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Zhang Y, Wang Q, Ni S, Ji L, Cao Z, Qi J. The effect of spin-orbit coupling on molecular properties: Potential energy curve, transition dipole moment and laser cooling scheme of NH. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2022; 267:120578. [PMID: 34815177 DOI: 10.1016/j.saa.2021.120578] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Revised: 10/08/2021] [Accepted: 10/31/2021] [Indexed: 06/13/2023]
Abstract
The influence of spin-orbit coupling on the cooling of NH molecular laser is investigated based on the ab initio theory. The potential energy curves (PECs) and spectral constants for four Λ-S states (X3Σ-, a1Δ, b1Σ+ and A3Π) and eight Ω states [Formula: see text] a1Δ2, [Formula: see text] and [Formula: see text] ) of NH molecule are obtained by the multi-reference configuration interaction (MRCI) plus Davidson correction. The spectroscopic constants (Re, ωe, ωeχe, Be, De) are obtained by solving the one dimensional radial Schrödinger equation, and the results are almost the same as the previously reported data. In addition, the transition dipole moment, permanent dipole moment, Franck-Condon factors, and radiative lifetime of NH molecule are also acquired. Also, the effects of the intermediate state on the [Formula: see text] , [Formula: see text] and [Formula: see text] transitions are considered. The feasible laser cooling schemes using a single laser are formulated. In the proposed cooling scheme, there wavelengths for the [Formula: see text] are used, the main pump lasers are λ00 = 335.74 nm. The feasible transition is based on this. It is found that spin-orbit coupling has a significant effect on potential energy curves, permanent dipole moments, transition dipole moments and vibration energy levels.
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Affiliation(s)
- Yunguang Zhang
- School of Science, Xi'an University of Posts and Telecommunications, Xi'an 710121, China.
| | - Qihao Wang
- School of Science, Xi'an University of Posts and Telecommunications, Xi'an 710121, China
| | - Simin Ni
- School of Science, Xi'an University of Posts and Telecommunications, Xi'an 710121, China
| | - Lingling Ji
- School of Science, Xi'an University of Posts and Telecommunications, Xi'an 710121, China
| | - Zhanli Cao
- School of Science, Xi'an University of Posts and Telecommunications, Xi'an 710121, China
| | - Jiangxia Qi
- School of Science, Xi'an University of Posts and Telecommunications, Xi'an 710121, China
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2
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Lewis TN, Wang C, Daniel JR, Dhital M, Bardeen CJ, Hemmerling B. Optimizing pulsed-laser ablation production of AlCl molecules for laser cooling. Phys Chem Chem Phys 2021; 23:22785-22793. [PMID: 34610064 DOI: 10.1039/d1cp03515k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Aluminum monochloride (AlCl) has been proposed as a promising candidate for laser cooling to ultracold temperatures, and recent spectroscopy results support this prediction. It is challenging to produce large numbers of AlCl molecules because it is a highly reactive open-shell molecule and must be generated in situ. Here we show that pulsed-laser ablation of stable, non-toxic mixtures of Al with alkali or alkaline earth chlorides, denoted XCln, can provide a robust and reliable source of cold AlCl molecules. Both the chemical identity of XCln and the Al : XCln molar ratio are varied, and the yield of AlCl is monitored using absorption spectroscopy in a cryogenic gas. For KCl, the production of Al and K atoms was also monitored. We model the AlCl production in the limits of nonequilibrium recombination dominated by first-encounter events. The non-equilibrium model is in agreement with the data and also reproduces the observed trend with different XCln precursors. We find that AlCl production is limited by the solid-state densities of Al and Cl atoms and the recondensation of Al atoms in the ablation plume. We suggest future directions for optimizing the production of cold AlCl molecules using laser ablation.
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Affiliation(s)
- Taylor N Lewis
- Department of Chemistry, University of California, Riverside, CA 92521, USA.
| | - Chen Wang
- Department of Physics and Astronomy, University of California, Riverside, CA 92521, USA.
| | - John R Daniel
- Department of Physics and Astronomy, University of California, Riverside, CA 92521, USA.
| | - Madhav Dhital
- Department of Physics and Astronomy, University of California, Riverside, CA 92521, USA.
| | | | - Boerge Hemmerling
- Department of Physics and Astronomy, University of California, Riverside, CA 92521, USA.
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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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5
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Fu M, Ma H, Cao J, Bian W. Extensive theoretical study on electronically excited states of calcium monochloride: Molecular laser cooling and production of ultracold chlorine atoms. J Chem Phys 2017; 144:184302. [PMID: 27179479 DOI: 10.1063/1.4948631] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Nine doublet Λ-S states of calcium monochloride (CaCl) are calculated using the internally contracted multireference configuration interaction method with the Davidson correction. Both the core subvalence and spin-orbit coupling effects are taken into account. Laser cooling of CaCl and production of ultracold chlorine atoms are investigated and assessed. Our computed spectroscopic constants and radiative lifetimes match the available experimental data very well. The determined Franck-Condon factors and vibrational branching ratios of the A(2)Π1/2(ν('))←X(2)Σ1/2 (+)(ν) transition are highly diagonally distributed and the evaluated radiative lifetime for the A(2)Π1/2(ν' = 0) state is 28.2 ns, which is short enough for rapid laser cooling. Subsequently, detection of cold molecules via resonance enhanced multiphoton ionization to determine the final quantum state populations is discussed and the ionization energy calculated. A multi-pulse excitation scheme is proposed for producing ultracold chlorine atoms from zero-energy photodissociation of the cooled CaCl. Our results demonstrate the possibility of producing ultracold CaCl molecules and Cl atoms.
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Affiliation(s)
- Mingkai Fu
- Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | - Haitao Ma
- Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | - Jianwei Cao
- Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | - Wensheng Bian
- Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
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6
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Affiliation(s)
- Quan-Shun Yang
- Institute of Atomic and Molecular Physics, Sichuan University, Chengdu, China
| | - Tao Gao
- Institute of Atomic and Molecular Physics, Sichuan University, Chengdu, China
- Key Laboratory of High Energy Density Physics and Technology of Ministry of Education, Sichuan University, Chengdu, China
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7
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Zhang YG, Zhang H, Song HY, Yu Y, Wan MJ. Theoretical investigation on spin-forbidden cooling transitions of gallium hydride. Phys Chem Chem Phys 2017; 19:24647-24655. [DOI: 10.1039/c7cp02295f] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The feasibility of laser cooling of gallium hydride is investigated using ab initio quantum chemistry.
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Affiliation(s)
- Yun-Guang Zhang
- School of Science
- Xi’an University of Posts and Telecommunications
- Xi’an 710121
- China
| | - Hua Zhang
- School of Science
- Xi’an University of Posts and Telecommunications
- Xi’an 710121
- China
| | - Hai-Yang Song
- School of Science
- Xi’an University of Posts and Telecommunications
- Xi’an 710121
- China
| | - You Yu
- College of Optoelectronic Technology
- Chengdu University of Information Technology
- Chengdu 610225
- China
| | - Ming-Jie Wan
- Computational Physics Key Laboratory of Sichuan Province
- Yibin University
- Yibin 644007
- China
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8
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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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9
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Abstract
Over the past decade, and particularly the past five years, a quiet revolution has been building at the border between atomic physics and experimental quantum chemistry. The rapid development of techniques for producing cold and even ultracold molecules without a perturbing rare-gas cluster shell is now enabling the study of chemical reactions and scattering at the quantum scattering limit with only a few partial waves contributing to the incident channel. Moreover, the ability to perform these experiments with nonthermal distributions comprising one or a few specific states enables the observation and even full control of state-to-state collision rates in this computation-friendly regime: This is perhaps the most elementary study possible of scattering and reaction dynamics.
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Affiliation(s)
- Benjamin K Stuhl
- Joint Quantum Institute, National Institute of Standards and Technology and University of Maryland, Gaithersburg, Maryland 20899
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10
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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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11
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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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12
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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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13
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Nesbitt DJ. Toward State-to-State Dynamics in Ultracold Collisions: Lessons from High-Resolution Spectroscopy of Weakly Bound Molecular Complexes. Chem Rev 2012; 112:5062-72. [DOI: 10.1021/cr300208b] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- David J. Nesbitt
- JILA, National Institute of Standards and Technology, and Department of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado 80309, United
States
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14
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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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15
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Liu Y, Wang BS, Xie SY, Bo Y, Wang PY, Zuo JW, Xu YT, Xu JL, Peng QJ, Cui DF, Xu ZY. High-power narrow-linewidth quasi-CW diode-pumped TEM00 1064 nm Nd:YAG ring laser. APPLIED OPTICS 2012; 51:C27-C31. [PMID: 22505107 DOI: 10.1364/ao.51.000c27] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2011] [Accepted: 02/15/2012] [Indexed: 05/31/2023]
Abstract
We demonstrated a high average power, narrow-linewidth, quasi-CW diode-pumped Nd:YAG 1064 nm laser with near-diffraction-limited beam quality. A symmetrical three-mirror ring cavity with unidirectional operation elements and an etalon was employed to realize the narrow-linewidth laser output. Two highly efficient laser modules and a 90° quartz rotator for birefringence compensation were used for the high output power. The maximum average output power of 62.5 W with the beam quality factor M(2) of 1.15 was achieved under a pump power of 216 W at a repetition rate of 500 Hz, corresponding to the optical-to-optical conversion efficiency of 28.9%. The linewidth of the laser at the maximum output power was measured to be less than 0.2 GHz.
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Affiliation(s)
- Yuan Liu
- RCLPT, Key Lab of Functional Crystal and Laser Technology, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing, China
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16
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van de Meerakker SYT, Bethlem HL, Vanhaecke N, Meijer G. Manipulation and Control of Molecular Beams. Chem Rev 2012; 112:4828-78. [DOI: 10.1021/cr200349r] [Citation(s) in RCA: 247] [Impact Index Per Article: 20.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
| | - Hendrick L. Bethlem
- Institute for Lasers, Life and
Biophotonics, VU University Amsterdam,
De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands
| | - Nicolas Vanhaecke
- Laboratoire Aimé Cotton, CNRS, Bâtiment 505, Université Paris-Sud,
91405 Orsay, France
| | - Gerard Meijer
- Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, 14195 Berlin,
Germany
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17
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Marian A, Friedrich B. Light Gives Molecules the Chills. Chemphyschem 2011; 12:259-61. [DOI: 10.1002/cphc.201000967] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2010] [Indexed: 11/11/2022]
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18
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Sofikitis D, Fioretti A, Weber S, Horchani R, Pichler M, Li X, Allegrini M, Chatel B, Comparat D, Pillet P. Vibrational cooling of cold molecules with optimised shaped pulses. Mol Phys 2010. [DOI: 10.1080/00268971003689899] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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19
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Viteau M, Chotia A, Sofikitis D, Allegrini M, Bouloufa N, Dulieu O, Comparat D, Pillet P. Broadband lasers to detect and cool the vibration of cold molecules. Faraday Discuss 2010; 142:257-70; discussion 319-34. [PMID: 20151547 DOI: 10.1039/b819697d] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
By using broadband lasers, we demonstrate the possibilities for control of cold molecules formed via photoassociation. Firstly, we present a detection REMPI scheme (M. Viteau et al., Phys. Rev. A, 2009, 79, 021402) to systematically investigate the mechanisms of formation of ultracold Cs2 molecules in deeply bound levels of their electronic ground state X1sigma(g)+. This broadband detection scheme could be generalized to other molecular species. Then we report a vibrational cooling technique (M. Viteau et al., Science, 2008, 321, 232) through optical pumping obtained by using a shaped mode locked femtosecond laser. The broadband femtosecond laser excites the molecules electronically, leading to a redistribution of the vibrational population in the ground state via a few absorption-spontaneous emission cycles. By removing the laser frequencies corresponding to the excitation of the v = 0 level, we realize a dark state for the so-shaped femtosecond laser, leading, with the successive laser pulses, to an accumulation of the molecules in the v = 0 level, ie. a laser cooling of the vibration. The simulation of the vibrational laser cooling allows us to characterize the criteria to extend the mechanism to other molecular species (R. V. Krems, Int. Rev. Phys. Chem., 2005, 24, 99). We finally discuss the generalization of the technique to laser cooling of the rotation of the molecule.
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Affiliation(s)
- Matthieu Viteau
- Laboratoire Aimé Cotton, CNRS, Univ Paris-Sud, Bât. 505, 91405 Orsay, France
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20
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Chang DE, Regal CA, Papp SB, Wilson DJ, Ye J, Painter O, Kimble HJ, Zoller P. Cavity opto-mechanics using an optically levitated nanosphere. Proc Natl Acad Sci U S A 2010; 107:1005-10. [PMID: 20080573 PMCID: PMC2824320 DOI: 10.1073/pnas.0912969107] [Citation(s) in RCA: 439] [Impact Index Per Article: 31.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Recently, remarkable advances have been made in coupling a number of high-Q modes of nano-mechanical systems to high-finesse optical cavities, with the goal of reaching regimes in which quantum behavior can be observed and leveraged toward new applications. To reach this regime, the coupling between these systems and their thermal environments must be minimized. Here we propose a novel approach to this problem, in which optically levitating a nano-mechanical system can greatly reduce its thermal contact, while simultaneously eliminating dissipation arising from clamping. Through the long coherence times allowed, this approach potentially opens the door to ground-state cooling and coherent manipulation of a single mesoscopic mechanical system or entanglement generation between spatially separate systems, even in room-temperature environments. As an example, we show that these goals should be achievable when the mechanical mode consists of the center-of-mass motion of a levitated nanosphere.
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Affiliation(s)
- D. E. Chang
- Institute for Quantum Information and Center for the Physics of Information, California Institute of Technology, Pasadena, CA 91125
| | - C. A. Regal
- Norman Bridge Laboratory of Physics 12-33, California Institute of Technology, Pasadena, CA 91125
| | - S. B. Papp
- Norman Bridge Laboratory of Physics 12-33, California Institute of Technology, Pasadena, CA 91125
| | - D. J. Wilson
- Norman Bridge Laboratory of Physics 12-33, California Institute of Technology, Pasadena, CA 91125
| | - J. Ye
- Norman Bridge Laboratory of Physics 12-33, California Institute of Technology, Pasadena, CA 91125
- JILA, National Institute of Standards and Technology, and Department of Physics, University of Colorado, Boulder, CO 80309
| | - O. Painter
- Department of Applied Physics, California Institute of Technology, Pasadena, CA 91125; and
| | - H. J. Kimble
- Norman Bridge Laboratory of Physics 12-33, California Institute of Technology, Pasadena, CA 91125
| | - P. Zoller
- Norman Bridge Laboratory of Physics 12-33, California Institute of Technology, Pasadena, CA 91125
- Institute for Quantum Optics and Quantum Information of the Austrian Academy of Sciences, A-6020 Innsbruck, Austria
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21
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Shuman ES, Barry JF, Glenn DR, DeMille D. Radiative force from optical cycling on a diatomic molecule. PHYSICAL REVIEW LETTERS 2009; 103:223001. [PMID: 20366090 DOI: 10.1103/physrevlett.103.223001] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2009] [Indexed: 05/29/2023]
Abstract
We demonstrate a scheme for optical cycling in the polar, diatomic molecule strontium monofluoride (SrF) using the X2Sigma+ --> A2Pi(1/2) electronic transition. SrF's highly diagonal Franck-Condon factors suppress vibrational branching. We eliminate rotational branching by employing a quasicycling N = 1 --> N' = 0 type transition in conjunction with magnetic field remixing of dark Zeeman sublevels. We observe cycling fluorescence and deflection through radiative force of an SrF molecular beam using this scheme. With straightforward improvements our scheme promises to allow more than 10(5) photon scatters, possibly enabling the direct laser cooling of SrF.
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Affiliation(s)
- E S Shuman
- Department of Physics, Yale University, P.O. Box 208120, New Haven, Connecticut 06520, USA
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22
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Sofikitis D, Fioretti A, Weber S, Viteau M, Chotia A, Horchani R, Allegrini M, Chatel B, Comparat D, Pillet P. Broadband Vibrational Cooling of Cold Cesium Molecules: Theory and Experiments. CHINESE J CHEM PHYS 2009. [DOI: 10.1088/1674-0068/22/02/149-156] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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23
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24
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Julienne PS. Ultracold molecules from ultracold atoms: a case study with the KRb molecule. Faraday Discuss 2009; 142:361-88; discussion 429-61. [DOI: 10.1039/b820917k] [Citation(s) in RCA: 46] [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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25
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Stuhl BK, Sawyer BC, Wang D, Ye J. Magneto-optical trap for polar molecules. PHYSICAL REVIEW LETTERS 2008; 101:243002. [PMID: 19113618 DOI: 10.1103/physrevlett.101.243002] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/14/2008] [Indexed: 05/27/2023]
Abstract
We propose a method for laser cooling and trapping a substantial class of polar molecules and, in particular, titanium (II) oxide (TiO). This method uses pulsed electric fields to nonadiabatically remix the ground-state magnetic sublevels of the molecule, allowing one to build a magneto-optical trap based on a quasicycling J' = J'' -1 transition. Monte Carlo simulations of this electrostatically remixed magneto-optical trap demonstrate the feasibility of cooling TiO to a temperature of 10 micrpK and trapping it with a radiation-pumping-limited lifetime on the order of 80 ms.
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Affiliation(s)
- Benjamin K Stuhl
- JILA, National Institute of Standards and Technology, University of Colorado, Boulder, Colorado 80309-0440, USA.
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26
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Affiliation(s)
- P. L. Gould
- Department of Physics, University of Connecticut, Storrs, CT 06269-3046, USA
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27
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Viteau M, Chotia A, Allegrini M, Bouloufa N, Dulieu O, Comparat D, Pillet P. Optical Pumping and Vibrational Cooling of Molecules. Science 2008; 321:232-4. [DOI: 10.1126/science.1159496] [Citation(s) in RCA: 231] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- Matthieu Viteau
- Laboratoire Aimé Cotton, CNRS, Université Paris-Sud, Bâtiment 505, 91405 Orsay, France
- Consorzio Nazionale Interuniversitario per le Scienze Fisiche della Materia, Dipartimento di Fisica, Università di Pisa, Largo Pontecorvo 3,56127 Pisa, Italy
| | - Amodsen Chotia
- Laboratoire Aimé Cotton, CNRS, Université Paris-Sud, Bâtiment 505, 91405 Orsay, France
- Consorzio Nazionale Interuniversitario per le Scienze Fisiche della Materia, Dipartimento di Fisica, Università di Pisa, Largo Pontecorvo 3,56127 Pisa, Italy
| | - Maria Allegrini
- Laboratoire Aimé Cotton, CNRS, Université Paris-Sud, Bâtiment 505, 91405 Orsay, France
- Consorzio Nazionale Interuniversitario per le Scienze Fisiche della Materia, Dipartimento di Fisica, Università di Pisa, Largo Pontecorvo 3,56127 Pisa, Italy
| | - Nadia Bouloufa
- Laboratoire Aimé Cotton, CNRS, Université Paris-Sud, Bâtiment 505, 91405 Orsay, France
- Consorzio Nazionale Interuniversitario per le Scienze Fisiche della Materia, Dipartimento di Fisica, Università di Pisa, Largo Pontecorvo 3,56127 Pisa, Italy
| | - Olivier Dulieu
- Laboratoire Aimé Cotton, CNRS, Université Paris-Sud, Bâtiment 505, 91405 Orsay, France
- Consorzio Nazionale Interuniversitario per le Scienze Fisiche della Materia, Dipartimento di Fisica, Università di Pisa, Largo Pontecorvo 3,56127 Pisa, Italy
| | - Daniel Comparat
- Laboratoire Aimé Cotton, CNRS, Université Paris-Sud, Bâtiment 505, 91405 Orsay, France
- Consorzio Nazionale Interuniversitario per le Scienze Fisiche della Materia, Dipartimento di Fisica, Università di Pisa, Largo Pontecorvo 3,56127 Pisa, Italy
| | - Pierre Pillet
- Laboratoire Aimé Cotton, CNRS, Université Paris-Sud, Bâtiment 505, 91405 Orsay, France
- Consorzio Nazionale Interuniversitario per le Scienze Fisiche della Materia, Dipartimento di Fisica, Università di Pisa, Largo Pontecorvo 3,56127 Pisa, Italy
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Morigi G, Pinkse PWH, Kowalewski M, de Vivie-Riedle R. Cavity cooling of internal molecular motion. PHYSICAL REVIEW LETTERS 2007; 99:073001. [PMID: 17930891 DOI: 10.1103/physrevlett.99.073001] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2007] [Indexed: 05/25/2023]
Abstract
We predict that it is possible to cool rotational, vibrational, and translational degrees of freedom of molecules by coupling a molecular dipole transition to an optical cavity. The dynamics is numerically simulated for a realistic set of experimental parameters using OH molecules. The results show that the translational motion is cooled to a few muK and the internal state is prepared in one of the two ground states of the two decoupled rotational ladders in a few seconds. Shorter cooling times are expected for molecules with larger polarizability.
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Affiliation(s)
- Giovanna Morigi
- Departament de Fisica, Universitat Autonoma de Barcelona, E-08193 Bellaterra, Spain
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29
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Lee TG, Balakrishnan N, Forrey RC, Stancil PC, Schultz DR, Ferland GJ. State-to-state rotational transitions in H2+H2 collisions at low temperatures. J Chem Phys 2006; 125:114302. [PMID: 16999469 DOI: 10.1063/1.2338319] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
We present quantum mechanical close-coupling calculations of collisions between two hydrogen molecules over a wide range of energies, extending from the ultracold limit to the superthermal region. The two most recently published potential energy surfaces for the H(2)-H(2) complex, the so-called Diep-Johnson (DJ) [J. Chem. Phys. 112, 4465 (2000); 113, 3480 (2000)] and Boothroyd-Martin-Keogh-Peterson (BMKP) [J. Chem. Phys. 116, 666 (2002)] surfaces, are quantitatively evaluated and compared through the investigation of rotational transitions in H(2)+H(2) collisions within rigid rotor approximation. The BMKP surface is expected to be an improvement, approaching chemical accuracy, over all conformations of the potential energy surface compared to previous calculations of H(2)-H(2) interaction. We found significant differences in rotational excitation/deexcitation cross sections computed on the two surfaces in collisions between two para-H(2) molecules. The discrepancy persists over a large range of energies from the ultracold regime to thermal energies and occurs for several low-lying initial rotational levels. Good agreement is found with experiment B. Mate et al., [J. Chem. Phys. 122, 064313 (2005)] for the lowest rotational excitation process, but only with the use of the DJ potential. Rate coefficients computed with the BMKP potential are an order of magnitude smaller.
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Affiliation(s)
- Teck-Ghee Lee
- Department of Physics and Astronomy, University of Kentucky, Lexington, Kentucky 40506, USA.
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Uudus N, Magaki S, Balakrishnan N. Quantum mechanical investigation of rovibrational relaxation of H2 and D2 by collisions with Ar atoms. J Chem Phys 2005; 122:024304. [PMID: 15638583 DOI: 10.1063/1.1829976] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We report quantum mechanical calculations of cross sections and rate coefficients for rovibrational relaxation of H2 and D2 by collisions with Ar atoms over a wide range of temperatures including the ultracold limit. Limiting values of the rate coefficients for vibrational and rotational quenching at zero temperature were computed and sensitivity of the results to the choice of the interaction potential is investigated. We also demonstrate dramatic change in the behavior of the rate coefficients at low temperatures when the van der Waals potential supports a quasibound level very close to the dissociation threshold.
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Affiliation(s)
- Nyamsuren Uudus
- Department of Chemistry, University of Nevada Las Vegas, Las Vegas, Nevada 89154, USA
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31
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Lee TG, Rochow C, Martin R, Clark TK, Forrey RC, Balakrishnan N, Stancil PC, Schultz DR, Dalgarno A, Ferland GJ. Close-coupling calculations of low-energy inelastic and elastic processes in 4He collisions with H2: A comparative study of two potential energy surfaces. J Chem Phys 2005; 122:024307. [PMID: 15638586 DOI: 10.1063/1.1833351] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The two most recently published potential energy surfaces (PESs) for the HeH2 complex, the so-called MR (Muchnick and Russek) and BMP (Boothroyd, Martin, and Peterson) surfaces, are quantitatively evaluated and compared through the investigation of atom-diatom collision processes. The BMP surface is expected to be an improvement, approaching chemical accuracy, over all conformations of the PES compared to that of the MR surface. We found significant differences in inelastic rovibrational cross sections computed on the two surfaces for processes dominated by large changes in target rotational angular momentum. In particular, the H2(nu=1,j=0) total quenching cross section computed using the BMP potential was found to be a factor of 1000 larger than that obtained with the MR surface. A lesser discrepancy persists over a large range of energies from the ultracold to thermal and occurs for other low-lying initial rovibrational levels. The MR surface was used in previous calculations of the H2(nu=1,j=0) quenching rate coefficient and gave results in close agreement with the experimental data of Audibert et al. which were obtained for temperatures between 50 and 300 K. Examination of the rovibronic coupling matrix elements, which are obtained following a Legendre expansion of the PES, suggests that the magnitude of the anisotropy of the BMP potential is too large in the interaction region. However, cross sections for elastic and pure rotational processes obtained from the two PESs differ typically by less than a factor of 2. The small differences may be ascribed to the long-range and anharmonic components of the PESs. Exceptions occur for (nu=10,j=0) and (nu=11,j=1) where significant enhancements have been found for the low-energy quenching and elastic cross sections due to zero-energy resonances in the BMP PES which are not present in the MR potential.
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Affiliation(s)
- Teck-Ghee Lee
- Department of Physics and Astronomy, University of Kentucky, Lexington, Kentucky 40506, USA
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32
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Dulieu O, Pillet P. Playing With a Pair of Ultracold Atoms and Lasers: Towards a Novel Ultracold Photochemistry? Isr J Chem 2004. [DOI: 10.1560/rhhr-c4m6-pffn-8a8j] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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33
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Balakrishnan N. On the role of van der Waals interaction in chemical reactions at low temperatures. J Chem Phys 2004; 121:5563-6. [PMID: 15366978 DOI: 10.1063/1.1799571] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
It is shown that van der Waals interaction potential plays a crucial role in chemical reactions at low temperatures. By taking the Cl+HD reaction as an illustrative example, we demonstrate that quasibound states of the van der Waals potential preferentially undergo chemical reaction rather than vibrational predissociation. Prereaction occurs even when the wave functions of the quasibound states peak far out into the entrance channel, outside the region of the van der Waals well. It is found that chemical reaction dominates over nonreactive vibrational quenching in collisions of vibrationally excited HD molecules with ground state chlorine atoms at ultracold temperatures.
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Affiliation(s)
- N Balakrishnan
- Department of Chemistry, University of Nevada Las Vegas, Las Vegas, Nevada 89154, USA.
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Abstract
There has been much progress in the control of chemical reactions since methods of active control were first proposed by Brumer & Shapiro and by Tannor & Rice ten years ago. This chapter reviews both theoretical and experimental advances in the field. Control schemes based on quantum mechanical interference between competing paths and the manipulation of wave packets with tailored laser pulses are discussed. The theory of optimal control, the limitations of control theory applied to many-body dynamics, and the effects of constraints on the trajectory of the controlled observable are presented. Experimental progress in controlling the population of specific quantum states, in manipulating the dynamics of bound wave packets, and in the control of chemical reactions are reviewed, and current problems in the field are summarized.
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Affiliation(s)
- R J Gordon
- Department of Chemistry (m/c 111), University of Illinois at Chicago, 845 W Taylor Street, Chicago, IL 60607-7061, USA.
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Xu K, Mukaiyama T, Abo-Shaeer JR, Chin JK, Miller DE, Ketterle W. Formation of quantum-degenerate sodium molecules. PHYSICAL REVIEW LETTERS 2003; 91:210402. [PMID: 14683282 DOI: 10.1103/physrevlett.91.210402] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/01/2003] [Indexed: 05/24/2023]
Abstract
Ultracold sodium molecules were produced from an atomic Bose-Einstein condensate by ramping an applied magnetic field across a Feshbach resonance. More than 10(5) molecules were generated with a conversion efficiency of approximately 4%. Using laser light resonant with an atomic transition, the remaining atoms could be selectively removed, preventing fast collisional relaxation of the molecules. Time-of-flight analysis of the pure molecular sample yielded an instantaneous phase-space density greater than 20.
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Affiliation(s)
- K Xu
- Department of Physics, MIT-Harvard Center for Ultracold Atoms, and Research Laboratory of Electronics, MIT, Cambridge, Massachusetts 02139, USA
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Balakrishnan N, Dalgarno A. On the Isotope Effect in F + HD Reaction at Ultracold Temperatures. J Phys Chem A 2003. [DOI: 10.1021/jp022654v] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Affiliation(s)
- N. Balakrishnan
- Department of Chemistry, University of Nevada Las Vegas, 4505 Maryland Parkway, Las Vegas, Nevada 89154
| | - A. Dalgarno
- Institute for Theoretical Atomic and Molecular Physics, Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, Massachusetts 02138
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37
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Balakrishnan N, Groenenboom GC, Krems RV, Dalgarno A. The He–CaH([sup 2]Σ[sup +]) interaction. II. Collisions at cold and ultracold temperatures. J Chem Phys 2003. [DOI: 10.1063/1.1562947] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Groenenboom GC, Balakrishnan N. The He–CaH ([sup 2]Σ[sup +]) interaction. I. Three-dimensional ab initio potential energy surface. J Chem Phys 2003. [DOI: 10.1063/1.1562946] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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39
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Krems R, Dalgarno A. Electronic and rotational energy transfer in F(2P1/2)+H2 collisions at ultracold temperatures. J Chem Phys 2002. [DOI: 10.1063/1.1480004] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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40
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Hotta S, Doi K, Nakamura K, Tachibana A. High-spin electronic interaction of small lithium and sodium cluster formation in the excited states. J Chem Phys 2002. [DOI: 10.1063/1.1480869] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Baba T, Waki I. Chemical reaction of sympathetically laser-cooled molecular ions. J Chem Phys 2002. [DOI: 10.1063/1.1431273] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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44
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Zhu C, Balakrishnan N, Dalgarno A. Vibrational relaxation of CO in ultracold 3He collisions. J Chem Phys 2001. [DOI: 10.1063/1.1379581] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Abstract
This review focuses on the study of the dynamics of isolated molecules and their control using coherent nonlinear spectroscopic methods. Emphasis is placed on topics such as bound-to-free excitation and the study of concerted elimination reactions, free-to-bound excitation and the study of bimolecular reactions, and bound-to-bound excitation and the study of intramolecular rovibrational dynamics and coherence relaxation. For each case the detailed time-resolved information reveals possible strategies to control the outcome. Experimental results are shown for each of the reactions discussed. The methods discussed include pump-probe and four-wave mixing processes such as transient grating and photon echo spectroscopy. Off-resonance transient-grating experiments are shown to be ideal for the study of ground state dynamics, molecular structure, and the molecular response to strong field excitation.
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Affiliation(s)
- M Dantus
- Department of Chemistry and Center for Fundamental Materials Research, Michigan State University, East Lansing, Michigan 48824, USA.
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48
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Balakrishnan N, Dalgarno A. On the Quenching of Rovibrationally Excited Molecular Oxygen at Ultracold Temperatures. J Phys Chem A 2001. [DOI: 10.1021/jp0034224] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- N. Balakrishnan
- Institute for Theoretical Atomic and Molecular Physics, Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, Massachusetts 02138
| | - A. Dalgarno
- Institute for Theoretical Atomic and Molecular Physics, Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, Massachusetts 02138
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Balakrishnan N, Dalgarno A, Forrey RC. Vibrational relaxation of CO by collisions with 4He at ultracold temperatures. J Chem Phys 2000. [DOI: 10.1063/1.481838] [Citation(s) in RCA: 99] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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