1
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Wang Z, Hu X, Xue X, Zhou S, Li X, Yang Y, Zhou J, Shu Z, Zhao B, Yu X, Gong M, Wang Z, Ma P, Wu Y, Chen X, Wang J, Ren X, Wang C, Ding D. Directly imaging excited state-resolved transient structures of water induced by valence and inner-shell ionisation. Nat Commun 2023; 14:5420. [PMID: 37669964 PMCID: PMC10480213 DOI: 10.1038/s41467-023-41204-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Accepted: 08/24/2023] [Indexed: 09/07/2023] Open
Abstract
Real-time imaging of transient structure of the electronic excited state is fundamentally critical to understand and control ultrafast molecular dynamics. The ejection of electrons from the inner-shell and valence level can lead to the population of different excited states, which trigger manifold ultrafast relaxation processes, however, the accurate imaging of such electronic state-dependent structural evolutions is still lacking. Here, by developing the laser-induced electron recollision-assisted Coulomb explosion imaging approach and molecular dynamics simulations, snapshots of the vibrational wave-packets of the excited (A) and ground states (X) of D2O+ are captured simultaneously with sub-10 picometre and few-femtosecond precision. We visualise that θDOD and ROD are significantly increased by around 50∘ and 10 pm, respectively, within approximately 8 fs after initial ionisation for the A state, and the ROD further extends 9 pm within 2 fs along the ground state of the dication in the present condition. Moreover, the ROD can stretch more than 50 pm within 5 fs along autoionisation state of dication. The accuracies of the results are limited by the simulations. These results provide comprehensive structural information for studying the fascinating molecular dynamics of water, and pave the way towards to make a movie of excited state-resolved ultrafast molecular dynamics and light-induced chemical reaction.
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Affiliation(s)
- Zhenzhen Wang
- Institute of Atomic and Molecular Physics and Jilin Provincial Key Laboratory of Applied Atomic and Molecular Spectroscopy, Jilin University, 130012, Changchun, China
| | - Xiaoqing Hu
- Key Laboratory of Computational Physics, Institute of Applied Physics and Computational Mathematics, 100088, Beijing, China
| | - Xiaorui Xue
- School of Physics, Xi'an Jiaotong University, 710049, Xi'an, China
| | - Shengpeng Zhou
- Institute of Atomic and Molecular Physics and Jilin Provincial Key Laboratory of Applied Atomic and Molecular Spectroscopy, Jilin University, 130012, Changchun, China
| | - Xiaokai Li
- Institute of Atomic and Molecular Physics and Jilin Provincial Key Laboratory of Applied Atomic and Molecular Spectroscopy, Jilin University, 130012, Changchun, China
| | - Yizhang Yang
- Institute of Atomic and Molecular Physics and Jilin Provincial Key Laboratory of Applied Atomic and Molecular Spectroscopy, Jilin University, 130012, Changchun, China
| | - Jiaqi Zhou
- School of Physics, Xi'an Jiaotong University, 710049, Xi'an, China
| | - Zheng Shu
- Key Laboratory of Computational Physics, Institute of Applied Physics and Computational Mathematics, 100088, Beijing, China
| | - Banchi Zhao
- Institute of Atomic and Molecular Physics and Jilin Provincial Key Laboratory of Applied Atomic and Molecular Spectroscopy, Jilin University, 130012, Changchun, China
| | - Xitao Yu
- Institute of Atomic and Molecular Physics and Jilin Provincial Key Laboratory of Applied Atomic and Molecular Spectroscopy, Jilin University, 130012, Changchun, China
| | - Maomao Gong
- Hefei National Research Center for Physical Sciences at Microscale and Department of Modern Physic, University of Science and Technology of China, 230026, Hefei, China
- School of Physics and Information Technology, Shaanxi Normal University, 710119, Xi' an, China
| | - Zhenpeng Wang
- Key Laboratory of Computational Physics, Institute of Applied Physics and Computational Mathematics, 100088, Beijing, China
- Hefei National Research Center for Physical Sciences at Microscale and Department of Modern Physic, University of Science and Technology of China, 230026, Hefei, China
| | - Pan Ma
- Institute of Atomic and Molecular Physics and Jilin Provincial Key Laboratory of Applied Atomic and Molecular Spectroscopy, Jilin University, 130012, Changchun, China
| | - Yong Wu
- Key Laboratory of Computational Physics, Institute of Applied Physics and Computational Mathematics, 100088, Beijing, China.
- HEDPS, Center of Applied Physics and Technology, Peking University, 100871, Beijing, China.
| | - Xiangjun Chen
- Hefei National Research Center for Physical Sciences at Microscale and Department of Modern Physic, University of Science and Technology of China, 230026, Hefei, China
| | - Jianguo Wang
- Key Laboratory of Computational Physics, Institute of Applied Physics and Computational Mathematics, 100088, Beijing, China
| | - Xueguang Ren
- School of Physics, Xi'an Jiaotong University, 710049, Xi'an, China.
| | - Chuncheng Wang
- Institute of Atomic and Molecular Physics and Jilin Provincial Key Laboratory of Applied Atomic and Molecular Spectroscopy, Jilin University, 130012, Changchun, China.
| | - Dajun Ding
- Institute of Atomic and Molecular Physics and Jilin Provincial Key Laboratory of Applied Atomic and Molecular Spectroscopy, Jilin University, 130012, Changchun, China.
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2
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Allum F, McManus J, Denby O, Burt M, Brouard M. Photoionization and Photofragmentation Dynamics of I 2 in Intense Laser Fields: A Velocity-Map Imaging Study. J Phys Chem A 2022; 126:8577-8587. [DOI: 10.1021/acs.jpca.2c04379] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Felix Allum
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford OX1 3TA, U.K
| | - Joseph McManus
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford OX1 3TA, U.K
| | - Oskar Denby
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford OX1 3TA, U.K
| | - Michael Burt
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford OX1 3TA, U.K
| | - Mark Brouard
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford OX1 3TA, U.K
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3
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Filming movies of attosecond charge migration in single molecules with high harmonic spectroscopy. Nat Commun 2022; 13:4595. [PMID: 35933558 PMCID: PMC9357086 DOI: 10.1038/s41467-022-32313-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Accepted: 07/26/2022] [Indexed: 11/08/2022] Open
Abstract
Electron migration in molecules is the progenitor of chemical reactions and biological functions after light-matter interaction. Following this ultrafast dynamics, however, has been an enduring endeavor. Here we demonstrate that, by using machine learning algorithm to analyze high-order harmonics generated by two-color laser pulses, we are able to retrieve the complex amplitudes and phases of harmonics of single fixed-in-space molecules. These complex dipoles enable us to construct movies of laser-driven electron migration after tunnel ionization of N2 and CO2 molecules at time steps of 50 attoseconds. Moreover, the angular dependence of the migration dynamics is fully resolved. By examining the movies, we observe that electron holes do not just migrate along the laser polarization direction, but may swirl around the atom centers. Our result establishes a general scheme for studying ultrafast electron dynamics in molecules, paving a way for further advance in tracing and controlling photochemical reactions by femtosecond lasers.
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4
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Dowek D, Decleva P. Trends in angle-resolved molecular photoelectron spectroscopy. Phys Chem Chem Phys 2022; 24:24614-24654. [DOI: 10.1039/d2cp02725a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
In this perspective article, main trends of angle-resolved molecular photoelectron spectroscopy in the laboratory up to the molecular frame, in different regimes of light-matter interactions, are highlighted with emphasis on foundations and most recent applications.
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Affiliation(s)
- Danielle Dowek
- Université Paris-Saclay, CNRS, Institut des Sciences Moléculaires d’Orsay, 91405 Orsay, France
| | - Piero Decleva
- CNR IOM and Dipartimento DSCF, Università di Trieste, Trieste, Italy
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5
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Liu X, Amini K, Sanchez A, Belsa B, Steinle T, Biegert J. Machine learning for laser-induced electron diffraction imaging of molecular structures. Commun Chem 2021; 4:154. [PMID: 36697668 PMCID: PMC9814146 DOI: 10.1038/s42004-021-00594-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Accepted: 10/25/2021] [Indexed: 01/28/2023] Open
Abstract
Ultrafast diffraction imaging is a powerful tool to retrieve the geometric structure of gas-phase molecules with combined picometre spatial and attosecond temporal resolution. However, structural retrieval becomes progressively difficult with increasing structural complexity, given that a global extremum must be found in a multi-dimensional solution space. Worse, pre-calculating many thousands of molecular configurations for all orientations becomes simply intractable. As a remedy, here, we propose a machine learning algorithm with a convolutional neural network which can be trained with a limited set of molecular configurations. We demonstrate structural retrieval of a complex and large molecule, Fenchone (C10H16O), from laser-induced electron diffraction (LIED) data without fitting algorithms or ab initio calculations. Retrieval of such a large molecular structure is not possible with other variants of LIED or ultrafast electron diffraction. Combining electron diffraction with machine learning presents new opportunities to image complex and larger molecules in static and time-resolved studies.
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Affiliation(s)
- Xinyao Liu
- grid.473715.30000 0004 6475 7299ICFO - Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, 08860 Castelldefels, Barcelona, Spain
| | - Kasra Amini
- grid.473715.30000 0004 6475 7299ICFO - Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, 08860 Castelldefels, Barcelona, Spain
| | - Aurelien Sanchez
- grid.473715.30000 0004 6475 7299ICFO - Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, 08860 Castelldefels, Barcelona, Spain
| | - Blanca Belsa
- grid.473715.30000 0004 6475 7299ICFO - Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, 08860 Castelldefels, Barcelona, Spain
| | - Tobias Steinle
- grid.473715.30000 0004 6475 7299ICFO - Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, 08860 Castelldefels, Barcelona, Spain
| | - Jens Biegert
- grid.473715.30000 0004 6475 7299ICFO - Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, 08860 Castelldefels, Barcelona, Spain ,grid.425902.80000 0000 9601 989XICREA, Pg. Lluís Companys 23, 08010 Barcelona, Spain
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6
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Wang SJ, Daněk J, Blaga CI, DiMauro LF, Biegert J, Lin CD. Two-dimensional retrieval methods for ultrafast imaging of molecular structure using laser-induced electron diffraction. J Chem Phys 2021; 155:164104. [PMID: 34717362 DOI: 10.1063/5.0064761] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Molecular structural retrieval based on electron diffraction has been proposed to determine the atomic positions of molecules with sub-angstrom spatial and femtosecond temporal resolutions. Given its success on small molecular systems, in this work, we point out that the accuracy of structure retrieval is constrained by the availability of a wide range of experimental data in the momentum space in all molecular systems. To mitigate the limitations, for laser-induced electron diffraction, here we retrieve molecular structures using two-dimensional (energy and angle) electron momentum spectra in the laboratory frame for a number of small molecular systems, which have previously been studied with 1D methods. Compared to the conventional single-energy or single-angle analysis, our 2D methods effectively expand the momentum range of the measured data. Besides utilization of the 2D data, two complementary methods are developed for consistency check on the retrieved results. The 2D nature of our methods also offers a way of estimating the error from retrieval, which has never been explored before. Comparing with results from prior experiments, our findings show evidence that our 2D methods outperform the conventional 1D methods. Paving the way to the retrieval of large molecular systems, in which their tunneling ionization rates are challenging to obtain, we estimate the error of using the isotropic model in place of including the orientation-dependent ionization rate.
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Affiliation(s)
- Su-Ju Wang
- J. R. Macdonald Laboratory, Department of Physics, Kansas State University, Manhattan, Kansas 66506, USA
| | - Jiří Daněk
- J. R. Macdonald Laboratory, Department of Physics, Kansas State University, Manhattan, Kansas 66506, USA
| | - Cosmin I Blaga
- J. R. Macdonald Laboratory, Department of Physics, Kansas State University, Manhattan, Kansas 66506, USA
| | - Louis F DiMauro
- Department of Physics, The Ohio State University, Columbus, Ohio 43210, USA
| | - Jens Biegert
- ICFO-Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, 08860 Castelldefels, Barcelona, Spain
| | - C D Lin
- J. R. Macdonald Laboratory, Department of Physics, Kansas State University, Manhattan, Kansas 66506, USA
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7
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García
de Abajo FJ, Di Giulio V. Optical Excitations with Electron Beams: Challenges and Opportunities. ACS PHOTONICS 2021; 8:945-974. [PMID: 35356759 PMCID: PMC8939335 DOI: 10.1021/acsphotonics.0c01950] [Citation(s) in RCA: 42] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Revised: 02/17/2021] [Accepted: 02/19/2021] [Indexed: 05/20/2023]
Abstract
Free electron beams such as those employed in electron microscopes have evolved into powerful tools to investigate photonic nanostructures with an unrivaled combination of spatial and spectral precision through the analysis of electron energy losses and cathodoluminescence light emission. In combination with ultrafast optics, the emerging field of ultrafast electron microscopy utilizes synchronized femtosecond electron and light pulses that are aimed at the sampled structures, holding the promise to bring simultaneous sub-Å-sub-fs-sub-meV space-time-energy resolution to the study of material and optical-field dynamics. In addition, these advances enable the manipulation of the wave function of individual free electrons in unprecedented ways, opening sound prospects to probe and control quantum excitations at the nanoscale. Here, we provide an overview of photonics research based on free electrons, supplemented by original theoretical insights and discussion of several stimulating challenges and opportunities. In particular, we show that the excitation probability by a single electron is independent of its wave function, apart from a classical average over the transverse beam density profile, whereas the probability for two or more modulated electrons depends on their relative spatial arrangement, thus reflecting the quantum nature of their interactions. We derive first-principles analytical expressions that embody these results and have general validity for arbitrarily shaped electrons and any type of electron-sample interaction. We conclude with some perspectives on various exciting directions that include disruptive approaches to noninvasive spectroscopy and microscopy, the possibility of sampling the nonlinear optical response at the nanoscale, the manipulation of the density matrices associated with free electrons and optical sample modes, and appealing applications in optical modulation of electron beams, all of which could potentially revolutionize the use of free electrons in photonics.
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Affiliation(s)
- F. Javier García
de Abajo
- ICFO-Institut
de Ciencies Fotoniques, The Barcelona Institute
of Science and Technology, 08860 Castelldefels, Barcelona, Spain
- ICREA-Institució
Catalana de Recerca i Estudis Avançats, Passeig Lluís Companys 23, 08010 Barcelona, Spain
- E-mail:
| | - Valerio Di Giulio
- ICFO-Institut
de Ciencies Fotoniques, The Barcelona Institute
of Science and Technology, 08860 Castelldefels, Barcelona, Spain
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8
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Sun Z, Yao H, Ren X, Liu Y, Wang D, Zhao W, Wang C, Yang C. Imaging of electron transition and bond breaking in the photodissociation of H 2+ via ultrafast X-ray photoelectron diffraction. OPTICS EXPRESS 2021; 29:10893-10902. [PMID: 33820212 DOI: 10.1364/oe.416927] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Accepted: 03/08/2021] [Indexed: 06/12/2023]
Abstract
We theoretically investigate the photodissociation dynamics of H2+ using the methodology of ultrafast X-ray photoelectron diffraction (UXPD). We use a femtosecond infrared pulse to prompt a coherent excitation from the molecular vibrational state (v = 9) of the electronic ground state (1sσg) and then adopt another time-delayed attosecond X-ray pulse to probe the dynamical properties. We have calculated photoionization momentum distributions by solving the non-Born-Oppenheimer time-dependent Schrödinger equation (TDSE). We unambiguously identify the phenomena associated with the g - u symmetry breakdown in the time-resolved photoelectron diffraction spectra. Using the two-center interference model, we can determine the variation in nuclear spacing with high accuracy. In addition, we use a strong field approximation (SFA) model to interpret the UXPD profile, and the SFA simulations can reproduce the TDSE results in a quantitative way.
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9
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Sanchez A, Amini K, Wang SJ, Steinle T, Belsa B, Danek J, Le AT, Liu X, Moshammer R, Pfeifer T, Richter M, Ullrich J, Gräfe S, Lin CD, Biegert J. Molecular structure retrieval directly from laboratory-frame photoelectron spectra in laser-induced electron diffraction. Nat Commun 2021; 12:1520. [PMID: 33750798 PMCID: PMC7943781 DOI: 10.1038/s41467-021-21855-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Accepted: 02/17/2021] [Indexed: 01/31/2023] Open
Abstract
Ubiquitous to most molecular scattering methods is the challenge to retrieve bond distance and angle from the scattering signals since this requires convergence of pattern matching algorithms or fitting methods. This problem is typically exacerbated when imaging larger molecules or for dynamic systems with little a priori knowledge. Here, we employ laser-induced electron diffraction (LIED) which is a powerful means to determine the precise atomic configuration of an isolated gas-phase molecule with picometre spatial and attosecond temporal precision. We introduce a simple molecular retrieval method, which is based only on the identification of critical points in the oscillating molecular interference scattering signal that is extracted directly from the laboratory-frame photoelectron spectrum. The method is compared with a Fourier-based retrieval method, and we show that both methods correctly retrieve the asymmetrically stretched and bent field-dressed configuration of the asymmetric top molecule carbonyl sulfide (OCS), which is confirmed by our quantum-classical calculations.
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Affiliation(s)
- A Sanchez
- ICFO - Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, Barcelona, Spain
| | - K Amini
- ICFO - Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, Barcelona, Spain
| | - S-J Wang
- Department of Physics, J. R. Macdonald Laboratory, Kansas State University, Manhattan, KS, USA
| | - T Steinle
- ICFO - Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, Barcelona, Spain
| | - B Belsa
- ICFO - Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, Barcelona, Spain
| | - J Danek
- Department of Physics, J. R. Macdonald Laboratory, Kansas State University, Manhattan, KS, USA
| | - A T Le
- Department of Physics, J. R. Macdonald Laboratory, Kansas State University, Manhattan, KS, USA
- Department of Physics, Missouri University of Science and Technology, Rolla, MO, USA
| | - X Liu
- ICFO - Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, Barcelona, Spain
| | - R Moshammer
- Max-Planck-Institut für Kernphysik, Heidelberg, Germany
| | - T Pfeifer
- Max-Planck-Institut für Kernphysik, Heidelberg, Germany
| | - M Richter
- Physikalisch-Technische Bundesanstalt, Braunschweig, Germany
| | - J Ullrich
- Max-Planck-Institut für Kernphysik, Heidelberg, Germany
- Physikalisch-Technische Bundesanstalt, Braunschweig, Germany
| | - S Gräfe
- Institute of Physical Chemistry and Abbe Center of Photonics, Friedrich-Schiller-Universität Jena, Jena, Germany
| | - C D Lin
- Department of Physics, J. R. Macdonald Laboratory, Kansas State University, Manhattan, KS, USA
| | - J Biegert
- ICFO - Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, Barcelona, Spain.
- ICREA, Barcelona, Spain.
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10
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Belsa B, Amini K, Liu X, Sanchez A, Steinle T, Steinmetzer J, Le AT, Moshammer R, Pfeifer T, Ullrich J, Moszynski R, Lin CD, Gräfe S, Biegert J. Laser-induced electron diffraction of the ultrafast umbrella motion in ammonia. STRUCTURAL DYNAMICS (MELVILLE, N.Y.) 2021; 8:014301. [PMID: 34026922 PMCID: PMC8121549 DOI: 10.1063/4.0000046] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Accepted: 12/25/2020] [Indexed: 06/12/2023]
Abstract
Visualizing molecular transformations in real-time requires a structural retrieval method with Ångström spatial and femtosecond temporal atomic resolution. Imaging of hydrogen-containing molecules additionally requires an imaging method sensitive to the atomic positions of hydrogen nuclei, with most methods possessing relatively low sensitivity to hydrogen scattering. Laser-induced electron diffraction (LIED) is a table-top technique that can image ultrafast structural changes of gas-phase polyatomic molecules with sub-Ångström and femtosecond spatiotemporal resolution together with relatively high sensitivity to hydrogen scattering. Here, we image the umbrella motion of an isolated ammonia molecule (NH3) following its strong-field ionization. Upon ionization of a neutral ammonia molecule, the ammonia cation (NH3 +) undergoes an ultrafast geometrical transformation from a pyramidal ( Φ HNH = 107 ° ) to planar ( Φ HNH = 120 ° ) structure in approximately 8 femtoseconds. Using LIED, we retrieve a near-planar ( Φ HNH = 117 ± 5 ° ) field-dressed NH3 + molecular structure 7.8 - 9.8 femtoseconds after ionization. Our measured field-dressed NH3 + structure is in excellent agreement with our calculated equilibrium field-dressed structure using quantum chemical ab initio calculations.
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Affiliation(s)
- B. Belsa
- ICFO—Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, 08860 Castelldefels, Barcelona, Spain
| | | | - X. Liu
- ICFO—Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, 08860 Castelldefels, Barcelona, Spain
| | - A. Sanchez
- ICFO—Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, 08860 Castelldefels, Barcelona, Spain
| | - T. Steinle
- ICFO—Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, 08860 Castelldefels, Barcelona, Spain
| | - J. Steinmetzer
- Institute of Physical Chemistry and Abbe Center of Photonics, Friedrich-Schiller-Universität Jena, Helmholtzweg 4, 07743 Jena, Germany
| | - A. T. Le
- Department of Physics, Missouri University of Science and Technology, Rolla, Missouri 65409, USA
| | - R. Moshammer
- Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg, Germany
| | - T. Pfeifer
- Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg, Germany
| | | | - R. Moszynski
- Department of Chemistry, University of Warsaw, 02-093 Warsaw, Poland
| | - C. D. Lin
- Department of Physics, J. R. Macdonald Laboratory, Kansas State University, Manhattan, Kansas 66506-2604, USA
| | - S. Gräfe
- Institute of Physical Chemistry and Abbe Center of Photonics, Friedrich-Schiller-Universität Jena, Helmholtzweg 4, 07743 Jena, Germany
| | - J. Biegert
- Author to whom correspondence should be addressed:
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11
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Setting the photoelectron clock through molecular alignment. Nat Commun 2020; 11:2546. [PMID: 32439923 PMCID: PMC7242449 DOI: 10.1038/s41467-020-16270-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Accepted: 04/16/2020] [Indexed: 11/09/2022] Open
Abstract
The interaction of strong laser fields with matter intrinsically provides a powerful tool for imaging transient dynamics with an extremely high spatiotemporal resolution. Here, we study strong-field ionisation of laser-aligned molecules, and show a full real-time picture of the photoelectron dynamics in the combined action of the laser field and the molecular interaction. We demonstrate that the molecule has a dramatic impact on the overall strong-field dynamics: it sets the clock for the emission of electrons with a given rescattering kinetic energy. This result represents a benchmark for the seminal statements of molecular-frame strong-field physics and has strong impact on the interpretation of self-diffraction experiments. Furthermore, the resulting encoding of the time-energy relation in molecular-frame photoelectron momentum distributions shows the way of probing the molecular potential in real-time, and accessing a deeper understanding of electron transport during strong-field interactions. Interaction of strong laser fields with matter provides powerful tools to image transient dynamics with high spatiotemporal resolution. The authors investigate strong-field ionisation of laser-aligned molecules showing the effect of molecular alignment on the photoelectron dynamics and the resulting influence of the molecular frame in imaging experiments.
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12
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Yuan KJ, Bandrauk AD. Ultrafast X-ray photoelectron diffraction in triatomic molecules by circularly polarized attosecond light pulses. Phys Chem Chem Phys 2020; 22:325-336. [DOI: 10.1039/c9cp05213e] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We theoretically study ultrafast photoelectron diffraction in triatomic molecules with cyclic geometry by ultrafast circular soft X-ray attosecond pulses.
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Affiliation(s)
- Kai-Jun Yuan
- Institute of Atomic and Molecular Physics
- Jilin University
- Changchun
- China
- Laboratoire de Chimie Théorique
| | - André D. Bandrauk
- Laboratoire de Chimie Théorique
- Faculté des Sciences
- Université de Sherbrooke
- Québec
- Canada
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13
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Amini K, Biegert J, Calegari F, Chacón A, Ciappina MF, Dauphin A, Efimov DK, Figueira de Morisson Faria C, Giergiel K, Gniewek P, Landsman AS, Lesiuk M, Mandrysz M, Maxwell AS, Moszyński R, Ortmann L, Antonio Pérez-Hernández J, Picón A, Pisanty E, Prauzner-Bechcicki J, Sacha K, Suárez N, Zaïr A, Zakrzewski J, Lewenstein M. Symphony on strong field approximation. REPORTS ON PROGRESS IN PHYSICS. PHYSICAL SOCIETY (GREAT BRITAIN) 2019; 82:116001. [PMID: 31226696 DOI: 10.1088/1361-6633/ab2bb1] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
This paper has been prepared by the Symphony collaboration (University of Warsaw, Uniwersytet Jagielloński, DESY/CNR and ICFO) on the occasion of the 25th anniversary of the 'simple man's models' which underlie most of the phenomena that occur when intense ultrashort laser pulses interact with matter. The phenomena in question include high-harmonic generation (HHG), above-threshold ionization (ATI), and non-sequential multielectron ionization (NSMI). 'Simple man's models' provide both an intuitive basis for understanding the numerical solutions of the time-dependent Schrödinger equation and the motivation for the powerful analytic approximations generally known as the strong field approximation (SFA). In this paper we first review the SFA in the form developed by us in the last 25 years. In this approach the SFA is a method to solve the TDSE, in which the non-perturbative interactions are described by including continuum-continuum interactions in a systematic perturbation-like theory. In this review we focus on recent applications of the SFA to HHG, ATI and NSMI from multi-electron atoms and from multi-atom molecules. The main novel part of the presented theory concerns generalizations of the SFA to: (i) time-dependent treatment of two-electron atoms, allowing for studies of an interplay between electron impact ionization and resonant excitation with subsequent ionization; (ii) time-dependent treatment in the single active electron approximation of 'large' molecules and targets which are themselves undergoing dynamics during the HHG or ATI processes. In particular, we formulate the general expressions for the case of arbitrary molecules, combining input from quantum chemistry and quantum dynamics. We formulate also theory of time-dependent separable molecular potentials to model analytically the dynamics of realistic electronic wave packets for molecules in strong laser fields. We dedicate this work to the memory of Bertrand Carré, who passed away in March 2018 at the age of 60.
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Affiliation(s)
- Kasra Amini
- Faculty of Chemistry, University of Warsaw, Pasteura 1, 02-093 Warsaw, Poland. ICFO-Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, 08860 Castelldefels (Barcelona), Spain
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14
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Femtosecond Laser-Assisted Electron Scattering for Ultrafast Dynamics of Atoms and Molecules. ATOMS 2019. [DOI: 10.3390/atoms7030085] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
The recent progress in experimental studies of laser-assisted electron scattering (LAES) induced by ultrashort intense laser fields is reviewed. After a brief survey of the theoretical backgrounds of the LAES process and earlier LAES experiments started in the 1970s, new concepts of optical gating and optical streaking for the LAES processes, which can be realized by LAES experiments using ultrashort intense laser pulses, are discussed. A new experimental setup designed for measurements of LAES induced by ultrashort intense laser fields is described. The experimental results of the energy spectra, angular distributions, and laser polarization dependence of the LAES signals are presented with the results of the numerical simulations. A light-dressing effect that appeared in the recorded LAES signals is also shown with the results of the numerical calculations. In addition, as applications of the LAES process, laser-assisted electron diffraction and THz-wave-assisted electron diffraction, both of which have been developed for the determination of instantaneous geometrical structure of molecules, are introduced.
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15
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Chang BY, Shin S, Malinovsky VS, Sola IR. Grid-Based Ehrenfest Model To Study Electron-Nuclear Processes. J Phys Chem A 2019; 123:7171-7176. [PMID: 31314529 DOI: 10.1021/acs.jpca.9b05214] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The two-dimensional electron-nuclear Schrödinger equation using soft-core Coulomb potentials has been a cornerstone for modeling and predicting the behavior of one-active-electron diatomic molecules, particularly for processes where both bound and continuum states are important. The model, however, is computationally expensive to extend to more electron or nuclear coordinates. Here we propose use of the Ehrenfest approach to treat the nuclear motion, while the electronic motion is still solved by quantum propagation on a grid. In this work, we present results for a one-dimensional treatment of H2+, where the quantum and semiclassical dynamics can be directly compared, showing remarkably good agreement for a variety of situations. The advantage of the Ehrenfest approach is that it can be easily extended to treat as many nuclear degrees of freedom as needed.
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Affiliation(s)
- Bo Y Chang
- School of Chemistry , Seoul National University , Seoul 08826 , Republic of Korea
| | - Seokmin Shin
- School of Chemistry , Seoul National University , Seoul 08826 , Republic of Korea
| | | | - Ignacio R Sola
- Departamento de Química Física , Universidad Complutense , 28040 Madrid , Spain
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16
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Liu X, Amini K, Steinle T, Sanchez A, Shaikh M, Belsa B, Steinmetzer J, Le AT, Moshammer R, Pfeifer T, Ullrich J, Moszynski R, Lin CD, Gräfe S, Biegert J. Imaging an isolated water molecule using a single electron wave packet. J Chem Phys 2019; 151:024306. [PMID: 31301712 DOI: 10.1063/1.5100520] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Observing changes in molecular structure requires atomic-scale Ångstrom and femtosecond spatio-temporal resolution. We use the Fourier transform (FT) variant of laser-induced electron diffraction (LIED), FT-LIED, to directly retrieve the molecular structure of H2O+ with picometer and femtosecond resolution without a priori knowledge of the molecular structure nor the use of retrieval algorithms or ab initio calculations. We identify a symmetrically stretched H2O+ field-dressed structure that is most likely in the ground electronic state. We subsequently study the nuclear response of an isolated water molecule to an external laser field at four different field strengths. We show that upon increasing the laser field strength from 2.5 to 3.8 V/Å, the O-H bond is further stretched and the molecule slightly bends. The observed ultrafast structural changes lead to an increase in the dipole moment of water and, in turn, a stronger dipole interaction between the nuclear framework of the molecule and the intense laser field. Our results provide important insights into the coupling of the nuclear framework to a laser field as the molecular geometry of H2O+ is altered in the presence of an external field.
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Affiliation(s)
- Xinyao Liu
- ICFO-Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, 08860 Castelldefels, Barcelona, Spain
| | - Kasra Amini
- ICFO-Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, 08860 Castelldefels, Barcelona, Spain
| | - Tobias Steinle
- ICFO-Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, 08860 Castelldefels, Barcelona, Spain
| | - Aurelien Sanchez
- ICFO-Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, 08860 Castelldefels, Barcelona, Spain
| | - Moniruzzaman Shaikh
- ICFO-Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, 08860 Castelldefels, Barcelona, Spain
| | - Blanca Belsa
- ICFO-Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, 08860 Castelldefels, Barcelona, Spain
| | - Johannes Steinmetzer
- Institute of Physical Chemistry, Friedrich-Schiller University, 07743 Jena, Germany
| | - Anh-Thu Le
- Missouri University of Science and Technology, Rolla, Missouri 65409, USA
| | - Robert Moshammer
- Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117, Heidelberg, Germany
| | - Thomas Pfeifer
- Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117, Heidelberg, Germany
| | - Joachim Ullrich
- Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117, Heidelberg, Germany
| | - Robert Moszynski
- Department of Chemistry, University of Warsaw, 02-093 Warsaw, Poland
| | - C D Lin
- Abbe Center of Photonics, Friedrich-Schiller University, 07745 Jena, Germany
| | - Stefanie Gräfe
- Institute of Physical Chemistry, Friedrich-Schiller University, 07743 Jena, Germany
| | - Jens Biegert
- ICFO-Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, 08860 Castelldefels, Barcelona, Spain
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