using TeH + . We find that laser cooling of TeH + can lead to significant improvements on current μ variation limits.
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15
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Solaro C, Meyer S, Fisher K, DePalatis MV, Drewsen M. Direct Frequency-Comb-Driven Raman Transitions in the Terahertz Range. PHYSICAL REVIEW LETTERS 2018; 120:253601. [PMID: 29979052 DOI: 10.1103/physrevlett.120.253601] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2017] [Indexed: 06/08/2023]
Abstract
We demonstrate the use of a femtosecond frequency comb to coherently drive stimulated Raman transitions between terahertz-spaced atomic energy levels. More specifically, we address the 3d ^{2}D_{3/2} and 3d ^{2}D_{5/2} fine structure levels of a single trapped ^{40}Ca^{+} ion and spectroscopically resolve the transition frequency to be ν_{D}=1,819,599,021,534±8 Hz. The achieved accuracy is nearly a factor of five better than the previous best Raman spectroscopy, and is currently limited by the stability of our atomic clock reference. Furthermore, the population dynamics of frequency-comb-driven Raman transitions can be fully predicted from the spectral properties of the frequency comb, and Rabi oscillations with a contrast of 99.3(6)% and millisecond coherence time have been achieved. Importantly, the technique can be easily generalized to transitions in the sub-kHz to tens of THz range and should be applicable for driving, e.g., spin-resolved rovibrational transitions in molecules and hyperfine transitions in highly charged ions.
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Affiliation(s)
- C Solaro
- Department of Physics and Astronomy, Aarhus University, DK-8000 Aarhus C, Denmark
| | - S Meyer
- Department of Physics and Astronomy, Aarhus University, DK-8000 Aarhus C, Denmark
| | - K Fisher
- Department of Physics and Astronomy, Aarhus University, DK-8000 Aarhus C, Denmark
| | - M V DePalatis
- Department of Physics and Astronomy, Aarhus University, DK-8000 Aarhus C, Denmark
| | - M Drewsen
- Department of Physics and Astronomy, Aarhus University, DK-8000 Aarhus C, Denmark
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16
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Broadway DA, Tetienne JP, Stacey A, Wood JDA, Simpson DA, Hall LT, Hollenberg LCL. Quantum probe hyperpolarisation of molecular nuclear spins. Nat Commun 2018; 9:1246. [PMID: 29593304 PMCID: PMC5871805 DOI: 10.1038/s41467-018-03578-1] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Accepted: 02/20/2018] [Indexed: 12/15/2022] Open
Abstract
Hyperpolarisation of nuclear spins is important in overcoming sensitivity and resolution limitations of magnetic resonance imaging and nuclear magnetic resonance spectroscopy. Current hyperpolarisation techniques require high magnetic fields, low temperatures, or catalysts. Alternatively, the emergence of room temperature spin qubits has opened new pathways to achieve direct nuclear spin hyperpolarisation. Employing a microwave-free cross-relaxation induced polarisation protocol applied to a nitrogen vacancy qubit, we demonstrate quantum probe hyperpolarisation of external molecular nuclear spins to ~50% under ambient conditions, showing a single qubit increasing the polarisation of ~106 nuclear spins by six orders of magnitude over the thermal background. Results are verified against a detailed theoretical treatment, which also describes how the system can be scaled up to a universal quantum hyperpolarisation platform for macroscopic samples. Our results demonstrate the prospects for this approach to nuclear spin hyperpolarisation for molecular imaging and spectroscopy and its potential to extend beyond into other scientific areas. Molecules with ‘hyperpolarised’ nuclear spins can be used to improve MRI performance but require an efficient polarisation method. Broadway et al. demonstrate a quantum control protocol using a nitrogen vacancy centre inside a diamond to hyperpolarise protons within molecules deposited on the surface.
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Affiliation(s)
- David A Broadway
- Centre for Quantum Computation and Communication Technology, School of Physics, University of Melbourne, Parkville, VIC 3010, Australia. .,School of Physics, University of Melbourne, Parkville, VIC 3010, Australia.
| | - Jean-Philippe Tetienne
- Centre for Quantum Computation and Communication Technology, School of Physics, University of Melbourne, Parkville, VIC 3010, Australia.,School of Physics, University of Melbourne, Parkville, VIC 3010, Australia
| | - Alastair Stacey
- Centre for Quantum Computation and Communication Technology, School of Physics, University of Melbourne, Parkville, VIC 3010, Australia.,School of Physics, University of Melbourne, Parkville, VIC 3010, Australia.,Melbourne Centre for Nanofabrication, Clayton, VIC 3168, Australia
| | - James D A Wood
- Centre for Quantum Computation and Communication Technology, School of Physics, University of Melbourne, Parkville, VIC 3010, Australia.,School of Physics, University of Melbourne, Parkville, VIC 3010, Australia.,Department of Physics, University of Basel, Klingelbergstrasse 82, 4056, Basel, Switzerland
| | - David A Simpson
- School of Physics, University of Melbourne, Parkville, VIC 3010, Australia
| | - Liam T Hall
- School of Physics, University of Melbourne, Parkville, VIC 3010, Australia.
| | - Lloyd C L Hollenberg
- Centre for Quantum Computation and Communication Technology, School of Physics, University of Melbourne, Parkville, VIC 3010, Australia. .,School of Physics, University of Melbourne, Parkville, VIC 3010, Australia.
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17
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Li Z, Gong T, Ji Z, Zhao Y, Xiao L, Jia S. A dynamical process of optically trapped singlet ground state 85Rb 133Cs molecules produced via short-range photoassociation. Phys Chem Chem Phys 2018; 20:4893-4900. [PMID: 29384158 DOI: 10.1039/c7cp07756d] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
We investigate the dynamical process of optically trapped X1Σ+ (v'' = 0) state 85Rb133Cs molecules distributed in J'' = 1 and J'' = 3 rotational states. The considered molecules, formed from short-range photoassociation of mixed cold atoms, are subsequently confined in a crossed optical dipole trap. Based on a phenomenological rate equation, we provide a detailed study of the dynamics of 85Rb133Cs molecules during the loading and holding processes. The inelastic collisions of 85Rb133Cs molecules in the X1Σ+ (v'' = 0, J'' = 1 and J'' = 3) states with ultracold 85Rb (or 133Cs) atoms are measured to be 1.0 (2) × 10-10 cm3 s-1 (1.2 (3) × 10-10 cm3 s-1). Our work provides a simple and generic procedure for studying the dynamical process of trapped cold molecules in the singlet ground states.
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Affiliation(s)
- Zhonghao Li
- Shanxi University, State Key Laboratory of Quantum Optics and Quantum Optics Devices, Institute of Laser Spectroscopy, Wucheng Rd. 92, 030006 Taiyuan, China.
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18
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Hai Y, Hu XJ, Li JL, Cong SL. Efficient photoassociation of ultracold cesium atoms with picosecond pulse laser. Mol Phys 2017. [DOI: 10.1080/00268976.2017.1332786] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
- Yang Hai
- School of Physics and Optoelectronic Technology, Dalian University of Technology , Dalian, China
| | - Xue-Jin Hu
- School of Physics and Optoelectronic Technology, Dalian University of Technology , Dalian, China
| | - Jing-Lun Li
- School of Physics and Optoelectronic Technology, Dalian University of Technology , Dalian, China
| | - Shu-Lin Cong
- School of Physics and Optoelectronic Technology, Dalian University of Technology , Dalian, China
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19
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Hosseini M, Duan Y, Beck KM, Chen YT, Vuletić V. Cavity Cooling of Many Atoms. PHYSICAL REVIEW LETTERS 2017; 118:183601. [PMID: 28524680 DOI: 10.1103/physrevlett.118.183601] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2017] [Indexed: 06/07/2023]
Abstract
We demonstrate cavity cooling of all motional degrees of freedom of an atomic ensemble using light that is far detuned from the atomic transitions by several gigahertz. The cooling is achieved by cavity-induced frequency-dependent asymmetric enhancement of the atomic emission spectrum, thereby extracting thermal kinetic energy from the atomic system. Within 100 ms, the atomic temperature is reduced from 200 to 10 μK, where the final temperature is mainly limited by the linewidth of the cavity. In principle, the technique can be applied to molecules and atoms with complex internal energy structure.
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Affiliation(s)
- Mahdi Hosseini
- Department of Physics and Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - Yiheng Duan
- Department of Physics and Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - Kristin M Beck
- Department of Physics and Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - Yu-Ting Chen
- Department of Physics and Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
| | - Vladan Vuletić
- Department of Physics and Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
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20
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Kozyryev I, Baum L, Matsuda K, Doyle JM. Proposal for Laser Cooling of Complex Polyatomic Molecules. Chemphyschem 2016; 17:3641-3648. [DOI: 10.1002/cphc.201601051] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2016] [Indexed: 11/09/2022]
Affiliation(s)
- Ivan Kozyryev
- Harvard-MIT Center for Ultracold Atoms Cambridge MA 02138 USA
- Department of Physics Harvard University Cambridge MA 02138 USA
| | - Louis Baum
- Harvard-MIT Center for Ultracold Atoms Cambridge MA 02138 USA
- Department of Physics Harvard University Cambridge MA 02138 USA
| | - Kyle Matsuda
- Harvard-MIT Center for Ultracold Atoms Cambridge MA 02138 USA
- Department of Physics Harvard University Cambridge MA 02138 USA
| | - John M. Doyle
- Harvard-MIT Center for Ultracold Atoms Cambridge MA 02138 USA
- Department of Physics Harvard University Cambridge MA 02138 USA
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21
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Wu X, Gantner T, Zeppenfeld M, Chervenkov S, Rempe G. Thermometry of Guided Molecular Beams from a Cryogenic Buffer‐Gas Cell. Chemphyschem 2016; 17:3631-3640. [DOI: 10.1002/cphc.201600559] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2016] [Indexed: 11/06/2022]
Affiliation(s)
- Xing Wu
- Max-Planck-Institut für Quantenoptik Hans-Kopfermann-Strasse 1 85748 Garching Germany
| | - Thomas Gantner
- 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
| | - Sotir Chervenkov
- 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
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22
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Saßmannshausen H, Deiglmayr J. Observation of Rydberg-Atom Macrodimers: Micrometer-Sized Diatomic Molecules. PHYSICAL REVIEW LETTERS 2016; 117:083401. [PMID: 27588856 DOI: 10.1103/physrevlett.117.083401] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2016] [Indexed: 06/06/2023]
Abstract
Long-range metastable molecules consisting of two cesium atoms in high Rydberg states have been observed in an ultracold gas. A sequential three-photon two-color photoassociation scheme is employed to form these molecules in states, which correlate to np(n+1)s dissociation asymptotes. Spectral signatures of bound molecular states are clearly resolved at the positions of avoided crossings between long-range van der Waals potential curves. The experimental results are in agreement with simulations based on a detailed model of the long-range multipole-multipole interactions of Rydberg-atom pair states. We show that a full model is required to accurately predict the occurrence of bound Rydberg macrodimers. The macrodimers are distinguished from repulsive molecular states by their behavior with respect to spontaneous ionization and possible decay channels are discussed.
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Affiliation(s)
- Heiner Saßmannshausen
- Laboratory of Physical Chemistry, ETH Vladimir-Prelog-Weg 2, 8093 Zurich, Switzerland
| | - Johannes Deiglmayr
- Laboratory of Physical Chemistry, ETH Vladimir-Prelog-Weg 2, 8093 Zurich, Switzerland
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23
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Koch CP. Controlling open quantum systems: tools, achievements, and limitations. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2016; 28:213001. [PMID: 27143501 DOI: 10.1088/0953-8984/28/21/213001] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The advent of quantum devices, which exploit the two essential elements of quantum physics, coherence and entanglement, has sparked renewed interest in the control of open quantum systems. Successful implementations face the challenge of preserving relevant nonclassical features at the level of device operation. A major obstacle is decoherence, which is caused by interaction with the environment. Optimal control theory is a tool that can be used to identify control strategies in the presence of decoherence. Here we review recent advances in optimal control methodology that allow typical tasks in device operation for open quantum systems to be tackled and discuss examples of relaxation-optimized dynamics. Optimal control theory is also a useful tool to exploit the environment for control. We discuss examples and point out possible future extensions.
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Affiliation(s)
- Christiane P Koch
- Theoretische Physik, Universität Kassel, Heinrich-Plett-Str. 40, 34132 Kassel, Germany
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24
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Glöckner R, Prehn A, Englert BGU, Rempe G, Zeppenfeld M. Rotational Cooling of Trapped Polyatomic Molecules. PHYSICAL REVIEW LETTERS 2015; 115:233001. [PMID: 26684114 DOI: 10.1103/physrevlett.115.233001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2015] [Indexed: 06/05/2023]
Abstract
Controlling the internal degrees of freedom is a key challenge for applications of cold and ultracold molecules. Here, we demonstrate rotational-state cooling of trapped methyl fluoride molecules (CH_{3}F) by optically pumping the population of 16 M sublevels in the rotational states J=3, 4, 5 and 6 into a single level. By combining rotational-state cooling with motional cooling, we increase the relative number of molecules in the state J=4, K=3, M=4 from a few percent to over 70%, thereby generating a translationally cold (≈30 mK) and nearly pure state ensemble of about 10^{6} molecules. Our scheme is extendable to larger sets of initial states, other final states, and a variety of molecule species, thus paving the way for internal-state control of ever-larger molecules.
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Affiliation(s)
- Rosa Glöckner
- Max-Planck-Institut für Quantenoptik, Hans-Kopfermann-Straße 1, D-85748 Garching, Germany
| | - Alexander Prehn
- Max-Planck-Institut für Quantenoptik, Hans-Kopfermann-Straße 1, D-85748 Garching, Germany
| | - Barbara G U Englert
- Max-Planck-Institut für Quantenoptik, Hans-Kopfermann-Straße 1, D-85748 Garching, Germany
| | - Gerhard Rempe
- Max-Planck-Institut für Quantenoptik, Hans-Kopfermann-Straße 1, D-85748 Garching, Germany
| | - Martin Zeppenfeld
- Max-Planck-Institut für Quantenoptik, Hans-Kopfermann-Straße 1, D-85748 Garching, Germany
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25
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Pazyuk EA, Zaitsevskii AV, Stolyarov AV, Tamanis M, Ferber R. Laser synthesis of ultracold alkali metal dimers: optimization and control. RUSSIAN CHEMICAL REVIEWS 2015. [DOI: 10.1070/rcr4534] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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26
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Sun W, Zhang Y, Fan Q, Feng H, Fu J, Li H, Ma J, Xiao L, Jia S. Hidden physics in molecular rovibrational spectrum. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2014; 132:32-37. [PMID: 24854134 DOI: 10.1016/j.saa.2014.04.137] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2014] [Revised: 04/02/2014] [Accepted: 04/13/2014] [Indexed: 06/03/2023]
Abstract
An algebraic method for rotational energies (AMr) is proposed to unearth the rotational spectrum {ɛJ} and the rovibrational interaction energies ευJint that are hidden in the rovibrational energies EυJ. The applications to the excited electronic state a3Σu+ of 7Li2 and the ground state X1Σ+ of NaF molecules show that: (1) the rotational energies ɛJ of the lighter 7Li2 molecule have better accuracies than the widely used rigid rotor rotational energies εJrr particularly for the lowest two rotational states, while the rigid rotor model produces satisfied rotational energies for the heavier NaF molecule and (2) the attractive rovibrational interaction energies ευJint stabilize a molecular rovibrational system.
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Affiliation(s)
- Weiguo Sun
- School of Physics and Chemistry, Research Center for Advanced Computation, Xihua University, Chengdu, Sichuan 610039, PR China; Institute of Atomic and Molecular Physics, Sichuan University, Chengdu, Sichuan 610065, PR China.
| | - Yi Zhang
- School of Physics and Chemistry, Research Center for Advanced Computation, Xihua University, Chengdu, Sichuan 610039, PR China; School of Physics, Sichuan University, Chengdu, Sichuan 610065, PR China
| | - Qunchao Fan
- School of Physics and Chemistry, Research Center for Advanced Computation, Xihua University, Chengdu, Sichuan 610039, PR China
| | - Hao Feng
- School of Physics and Chemistry, Research Center for Advanced Computation, Xihua University, Chengdu, Sichuan 610039, PR China
| | - Jia Fu
- School of Physics and Chemistry, Research Center for Advanced Computation, Xihua University, Chengdu, Sichuan 610039, PR China; School of Physics, Sichuan University, Chengdu, Sichuan 610065, PR China
| | - Huidong Li
- School of Physics and Chemistry, Research Center for Advanced Computation, Xihua University, Chengdu, Sichuan 610039, PR China; Institute of Atomic and Molecular Physics, Sichuan University, Chengdu, Sichuan 610065, PR China
| | - Jie Ma
- State Key Laboratory of Quantum Optics and Quantum Optics Devices, Laser Spectroscopy Laboratory, Shanxi University, Taiyuan 030006, PR China
| | - Liantuan Xiao
- State Key Laboratory of Quantum Optics and Quantum Optics Devices, Laser Spectroscopy Laboratory, Shanxi University, Taiyuan 030006, PR China
| | - Suotang Jia
- State Key Laboratory of Quantum Optics and Quantum Optics Devices, Laser Spectroscopy Laboratory, Shanxi University, Taiyuan 030006, PR China
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27
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Broadband optical cooling of molecular rotors from room temperature to the ground state. Nat Commun 2014; 5:4783. [DOI: 10.1038/ncomms5783] [Citation(s) in RCA: 73] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2014] [Accepted: 07/23/2014] [Indexed: 11/08/2022] Open
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29
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Affiliation(s)
- Mikhail Lemeshko
- a ITAMP, Harvard-Smithsonian Center for Astrophysics , Cambridge , MA , 02138 , USA
- b Physics Department , Harvard University , Cambridge , MA , 02138 , USA
- c Kavli Institute for Theoretical Physics , University of California , Santa Barbara , CA , 93106 , USA
| | - Roman V. Krems
- c Kavli Institute for Theoretical Physics , University of California , Santa Barbara , CA , 93106 , USA
- d Department of Chemistry , University of British Columbia , BC V6T 1Z1, Vancouver , Canada
| | - John M. Doyle
- b Physics Department , Harvard University , Cambridge , MA , 02138 , USA
| | - Sabre Kais
- e Departments of Chemistry and Physics , Purdue University , West Lafayette , IN , 47907 , USA
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30
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Manai I, Horchani R, Hamamda M, Fioretti A, Allegrini M, Lignier H, Pillet P, Comparat D. Laser cooling of rotation and vibration by optical pumping. Mol Phys 2013. [DOI: 10.1080/00268976.2013.813980] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Affiliation(s)
- I. Manai
- a Laboratoire Aimé Cotton, CNRS , Université Paris-Sud 11 , ENS Cachan, Bât 505, Campus d’Orsay , 91405 , Orsay , France
| | - R. Horchani
- a Laboratoire Aimé Cotton, CNRS , Université Paris-Sud 11 , ENS Cachan, Bât 505, Campus d’Orsay , 91405 , Orsay , France
| | - M. Hamamda
- a Laboratoire Aimé Cotton, CNRS , Université Paris-Sud 11 , ENS Cachan, Bât 505, Campus d’Orsay , 91405 , Orsay , France
| | - A. Fioretti
- b Istituto Nazionale di Ottica , INO-CNR, U. O. S. Pisa “Adriano Gozzini” Via Moruzzi 1 , Pisa , 56124 , Italy
| | - M. Allegrini
- c Dipartimento di Fisica , Università di Pisa and INO-CNR Sezione di Pisa , Largo Pontecorvo 3, Pisa , 56127 , Italy
| | - H. Lignier
- a Laboratoire Aimé Cotton, CNRS , Université Paris-Sud 11 , ENS Cachan, Bât 505, Campus d’Orsay , 91405 , Orsay , France
| | - P. Pillet
- a Laboratoire Aimé Cotton, CNRS , Université Paris-Sud 11 , ENS Cachan, Bât 505, Campus d’Orsay , 91405 , Orsay , France
| | - D. Comparat
- a Laboratoire Aimé Cotton, CNRS , Université Paris-Sud 11 , ENS Cachan, Bât 505, Campus d’Orsay , 91405 , Orsay , France
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31
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Manai I, Horchani R, Lignier H, Pillet P, Comparat D, Fioretti A, Allegrini M. Rovibrational cooling of molecules by optical pumping. PHYSICAL REVIEW LETTERS 2012; 109:183001. [PMID: 23215275 DOI: 10.1103/physrevlett.109.183001] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2012] [Indexed: 06/01/2023]
Abstract
We demonstrate rotational and vibrational cooling of cesium dimers by optical pumping techniques. We use two laser sources exciting all the populated rovibrational states, except a target state that thus behaves like a dark state where molecules pile up thanks to absorption-spontaneous emission cycles. We are able to accumulate photoassociated cold Cs(2) molecules in their absolute ground state (v = 0, J = 0) with up to 40% efficiency. Given its simplicity, the method could be extended to other molecules and molecular beams. It also opens up general perspectives in laser cooling the external degrees of freedom of molecules.
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Affiliation(s)
- I Manai
- Laboratoire Aimé Cotton, CNRS, Université Paris-Sud, ENS Cachan, 11, 91405 Orsay, France
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32
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Ulmanis J, Deiglmayr J, Repp M, Wester R, Weidemüller M. Ultracold Molecules Formed by Photoassociation: Heteronuclear Dimers, Inelastic Collisions, and Interactions with Ultrashort Laser Pulses. Chem Rev 2012; 112:4890-927. [PMID: 22931226 DOI: 10.1021/cr300215h] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Juris Ulmanis
- Physikalisches Institut, Ruprecht-Karls-Universität Heidelberg, Philosophenweg
12, 69120 Heidelberg, Germany
| | - Johannes Deiglmayr
- Laboratorium für Physikalische
Chemie, ETH Zürich, Wolfgang-Pauli-Strasse
10, 8093 Zürich, Switzerland
| | - Marc Repp
- Physikalisches Institut, Ruprecht-Karls-Universität Heidelberg, Philosophenweg
12, 69120 Heidelberg, Germany
| | - Roland Wester
- Institut für Ionenphysik
und Angewandte Physik, Universität Innsbruck, Technikerstrasse 25/3, 6020 Innsbruck, Austria
| | - Matthias Weidemüller
- Physikalisches Institut, Ruprecht-Karls-Universität Heidelberg, Philosophenweg
12, 69120 Heidelberg, Germany
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33
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Affiliation(s)
- Goulven Quéméner
- JILA, University of Colorado,
Boulder, CO 80309-0440, United States
| | - Paul S. Julienne
- Joint Quantum Institute, NIST
and the University of Maryland, Gaithersburg, Maryland 20899-8423,
United States
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34
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Wakim A, Zabawa P, Haruza M, Bigelow NP. Luminorefrigeration: vibrational cooling of NaCs. OPTICS EXPRESS 2012; 20:16083-16091. [PMID: 22772299 DOI: 10.1364/oe.20.016083] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
We demonstrate the use of optical pumping of kinetically ultracold NaCs to cool an initial vibrational distribution of electronic ground state molecules X(1)Σ(+)(v ≥ 4) into the vibrational ground state X(1)Σ(+)(v=0). Our approach is based on the use of simple, commercially available multimode diode lasers selected to optically pump population into X(1)Σ(+)(v=0). We investigate the impact of the cooling process on the rotational state distribution of the vibrational ground state, and observe that an initial distribution, J(initial)=0-2 is only moderately affected resulting in J(final)=0-4. This method provides an inexpensive approach to creation of vibrational ground state ultracold polar molecules.
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Affiliation(s)
- A Wakim
- Department of Physics and Astronomy, University of Rochester, Rochester, NY 14627, USA.
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35
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Li X, Shapiro M. The Dipole Correction Method for Extracting Excited State Potentials and Electronic Transition Dipoles from Fluorescence Data. Isr J Chem 2012. [DOI: 10.1002/ijch.201100095] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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36
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Dardouri R, Habli H, Oujia B, Gadéa FX. Theoretical study of the electronic structure of KLi molecule: Adiabatic and diabatic potential energy curves and dipole moments. Chem Phys 2012. [DOI: 10.1016/j.chemphys.2011.07.010] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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37
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Affiliation(s)
- Christiane P. Koch
- Theoretische Physik, Universität Kassel, Heinrich-Plett-Strasse 40,
34132 Kassel, Germany
| | - Moshe Shapiro
- Department
of Chemistry, University of British Columbia, Vancouver, Canada V6T
1Z1, and Department of Chemical Physics, The Weizmann Institute, Rehovot, Israel 76100
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38
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Willitsch S. Coulomb-crystallised molecular ions in traps: methods, applications, prospects. INT REV PHYS CHEM 2012. [DOI: 10.1080/0144235x.2012.667221] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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39
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Allouche AR, Aubert-Frécon M. Transition dipole moments between the low-lying Ωg,u(+/−)states of the Rb2and Cs2molecules. J Chem Phys 2012; 136:114302. [DOI: 10.1063/1.3694014] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
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40
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Brue DA, Hutson JM. Magnetically tunable Feshbach resonances in ultracold Li-Yb mixtures. PHYSICAL REVIEW LETTERS 2012; 108:043201. [PMID: 22400838 DOI: 10.1103/physrevlett.108.043201] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/08/2011] [Revised: 10/25/2011] [Indexed: 05/31/2023]
Abstract
We investigate the possibility of forming Li+Yb ultracold molecules by magnetoassociation in mixtures of ultracold atoms. We find that magnetically tunable Feshbach resonances exist, but are extremely narrow for even-mass ytterbium isotopes, which all have zero spin. For odd-mass Yb isotopes, however, there is a new mechanism due to hyperfine coupling between the electron spin and the Yb nuclear magnetic moment. This mechanism produces Feshbach resonances for fermionic Yb isotopes that can be more than 2 orders of magnitude larger than for the bosonic counterparts.
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Affiliation(s)
- Daniel A Brue
- Department of Chemistry, Durham University, South Road, Durham DH1 3LE, United Kingdom.
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41
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Lignier H, Fioretti A, Horchani R, Drag C, Bouloufa N, Allegrini M, Dulieu O, Pruvost L, Pillet P, Comparat D. Deeply bound cold caesium molecules formed after 0(-)(g) resonant coupling. Phys Chem Chem Phys 2011; 13:18910-20. [PMID: 21814669 DOI: 10.1039/c1cp21488h] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Translationally cold caesium molecules are created by photoassociation below the 6s + 6p(1/2) excited state and selectively detected by resonance enhanced two photon ionization (RE2PI). A series of excited vibrational levels belonging to the 0(-)(g) symmetry is identified. The regular progression of the vibrational spacings and of the rotational constants of the 0(-)(g) (6s + 6p(1/2)) levels is strongly altered in two energy domains. These deviations are interpreted in terms of resonant coupling with deeply bound energy levels of two upper 0(-)(g) states dissociating into the 6s + 6p(3/2) and 6s + 5d(3/2) asymptotes. A theoretical model is proposed to explain the coupling and a quantum defect analysis of the perturbed level position is performed. Moreover, the resonant coupling changes dramatically the spontaneous decay products of the photoexcited molecules, strongly enhancing the decay into deeply bound levels of the a(3)Σ(+)(u) triplet state and of the X(1)Σ(+)(g) ground state. These results may be relevant when conceiving population transferring schemes in cold molecule systems.
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Affiliation(s)
- H Lignier
- Laboratoire Aimé Cotton, CNRS, Univ. Paris Sud, bât. 505, Campus d'Orsay, 91405, Orsay Cedex, France.
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42
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Wakim A, Zabawa P, Bigelow NP. Photoassociation studies of ultracold NaCs from the Cs 6(2)P(3/2) asymptote. Phys Chem Chem Phys 2011; 13:18887-92. [PMID: 21804986 DOI: 10.1039/c1cp20928k] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A combination of pulsed depletion spectroscopy and photoassociation spectroscopy is utilized to assign photoassociation spectra of NaCs. These methods investigate the ab initio Ω = 2 potential energy curve and indicate a previously unknown avoided crossing between the (3)Ω = 1 and (4)Ω = 1 electronic states. We present rotational assignments of deeply bound singlet ground state molecules, an improved C(6) coefficient for the (4)Ω = 1 and assignments for all twenty-three photoassociation resonances detuned from the Cs 6(2)P(3/2) asymptote.
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Affiliation(s)
- A Wakim
- Department of Physics and Astronomy, University of Rochester, Rochester, NY 14627, USA.
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Ahmed EH, Ingram S, Kirova T, Salihoglu O, Huennekens J, Qi J, Guan Y, Lyyra AM. Quantum control of the spin-orbit interaction using the Autler-Townes effect. PHYSICAL REVIEW LETTERS 2011; 107:163601. [PMID: 22107380 DOI: 10.1103/physrevlett.107.163601] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2011] [Indexed: 05/31/2023]
Abstract
We have demonstrated quantum control of the spin-orbit interaction based on the Autler-Townes (ac-Stark) effect in a molecular system using a cw optical field. We show that the enhancement of the spin-orbit interaction between a pair of weakly interacting singlet-triplet rovibrational levels, G (1)Π(g)(v=12,J=21,f)-1 (3)Σ(g)(-)(v=1,N=21,f), separated by 750 MHz in the lithium dimer, depends on the Rabi frequency (laser power) of the control laser. The increase in the spin-orbit interaction due to the control field is observed as a change in the spin character of the individual components of the perturbed pair.
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Affiliation(s)
- E H Ahmed
- Department of Physics, Temple University, Philadelphia, Pennsylvania 19122, USA.
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Marskar R, Osterberg U. Multilevel Maxwell-Bloch simulations in inhomogeneously broadened media. OPTICS EXPRESS 2011; 19:16784-16796. [PMID: 21935040 DOI: 10.1364/oe.19.016784] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
A compact numerical method for simulating ultrafast pulse interaction with inhomogeneously broadened multi-level media is reported. We use a low-dispersion pseudospectral scheme with fourth order time stepping for Maxwell's equations, and a weakly coupled operator splitting method for the Bloch equations where inhomogeneous broadening and relaxations are also taken into account. The underlying physics is briefly discussed with emphasis on the formalism used.
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Affiliation(s)
- Robert Marskar
- Norwegian University of Science and Technology, Department of Electronics and Telecommunication, Trondheim, Norway.
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Aymar M, Guérout R, Dulieu O. Structure of the alkali-metal-atom + strontium molecular ions: Towards photoassociation and formation of cold molecular ions. J Chem Phys 2011; 135:064305. [DOI: 10.1063/1.3611399] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Affiliation(s)
- M Aymar
- Laboratoire Aimé Cotton, CNRS, UPR3321, Bât. 505, Univ Paris-Sud, 91405 Orsay Cedex, France
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Atabek O, Lefebvre R, Lepers M, Jaouadi A, Dulieu O, Kokoouline V. Proposal for a laser control of vibrational cooling in Na(2) using resonance coalescence. PHYSICAL REVIEW LETTERS 2011; 106:173002. [PMID: 21635034 DOI: 10.1103/physrevlett.106.173002] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2010] [Indexed: 05/30/2023]
Abstract
With a specific choice of laser parameters resulting in a so-called exceptional point (EP) in the wavelength-intensity parameter plane, it is possible to produce the coalescence of two Floquet resonances describing the photodissociation of the Na(2) molecule, which is one of the candidates for the formation of samples of translationally cold molecules. By appropriately tuning laser parameters along a contour encircling the exceptional point, the resonances exchange their quantum nature. Thus a laser-controlled transfer of the probability density from one field-free vibrational level to another is achieved through adiabatic transport involving these resonances. We propose an efficient scenario for vibrational cooling of Na(2) referring to cascade transfers involving multiple EPs and predicted to be robust up to a 78% rate against laser-induced dissociation.
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Affiliation(s)
- O Atabek
- Institut des Sciences Moléculaires d'Orsay, CNRS, Bât 350, Univ. Paris-Sud, 91405 Orsay, France.
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Stoecklin T, Halvick P. Collisional relaxation of MnH (X7Σ+) in a magnetic field: effect of the nuclear spin of Mn. Phys Chem Chem Phys 2011; 13:19142-7. [DOI: 10.1039/c1cp21466g] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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Gabbanini C, Dulieu O. Formation of ultracold metastable RbCs molecules by short-range photoassociation. Phys Chem Chem Phys 2011; 13:18905-9. [DOI: 10.1039/c1cp21497g] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Tomza M, Pawłowski F, Jeziorska M, Koch CP, Moszynski R. Formation of ultracold SrYb molecules in an optical lattice by photoassociation spectroscopy: theoretical prospects. Phys Chem Chem Phys 2011; 13:18893-904. [DOI: 10.1039/c1cp21196j] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Julienne PS, Hanna TM, Idziaszek Z. Universal ultracold collision rates for polar molecules of two alkali-metal atoms. Phys Chem Chem Phys 2011; 13:19114-24. [DOI: 10.1039/c1cp21270b] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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