1
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Le Duc V, Zou J, Osterwalder A. Alignment of ND3 molecules in dc-electric fields. J Chem Phys 2024; 160:204305. [PMID: 38804496 DOI: 10.1063/5.0210431] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2024] [Accepted: 05/08/2024] [Indexed: 05/29/2024] Open
Abstract
The control of movement and orientation of gas-phase molecules has become the focus of many research areas in molecular physics. Here, ND3 molecules are polarized in a segmented, curved electrostatic guide and adiabatically aligned inside a rotatable mass spectrometer (MS). Alignment is probed by photoionization using a linearly polarized laser. Rotation of the polarization at fixed MS orientation has the same effect as the rotation of the MS at fixed polarization, proving that the molecular alignment adiabatically follows the MS axis. Polarization-dependent ion signals reveal state-specific populations and allow for a quantification of the aligned sample in the space-fixed reference frame.
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Affiliation(s)
- Viet Le Duc
- Institute for Chemical Sciences and Engineering (ISIC), Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
| | - Junwen Zou
- Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT, United Kingdom
| | - Andreas Osterwalder
- Institute for Chemical Sciences and Engineering (ISIC), Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
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2
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Devi S, Prasad V. Dynamics of coupled rotors in external fields. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2023; 302:122983. [PMID: 37393672 DOI: 10.1016/j.saa.2023.122983] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Revised: 05/19/2023] [Accepted: 06/03/2023] [Indexed: 07/04/2023]
Abstract
Coupled hindered rotor model is crucial for exploring the rotational dynamics of complex molecules under different external environments. When coupled hindered rotor molecules are subjected to the combined action of static electric and laser fields, their rotational dynamics get significantly modified, leading to interesting physics. In this study, we solve the time-independent Schrödinger equation for the coupled pair of rotors in the combined action of static electric and laser fields using the nine-point finite difference method and obtain rotational energy spectra and eigenvectors. We then use the partition function approach to understand thermal behaviour by studying thermal properties like heat capacity and entropy. We also explore the impact of temperature, coupling strength, and external fields strength parameters on these properties. The orientation of the coupled rotor is strongly dependent on the coupling strength between the coupled rotors as well as the hindrance. We analyse this directional parameter under a broad range of barrier height, coupling strength, and external fields strength parameters. Our analysis may provide insight into the rich and interesting physics, which may pave the way for future experimental and theoretical studies in this area.
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Affiliation(s)
- Sumana Devi
- Department of Physics and Astrophysics, University of Delhi, Delhi 110007, India; Department of Physics, Miranda House, University of Delhi, Delhi 110007, India.
| | - Vinod Prasad
- Department of Physics, Swami Shradhanand College, University of Delhi, Delhi 110036, India.
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3
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Zhang Y, Jiang B. Universal machine learning for the response of atomistic systems to external fields. Nat Commun 2023; 14:6424. [PMID: 37827998 PMCID: PMC10570356 DOI: 10.1038/s41467-023-42148-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2023] [Accepted: 10/01/2023] [Indexed: 10/14/2023] Open
Abstract
Machine learned interatomic interaction potentials have enabled efficient and accurate molecular simulations of closed systems. However, external fields, which can greatly change the chemical structure and/or reactivity, have been seldom included in current machine learning models. This work proposes a universal field-induced recursively embedded atom neural network (FIREANN) model, which integrates a pseudo field vector-dependent feature into atomic descriptors to represent system-field interactions with rigorous rotational equivariance. This "all-in-one" approach correlates various response properties like dipole moment and polarizability with the field-dependent potential energy in a single model, very suitable for spectroscopic and dynamics simulations in molecular and periodic systems in the presence of electric fields. Especially for periodic systems, we find that FIREANN can overcome the intrinsic multiple-value issue of the polarization by training atomic forces only. These results validate the universality and capability of the FIREANN method for efficient first-principles modeling of complicated systems in strong external fields.
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Affiliation(s)
- Yaolong Zhang
- Key Laboratory of Precision and Intelligent Chemistry, Department of Chemical Physics, Key Laboratory of Surface and Interface Chemistry and Energy Catalysis of Anhui Higher Education Institutes, University of Science and Technology of China, Hefei, Anhui, 230026, China
- École Polytechnique Fédérale de Lausanne, 1015, Lausanne, Switzerland
| | - Bin Jiang
- Key Laboratory of Precision and Intelligent Chemistry, Department of Chemical Physics, Key Laboratory of Surface and Interface Chemistry and Energy Catalysis of Anhui Higher Education Institutes, University of Science and Technology of China, Hefei, Anhui, 230026, China.
- Hefei National Laboratory, University of Science and Technology of China, Hefei, 230088, China.
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4
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Liu YY, Cui Y, Zhang XZ, Yang RB, Li ZQ, Wang ZW. Theory of all-coupling angulon for molecules rotating in many-body environment. J Chem Phys 2023; 159:114305. [PMID: 37721329 DOI: 10.1063/5.0162004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2023] [Accepted: 08/25/2023] [Indexed: 09/19/2023] Open
Abstract
The formation of angulon, stemming from the rotor (molecule or impurity), rotating in the quantum many-body field, adds a new member to the quasi-particles' family and has aroused intense interest in multiple research fields. However, the analysis of the coupling strength between the rotor and its hosting environment remains a challenging task, both in theory and experiment. Here, we develop the all-coupling theory of the angulon by introducing a unitary transformation, where the renormalization of the rotational constants for different molecules in the helium nanodroplets is reproduced, getting excellent agreement with the experimental data collected during the past decades. Moreover, the strength of molecule-helium coupling and the effective radius of the solvation shell co-rotating along with the molecular rotor could be estimated qualitatively. This model not only provides significant enlightenment for analyzing the rotational spectroscopy of molecules in the phononic environment, but also provides a new method to study the transfer of the phonon angular momentum in the angulon frame.
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Affiliation(s)
- Yi-Yan Liu
- Tianjin Key Laboratory of Low Dimensional Materials Physics and Preparing Technology, Department of Physics, School of Science, Tianjin University, Tianjin 300354, China
| | - Yu Cui
- Tianjin Key Laboratory of Low Dimensional Materials Physics and Preparing Technology, Department of Physics, School of Science, Tianjin University, Tianjin 300354, China
| | - Xiao-Zhe Zhang
- Tianjin Key Laboratory of Low Dimensional Materials Physics and Preparing Technology, Department of Physics, School of Science, Tianjin University, Tianjin 300354, China
| | - Ran-Bo Yang
- Tianjin Key Laboratory of Low Dimensional Materials Physics and Preparing Technology, Department of Physics, School of Science, Tianjin University, Tianjin 300354, China
| | - Zhi-Qing Li
- Tianjin Key Laboratory of Low Dimensional Materials Physics and Preparing Technology, Department of Physics, School of Science, Tianjin University, Tianjin 300354, China
| | - Zi-Wu Wang
- Tianjin Key Laboratory of Low Dimensional Materials Physics and Preparing Technology, Department of Physics, School of Science, Tianjin University, Tianjin 300354, China
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5
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Hong QQ, Lian ZZ, Shu CC, Henriksen NE. Quantum control of field-free molecular orientation. Phys Chem Chem Phys 2023. [PMID: 37724061 DOI: 10.1039/d3cp03115b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/20/2023]
Abstract
Generating field-free (non-stationary) orientation of molecules in space has been a longstanding goal in the field of quantum control of molecular rotation, which has significant applications in physical chemistry, chemical physics, strong-field physics, and quantum information science. In this Perspective, we review and examine several representative control schemes developed in recent years and implemented in theoretical and experimental areas for generating field-free orientation of molecules. By conducting numerical simulations of different control schemes on the same molecular system, we demonstrate that quantum coherent control, specifically targeting a limited number of the lowest-lying rotational levels to achieve an optimal superposition, can result in a high degree of orientation. To this end, we provide an overview of our latest developed analytical method, which enables the precise design of terahertz field parameters through resonant excitation. This design approach facilitates the attainment of desired field-free orientations by optimizing the amplitudes and phases of rotational wave functions for the selected rotational levels. Finally, we outlook the significance of such progress in multiple frontier research fields, highlighting its potential applications in ultracold physics, quantum computation, quantum simulation, and quantum metrology.
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Affiliation(s)
- Qian-Qian Hong
- Hunan Key Laboratory of Nanophotonics and Devices, School of Physics and Electronics, Central South University, Changsha 410083, China.
| | - Zhen-Zhong Lian
- Hunan Key Laboratory of Nanophotonics and Devices, School of Physics and Electronics, Central South University, Changsha 410083, China.
| | - Chuan-Cun Shu
- Hunan Key Laboratory of Nanophotonics and Devices, School of Physics and Electronics, Central South University, Changsha 410083, China.
| | - Niels E Henriksen
- Department of Chemistry, Technical University of Denmark, Building 207, DK-2800 Kongens Lyngby, Denmark
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6
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Asnaashari K, Krems RV, Tscherbul TV. General Classification of Qubit Encodings in Ultracold Diatomic Molecules. J Phys Chem A 2023; 127:6593-6602. [PMID: 37494464 DOI: 10.1021/acs.jpca.3c02835] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/28/2023]
Abstract
Owing to their rich internal structure and significant long-range interactions, ultracold molecules have been widely explored as carriers of quantum information. Several different schemes for encoding qubits into molecular states, both bare and field-dressed, have been proposed. At the same time, the rich internal structure of molecules leaves many unexplored possibilities for qubit encodings. We show that all molecular qubit encodings can be classified into four classes by the type of the effective interaction between the qubits. In the case of polar molecules, the four classes are determined by the relative magnitudes of matrix elements of the dipole moment operator in the single-molecule basis. We exemplify our classification scheme by considering the encoding of the effective spin-1/2 system into nonadjacent rotational states (e.g., N = 0 and 2) of polar and nonpolar molecules with the same nuclear spin projection. Our classification scheme is designed to inform the optimal choice of molecular qubit encoding for quantum information storage and processing applications, as well as for dynamical generation of many-body entangled states and for quantum annealing.
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Affiliation(s)
- Kasra Asnaashari
- Department of Chemistry, University of British Columbia, Vancouver V6T 1Z1, Canada
| | - Roman V Krems
- Department of Chemistry, University of British Columbia, Vancouver V6T 1Z1, Canada
| | - Timur V Tscherbul
- Department of Physics, University of Nevada, Reno, Nevada 89557, United States
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7
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Zielińska JA, van der Laan F, Norrman A, Rimlinger M, Reimann R, Novotny L, Frimmer M. Controlling Optomechanical Libration with the Degree of Polarization. PHYSICAL REVIEW LETTERS 2023; 130:203603. [PMID: 37267539 DOI: 10.1103/physrevlett.130.203603] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2023] [Revised: 03/07/2023] [Accepted: 04/04/2023] [Indexed: 06/04/2023]
Abstract
Control of the potential energy and free evolution lie at the heart of levitodynamics as key requirements for sensing, wave function expansion, and mechanical squeezing protocols. Here, we experimentally demonstrate versatile control over the optical potential governing the libration motion of a levitated anisotropic nanoparticle. This control is achieved by introducing the degree of polarization as a new tool for rotational levitodynamics. We demonstrate thermally driven free rotation of a levitated anisotropic scatterer around its short axis and we use the rotational degrees of freedom to probe the local spin of a strongly focused laser beam.
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Affiliation(s)
- J A Zielińska
- Photonics Laboratory, ETH Zürich, CH-8093 Zürich, Switzerland
| | - F van der Laan
- Photonics Laboratory, ETH Zürich, CH-8093 Zürich, Switzerland
| | - A Norrman
- Photonics Laboratory, ETH Zürich, CH-8093 Zürich, Switzerland
- Center for Photonics Sciences, University of Eastern Finland, P.O. Box 111, FI-80101 Joensuu, Finland
| | - M Rimlinger
- Photonics Laboratory, ETH Zürich, CH-8093 Zürich, Switzerland
| | - R Reimann
- Photonics Laboratory, ETH Zürich, CH-8093 Zürich, Switzerland
- Quantum Research Center, Technology Innovation Institute, Abu Dhabi, United Arab Emirates
| | - L Novotny
- Photonics Laboratory, ETH Zürich, CH-8093 Zürich, Switzerland
| | - M Frimmer
- Photonics Laboratory, ETH Zürich, CH-8093 Zürich, Switzerland
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8
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Damari R, Beer A, Flaxer E, Fleischer S. Enhanced molecular orientation via NIR-delay-THz scheme: Experimental results at room temperature. J Chem Phys 2023; 158:014201. [PMID: 36610970 DOI: 10.1063/5.0132656] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Light-induced orientation of gas phase molecules is a long-pursued goal in physics and chemistry. Here, we experimentally demonstrate a six-fold increase in the terahertz-induced orientation of iodomethane (CH3I) molecules at room temperature, provided by rotational pre-excitation with a moderately intense near-IR pulse. The paper highlights the underlying interference of multiple coherent transition pathways within the rotational coherence manifold and is analyzed accordingly. Our experimental and theoretical results provide desirable and practical means for all-optical experiments on oriented molecular ensembles.
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Affiliation(s)
- Ran Damari
- Raymond and Beverly Sackler Faculty of Exact Sciences, School of Chemistry, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Amit Beer
- Raymond and Beverly Sackler Faculty of Exact Sciences, School of Chemistry, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Eli Flaxer
- Raymond and Beverly Sackler Faculty of Exact Sciences, School of Chemistry, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Sharly Fleischer
- Raymond and Beverly Sackler Faculty of Exact Sciences, School of Chemistry, Tel Aviv University, Tel Aviv 6997801, Israel
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9
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Damari R, Beer A, Rosenberg D, Fleischer S. Molecular orientation echoes via concerted terahertz and near-IR excitations. OPTICS EXPRESS 2022; 30:44464-44471. [PMID: 36522870 DOI: 10.1364/oe.474024] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2022] [Accepted: 10/26/2022] [Indexed: 06/17/2023]
Abstract
A new and efficient method for orientation echo spectroscopy is presented and realized experimentally. The excitation scheme utilizes concerted rotational excitations by both ultrashort terahertz and near-IR pulses and its all-optical detection is enabled by the molecular orientation-induced second harmonic method [J. Phys. Chem. A126, 3732 (2022)10.1021/acs.jpca.2c03237]. This method provides practical means for orientation echo spectroscopy of gas phase molecules and highlights the intriguing underlying physics of coherent rotational dynamics induced by judiciously-orchestrated interactions with both resonant (terahertz) and nonresonant (NIR) fields.
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10
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Djienbekov NE, Bastykova NK, Bekbussyn AM, Ramazanov TS, Kodanova SK. Shear viscosity in two-dimensional dipole systems. Phys Rev E 2022; 106:065203. [PMID: 36671159 DOI: 10.1103/physreve.106.065203] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2022] [Accepted: 10/14/2022] [Indexed: 06/17/2023]
Abstract
The results of modeling shear flows in classical two-dimensional (2D) dipole systems are presented. We used the method of nonequilibrium molecular dynamics to calculate the viscosity at various shear rates. The coefficients of shear viscosity are given in the limit of low shear rates for various regimes of interparticle correlation from a weakly correlated gaseous state to a strongly nonideal liquid state near the crystallization point. The calculations were carried out for bare (unscreened) dipole systems, as well as for dipole systems in a polarizable medium that provide screening of the dipole-dipole interaction. The effect of shear thinning in 2D dipole systems is reported for low values of the coupling parameter. In addition, it is shown that dipole systems can become both less and more viscous due to the presence of a screening medium, depending on the degree of interparticle correlation. The optimal simulation parameters are discussed within the framework of the method of nonequilibrium molecular dynamics for determining the shear viscosity of two-dimensional dipole systems. Moreover, we present a simple fitting curve which provides a universal scaling law for both bare dipole-dipole interaction and screened dipole-dipole interaction.
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Affiliation(s)
- N E Djienbekov
- Institute for Experimental and Theoretical Physics, Al-Farabi Kazakh National University, 71 Al-Farabi Avenue, 050040 Almaty, Kazakhstan
| | - N Kh Bastykova
- Institute for Experimental and Theoretical Physics, Al-Farabi Kazakh National University, 71 Al-Farabi Avenue, 050040 Almaty, Kazakhstan
| | - A M Bekbussyn
- Institute for Experimental and Theoretical Physics, Al-Farabi Kazakh National University, 71 Al-Farabi Avenue, 050040 Almaty, Kazakhstan
| | - T S Ramazanov
- Institute for Experimental and Theoretical Physics, Al-Farabi Kazakh National University, 71 Al-Farabi Avenue, 050040 Almaty, Kazakhstan
| | - S K Kodanova
- Institute for Experimental and Theoretical Physics, Al-Farabi Kazakh National University, 71 Al-Farabi Avenue, 050040 Almaty, Kazakhstan
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11
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Hosseinnia A, Raveesh M, Dominguez A, Ruchkina M, Linne M, Bood J. Single-shot coherent control of molecular rotation by fs/ns rotational coherent anti-Stokes Raman spectroscopy. OPTICS EXPRESS 2022; 30:32204-32214. [PMID: 36242287 DOI: 10.1364/oe.459396] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Accepted: 06/28/2022] [Indexed: 06/16/2023]
Abstract
We present a novel method, to our knowledge, to control the shape of the spectra using 2-beam hybrid femtosecond (fs)/nanosecond (ns) coherent anti-Stokes Raman scattering (RCARS). The method is demonstrated experimentally and theoretically by utilizing a species-selective excitation approach via a field-free molecular alignment as an illustrative example. Two non-resonant fs laser pulses with proper delay selectively create and then annihilate N2 resonances in a binary mixture with O2 molecules. The RCARS signal is simultaneously resolved in spectral and temporal domains within a single-shot acquisition. The method requires very low pulse energies for excitation, hence minimizing multiphoton ionization probability, allowing for coherent control at various temperatures and pressures, with spectroscopic applications in non-stationary and unpredictable reacting flows.
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12
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Beer A, Damari R, Chen Y, Fleischer S. Molecular Orientation-Induced Second-Harmonic Generation: Deciphering Different Contributions Apart. J Phys Chem A 2022; 126:3732-3738. [PMID: 35654048 PMCID: PMC9207934 DOI: 10.1021/acs.jpca.2c03237] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
Abstract
![]()
We demonstrate and
explore an all-optical technique for direct
monitoring of the orientation dynamics in gas-phase molecular ensembles.
The technique termed “MOISH” utilizes the transiently
lifted inversion symmetry of polar gas media and provides a sensitive
and spatially localized probing of the second-harmonic generation
signal that is directly correlated with the orientation of the gas.
Our experimental results reveal selective electronic and nuclear dynamical
contributions to the overall nonlinear optical signal and decipher
them apart using the “reporter gas” approach. “MOISH”
provides new crucial means for implementing advanced coherent rotational
control via concerted excitation by both terahertz and optical fields.
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Affiliation(s)
- Amit Beer
- Raymond and Beverly Sackler Faculty of Exact Sciences, School of Chemistry, Tel Aviv University, Tel Aviv 6997801, Israel.,Tel-Aviv University Center for Light-Matter-Interaction, Tel Aviv 6997801, Israel
| | - Ran Damari
- Raymond and Beverly Sackler Faculty of Exact Sciences, School of Chemistry, Tel Aviv University, Tel Aviv 6997801, Israel.,Tel-Aviv University Center for Light-Matter-Interaction, Tel Aviv 6997801, Israel
| | - Yun Chen
- Raymond and Beverly Sackler Faculty of Exact Sciences, School of Chemistry, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Sharly Fleischer
- Raymond and Beverly Sackler Faculty of Exact Sciences, School of Chemistry, Tel Aviv University, Tel Aviv 6997801, Israel.,Tel-Aviv University Center for Light-Matter-Interaction, Tel Aviv 6997801, Israel
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13
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Liang H, Peng LY. Upper bound for permanent orientation of symmetric-top molecule induced by linearly polarized electric fields. J Chem Phys 2022; 156:204302. [DOI: 10.1063/5.0094115] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Many symmetric top molecules are among the most important polyatomic molecules. The orientation of a polyatomic molecule is a challenging task, which is at the heart of its quantum control and crucial for many subsequent applications in various fields. Most recent studies focus on the temporary orientation achieved via the quantum revivals. In this study, we reveal the underlying mechanism behind the observed permanent orientation and discuss strategies for a higher degree of permanent orientation. By a careful analysis of symmetry and unitary, it is possible to estimate an upper bound of [Formula: see text] for a molecule in its thermal equilibrium states using a linear field. We show that this bound can be reached for an oblate symmetric-top molecule in the high temperature limit. To demonstrate different possible schemes, we take CHCl3 as an example. Simply with designed microwave fields, one can permanently orient CHCl3 with a degree of ⟨cos θ⟩ ≈ 0.045. We show that this value can be significantly increased by adding one or more pump pulses.
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Affiliation(s)
- Hao Liang
- State Key Laboratory for Mesoscopic Physics and Frontiers Science Center for Nano-optoelectronics, School of Physics, Peking University, 100871 Beijing, China
| | - Liang-You Peng
- State Key Laboratory for Mesoscopic Physics and Frontiers Science Center for Nano-optoelectronics, School of Physics, Peking University, 100871 Beijing, China
- Collaborative Innovation Center of Quantum Matter, 100871 Beijing, China
- Collaborative Innovation Center of Extreme Optics, Shanxi University, 030006 Taiyuan, China
- Peking University Yangtze Delta Institute of Optoelectronics, 226010 Nantong, Jiangsu, China
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14
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Hossain MM, Zhang X, Minemoto S, Sakai H. Stronger orientation of state-selected OCS molecules with relative-delay-adjusted nanosecond two-color laser pulses. J Chem Phys 2022; 156:041101. [DOI: 10.1063/5.0075849] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Md. Maruf Hossain
- Department of Physics, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Xiang Zhang
- Department of Physics, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Shinichirou Minemoto
- Department of Physics, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Hirofumi Sakai
- Department of Physics, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
- Institute for Photon Science and Technology, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
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15
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Simkó I, Chordiya K, Császár AG, Kahaly MU, Szidarovszky T. A quantum-chemical perspective on the laser-induced alignment and orientation dynamics of the CH 3 X (X = F, Cl, Br, I) molecules. J Comput Chem 2022; 43:519-538. [PMID: 35084047 PMCID: PMC9303447 DOI: 10.1002/jcc.26811] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Revised: 01/04/2022] [Accepted: 01/07/2022] [Indexed: 11/08/2022]
Abstract
Motivated by recent experiments, the laser-induced alignment-and-orientation (A&O) dynamics of the prolate symmetric top CH3 X (X = F, Cl, Br, I) molecules is investigated, with particular emphasis on the effect of halogen substitution on the rotational constants, dipole moments, and polarizabilities of these species, as these quantities determine the A&O dynamics. Insight into possible control schemes for preferred A&O dynamics of halogenated molecules and best practices for A&O simulations are provided, as well. It is shown that for accurate A&O -dynamics simulations it is necessary to employ large basis sets and high levels of electron correlation when computing the rotational constants, dipole moments, and polarizabilities. The benchmark-quality values of these molecular parameters, corresponding to the equilibrium, as well as the vibrationally averaged structures are obtained with the help of the focal-point analysis (FPA) technique and explicit electronic-structure computations utilizing the gold-standard CCSD(T) approach, basis sets up to quintuple-zeta quality, core-correlation contributions and, in particular, relativistic effects for CH3 Br and CH3 I. It is shown that the different A&O behavior of the CH3 X molecules in the optical regime is mostly caused by the differences in their polarizability anisotropy, in other terms, the size of the halogen atom. In contrast, the A&O dynamics of the CH3 X series induced by an intense few-cycle THz pulse is mostly governed by changes in the rotational constants, due to the similar dipole moments of the CH3 X molecules. The A&O dynamics is most sensitive to the B rotational constant: even the difference between its equilibrium and vibrationally-averaged values results in noticeably different A&O dynamics. The contribution of rotational states having different symmetry, weighted by nuclear-spin statistics, to the A&O dynamics is also studied.
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Affiliation(s)
- Irén Simkó
- Institute of Chemistry, ELTE Eötvös Loránd University, Budapest, Hungary.,ELKH-ELTE Complex Chemical Systems Research Group, Budapest, Hungary
| | - Kalyani Chordiya
- ELI-ALPS, ELI-HU Non-Profit Ltd. and University of Szeged, Szeged, Hungary
| | - Attila G Császár
- Institute of Chemistry, ELTE Eötvös Loránd University, Budapest, Hungary.,ELKH-ELTE Complex Chemical Systems Research Group, Budapest, Hungary
| | | | - Tamás Szidarovszky
- Institute of Chemistry, ELTE Eötvös Loránd University, Budapest, Hungary.,ELKH-ELTE Complex Chemical Systems Research Group, Budapest, Hungary
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16
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Sub-Hz Differential Rotational Spectroscopy of Enantiomers. Symmetry (Basel) 2021. [DOI: 10.3390/sym14010028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
We demonstrate for the first time high-precision differential microwave spectroscopy, achieving sub-Hz precision by coupling a cryogenic buffer gas cell with a tunable microwave Fabry–Perot cavity. We report statistically limited sub-Hz precision of (0.08 ± 0.72) Hz, observed between enantiopure samples of (R)-1,2-propanediol and (S)-1,2-propanediol at frequencies near 15 GHz. We confirm highly repeatable spectroscopic measurements compared to traditional pulsed-jet methods, opening up new capabilities in probing subtle molecular structural effects at the 10−10 level and providing a platform for exploring sources of systematic error in parity-violation searches. We discuss dominant systematic effects at this level and propose possible extensions of the technique for higher precision.
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17
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Karra M, Schmidt B, Friedrich B. Quantum dynamics of a polar rotor acted upon by an electric rectangular pulse of variable duration. Mol Phys 2021. [DOI: 10.1080/00268976.2021.1966111] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Affiliation(s)
| | - Burkhard Schmidt
- Institut für Mathematik, Freie Universität Berlin, Berlin, Germany
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18
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Song YC, Woo JH, Oh GG, Kim DH, Lee CY, Kim HW. External electric field promotes ammonia stripping from wastewater. WATER RESEARCH 2021; 203:117518. [PMID: 34403844 DOI: 10.1016/j.watres.2021.117518] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Revised: 07/25/2021] [Accepted: 07/29/2021] [Indexed: 06/13/2023]
Abstract
The gas stripping process is widely used for the removal and recovery of ammonia from wastewater. The ammonia removal in the stripping process depends on the pH, temperature, and air supply, and in general, 10.5, 60 °C, 5 L/min or more are recommended as near-optimal. However, alkaline chemicals and energy can seriously burden the stripping process operation, depending on the wastewater characteristics. Herein, external electric field-coupled ammonia stripping, which improves ammonia removal from aqueous solutions, was investigated. The ammonia removal in the conventional stripping was between 17.7 % and 90.6 %, depending on how close to the near-optimal conditions. The electric field increased the removal efficiency from 51.1 % to 94.3 %, as the strength and frequency increased to 15 V/cm and 50 MHz. The electric field promotion of ammonia stripping correlated closely with the increase in ammonia molecular diffusion. The electric field has been shown to improve the diffusion of ammonia molecules without dielectric heating by increasing the kinetic energy. The electric field improved the ammonia removal more as the pH, temperature, and air supply conditions were far from optimal. The electric field reduces the alkaline chemicals and the electric energy for heating and air supply, and the energy consumption to form the electric field is only a few watts. The electric field-coupled process offers a new gas stripping platform that can economically improve ammonia removal from wastewater.
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Affiliation(s)
- Young-Chae Song
- Department of Environmental Engineering, Korea Maritime and Ocean University, Busan 49112, South Korea; Interdisciplinary Major of Ocean Renewable Energy Engineering, Korea Maritime and Ocean University, Busan 49112, South Korea.
| | - Jung-Hui Woo
- Nuclear Power Equipment Research Center, Korea Maritime and Ocean University, Busan 49112, Korea
| | - Gyung-Geun Oh
- Department of Environmental Engineering, Korea Maritime and Ocean University, Busan 49112, South Korea
| | - Dong-Hoon Kim
- Department of Civil Engineering, Inha University, Incheon 22212, South Korea
| | - Chae-Young Lee
- Department of Civil and Environmental Engineering, The University of Suwon, Gyeonggi-do 18323, South Korea
| | - Hyun-Woo Kim
- Department of Environmental Engineering, Jeonbuk National University, Jeonbuk 54896, South Korea
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19
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Haase PAB, Doeglas DJ, Boeschoten A, Eliav E, Iliaš M, Aggarwal P, Bethlem HL, Borschevsky A, Esajas K, Hao Y, Hoekstra S, Marshall VR, Meijknecht TB, Mooij MC, Steinebach K, Timmermans RGE, Touwen AP, Ubachs W, Willmann L, Yin Y. Systematic study and uncertainty evaluation of P, T-odd molecular enhancement factors in BaF. J Chem Phys 2021; 155:034309. [PMID: 34293876 DOI: 10.1063/5.0047344] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
A measurement of the magnitude of the electric dipole moment of the electron (eEDM) larger than that predicted by the Standard Model (SM) of particle physics is expected to have a huge impact on the search for physics beyond the SM. Polar diatomic molecules containing heavy elements experience enhanced sensitivity to parity (P) and time-reversal (T)-violating phenomena, such as the eEDM and the scalar-pseudoscalar (S-PS) interaction between the nucleons and the electrons, and are thus promising candidates for measurements. The NL-eEDM collaboration is preparing an experiment to measure the eEDM and S-PS interaction in a slow beam of cold BaF molecules [P. Aggarwal et al., Eur. Phys. J. D 72, 197 (2018)]. Accurate knowledge of the electronic structure parameters, Wd and Ws, connecting the eEDM and the S-PS interaction to the measurable energy shifts is crucial for the interpretation of these measurements. In this work, we use the finite field relativistic coupled cluster approach to calculate the Wd and Ws parameters in the ground state of the BaF molecule. Special attention was paid to providing a reliable theoretical uncertainty estimate based on investigations of the basis set, electron correlation, relativistic effects, and geometry. Our recommended values of the two parameters, including conservative uncertainty estimates, are 3.13 ±0.12×1024Hzecm for Wd and 8.29 ± 0.12 kHz for Ws.
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Affiliation(s)
- Pi A B Haase
- Van Swinderen Institute for Particle Physics and Gravity, University of Groningen, 9747 AG Groningen, The Netherlands
| | - Diewertje J Doeglas
- Van Swinderen Institute for Particle Physics and Gravity, University of Groningen, 9747 AG Groningen, The Netherlands
| | - Alexander Boeschoten
- Van Swinderen Institute for Particle Physics and Gravity, University of Groningen, 9747 AG Groningen, The Netherlands
| | - Ephraim Eliav
- School of Chemistry, Tel Aviv University, 69978 Tel Aviv, Israel
| | - Miroslav Iliaš
- Department of Chemistry, Faculty of Natural Sciences, Matej Bel University, Tajovského 40, 97401 Banská Bystrica, Slovakia
| | - Parul Aggarwal
- Van Swinderen Institute for Particle Physics and Gravity, University of Groningen, 9747 AG Groningen, The Netherlands
| | - H L Bethlem
- Van Swinderen Institute for Particle Physics and Gravity, University of Groningen, 9747 AG Groningen, The Netherlands
| | - Anastasia Borschevsky
- Van Swinderen Institute for Particle Physics and Gravity, University of Groningen, 9747 AG Groningen, The Netherlands
| | - Kevin Esajas
- Van Swinderen Institute for Particle Physics and Gravity, University of Groningen, 9747 AG Groningen, The Netherlands
| | - Yongliang Hao
- Van Swinderen Institute for Particle Physics and Gravity, University of Groningen, 9747 AG Groningen, The Netherlands
| | - Steven Hoekstra
- Van Swinderen Institute for Particle Physics and Gravity, University of Groningen, 9747 AG Groningen, The Netherlands
| | - Virginia R Marshall
- Van Swinderen Institute for Particle Physics and Gravity, University of Groningen, 9747 AG Groningen, The Netherlands
| | - Thomas B Meijknecht
- Van Swinderen Institute for Particle Physics and Gravity, University of Groningen, 9747 AG Groningen, The Netherlands
| | - Maarten C Mooij
- Nikhef, National Institute for Subatomic Physics, 1098 XG Amsterdam, The Netherlands
| | - Kees Steinebach
- Van Swinderen Institute for Particle Physics and Gravity, University of Groningen, 9747 AG Groningen, The Netherlands
| | - Rob G E Timmermans
- Van Swinderen Institute for Particle Physics and Gravity, University of Groningen, 9747 AG Groningen, The Netherlands
| | - Anno P Touwen
- Van Swinderen Institute for Particle Physics and Gravity, University of Groningen, 9747 AG Groningen, The Netherlands
| | - Wim Ubachs
- Department of Physics and Astronomy, VU University Amsterdam, 1081 HV Amsterdam, The Netherlands
| | - Lorenz Willmann
- Van Swinderen Institute for Particle Physics and Gravity, University of Groningen, 9747 AG Groningen, The Netherlands
| | - Yanning Yin
- Van Swinderen Institute for Particle Physics and Gravity, University of Groningen, 9747 AG Groningen, The Netherlands
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- Van Swinderen Institute for Particle Physics and Gravity, University of Groningen, 9747 AG Groningen, The Netherlands
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20
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Nautiyal VV, Devi S, Tyagi A, Vidhani B, Maan A, Prasad V. Orientation and Alignment dynamics of polar molecule driven by shaped laser pulses. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2021; 256:119663. [PMID: 33827039 DOI: 10.1016/j.saa.2021.119663] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Revised: 02/17/2021] [Accepted: 02/28/2021] [Indexed: 06/12/2023]
Abstract
We review the theoretical status of intense laser induced orientation and alignment-a field of study which lies at the interface of intense laser physics and chemical dynamics and having potential applications such as high harmonic generation, nano-scale processing and control of chemical reactions. The evolution of the rotational wave packet and its dynamics leading to orientation and alignment is the topic of the present discussion. The major part of this article primarily presents an overview of recent theoretical progress in controlling the orientation and alignment dynamics of a molecule by means of shaped laser pulses. The various theoretical approaches that lead to orientation and alignment such as static electrostatic field in combination with laser field(s), combination of orienting and aligning field, combination of aligning fields, combination of orienting fields, application of train of pulses etc. are discussed. It is observed that the train of pulses is quite an efficient tool for increasing the orientation or alignment of a molecule without causing the molecule to ionize. The orientation and alignment both can occur in adiabatic and non-adiabatic conditions with the rotational period of the molecule taken under consideration. The discussion is mostly limited to non-adiabatic rotational excitation (NAREX) i.e. cases in which the pulse duration is shorter than the rotational period of the molecule. We have emphasised on the so called half-cycle pulse (HCP) and square pulse (SQP). The effect of ramped pulses and of collision on the various laser parameters is also studied. We summarize the current discussion by presenting a consistent theoretical approach for describing the action of such pulses on movement of molecules. The impact of a particular pulse shape on the post-pulse dynamics is also calculated and analysed. In addition to this, the roles played by various laser parameters including the laser frequency, the pulse duration and the system temperature etc. are illustrated and discussed. The concept of alignment is extended from one-dimensional alignment to three-dimensional alignment with the proper choice of molecule and the polarised light. We conclude the article by discussing the potential applications of intense laser orientation and alignment.
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Affiliation(s)
- Vijit V Nautiyal
- Department of Physics and Astrophysics, University of Delhi, Delhi, Delhi 110007, India
| | - Sumana Devi
- Department of Physics and Astrophysics, University of Delhi, Delhi, Delhi 110007, India; Department of Physics, Miranda House College, University of Delhi, Delhi, Delhi 110007, India
| | - Ashish Tyagi
- Department of Physics, Swami Shradhanand College, University of Delhi, Delhi, Delhi 110036, India
| | - Bhavna Vidhani
- Department of Physics, Hansraj College, University of Delhi, Delhi, Delhi 110007, India
| | - Anjali Maan
- Department of Physics, Pt.N.R.S.G.C.Rohtak, Maharshi Dayanand University, Rohtak 124001, Haryana, India
| | - Vinod Prasad
- Department of Physics, Swami Shradhanand College, University of Delhi, Delhi, Delhi 110036, India.
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21
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Matsuda K, De Marco L, Li JR, Tobias WG, Valtolina G, Quéméner G, Ye J. Resonant collisional shielding of reactive molecules using electric fields. Science 2021; 370:1324-1327. [PMID: 33303614 DOI: 10.1126/science.abe7370] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Accepted: 11/09/2020] [Indexed: 11/03/2022]
Abstract
Full control of molecular interactions, including reactive losses, would open new frontiers in quantum science. We demonstrate extreme tunability of ultracold chemical reaction rates by inducing resonant dipolar interactions by means of an external electric field. We prepared fermionic potassium-rubidium molecules in their first excited rotational state and observed a modulation of the chemical reaction rate by three orders of magnitude as we tuned the electric field strength by a few percent across resonance. In a quasi-two-dimensional geometry, we accurately determined the contributions from the three dominant angular momentum projections of the collisions. Using the resonant features, we shielded the molecules from loss and suppressed the reaction rate by an order of magnitude below the background value, thereby realizing a long-lived sample of polar molecules in large electric fields.
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Affiliation(s)
- Kyle Matsuda
- JILA, National Institute of Standards and Technology, and Department of Physics, University of Colorado, Boulder, CO 80309, USA.
| | - Luigi De Marco
- JILA, National Institute of Standards and Technology, and Department of Physics, University of Colorado, Boulder, CO 80309, USA
| | - Jun-Ru Li
- JILA, National Institute of Standards and Technology, and Department of Physics, University of Colorado, Boulder, CO 80309, USA
| | - William G Tobias
- JILA, National Institute of Standards and Technology, and Department of Physics, University of Colorado, Boulder, CO 80309, USA
| | - Giacomo Valtolina
- JILA, National Institute of Standards and Technology, and Department of Physics, University of Colorado, Boulder, CO 80309, USA
| | - Goulven Quéméner
- Université Paris-Saclay, CNRS, Laboratoire Aimé Cotton, 91405 Orsay, France
| | - Jun Ye
- JILA, National Institute of Standards and Technology, and Department of Physics, University of Colorado, Boulder, CO 80309, USA.
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22
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Park Y, Shin S, Kang H. Recent Progress in the Manipulation of Molecules with DC Electric Fields. Acc Chem Res 2021; 54:323-331. [PMID: 33377765 DOI: 10.1021/acs.accounts.0c00609] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The structure and reactivity of a molecule in the condensed phase are governed by its intermolecular interactions with the surrounding environment. The multipole expansion of each molecule in the condensed phase indicates that the intermolecular interactions are essentially electrostatic (e.g., ion-dipole, dipole-dipole, dipole-quadrupole, dipole-induced dipole). The electrostatic field is a fundamental language of intermolecular communications. Therefore, understanding the influence of the electrostatic field on a molecule, that is, the mechanisms by which an electrostatic field manipulates a molecule, from the perspective of molecular structure, energy states, and dynamics is indispensable for illustrating and, by extension, controlling the chemistry in molecular systems.In this Account, we describe the recent progress made in manipulation of molecular processes using an external DC electrostatic field. An electrostatic field with unprecedentedly high strength (≤4 × 108 V/m) was applied in a controlled manner across a molecular film sample using the ice film nanocapacitor method. This field strength is comparable in magnitude to that of weak intermolecular interactions such as van der Waals interactions in the condensed phases. The samples were prepared using a thin film growing technique in vacuum to obtain the desired chemically tailored molecular systems. The examples of prepared systems included small molecules and molecular clusters isolated in cryogenic Ar matrices, frozen molecular films in amorphous or crystalline phase, and interfaces of multilayered molecular films. The response of the molecules to the external field was monitored by reflection-absorption infrared spectroscopy. This approach allowed us to investigate a variety of molecular systems with various intermolecular strength and environments under the influence of strong electrostatic fields. The range of observed molecular behaviors includes the manipulation of molecular orientation, intramolecular dynamics, and proton transfer reactions as an example of stereodynamic control of chemical reactivity. These observations improve our understanding of molecular behaviors in strong electric fields and broaden our perspective on electrostatic manipulation of molecules. This information is also relevant to a variety of research topics in physical and biological sciences where electric fields play a role in molecular and biological functions.
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Affiliation(s)
- Youngwook Park
- Department of Chemistry, Seoul National University, 1 Gwanak-ro, Seoul 08826, South Korea
| | - Sunghwan Shin
- Department of Chemistry, Seoul National University, 1 Gwanak-ro, Seoul 08826, South Korea
| | - Heon Kang
- Department of Chemistry, Seoul National University, 1 Gwanak-ro, Seoul 08826, South Korea
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23
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Brooks M, Lemeshko M, Lundholm D, Yakaboylu E. Molecular Impurities as a Realization of Anyons on the Two-Sphere. PHYSICAL REVIEW LETTERS 2021; 126:015301. [PMID: 33480760 DOI: 10.1103/physrevlett.126.015301] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Accepted: 12/03/2020] [Indexed: 06/12/2023]
Abstract
Studies on the experimental realization of two-dimensional anyons in terms of quasiparticles have been restricted, so far, to only anyons on the plane. It is known, however, that the geometry and topology of space can have significant effects on quantum statistics for particles moving on it. Here, we have undertaken the first step toward realizing the emerging fractional statistics for particles restricted to move on the sphere instead of on the plane. We show that such a model arises naturally in the context of quantum impurity problems. In particular, we demonstrate a setup in which the lowest-energy spectrum of two linear bosonic or fermionic molecules immersed in a quantum many-particle environment can coincide with the anyonic spectrum on the sphere. This paves the way toward the experimental realization of anyons on the sphere using molecular impurities. Furthermore, since a change in the alignment of the molecules corresponds to the exchange of the particles on the sphere, such a realization reveals a novel type of exclusion principle for molecular impurities, which could also be of use as a powerful technique to measure the statistics parameter. Finally, our approach opens up a simple numerical route to investigate the spectra of many anyons on the sphere. Accordingly, we present the spectrum of two anyons on the sphere in the presence of a Dirac monopole field.
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Affiliation(s)
- M Brooks
- IST Austria (Institute of Science and Technology Austria), Am Campus 1, 3400 Klosterneuburg, Austria
| | - M Lemeshko
- IST Austria (Institute of Science and Technology Austria), Am Campus 1, 3400 Klosterneuburg, Austria
| | - D Lundholm
- Department of Mathematics, Uppsala University, Box 480, SE-751 06 Uppsala, Sweden
| | - E Yakaboylu
- IST Austria (Institute of Science and Technology Austria), Am Campus 1, 3400 Klosterneuburg, Austria
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24
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Dawid A, Tomza M. Magnetic properties and quench dynamics of two interacting ultracold molecules in a trap. Phys Chem Chem Phys 2020; 22:28140-28153. [PMID: 33290463 DOI: 10.1039/d0cp05542e] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We theoretically investigate the magnetic properties and nonequilibrium dynamics of two interacting ultracold polar and paramagnetic molecules in a one-dimensional harmonic trap in external electric and magnetic fields. The molecules interact via a multichannel two-body contact potential, incorporating the short-range anisotropy of intermolecular interactions. We show that various magnetization states arise from the interplay of the molecular interactions, electronic spins, dipole moments, rotational structures, external fields, and spin-rotation coupling. The rich magnetization diagrams depend primarily on the anisotropy of the intermolecular interaction and the spin-rotation coupling. These specific molecular properties are challenging to calculate or measure. Therefore, we propose the quench dynamics experiments for extracting them from observing the time evolution of the analyzed system. Our results indicate the possibility of controlling the molecular few-body magnetization with the external electric field and pave the way towards studying the magnetization of ultracold molecules trapped in optical tweezers or optical lattices and their application in quantum simulation of molecular multichannel many-body Hamiltonians and quantum information storing.
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Affiliation(s)
- Anna Dawid
- Faculty of Physics, University of Warsaw, Pasteura 5, 02-093 Warsaw, Poland.
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25
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Deng Z, Tutunnikov I, Averbukh IS, Thachuk M, Krems RV. Bayesian optimization for inverse problems in time-dependent quantum dynamics. J Chem Phys 2020; 153:164111. [DOI: 10.1063/5.0015896] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Affiliation(s)
- Z. Deng
- Department of Chemistry, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
| | - I. Tutunnikov
- AMOS and Department of Chemical and Biological Physics, The Weizmann Institute of Science, Rehovot 7610001, Israel
| | - I. Sh. Averbukh
- AMOS and Department of Chemical and Biological Physics, The Weizmann Institute of Science, Rehovot 7610001, Israel
| | - M. Thachuk
- Department of Chemistry, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
| | - R. V. Krems
- Department of Chemistry, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
- Quantum Matter Institute, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada
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26
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Affiliation(s)
- T. Grohmann
- Institut für Chemie und Biochemie, Freie Universität Berlin, Berlin, Germany
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27
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Jansen P, Merkt F. Manipulating beams of paramagnetic atoms and molecules using inhomogeneous magnetic fields. PROGRESS IN NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY 2020; 120-121:118-148. [PMID: 33198967 DOI: 10.1016/j.pnmrs.2020.08.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Revised: 08/07/2020] [Accepted: 08/10/2020] [Indexed: 06/11/2023]
Abstract
We review methods to manipulate the motion of pulsed supersonic atomic and molecular beams using time-independent and -dependent inhomogeneous magnetic fields. In addition, we discuss current and possible future applications and research directions.
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Affiliation(s)
- Paul Jansen
- Laboratory of Physical Chemistry, ETH Zurich, CH-8093 Zurich, Switzerland.
| | - Frédéric Merkt
- Laboratory of Physical Chemistry, ETH Zurich, CH-8093 Zurich, Switzerland
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28
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Hossain MM, Sakai H. All-optical orientation of linear molecules with combined linearly and elliptically polarized two-color laser fields. J Chem Phys 2020; 153:104102. [PMID: 32933273 DOI: 10.1063/5.0023396] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We show that a combination of a fundamental pulse with linear polarization along the vertical direction and an elliptically polarized second harmonic pulse with both vertical and horizontal electric field components can be used to orient linear molecules efficiently, leading to higher degrees of orientation. Due to this specific combination of polarizations, the asymmetric hyperpolarizability interaction potential, which remains the same as that in a linearly polarized two-color laser field, is created along the vertical component of the elliptically polarized second harmonic pulse. On the other hand, the horizontal component suppresses the otherwise strong symmetric polarizability potential responsible for alignment, increasing the tunneling probability from the shallower potential well to the deeper one. As a result, the degree of orientation increases and can be controlled by changing the intensity of the horizontal component of the elliptically polarized second harmonic pulse. This study is the generalization of the all-optical molecular orientation technique based on the anisotropic hyperpolarizability interaction.
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Affiliation(s)
- Md Maruf Hossain
- Department of Physics, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Hirofumi Sakai
- Department of Physics, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
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29
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Mitra D, Vilas NB, Hallas C, Anderegg L, Augenbraun BL, Baum L, Miller C, Raval S, Doyle JM. Direct laser cooling of a symmetric top molecule. Science 2020; 369:1366-1369. [DOI: 10.1126/science.abc5357] [Citation(s) in RCA: 64] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Accepted: 07/10/2020] [Indexed: 11/02/2022]
Abstract
Ultracold polyatomic molecules have potentially wide-ranging applications in quantum simulation and computation, particle physics, and quantum chemistry. For atoms and small molecules, direct laser cooling has proven to be a powerful tool for quantum science in the ultracold regime. However, the feasibility of laser-cooling larger, nonlinear polyatomic molecules has remained unknown because of their complex structure. We laser-cooled the symmetric top molecule calcium monomethoxide (CaOCH3), reducing the temperature of ~104 molecules from 22 ± 1 millikelvin to 1.8 ± 0.7 millikelvin in one dimension and state-selectively cooling two nuclear spin isomers. These results demonstrate that the use of proper ro-vibronic transitions enables laser cooling of nonlinear molecules, thereby opening a path to efficient cooling of chiral molecules and, eventually, optical tweezer arrays of complex polyatomic species.
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Affiliation(s)
- Debayan Mitra
- Department of Physics, Harvard University, Cambridge, MA 02138, USA, and Harvard-MIT Center for Ultracold Atoms, Cambridge, MA 02138, USA
| | - Nathaniel B. Vilas
- Department of Physics, Harvard University, Cambridge, MA 02138, USA, and Harvard-MIT Center for Ultracold Atoms, Cambridge, MA 02138, USA
| | - Christian Hallas
- Department of Physics, Harvard University, Cambridge, MA 02138, USA, and Harvard-MIT Center for Ultracold Atoms, Cambridge, MA 02138, USA
| | - Loïc Anderegg
- Department of Physics, Harvard University, Cambridge, MA 02138, USA, and Harvard-MIT Center for Ultracold Atoms, Cambridge, MA 02138, USA
| | - Benjamin L. Augenbraun
- Department of Physics, Harvard University, Cambridge, MA 02138, USA, and Harvard-MIT Center for Ultracold Atoms, Cambridge, MA 02138, USA
| | - Louis Baum
- Department of Physics, Harvard University, Cambridge, MA 02138, USA, and Harvard-MIT Center for Ultracold Atoms, Cambridge, MA 02138, USA
| | - Calder Miller
- Department of Physics, Harvard University, Cambridge, MA 02138, USA, and Harvard-MIT Center for Ultracold Atoms, Cambridge, MA 02138, USA
| | - Shivam Raval
- Department of Physics, Harvard University, Cambridge, MA 02138, USA, and Harvard-MIT Center for Ultracold Atoms, Cambridge, MA 02138, USA
| | - John M. Doyle
- Department of Physics, Harvard University, Cambridge, MA 02138, USA, and Harvard-MIT Center for Ultracold Atoms, Cambridge, MA 02138, USA
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30
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Aldakul YK, Moldabekov ZA, Ramazanov TS. Melting, freezing, and dynamics of two-dimensional dipole systems in screening bulk media. Phys Rev E 2020; 102:033205. [PMID: 33075926 DOI: 10.1103/physreve.102.033205] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Accepted: 08/31/2020] [Indexed: 06/11/2023]
Abstract
This paper reports on the molecular dynamics simulations of classical two-dimensional (2D) electric dipole systems. The properties of 2D systems with bare (nonscreened) and screened dipole-dipole interactions have been investigated. Based on the polygon construction method, we present simulation results on the phase transition, and we locate the melting and freezing points of 2D dipole systems in terms of a polygon disorder parameter, with the polygon disorder parameter being the sum of nontriangular polygon order parameters. It was found that the phase transition of the system occurs when the polygon disorder parameter has a value 0.165. This result was cross-checked by using both local and overall orientational order parameters. We also identified that the value of the average local orientational order parameter at the phase transition point is 0.67. These results are valid for the ordinary (bare) dipole-dipole interaction as well as the screened dipole-dipole interaction, and they are expected to be general for other 2D systems with repulsive pair interaction. We observed that both melting and freezing points shift to lower values of temperature due to screening. In the liquid state, the radial distribution function and polygon construction method show the loss of order in a structure as screening becomes more severe. Furthermore, the impact of screening on the system's collective excitation spectra and diffusive characteristics at liquid and solid states has been studied. Results show the decrease in the values of both longitudinal and transverse sound speeds and the emergence of anomalous superdiffusive motion in the liquid state due to screening.
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Affiliation(s)
- Ye K Aldakul
- Institute of Applied Sciences and IT, 40-48 Shashkin Str., 050038 Almaty, Kazakhstan and Institute for Experimental and Theoretical Physics, Al-Farabi Kazakh National University, 71 Al-Farabi Str., 050040 Almaty, Kazakhstan
| | | | - T S Ramazanov
- Institute for Experimental and Theoretical Physics, Al-Farabi Kazakh National University, 71 Al-Farabi Str., 050040 Almaty, Kazakhstan
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31
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Xu L, Tutunnikov I, Gershnabel E, Prior Y, Averbukh IS. Long-Lasting Molecular Orientation Induced by a Single Terahertz Pulse. PHYSICAL REVIEW LETTERS 2020; 125:013201. [PMID: 32678652 DOI: 10.1103/physrevlett.125.013201] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Revised: 05/10/2020] [Accepted: 06/03/2020] [Indexed: 06/11/2023]
Abstract
We present a novel, previously unreported phenomenon appearing in a thermal gas of nonlinear polar molecules excited by a single THz pulse. We find that the induced orientation lasts long after the excitation pulse is over. In the case of symmetric-top molecules, the time-averaged orientation remains indefinitely constant, whereas in the case of asymmetric-top molecules the orientation persists for a long time after the end of the pulse. We discuss the underlying mechanism, study its nonmonotonous temperature and amplitude dependencies, and show that there exist optimal parameters for maximal residual orientation. The persistent orientation implies a long-lasting macroscopic dipole moment, which may be probed by even harmonic generation and may enable deflection by inhomogeneous electrostatic fields.
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Affiliation(s)
- Long Xu
- AMOS and Department of Chemical and Biological Physics, The Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Ilia Tutunnikov
- AMOS and Department of Chemical and Biological Physics, The Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Erez Gershnabel
- AMOS and Department of Chemical and Biological Physics, The Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Yehiam Prior
- AMOS and Department of Chemical and Biological Physics, The Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Ilya Sh Averbukh
- AMOS and Department of Chemical and Biological Physics, The Weizmann Institute of Science, Rehovot 7610001, Israel
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32
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Kim LY, Jin BG, Kim TW, Lee JH, Zhao BS. Scattering of adiabatically aligned molecules by nonresonant optical standing waves. SCIENCE ADVANCES 2020; 6:eaaz0682. [PMID: 32284979 PMCID: PMC7124941 DOI: 10.1126/sciadv.aaz0682] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/12/2019] [Accepted: 01/09/2020] [Indexed: 06/11/2023]
Abstract
We study the effect of rotational state-dependent alignment in the scattering of molecules by optical fields. CS2 molecules in their lowest few rotational states are adiabatically aligned and transversely accelerated by a nonresonant optical standing wave. The width of the measured transverse velocity distribution increases to 160 m/s with the field intensity, while its central peak position moves from 10 to -10 m/s. These changes are well reproduced by numerical simulations based on the rotational state-dependent alignment but cannot be modeled when ignoring these effects. Moreover, the molecular scattering by an off-resonant optical field amounts to manipulating the translational motion of molecules in a rotational state-specific way. Conversely, our results demonstrate that scattering from a nonresonant optical standing wave is a viable method for rotational state selection of nonpolar molecules.
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Affiliation(s)
- Lee Yeong Kim
- Department of Physics, Ulsan National Institute of Science and Technology, Ulsan, Korea
| | - Byung Gwun Jin
- Department of Chemistry, Ulsan National Institute of Science and Technology, Ulsan, Korea
| | - Tae Woo Kim
- Department of Chemistry, Ulsan National Institute of Science and Technology, Ulsan, Korea
| | - Ju Hyeon Lee
- Department of Chemistry, Ulsan National Institute of Science and Technology, Ulsan, Korea
| | - Bum Suk Zhao
- Department of Physics, Ulsan National Institute of Science and Technology, Ulsan, Korea
- Department of Chemistry, Ulsan National Institute of Science and Technology, Ulsan, Korea
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33
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A resonant single frequency molecular detector with high sensitivity and selectivity for gas mixtures. Sci Rep 2020; 10:1537. [PMID: 32001803 PMCID: PMC6992780 DOI: 10.1038/s41598-020-58473-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2019] [Accepted: 01/08/2020] [Indexed: 12/19/2022] Open
Abstract
Air quality control is an important task in prevention of human exposure to toxic and harmful gases and requires reliable gas sensors. During last decades many gas sensing mechanisms, based on different physical or chemical interactions with sensitive materials, have been developed, but the problem of precise analysis of gas mixtures still remains. The problem can be solved by introducing new sensing mechanism based on an adiabatically changing electric field interacting with the rotational structure of the molecules with dipole moments. We have theoretically demonstrated a single low frequency gas detector that can be used for sensing of gas mixtures with high selectivity, accuracy, and sensitivity. The enhancement of the population difference between corresponding molecular levels and reached the theoretical maximum of absorption have been shown.
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34
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Toscano J, Lewandowski HJ, Heazlewood BR. Cold and controlled chemical reaction dynamics. Phys Chem Chem Phys 2020; 22:9180-9194. [DOI: 10.1039/d0cp00931h] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
State-to-state chemical reaction dynamics, with complete control over the reaction parameters, offers unparalleled insight into fundamental reactivity.
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Affiliation(s)
- Jutta Toscano
- JILA and the Department of Physics
- University of Colorado
- Boulder
- USA
| | | | - Brianna R. Heazlewood
- Physical and Theoretical Chemistry Laboratory (PTCL)
- Department of Chemistry
- University of Oxford
- Oxford
- UK
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35
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Communication of the Cell Periphery with the Golgi Apparatus: A Hypothesis. Results Probl Cell Differ 2019. [PMID: 31435804 DOI: 10.1007/978-3-030-23173-6_16] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
Abstract
The Golgi apparatus plays a central role in the numerous traffic tasks in cells. Whereas the well-investigated chemical signaling is sufficient to explain the information processes in the secretory output of cells, it is insufficient to do that for the substitution of structural elements in the three-dimensional space of the cell. Here we review recent work (Jaross, Front Biosci 23:940-946, 2018) suggesting that molecular vibration patterns of those macromolecules which have to be exchanged are recognized by molecules in the Golgi via resonance of the electromagnetic fingerprints. That results in the activation of specific molecules and induction of the whole substitution process. For bridging intracellular distances, the IR radiation must be coherent. It is discussed that coherence is achieved by chemical reaction during the changing process of the molecule along with the quasicrystalline structure of the neighboring water molecules. Several aspects of the relevance of that signaling to the direct interactions of molecules during various intracellular processes are discussed.
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36
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Niman JW, Kamerin BS, Merthe DJ, Kranabetter L, Kresin VV. Oriented Polar Molecules Trapped in Cold Helium Nanodropets: Electrostatic Deflection, Size Separation, and Charge Migration. PHYSICAL REVIEW LETTERS 2019; 123:043203. [PMID: 31491260 DOI: 10.1103/physrevlett.123.043203] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2019] [Indexed: 06/10/2023]
Abstract
Helium nanodroplets doped with polar molecules are studied by electrostatic deflection. This broadly applicable method allows even polyatomic molecules to attain subkelvin temperatures and nearly full orientation in the field. The resulting intense force from the field gradient strongly deflects even droplets with tens of thousands of atoms, the most massive neutral systems studied by beam "deflectometry." We use the deflections to extract droplet size distributions. Moreover, since each host droplet deflects according to its mass, spatial filtering of the deflected beam translates into size filtering of neutral fragile nanodroplets. As an example, we measure the dopant ionization probability as a function of droplet radius and determine the mean free path for charge hopping through the helium matrix. The technique will enable separation of doped and neat nanodroplets and size-dependent spectroscopic studies.
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Affiliation(s)
- John W Niman
- Department of Physics and Astronomy, University of Southern California, Los Angeles, California 90089-0484, USA
| | - Benjamin S Kamerin
- Department of Physics and Astronomy, University of Southern California, Los Angeles, California 90089-0484, USA
| | - Daniel J Merthe
- Department of Physics and Astronomy, University of Southern California, Los Angeles, California 90089-0484, USA
| | - Lorenz Kranabetter
- Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Technikerstrasse 25, A-6020 Innsbruck, Austria
| | - Vitaly V Kresin
- Department of Physics and Astronomy, University of Southern California, Los Angeles, California 90089-0484, USA
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37
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Mun JH, Minemoto S, Sakai H. Development of a plasma shutter applicable to 100-mJ-class, 10-ns laser pulses and the characterization of its performance. OPTICS EXPRESS 2019; 27:19130-19140. [PMID: 31503676 DOI: 10.1364/oe.27.019130] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Accepted: 05/30/2019] [Indexed: 06/10/2023]
Abstract
For the purpose of preparing a sample of aligned and oriented molecules in the laser-field-free condition, we developed a plasma shutter, which enables laser pulses with 100-mJ-class, 10-ns pulse durations to be rapidly turned off within ∼150 fs. Inthis work, the residual field intensity after the rapid turn off is carefully examined by applying the shaped laser pulse to OCS molecules in the rotational ground state. Based on the comparison between the observation of alignment revivals of the OCS molecules and the results of numerical simulations, we demonstrate that the residual field intensity is actually negligible (below 0.4% of the peak intensity) and, if any, does not influence the alignment and orientation dynamics at all.
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38
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Morita M, Krems RV, Tscherbul TV. Universal Probability Distributions of Scattering Observables in Ultracold Molecular Collisions. PHYSICAL REVIEW LETTERS 2019; 123:013401. [PMID: 31386401 DOI: 10.1103/physrevlett.123.013401] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2018] [Revised: 05/09/2019] [Indexed: 06/10/2023]
Abstract
Currently, quantum dynamics theory cannot be used for quantitative predictions of molecular scattering observables at low temperatures because of two problems. The first problem is the extreme sensitivity of the low-temperature observables to details of potential energy surfaces (PESs) parametrizing the nuclear Schrödinger equation. The second problem is the large size of the basis sets required for the numerical integration of the Schrödinger equation for strongly interacting molecules in the presence of fields, which precludes the application of rigorous quantum theory to all but a few atom-molecule systems. Here, we show that, if the scattering problem is formulated as a probabilistic prediction, quantum theory can provide reliable results with exponentially reduced numerical effort. Specifically, we show that the probability distributions that an observable is in a certain range of values can be obtained by averaging the results of scattering calculations with much smaller basis sets than required for calculations of individual scattering cross sections. Moreover, we show that such distributions do not rely on the precise knowledge of the PES. This opens the possibility of making probabilistic predictions of experimentally relevant observables for a wide variety of molecular systems, currently considered out of reach of quantum dynamics theory. We demonstrate the approach by computing the probability for elastic scattering of CaH and SrOH molecules by Li atoms and SrF molecules by Rb atoms.
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Affiliation(s)
- Masato Morita
- Department of Physics, University of Nevada, Reno, Nevada 89557, USA
| | - Roman V Krems
- Department of Chemistry, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
| | - Timur V Tscherbul
- Department of Physics, University of Nevada, Reno, Nevada 89557, USA
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39
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Sidler D, Bleiziffer P, Riniker S. Beyond the Rosenfeld Equation: Computation of Vibrational Circular Dichroism Spectra for Anisotropic Solutions. J Chem Theory Comput 2019; 15:2492-2503. [PMID: 30802403 DOI: 10.1021/acs.jctc.8b01156] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The difference in absorption of left and right circularly polarized light by chiral molecules can be described by the Rosenfeld equation for isotropic samples. It allows the assignment of the absolute stereochemistry by comparing experimental and computationally derived spectra. Despite the simple form of the Rosenfeld equation, its evaluation in the infrared regime remained challenging, as the contribution from the magnetic dipole operator is zero within the Born-Oppenheimer (BO) approximation. In order to resolve this issue, "beyond BO" theories had to be developed, among which Stephen's magnetic field perturbation (MFP) approach offers a computationally easily accessible form. In this work, optical activity is discussed for cylindrically symmetric solutions, which cannot be described anymore by Rosenfeld's equation due to broken spherical symmetry. Mathematical properties of natural and electric-field induced anisotropies are discussed on the basis of the gauge-independent theoretical framework of Buckingham and Dunn. The issue of achiral noise arising from external field perturbations is considered, and potential remedies are introduced. Natural anisotropic vibrational circular dichroism (VCD) equations are solved numerically by applying the MFP approach within the Hartree-Fock (HF) formalism. Properties of anisotropic VCD spectra are discussed for R-(+)-methyloxirane and (1 S,2 S)-cyclopropane-1,2-dicarbonitrile. In particular, by using a group theoretical argument, a gauge-independent lower bound for the quadrupole contribution of C2-symmetric molecules can be identified, which allows the importance of additional quadrupole terms in anisotropic VCD spectra calculation to be assessed.
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Affiliation(s)
- Dominik Sidler
- Laboratory of Physical Chemistry , ETH Zürich , Vladimir-Prelog-Weg 2 , 8093 Zürich , Switzerland
| | - Patrick Bleiziffer
- Laboratory of Physical Chemistry , ETH Zürich , Vladimir-Prelog-Weg 2 , 8093 Zürich , Switzerland
| | - Sereina Riniker
- Laboratory of Physical Chemistry , ETH Zürich , Vladimir-Prelog-Weg 2 , 8093 Zürich , Switzerland
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40
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Kapranov SV, Kouzaev GA. Nonlinear dynamics of dipoles in microwave electric field of a nanocoaxial tubular reactor. Mol Phys 2019. [DOI: 10.1080/00268976.2018.1524526] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Affiliation(s)
- Sergey V. Kapranov
- Department of Electronic Systems, Norwegian University of Science and Technology – NTNU, Gløshaugen, Trondheim, Norway
| | - Guennadi A. Kouzaev
- Department of Electronic Systems, Norwegian University of Science and Technology – NTNU, Gløshaugen, Trondheim, Norway
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41
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Stickler BA, Ghahramani FT, Hornberger K. Rotational Alignment Decay and Decoherence of Molecular Superrotors. PHYSICAL REVIEW LETTERS 2018; 121:243402. [PMID: 30608766 DOI: 10.1103/physrevlett.121.243402] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2018] [Indexed: 06/09/2023]
Abstract
We present the quantum master equation describing the coherent and incoherent dynamics of a rapidly rotating molecule in the presence of a thermal background gas. The master equation relates the rate of rotational alignment decay and decoherence to the microscopic scattering amplitudes, which we calculate for anisotropic van der Waals scattering. For large rotational energies, we find quantitative agreement of the resulting alignment decay rate with recent superrotor experiments.
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Affiliation(s)
- Benjamin A Stickler
- University of Duisburg-Essen, Faculty of Physics, Lotharstraße 1, 47048 Duisburg, Germany
| | - Farhad Taher Ghahramani
- School of Physics, Institute for Research in Fundamental Sciences (IPM), P.O. Box 19395-5531, Tehran, Iran
| | - Klaus Hornberger
- University of Duisburg-Essen, Faculty of Physics, Lotharstraße 1, 47048 Duisburg, Germany
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42
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Rosenberg D, Damari R, Fleischer S. Echo Spectroscopy in Multilevel Quantum-Mechanical Rotors. PHYSICAL REVIEW LETTERS 2018; 121:234101. [PMID: 30576185 DOI: 10.1103/physrevlett.121.234101] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2018] [Indexed: 06/09/2023]
Abstract
We study the dynamics of rotational echoes in gas phase molecular ensembles and their dependence on the delay and intensity of the excitation pulses. We explore the unique dynamics of alignment echoes that arise from the multilevel nature of the molecular rotors and impose severe difficulties in utilizing echo responses for rotational spectroscopy. We show experimentally and theoretically that judicious control of both the delay and intensity of the second pulse enables multilevel "rotational echo spectroscopy." The proposed methodology paves the way to rotational spectroscopy in high-density gas samples.
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Affiliation(s)
- Dina Rosenberg
- Raymond and Beverly Sackler Faculty of Exact Sciences, School of Chemistry, Tel Aviv University, Tel Aviv 6997801, Israel
- Tel-Aviv University center for Light-Matter-Interaction, Tel Aviv 6997801, Israel
| | - Ran Damari
- Raymond and Beverly Sackler Faculty of Exact Sciences, School of Chemistry, Tel Aviv University, Tel Aviv 6997801, Israel
- Tel-Aviv University center for Light-Matter-Interaction, Tel Aviv 6997801, Israel
| | - Sharly Fleischer
- Raymond and Beverly Sackler Faculty of Exact Sciences, School of Chemistry, Tel Aviv University, Tel Aviv 6997801, Israel
- Tel-Aviv University center for Light-Matter-Interaction, Tel Aviv 6997801, Israel
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43
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Lin K, Tutunnikov I, Qiang J, Ma J, Song Q, Ji Q, Zhang W, Li H, Sun F, Gong X, Li H, Lu P, Zeng H, Prior Y, Averbukh IS, Wu J. All-optical field-free three-dimensional orientation of asymmetric-top molecules. Nat Commun 2018; 9:5134. [PMID: 30510201 PMCID: PMC6277449 DOI: 10.1038/s41467-018-07567-2] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2018] [Accepted: 11/06/2018] [Indexed: 11/21/2022] Open
Abstract
Orientation and alignment of molecules by ultrashort laser pulses is crucial for a variety of applications and has long been of interest in physics and chemistry, with the special emphasis on stereodynamics in chemical reactions and molecular orbitals imaging. As compared to the laser-induced molecular alignment, which has been extensively studied and demonstrated, achieving molecular orientation is a much more challenging task, especially in the case of asymmetric-top molecules. Here, we report the experimental demonstration of all-optical field-free three-dimensional orientation of asymmetric-top molecules by means of phase-locked cross-polarized two-color laser pulse. This approach is based on nonlinear optical mixing process caused by the off-diagonal elements of the molecular hyperpolarizability tensor. It is demonstrated on SO2 molecules and is applicable to a variety of complex nonlinear molecules.
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Affiliation(s)
- Kang Lin
- State Key Laboratory of Precision Spectroscopy, East China Normal University, 200062, Shanghai, China
| | - Ilia Tutunnikov
- AMOS and Department of Chemical and Biological Physics, Weizmann Institute of Science, 7610001, Rehovot, Israel
| | - Junjie Qiang
- State Key Laboratory of Precision Spectroscopy, East China Normal University, 200062, Shanghai, China
| | - Junyang Ma
- State Key Laboratory of Precision Spectroscopy, East China Normal University, 200062, Shanghai, China
| | - Qiying Song
- State Key Laboratory of Precision Spectroscopy, East China Normal University, 200062, Shanghai, China
| | - Qinying Ji
- State Key Laboratory of Precision Spectroscopy, East China Normal University, 200062, Shanghai, China
| | - Wenbin Zhang
- State Key Laboratory of Precision Spectroscopy, East China Normal University, 200062, Shanghai, China
| | - Hanxiao Li
- State Key Laboratory of Precision Spectroscopy, East China Normal University, 200062, Shanghai, China
| | - Fenghao Sun
- State Key Laboratory of Precision Spectroscopy, East China Normal University, 200062, Shanghai, China
| | - Xiaochun Gong
- State Key Laboratory of Precision Spectroscopy, East China Normal University, 200062, Shanghai, China
| | - Hui Li
- State Key Laboratory of Precision Spectroscopy, East China Normal University, 200062, Shanghai, China
| | - Peifen Lu
- State Key Laboratory of Precision Spectroscopy, East China Normal University, 200062, Shanghai, China
| | - Heping Zeng
- State Key Laboratory of Precision Spectroscopy, East China Normal University, 200062, Shanghai, China
| | - Yehiam Prior
- State Key Laboratory of Precision Spectroscopy, East China Normal University, 200062, Shanghai, China.
- AMOS and Department of Chemical and Biological Physics, Weizmann Institute of Science, 7610001, Rehovot, Israel.
| | - Ilya Sh Averbukh
- AMOS and Department of Chemical and Biological Physics, Weizmann Institute of Science, 7610001, Rehovot, Israel.
| | - Jian Wu
- State Key Laboratory of Precision Spectroscopy, East China Normal University, 200062, Shanghai, China.
- Collaborative Innovation Center of Extreme Optics, Shanxi University, 030006, Taiyuan, Shanxi, China.
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44
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Suzuki YI. Circular dichroism in photoionization of degenerate orbitals: Spin-polarized photoelectrons and spontaneous separation of oriented photoions. J Chem Phys 2018; 149:204312. [PMID: 30501234 DOI: 10.1063/1.5054345] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
This work investigated the circular dichroic effect on the photoionization integral cross section of molecules in conjunction with irreducible tensor theory and effective operator formalism. The results show that the dichroic effect can be non-zero for complex orbitals, but becomes zero for all real orbitals due to time-reversal symmetry, within the electric dipole and Born-Oppenheimer approximations. Calculations were performed for carbon monoxide, boric acid, and fullerene, and implications of the first-order coefficient for the spin polarization of photoelectrons and the molecular axis orientation of photoions are discussed herein. The results of this work demonstrate that the photoionization of complex orbitals can cause photoions to become oriented such that photoions originating from complex conjugate orbitals are oriented opposite to one another. Due to electron-ion recoil, the spontaneous separation of these two kinds of photoions is expected for the point groups C n , C n v , C ∞ v , C nh , and S n with n ≥ 3.
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Affiliation(s)
- Yoshi-Ichi Suzuki
- School of Pharmaceutical Sciences, Health Sciences University of Hokkaido, 1757 Kanazawa, Tobetsucho, Ishikari, Hokkaido 061-0293, Japan
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45
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Hartmann JM, Boulet C, Zhang H, Billard F, Faucher O, Lavorel B. Collisional dissipation of the laser-induced alignment of ethane gas: A requantized classical model. J Chem Phys 2018; 149:154301. [PMID: 30342447 DOI: 10.1063/1.5046899] [Citation(s) in RCA: 5] [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 present the first theoretical study of collisional dissipation of the alignment of a symmetric-top molecule (ethane gas) impulsively induced by a linearly polarized non-resonant laser field. For this, Classical Molecular Dynamics Simulations (CMDSs) are carried out for an ensemble of C2H6 molecules based on knowledge of the laser-pulse characteristics and on an input intermolecular potential. These provide, for a given gas pressure and initial temperature, the orientations of all molecules at all times from which the alignment factor is directly obtained. Comparisons with measurements show that these CMDSs well predict the permanent alignment induced by the laser pulse and its decay with time but, as expected, fail in generating alignment revivals. However, it is shown that introducing a simple requantization procedure in the CMDS "creates" these revivals and that their predicted dissipation decay agrees very well with measured values. The calculations also confirm that, as for linear molecules, the permanent alignment of ethane decays more slowly than the transient revivals. The influence of the intermolecular potential is studied as well as that of the degree of freedom associated with the molecular rotation around the symmetry axis. This reveals that ethane practically behaves as a linear molecule because the intermolecular potential is only weakly sensitive to rotation around the C-C axis.
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Affiliation(s)
- J-M Hartmann
- Laboratoire de Météorologie Dynamique/IPSL, CNRS, École polytechnique, Sorbonne Université, École Normale Supérieure, PSL Research University, F-91120 Palaiseau, France
| | - C Boulet
- Institut des Sciences Moléculaires d'Orsay, CNRS, Université Paris-Sud, Université Paris-Saclay, Orsay F-91405, France
| | - H Zhang
- Laboratoire Interdisciplinaire Carnot de Bourgogne (ICB), UMR 6303 CNRS-Université, Bourgogne-Franche Comté, 9 Ave. A. Savary, BP 47 870, F-21078 Dijon Cedex, France
| | - F Billard
- Laboratoire Interdisciplinaire Carnot de Bourgogne (ICB), UMR 6303 CNRS-Université, Bourgogne-Franche Comté, 9 Ave. A. Savary, BP 47 870, F-21078 Dijon Cedex, France
| | - O Faucher
- Laboratoire Interdisciplinaire Carnot de Bourgogne (ICB), UMR 6303 CNRS-Université, Bourgogne-Franche Comté, 9 Ave. A. Savary, BP 47 870, F-21078 Dijon Cedex, France
| | - B Lavorel
- Laboratoire Interdisciplinaire Carnot de Bourgogne (ICB), UMR 6303 CNRS-Université, Bourgogne-Franche Comté, 9 Ave. A. Savary, BP 47 870, F-21078 Dijon Cedex, France
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46
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Lin YK, Show PL, Yap YJ, Ariff A, Annuar MSBM, Lai OM, Ling TC, Ng EP. Extractive Bioconversion of Gamma-Cyclodextrin and Recycling of Cyclodextrin Glycosyltransferase in Liquid Biphasic System Using Thermo-Separating Polymer. Front Chem 2018; 6:448. [PMID: 30345267 PMCID: PMC6182088 DOI: 10.3389/fchem.2018.00448] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2018] [Accepted: 09/07/2018] [Indexed: 11/13/2022] Open
Abstract
An extractive bioconversion conducted on soluble starch with cyclodextrin glycosyltransferase (CGTase) enzyme in ethylene oxide-propylene oxide (EOPO)/potassium phosphates liquid biphasic system (LBS) to extract gamma-cyclodextrin (γ-CD) was examined. A range of EOPO (with potassium phosphates) molecular weights was screen to investigate the effect of the latter on the partioning efficency of CGTase and γ-CD. The results show that the optimal top phase γ-CD yield (74.4%) was reached in 35.0% (w/w) EOPO 970 and 10.0% (w/w) potassium phosphate with 2.0% (w/w) sodium chloride. A theoretical explanation for the effect of NaCl on γ-CD was also presented. After a 2 h bioconversion process, a total of 0.87 mg/mL concentration of γ-CD was produced in the EOPO/ phosphates LBS top phase. After the extraction of top phase from LBS, four continuous repetitive batches were successfully conducted with relative CGTase activity of 1.00, 0.86, 0.45, and 0.40 respectively.
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Affiliation(s)
- Yu Kiat Lin
- Faculty of Science, Institute of Biological Sciences, University of Malaya, Kuala Lumpur, Malaysia
| | - Pau Loke Show
- Department of Chemical and Environmental Engineering, Faculty of Engineering, University of Nottingham Malaysia Campus, Semenyih, Malaysia
| | - Yee Jiun Yap
- Department of Applied Mathematics, Faculty of Engineering, University of Nottingham Malaysia Campus, Semenyih, Malaysia
| | - Arbakariya Ariff
- Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, Serdang, Malaysia
| | | | - Oi Ming Lai
- Department of Bioprocess Technology, Faculty of Biotechnology and Bimolecular Sciences, University Putra Malaysia, Serdang, Malaysia
| | - Tau Chuan Ling
- Faculty of Science, Institute of Biological Sciences, University of Malaya, Kuala Lumpur, Malaysia
| | - Eng Poh Ng
- School of Chemical Sciences, Universiti Sains Malaysia, Gelugor, Malaysia
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47
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Chen J, Kim M, Gathiaka S, Cho SJ, Kundu S, Yoon HJ, Thuo MM. Understanding Keesom Interactions in Monolayer-Based Large-Area Tunneling Junctions. J Phys Chem Lett 2018; 9:5078-5085. [PMID: 30126267 DOI: 10.1021/acs.jpclett.8b01731] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Charge transport across self-assembled monolayers (SAMs) has been widely studied. Discrepancies of charge tunneling data that arise from various studies, however, call for efforts to develop new statistical analytical approaches to understand charge tunneling across SAMs. Structure-property studies on charge tunneling across SAM-based junctions have largely been through comparison of average tunneling rates and associated variance. These early moments (especially the average) are dominated by barrier width-a static property of the junction. In this work, we show that analysis of higher statistical moments (skewness and kurtosis) reveals the dynamic nature of the tunnel junction. Intramolecular Keesom (dipole-dipole) interactions dynamically fluctuate with bias as dictated by stereoelectronic limitations. Analyzing variance in the distribution of tunneling data instead of the first statistical moment (average), for a series of n-alkanethiols containing internal amide and aromatic terminal groups, we observe that the direction of dipole moments affects molecule-electrode coupling. An applied bias induces changes in the tunneling probability, affecting the distribution of tunneling paths in large-area molecular junctions.
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Affiliation(s)
- Jiahao Chen
- Department of Materials Science and Engineering , Iowa State University , Ames , Iowa 50010 , United States
| | - Miso Kim
- Department of Chemistry , Korea University , Seongbuk-gu , Seoul 02841 , South Korea
| | - Symon Gathiaka
- School of Pharmacy and Pharmaceutical Science , University of California , La Jolla , California 92093-0657 , United States
| | - Soo Jin Cho
- Department of Chemistry , Korea University , Seongbuk-gu , Seoul 02841 , South Korea
| | - Souvik Kundu
- Department of Electrical and Computer Engineering , Iowa State University , Ames , Iowa 50010 , United States
| | - Hyo Jae Yoon
- Department of Chemistry , Korea University , Seongbuk-gu , Seoul 02841 , South Korea
| | - Martin M Thuo
- Department of Materials Science and Engineering , Iowa State University , Ames , Iowa 50010 , United States
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Leitner DM. Molecules and the Eigenstate Thermalization Hypothesis. ENTROPY 2018; 20:e20090673. [PMID: 33265762 PMCID: PMC7513195 DOI: 10.3390/e20090673] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/03/2018] [Revised: 09/02/2018] [Accepted: 09/03/2018] [Indexed: 11/18/2022]
Abstract
We review a theory that predicts the onset of thermalization in a quantum mechanical coupled non-linear oscillator system, which models the vibrational degrees of freedom of a molecule. A system of N non-linear oscillators perturbed by cubic anharmonic interactions exhibits a many-body localization (MBL) transition in the vibrational state space (VSS) of the molecule. This transition can occur at rather high energy in a sizable molecule because the density of states coupled by cubic anharmonic terms scales as N3, in marked contrast to the total density of states, which scales as exp(aN), where a is a constant. The emergence of a MBL transition in the VSS is seen by analysis of a random matrix ensemble that captures the locality of coupling in the VSS, referred to as local random matrix theory (LRMT). Upon introducing higher order anharmonicity, the location of the MBL transition of even a sizable molecule, such as an organic molecule with tens of atoms, still lies at an energy that may exceed the energy to surmount a barrier to reaction, such as a barrier to conformational change. Illustrative calculations are provided, and some recent work on the influence of thermalization on thermal conduction in molecular junctions is also discussed.
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Affiliation(s)
- David M Leitner
- Department of Chemistry, University of Nevada, Reno, NV 89557, USA
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Owens A, Yachmenev A, Küpper J. Coherent Control of the Rotation Axis of Molecular Superrotors. J Phys Chem Lett 2018; 9:4206-4209. [PMID: 29991265 DOI: 10.1021/acs.jpclett.8b01689] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The control of ultrafast molecular rotational motion has benefited from the development of innovative techniques in strong-field laser physics. Here, we theoretically demonstrate a novel type of coherent control by inducing rotation of an asymmetric-top molecule about two different molecular axes. An optical centrifuge is applied to the hydrogen sulfide (H2S) molecule to create a molecular superrotor, an object performing ultrafast rotation about a well-defined axis. Using two distinct pulse envelopes for the optical centrifuge, we show that H2S can be excited along separate pathways of rotational states. This leads to stable rotation about two entirely different molecular axes while ensuring rotation is about the propagation direction of the centrifuge, i.e., the laboratory-fixed Z-axis. The presented scheme to control the angular momentum alignment of a molecule will, for instance, be useful in studies of molecule-molecule or molecule-surface scattering, especially due to the large amounts of energy associated with superrotors, which can even be controlled by changing the duration of the optical centrifuge pulse.
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Affiliation(s)
- A Owens
- Center for Free-Electron Laser Science , Deutsches Elektronen-Synchrotron DESY , Notkestraße 85 , 22607 Hamburg , Germany
- The Hamburg Center for Ultrafast Imaging , Universität Hamburg , Luruper Chaussee 149 , 22761 Hamburg , Germany
| | - A Yachmenev
- Center for Free-Electron Laser Science , Deutsches Elektronen-Synchrotron DESY , Notkestraße 85 , 22607 Hamburg , Germany
- The Hamburg Center for Ultrafast Imaging , Universität Hamburg , Luruper Chaussee 149 , 22761 Hamburg , Germany
| | - J Küpper
- Center for Free-Electron Laser Science , Deutsches Elektronen-Synchrotron DESY , Notkestraße 85 , 22607 Hamburg , Germany
- The Hamburg Center for Ultrafast Imaging , Universität Hamburg , Luruper Chaussee 149 , 22761 Hamburg , Germany
- Department of Physics , Universität Hamburg , Luruper Chaussee 149 , 22761 Hamburg , Germany
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