1
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He L, Yuen CH, He Y, Sun S, Goetz E, Le AT, Deng Y, Xu C, Lan P, Lu P, Lin CD. Ultrafast Picometer-Resolved Molecular Structure Imaging by Laser-Induced High-Order Harmonics. PHYSICAL REVIEW LETTERS 2024; 133:023201. [PMID: 39073922 DOI: 10.1103/physrevlett.133.023201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2024] [Revised: 05/23/2024] [Accepted: 06/06/2024] [Indexed: 07/31/2024]
Abstract
Real-time visualization of molecular transformations is a captivating yet challenging frontier of ultrafast optical science and physical chemistry. While ultrafast x-ray and electron diffraction methods can achieve the needed subangstrom spatial resolution, their temporal resolution is still limited to hundreds of femtoseconds, much longer than the few femtoseconds required to probe real-time molecular dynamics. Here, we show that high-order harmonics generated by intense femtosecond lasers can be used to image molecules with few-ten-attosecond temporal resolution and few-picometer spatial resolution. This is achieved by exploiting the sensitive dependence of molecular recombination dipole moment to the geometry of the molecule at the time of harmonic emission. In a proof-of-principle experiment, we have applied this high-harmonic structure imaging (HHSI) method to monitor the structural rearrangement in NH_{3}, ND_{3}, and N_{2} from one to a few femtoseconds after the molecule is ionized by an intense laser. Our findings establish HHSI as an effective approach to resolve molecular dynamics with unprecedented spatiotemporal resolution, which can be extended to trace photochemical reactions in the future.
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2
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Rodríguez-Cuenca E, Picón A, Oberli S, Kuleff AI, Vendrell O. Core-Hole Coherent Spectroscopy in Molecules. PHYSICAL REVIEW LETTERS 2024; 132:263202. [PMID: 38996324 DOI: 10.1103/physrevlett.132.263202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2023] [Revised: 02/08/2024] [Accepted: 05/20/2024] [Indexed: 07/14/2024]
Abstract
We study the ultrafast dynamics initiated by a coherent superposition of core-excited states of nitrous oxide molecule. Using high-level ab initio methods, we show that the decoherence caused by the electronic decay and the nuclear dynamics is substantially slower than the induced ultrafast quantum beatings, allowing the system to undergo several oscillations before it dephases. We propose a proof-of-concept experiment using the harmonic up-conversion scheme available at x-ray free-electron laser facilities to trace the evolution of the created core-excited-state coherence through a time-resolved x-ray photoelectron spectroscopy.
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3
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Li Y, Song S, Han Y, Yue S, Du H. Coulomb-induced emission time shifts in high-order harmonic generation from H2. OPTICS EXPRESS 2024; 32:18984-18996. [PMID: 38859043 DOI: 10.1364/oe.522826] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2024] [Accepted: 04/30/2024] [Indexed: 06/12/2024]
Abstract
Accurate emission times of high-order harmonic generation (HHG) are vital for high-precision ultrafast detection in attosecond science, but a quantitative analysis of Coulomb effects on this time is absent in the molecular HHG. Here, we investigate the Coulomb-induced emission-time shift in HHG of H2+ with two different internuclear distances R, where the times obtained via the Gabor transform of numerical data from solving the time-dependent Schrödinger equation are used as simulation experiment results. Based on the molecular strong-field approximation, we develop a trajectory-resolved classical model that takes into account the molecular two-center structure. By selecting appropriate electron trajectories and including Coulomb interactions, the classical trajectory method can reproduce Gabor emission times well. This consistence reveals that Coulomb tails cause an emission-time shift of ∼35 as at the R = 2.0 a.u. case and of ∼40-60 as at the R = 2.6 a.u. case under the present laser parameters when compared to the Coulomb-free quantum-orbit model. Our results are of significance to probe the attosecond dynamics via two-center interference.
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4
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Cardosa-Gutierrez M, Levine RD, Remacle F. Electronic Coherences Excited by an Ultra Short Pulse Are Robust with Respect to Averaging over Randomly Oriented Molecules as Shown by Singular Value Decomposition. J Phys Chem A 2024; 128:2937-2947. [PMID: 38568803 DOI: 10.1021/acs.jpca.3c07856] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/05/2024]
Abstract
We report a methodology for averaging quantum photoexcitation vibronic dynamics over the initial orientations of the molecules with respect to an ultrashort light pulse. We use singular value decomposition of the ensemble density matrix of the excited molecules, which allows the identification of the few dominant principal molecular orientations with respect to the polarization direction of the electric field. The principal orientations provide insights into the specific stereodynamics of the corresponding principal molecular vibronic states. The massive compaction of the vibronic density matrix of the ensemble of randomly oriented pumped molecules enables a most efficient fully quantum mechanical time propagation scheme. Two examples are discussed for the quantum dynamics of the LiH molecule in the manifolds of its electronically excited Σ and Π states. Our results show that electronic and vibrational coherences between excited states of the same symmetry are resilient to averaging over an ensemble of molecular orientations and can be selectively excited at the ensemble level by tuning the pulse parameters.
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Affiliation(s)
| | - Raphael D Levine
- Fritz Haber Center, Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
- Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, Los Angeles, California 90095, United States
- Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095, United States
| | - Francoise Remacle
- Theoretical Physical Chemistry, UR MOLSYS, University of Liege, Liege B-4000, Belgium
- Fritz Haber Center, Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
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5
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Galán MF, Serrano J, Jarque EC, Borrego-Varillas R, Lucchini M, Reduzzi M, Nisoli M, Brahms C, Travers JC, Hernández-García C, San Roman J. Robust Isolated Attosecond Pulse Generation with Self-Compressed Subcycle Drivers from Hollow Capillary Fibers. ACS PHOTONICS 2024; 11:1673-1683. [PMID: 38645995 PMCID: PMC11027177 DOI: 10.1021/acsphotonics.3c01897] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/22/2023] [Revised: 03/05/2024] [Accepted: 03/05/2024] [Indexed: 04/23/2024]
Abstract
High-order harmonic generation (HHG) arising from the nonperturbative interaction of intense light fields with matter constitutes a well-established tabletop source of coherent extreme-ultraviolet and soft X-ray radiation, which is typically emitted as attosecond pulse trains. However, ultrafast applications increasingly demand isolated attosecond pulses (IAPs), which offer great promise for advancing precision control of electron dynamics. Yet, the direct generation of IAPs typically requires the synthesis of near-single-cycle intense driving fields, which is technologically challenging. In this work, we theoretically demonstrate a novel scheme for the straightforward and compact generation of IAPs from multicycle infrared drivers using hollow capillary fibers (HCFs). Starting from a standard, intense multicycle infrared pulse, a light transient is generated by extreme soliton self-compression in a HCF with decreasing pressure and is subsequently used to drive HHG in a gas target. Owing to the subcycle confinement of the HHG process, high-contrast IAPs are continuously emitted almost independently of the carrier-envelope phase (CEP) of the optimally self-compressed drivers. This results in a CEP-robust scheme which is also stable under macroscopic propagation of the high harmonics in a gas target. Our results open the way to a new generation of integrated all-fiber IAP sources, overcoming the efficiency limitations of usual gating techniques for multicycle drivers.
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Affiliation(s)
- Marina Fernández Galán
- Grupo
de Investigación en Aplicaciones del Láser y Fotónica,
Departamento de Física Aplicada, Universidad de Salamanca, Salamanca, 37008, Spain
- Unidad
de Excelencia en Luz y Materia Estructuradas (LUMES), Universidad de Salamanca, Salamanca, 37008, Spain
| | - Javier Serrano
- Grupo
de Investigación en Aplicaciones del Láser y Fotónica,
Departamento de Física Aplicada, Universidad de Salamanca, Salamanca, 37008, Spain
- Unidad
de Excelencia en Luz y Materia Estructuradas (LUMES), Universidad de Salamanca, Salamanca, 37008, Spain
| | - Enrique Conejero Jarque
- Grupo
de Investigación en Aplicaciones del Láser y Fotónica,
Departamento de Física Aplicada, Universidad de Salamanca, Salamanca, 37008, Spain
- Unidad
de Excelencia en Luz y Materia Estructuradas (LUMES), Universidad de Salamanca, Salamanca, 37008, Spain
| | - Rocío Borrego-Varillas
- Institute
for Photonics and Nanotechnologies (IFN), Consiglio Nazionale delle Ricerche (CNR), Piazza Leonardo da Vinci 32, Milano, 20133, Italy
| | - Matteo Lucchini
- Institute
for Photonics and Nanotechnologies (IFN), Consiglio Nazionale delle Ricerche (CNR), Piazza Leonardo da Vinci 32, Milano, 20133, Italy
- Department
of Physics, Politecnico di Milano, Piazza Leonardo da Vinci 32, Milano, 20133, Italy
| | - Maurizio Reduzzi
- Institute
for Photonics and Nanotechnologies (IFN), Consiglio Nazionale delle Ricerche (CNR), Piazza Leonardo da Vinci 32, Milano, 20133, Italy
- Department
of Physics, Politecnico di Milano, Piazza Leonardo da Vinci 32, Milano, 20133, Italy
| | - Mauro Nisoli
- Institute
for Photonics and Nanotechnologies (IFN), Consiglio Nazionale delle Ricerche (CNR), Piazza Leonardo da Vinci 32, Milano, 20133, Italy
- Department
of Physics, Politecnico di Milano, Piazza Leonardo da Vinci 32, Milano, 20133, Italy
| | - Christian Brahms
- School
of Engineering and Physical Sciences, Heriot-Watt
University, Edinburgh, EH14 4AS, United
Kingdom
| | - John C. Travers
- School
of Engineering and Physical Sciences, Heriot-Watt
University, Edinburgh, EH14 4AS, United
Kingdom
| | - Carlos Hernández-García
- Grupo
de Investigación en Aplicaciones del Láser y Fotónica,
Departamento de Física Aplicada, Universidad de Salamanca, Salamanca, 37008, Spain
- Unidad
de Excelencia en Luz y Materia Estructuradas (LUMES), Universidad de Salamanca, Salamanca, 37008, Spain
| | - Julio San Roman
- Grupo
de Investigación en Aplicaciones del Láser y Fotónica,
Departamento de Física Aplicada, Universidad de Salamanca, Salamanca, 37008, Spain
- Unidad
de Excelencia en Luz y Materia Estructuradas (LUMES), Universidad de Salamanca, Salamanca, 37008, Spain
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6
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Tran T, Ferté A, Vacher M. Simulating Attochemistry: Which Dynamics Method to Use? J Phys Chem Lett 2024; 15:3646-3652. [PMID: 38530933 PMCID: PMC11000647 DOI: 10.1021/acs.jpclett.4c00106] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2024] [Revised: 03/11/2024] [Accepted: 03/22/2024] [Indexed: 03/28/2024]
Abstract
Attochemistry aims to exploit the properties of coherent electronic wavepackets excited via attosecond pulses to control the formation of photoproducts. Such molecular processes can, in principle, be simulated with various nonadiabatic dynamics methods, yet the impact of the approximations underlying the methods is rarely assessed. The performances of widely used mixed quantum-classical approaches, Tully surface hopping, and classical Ehrenfest methods are evaluated against the high-accuracy DD-vMCG quantum dynamics. This comparison is conducted for the valence ionization of fluorobenzene. Analyzing the nuclear motion induced in the branching space of the nearby conical intersection, the results show that the mixed quantum-classical methods reproduce quantitatively the average motion of a quantum wavepacket when initiated on a single electronic state. However, they fail to properly capture the nuclear motion induced by an electronic wavepacket along the derivative coupling, the latter originating from the quantum electronic coherence property, key to attochemistry.
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Affiliation(s)
- Thierry Tran
- Nantes Université, CNRS, CEISAM
UMR 6230, F-44000 Nantes, France
| | - Anthony Ferté
- Nantes Université, CNRS, CEISAM
UMR 6230, F-44000 Nantes, France
| | - Morgane Vacher
- Nantes Université, CNRS, CEISAM
UMR 6230, F-44000 Nantes, France
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7
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Li S, Lu L, Bhattacharyya S, Pearce C, Li K, Nienhuis ET, Doumy G, Schaller RD, Moeller S, Lin MF, Dakovski G, Hoffman DJ, Garratt D, Larsen KA, Koralek JD, Hampton CY, Cesar D, Duris J, Zhang Z, Sudar N, Cryan JP, Marinelli A, Li X, Inhester L, Santra R, Young L. Attosecond-pump attosecond-probe x-ray spectroscopy of liquid water. Science 2024; 383:1118-1122. [PMID: 38359104 DOI: 10.1126/science.adn6059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2023] [Accepted: 02/06/2024] [Indexed: 02/17/2024]
Abstract
Attosecond-pump/attosecond-probe experiments have long been sought as the most straightforward method for observing electron dynamics in real time. Although there has been much success with overlapped near-infrared femtosecond and extreme ultraviolet attosecond pulses combined with theory, true attosecond-pump/attosecond-probe experiments have been limited. We used a synchronized attosecond x-ray pulse pair from an x-ray free-electron laser to study the electronic response to valence ionization in liquid water through all x-ray attosecond transient absorption spectroscopy (AX-ATAS). Our analysis showed that the AX-ATAS response is confined to the subfemtosecond timescale, eliminating any hydrogen atom motion and demonstrating experimentally that the 1b1 splitting in the x-ray emission spectrum is related to dynamics and is not evidence of two structural motifs in ambient liquid water.
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Affiliation(s)
- Shuai Li
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, IL, USA
| | - Lixin Lu
- Department of Chemistry, University of Washington, Seattle, WA, USA
| | - Swarnendu Bhattacharyya
- Center for Free-Electron Laser Science CFEL, Deutsches Elektronen-Synchrotron DESY, Hamburg, Germany
| | - Carolyn Pearce
- Pacific Northwest National Laboratory, Richland, WA, USA
- Department of Crop and Soil Sciences, Washington State University, Pullman, WA, USA
| | - Kai Li
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, IL, USA
- Department of Physics and James Franck Institute, The University of Chicago, Chicago, IL, USA
| | | | - Gilles Doumy
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, IL, USA
| | - R D Schaller
- Center for Nanoscale Materials, Argonne National Laboratory, Lemont, IL, USA
| | - S Moeller
- SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - M-F Lin
- SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - G Dakovski
- SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - D J Hoffman
- SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - D Garratt
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - Kirk A Larsen
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - J D Koralek
- SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - C Y Hampton
- SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - D Cesar
- SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - Joseph Duris
- SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - Z Zhang
- SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - Nicholas Sudar
- SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - James P Cryan
- SLAC National Accelerator Laboratory, Menlo Park, CA, USA
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - A Marinelli
- SLAC National Accelerator Laboratory, Menlo Park, CA, USA
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - Xiaosong Li
- Department of Chemistry, University of Washington, Seattle, WA, USA
| | - Ludger Inhester
- Center for Free-Electron Laser Science CFEL, Deutsches Elektronen-Synchrotron DESY, Hamburg, Germany
- The Hamburg Centre for Ultrafast Imaging, Hamburg, Germany
| | - Robin Santra
- Center for Free-Electron Laser Science CFEL, Deutsches Elektronen-Synchrotron DESY, Hamburg, Germany
- The Hamburg Centre for Ultrafast Imaging, Hamburg, Germany
- Department of Physics, Universität Hamburg, Hamburg, Germany
| | - Linda Young
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, IL, USA
- Department of Physics and James Franck Institute, The University of Chicago, Chicago, IL, USA
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8
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Zhu M, Tong J, Liu X, Yang W, Gong X, Jiang W, Lu P, Li H, Song X, Wu J. Tunnelling of electrons via the neighboring atom. LIGHT, SCIENCE & APPLICATIONS 2024; 13:18. [PMID: 38228578 DOI: 10.1038/s41377-023-01373-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Revised: 12/12/2023] [Accepted: 12/22/2023] [Indexed: 01/18/2024]
Abstract
As compared to the intuitive process that the electron emits straight to the continuum from its parent ion, there is an alternative route that the electron may transfer to and be trapped by a neighboring ionic core before the eventual release. Here, we demonstrate that electron tunnelling via the neighboring atomic core is a pronounced process in light-induced tunnelling ionization of molecules by absorbing multiple near-infrared photons. We devised a site-resolved tunnelling experiment using an Ar-Kr+ ion as a prototype system to track the electron tunnelling dynamics from the Ar atom towards the neighboring Kr+ by monitoring its transverse momentum distribution, which is temporally captured into the resonant excited states of the Ar-Kr+ before its eventual releasing. The influence of the Coulomb potential of neighboring ionic cores promises new insights into the understanding and controlling of tunnelling dynamics in complex molecules or environment.
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Affiliation(s)
- Ming Zhu
- School of Physics and Optoelectronic Engineering, Hainan University, Haikou, 570288, China
- School of Information and Communication Engineering, Hainan University, Haikou, 570288, China
| | - Jihong Tong
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai, 200241, China
| | - Xiwang Liu
- School of Physics and Optoelectronic Engineering, Hainan University, Haikou, 570288, China
| | - Weifeng Yang
- School of Physics and Optoelectronic Engineering, Hainan University, Haikou, 570288, China.
- Center for Theoretical Physics, Hainan University, Haikou, 570288, China.
| | - Xiaochun Gong
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai, 200241, China
| | - Wenyu Jiang
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai, 200241, China
| | - Peifen Lu
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai, 200241, China
| | - Hui Li
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai, 200241, China
| | - Xiaohong Song
- School of Physics and Optoelectronic Engineering, Hainan University, Haikou, 570288, China
| | - Jian Wu
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai, 200241, China
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9
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Ge P, Dou Y, Han M, Fang Y, Deng Y, Wu C, Gong Q, Liu Y. Spatiotemporal imaging and shaping of electron wave functions using novel attoclock interferometry. Nat Commun 2024; 15:497. [PMID: 38216557 PMCID: PMC10786904 DOI: 10.1038/s41467-024-44775-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2023] [Accepted: 01/03/2024] [Indexed: 01/14/2024] Open
Abstract
Electrons detached from atoms by photoionization carry valuable information about light-atom interactions. Characterizing and shaping the electron wave function on its natural timescale is of paramount importance for understanding and controlling ultrafast electron dynamics in atoms, molecules and condensed matter. Here we propose a novel attoclock interferometry to shape and image the electron wave function in atomic photoionization. Using a combination of a strong circularly polarized second harmonic and a weak linearly polarized fundamental field, we spatiotemporally modulate the atomic potential barrier and shape the electron wave functions, which are mapped into a temporal interferometry. By analyzing the two-color phase-resolved and angle-resolved photoelectron interference, we are able to reconstruct the spatiotemporal evolution of the shaping on the amplitude and phase of electron wave function in momentum space within the optical cycle, from which we identify the quantum nature of strong-field ionization and reveal the effect of the spatiotemporal properties of atomic potential on the departing electron. This study provides a new approach for spatiotemporal shaping and imaging of electron wave function in intense light-matter interactions and holds great potential for resolving ultrafast electronic dynamics in molecules, solids, and liquids.
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Affiliation(s)
- Peipei Ge
- State Key Laboratory for Mesoscopic Physics and Frontiers Science Center for Nano-optoelectronics, School of Physics, Peking University, Beijing, 100871, China
- Wuhan National Laboratory for Optoelectronics and School of Physics, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Yankun Dou
- State Key Laboratory for Mesoscopic Physics and Frontiers Science Center for Nano-optoelectronics, School of Physics, Peking University, Beijing, 100871, China
| | - Meng Han
- J. R. Macdonald Laboratory, Department of Physics, Kansas State University, Manhattan, KS, 66506, USA
| | - Yiqi Fang
- State Key Laboratory for Mesoscopic Physics and Frontiers Science Center for Nano-optoelectronics, School of Physics, Peking University, Beijing, 100871, China
| | - Yongkai Deng
- State Key Laboratory for Mesoscopic Physics and Frontiers Science Center for Nano-optoelectronics, School of Physics, Peking University, Beijing, 100871, China
| | - Chengyin Wu
- State Key Laboratory for Mesoscopic Physics and Frontiers Science Center for Nano-optoelectronics, School of Physics, Peking University, Beijing, 100871, China
| | - Qihuang Gong
- State Key Laboratory for Mesoscopic Physics and Frontiers Science Center for Nano-optoelectronics, School of Physics, Peking University, Beijing, 100871, China
- Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan, Shanxi, 030006, China
- Peking University Yangtze Delta Institute of Optoelectronics, Nantong, 226010, Jiangsu, China
| | - Yunquan Liu
- State Key Laboratory for Mesoscopic Physics and Frontiers Science Center for Nano-optoelectronics, School of Physics, Peking University, Beijing, 100871, China.
- Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan, Shanxi, 030006, China.
- Peking University Yangtze Delta Institute of Optoelectronics, Nantong, 226010, Jiangsu, China.
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10
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Hamer KA, Folorunso AS, Lopata K, Schafer KJ, Gaarde MB, Mauger F. Tracking Charge Migration with Frequency-Matched Strobo-Spectroscopy. J Phys Chem A 2024; 128:20-27. [PMID: 38165105 PMCID: PMC10788909 DOI: 10.1021/acs.jpca.3c04234] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Revised: 11/29/2023] [Accepted: 12/20/2023] [Indexed: 01/03/2024]
Abstract
We present frequency-matched strobo-spectroscopy (FMSS) of charge migration (CM) in bromobutadiyne, simulated with time-dependent density functional theory. CM + FMSS is a pump-probe scheme that uses a frequency-matched high harmonic generation (HHG)-driving laser as an independent probe step, following the creation of a localized hole on the bromine atom that induces CM dynamics. We show that the delay-dependent harmonic yield tracks the phase of the CM dynamics through its sensitivity to the amount of electron density on the bromine end of the molecule. FMSS takes advantage of the intrinsic attosecond time resolution of the HHG process in which different harmonics are emitted at different times and thus probe different locations of the electron hole. Finally, we show that the CM-induced modulation of the HHG signal is dominated by the recombination step of the HHG process, with a negligible contribution from the ionization step.
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Affiliation(s)
- Kyle A. Hamer
- Department
of Physics and Astronomy, Louisiana State
University, Baton
Rouge, Louisiana 70803, United States
| | - Aderonke S. Folorunso
- Department
of Chemistry, Louisiana State University, Baton Rouge, Louisiana 70803, United States
| | - Kenneth Lopata
- Department
of Chemistry, Louisiana State University, Baton Rouge, Louisiana 70803, United States
- Center
for Computation and Technology, Louisiana
State University, Baton Rouge, Louisiana 70803, United States
| | - Kenneth J. Schafer
- Department
of Physics and Astronomy, Louisiana State
University, Baton
Rouge, Louisiana 70803, United States
| | - Mette B. Gaarde
- Department
of Physics and Astronomy, Louisiana State
University, Baton
Rouge, Louisiana 70803, United States
| | - François Mauger
- Department
of Physics and Astronomy, Louisiana State
University, Baton
Rouge, Louisiana 70803, United States
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11
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Belles E, Rabilloud F, Kuleff AI, Despré V. Size Effect in Correlation-Driven Charge Migration in Correlation Bands of Alkyne Chains. J Phys Chem A 2024; 128:163-169. [PMID: 38150589 DOI: 10.1021/acs.jpca.3c06776] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2023]
Abstract
Correlation-driven charge migration initiated by inner-valence ionization leading to the population of the correlation bands of alkyne chains containing between 4 and 12 carbon atoms is explored through ab initio simulations. Scaling laws are observed, both for the time scale of the charge migration and for the slope of the density of states of the correlation bands. These can be used for predicting the relaxation time scale in much larger systems from the same molecular family and for finding promising candidates for the development of an attochemistry scheme taking advantages of the specificity of the dynamics in the correlation bands of molecules.
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Affiliation(s)
- Enguerran Belles
- Université de Lyon, Université Claude Bernard Lyon 1, CNRS, Institut Lumière Matière, UMR5306, Villeurbanne F-69622, France
| | - Franck Rabilloud
- Université de Lyon, Université Claude Bernard Lyon 1, CNRS, Institut Lumière Matière, UMR5306, Villeurbanne F-69622, France
| | - Alexander I Kuleff
- Theoretische Chemie, PCI, Universität Heidelberg, Im Neuenheimer Feld 229, Heidelberg D-69120, Germany
| | - Victor Despré
- Université de Lyon, Université Claude Bernard Lyon 1, CNRS, Institut Lumière Matière, UMR5306, Villeurbanne F-69622, France
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12
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Tehlar A, Casanova JT, Dnestryan A, Jensen F, Madsen LB, Tolstikhin OI, Wörner HJ. High-harmonic spectroscopy of impulsively aligned 1,3-cyclohexadiene: Signatures of attosecond charge migration. STRUCTURAL DYNAMICS (MELVILLE, N.Y.) 2024; 11:014304. [PMID: 38444565 PMCID: PMC10913099 DOI: 10.1063/4.0000227] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/03/2023] [Accepted: 02/02/2024] [Indexed: 03/07/2024]
Abstract
High-harmonic spectroscopy is an all-optical technique with inherent attosecond temporal resolution that has been successfully employed to reconstruct charge migration, electron-tunneling dynamics, and conical-intersection dynamics. Here, we demonstrate the extension of two key components of high-harmonic spectroscopy, i.e., impulsive alignment and measurements with multiple driving wavelengths to 1,3-cyclohexadiene and benzene. In the case of 1,3-cyclohexadiene, we find that the temporal sequence of maximal and minimal emitted high-harmonic intensities as a function of the delay between the alignment and probe pulses inverts between 25 and 30 eV and again between 35 and 40 eV when an 800-nm driver is used, but no inversions are observed with a 1420-nm driver. This observation is explained by the wavelength-dependent interference of emission from multiple molecular orbitals (HOMO to HOMO-3), as demonstrated by calculations based on the weak-field asymptotic theory and accurate photorecombination matrix elements. These results indicate that attosecond charge migration takes place in the 1,3-cyclohexadiene cation and can potentially be reconstructed with the help of additional measurements. Our experiments also demonstrate a pathway toward studying photochemical reactions in the molecular frame of 1,3-cyclohexadiene.
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Affiliation(s)
- Andres Tehlar
- Laboratory of Physical Chemistry, ETH Zürich, 8093 Zürich, Switzerland
| | - Jakob T. Casanova
- Laboratory of Physical Chemistry, ETH Zürich, 8093 Zürich, Switzerland
| | | | - Frank Jensen
- Department of Chemistry, Aarhus University, 8000 Aarhus C, Denmark
| | - Lars Bojer Madsen
- Department of Physics and Astronomy, Aarhus University, 8000 Aarhus C, Denmark
| | | | - Hans Jakob Wörner
- Laboratory of Physical Chemistry, ETH Zürich, 8093 Zürich, Switzerland
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13
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Min Y, Xu X, Lv X, Zhang Y, Lu Y, Hao X, Tan J. Probing the electron motion in molecules using forward-scattering photoelectron holography. OPTICS EXPRESS 2024; 32:857-870. [PMID: 38175105 DOI: 10.1364/oe.513783] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2023] [Accepted: 12/14/2023] [Indexed: 01/05/2024]
Abstract
Charge migration initiated by the coherent superposition of several electronic states is a basic process in intense laser-matter interactions. Observing this process on its intrinsic timescale is one of the central goals of attosecond science. Here, using forward-scattering photoelectron holography we theoretically demonstrate a scheme to probe the charge migration in molecules. In our scheme, by solving the time-dependent Schrödinger equation, the photoelectron momentum distributions (PEMDs) for strong-field tunneling ionization of the molecule are obtained. For a superposition state, it is shown that an intriguing shift of the holographic interference appears in the PEMDs, when the molecule is aligned perpendicularly to the linearly polarized laser field. With the quantum-orbit analysis, we demonstrate that this shift of the interference fringes is caused by the time evolution of the non-stationary superposition state. By analyzing the dependence of the shift on the final parallel momentum of the electrons, the relative phase and the expansion coefficient ratio of the two electronic states involved in the superposition state are determined accurately. Our study provides an efficient method for probing the charge migration in molecules. It will facilitate the application of the forward-scattering photoelectron holography to survey the electronic dynamics in more complex molecules.
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14
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Xiao Y, Sun H, Liu B, Zhao Z, Feng C. Self-Referenced Spectral Interferometry for Single-Shot Characterization of Ultrashort Free-Electron Laser Pulses. PHYSICAL REVIEW LETTERS 2023; 131:205002. [PMID: 38039478 DOI: 10.1103/physrevlett.131.205002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2023] [Revised: 06/17/2023] [Accepted: 10/18/2023] [Indexed: 12/03/2023]
Abstract
An attosecond x-ray pulse with known spectrotemporal information is an essential tool for the investigation of ultrafast electron dynamics in quantum systems. Ultrafast free-electron lasers (FELs) have the unique advantage on unprecedented high intensity at x-ray wavelengths. However, no suitable method has been established so far for the spectrotemporal characterization of these ultrashort x-ray pulses. In this Letter, a simple method has been proposed based on self-referenced spectral interferometry for reconstructing the temporal profile and phase of ultrashort FEL pulses. We have demonstrated that the proposed method is reliable to completely characterize the attosecond x-ray FEL pulses with an error at the level of a few percent. Moreover, the first proof-of-principle experiment has been performed to achieve the single-shot spectrotemporal characterization of ultrashort pulses from a high-gain FEL. The precision of the proposed method will be enhanced with the decrease of the pulse duration, paving a new way for complete attosecond pulse characterization at x-ray FELs.
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Affiliation(s)
- Yaozong Xiao
- Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, China
- University of Chinese Academy of Sciences, Beijing 100049, China
- Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai 201210, China
| | - Hao Sun
- Institute of Advanced Science Facilities, Shenzhen 518107, China
| | - Bo Liu
- Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, China
- Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai 201210, China
| | - Zhentang Zhao
- Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, China
- Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai 201210, China
| | - Chao Feng
- Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, China
- Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai 201210, China
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15
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Balbi A, Skeidsvoll AS, Koch H. Coupled Cluster Simulation of Impulsive Stimulated X-ray Raman Scattering. J Phys Chem A 2023; 127:8676-8684. [PMID: 37812082 PMCID: PMC10591507 DOI: 10.1021/acs.jpca.3c03678] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Revised: 08/22/2023] [Indexed: 10/10/2023]
Abstract
Time-dependent equation-of-motion coupled cluster (TD-EOM-CC) is used to simulate impulsive stimulated X-ray Raman scattering (ISXRS) of ultrashort laser pulses by neon, carbon monoxide, pyrrole, and p-aminophenol. The TD-EOM-CC equations are expressed in the basis of field-free EOM-CC states, where the calculation of the core-excited states is simplified through the use of the core-valence separation (CVS) approximation. The transfer of electronic population from the ground state to the core- and valence-excited states is calculated for different numbers of included core- and valence-excited states, as well as for electric field pulses with different polarizations and carrier frequencies. The results indicate that Gaussian pulses can transfer significant electronic populations to the valence states through the Raman process. The sensitivity of this population transfer to the model parameters is analyzed. The time-dependent electronic density for p-aminophenol is also showcased, supporting the interpretation that ISXRS involves localized core excitations and can be used to rapidly generate valence wavepackets.
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Affiliation(s)
- Alice Balbi
- Scuola
Normale Superiore, Piazza dei Cavalieri, 7, I-56126 Pisa, Italy
| | - Andreas S. Skeidsvoll
- Department
of Chemistry, Norwegian University of Science
and Technology, 7491 Trondheim, Norway
| | - Henrik Koch
- Scuola
Normale Superiore, Piazza dei Cavalieri, 7, I-56126 Pisa, Italy
- Department
of Chemistry, Norwegian University of Science
and Technology, 7491 Trondheim, Norway
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16
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Hanasaki K, Takatsuka K. Spin current in the early stage of radical reactions and its mechanisms. J Chem Phys 2023; 159:144111. [PMID: 37830453 DOI: 10.1063/5.0169281] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2023] [Accepted: 09/25/2023] [Indexed: 10/14/2023] Open
Abstract
We study the electronic spin flux (atomic-scale flow of the spin density in molecules) by a perturbation analysis and ab initio nonadiabatic calculations. We derive a general perturbative expression of the charge and spin fluxes and identify the driving perturbation of the fluxes to be the time derivative of the electron-nucleus interaction term in the Hamiltonian. We then expand the expression in molecular orbitals so as to identify relevant components of the fluxes. Our perturbation theory describes the electronic fluxes in the early stage of reactions in an intuitively clear manner. The perturbation theory is then applied to an analysis of the spin flux obtained in ab initio calculations of the radical reaction of O2 and CH3· starting from three distinct spin configurations; (a) CH3· and triplet O2 with total spin of the system set Stot=1/2 (b) CH3· and singlet O2, Stot=1/2, and (c) CH3· and triplet O2, Stot=3/2. Further analysis of the time-dependent behaviors of the spin flux in these numerical simulations reveals (i) the spin flux induces rearrangement of the local spin structure, such as reduction of the spin polarization arising from the triplet O2 and (ii) the spin flux flows from O2 to CH3· in the reaction starting from spin configuration (a) and from CH3· to O2 in that starting from configuration (b), whereas no major intermolecular spin flux was observed in that starting from configuration (c). Our study thus establishes the mechanism of the spin flux that rearranges the local spin structures associated with chemical bonds.
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Affiliation(s)
- Kota Hanasaki
- Fukui Institute for Fundamental Chemistry, Kyoto University, Kyoto 606-8103, Japan
| | - Kazuo Takatsuka
- Fukui Institute for Fundamental Chemistry, Kyoto University, Kyoto 606-8103, Japan
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17
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Mondal A, Waser B, Balciunas T, Neufeld O, Yin Z, Tancogne-Dejean N, Rubio A, Wörner HJ. High-harmonic generation in liquids with few-cycle pulses: effect of laser-pulse duration on the cut-off energy. OPTICS EXPRESS 2023; 31:34348-34361. [PMID: 37859193 DOI: 10.1364/oe.496686] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Accepted: 09/06/2023] [Indexed: 10/21/2023]
Abstract
High-harmonic generation (HHG) in liquids is opening new opportunities for attosecond light sources and attosecond time-resolved studies of dynamics in the liquid phase. In gas-phase HHG, few-cycle pulses are routinely used to create isolated attosecond pulses and to extend the cut-off energy. Here, we study the properties of HHG in liquids, including heavy water, ethanol and isopropanol, by continuously tuning the pulse duration of a mid-infrared driver from the multi- to the two-cycle regime. Similar to the gas phase, we observe the transition from discrete odd-order harmonics to continuous extreme-ultraviolet emission. However, the cut-off energy is shown to be entirely independent of the pulse duration. These observations are confirmed by ab-initio simulations of HHG in large liquid clusters. Our results support the notion that the cut-off energy is a fundamental property of the liquid, independent of the driving-pulse properties. Our work implies that few-cycle mid-infrared laser pulses are suitable drivers for generating isolated attosecond pulses from liquids and confirm the capability of high-harmonic spectroscopy to determine the mean-free paths of slow electrons in liquids.
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18
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Schlegel HB. Charge Migration in HCCI Cations Probed by Strong Field Ionization: Time-Dependent Configuration Interaction and Vibrational Wavepacket Simulations. J Phys Chem A 2023; 127:6040-6050. [PMID: 37459461 DOI: 10.1021/acs.jpca.3c02667] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/28/2023]
Abstract
Strong field ionization of neutral iodoacetylene (HCCI) can produce a coherent superposition of the X and A cations and results in charge migration between the CC π orbital and the iodine π-type lone pair. This charge migration causes oscillations in the rate of strong field ionization of the cation to the dication that can be monitored using intense few-cycle probe pulses. The dynamics and strong field ionization of the coherent superposition the X and A states of HCCI+ have been modeled by time-dependent configuration interaction (TDCI) simulations. When the nuclei are allowed to move, the electronic wavefunctions need to be multiplied by vibrational wavefunctions. Nuclear motion has been modeled by vibrational packets moving on quadratic approximations to the potential energy surfaces for the X and A states of the cation. The overlap of the vibrational wavepackets decays in about 10-15 fs. Consequently, the oscillations in the strong field ionization decay on the same time scale. A revival of the vibrational overlap and in the oscillations of the strong field ionization is seen at 60-110 fs. TDCI simulations show that the decay and revival of the charge migration can be monitored by strong field ionization with intense 2- and 4-cycle linearly polarized 800 nm pulses. The revival is also seen with 7-cycle pulses.
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Affiliation(s)
- H Bernhard Schlegel
- Department of Chemistry, Wayne State University, Detroit, Michigan 48202, United States
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19
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Ideböhn V, Linguerri R, Cornetta LM, Olsson E, Wallner M, Squibb RJ, Couto RC, Karlsson L, Nyman G, Hochlaf M, Eland JHD, Ågren H, Feifel R. Symmetry breaking in core-valence double ionisation of allene. Commun Chem 2023; 6:137. [PMID: 37400533 DOI: 10.1038/s42004-023-00934-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2023] [Accepted: 06/16/2023] [Indexed: 07/05/2023] Open
Abstract
Conventional electron spectroscopy is an established one-electron-at-the-time method for revealing the electronic structure and dynamics of either valence or inner shell ionized systems. By combining an electron-electron coincidence technique with the use of soft X-radiation we have measured a double ionisation spectrum of the allene molecule in which one electron is removed from a C1s core orbital and one from a valence orbital, well beyond Siegbahns Electron-Spectroscopy-for-Chemical-Analysis method. This core-valence double ionisation spectrum shows the effect of symmetry breaking in an extraordinary way, when the core electron is ejected from one of the two outer carbon atoms. To explain the spectrum we present a new theoretical approach combining the benefits of a full self-consistent field approach with those of perturbation methods and multi-configurational techniques, thus establishing a powerful tool to reveal molecular orbital symmetry breaking on such an organic molecule, going beyond Löwdins standard definition of electron correlation.
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Affiliation(s)
- Veronica Ideböhn
- University of Gothenburg, Department of Physics, Origovgen 6B, SE-412 58, Gothenburg, Sweden
| | - Roberto Linguerri
- Universite Gustave Eiffel, COSYS/IMSE, 5 Bd Descartes 77454, Champs sur Marne, France
| | - Lucas M Cornetta
- Uppsala University, Department of Physics and Astronomy, Box 516, SE-751 20, Uppsala, Sweden
- Department of Applied Physics, Gleb Wataghin Institute of Physics, State University of Campinas, Campinas, Brazil
| | - Emelie Olsson
- University of Gothenburg, Department of Physics, Origovgen 6B, SE-412 58, Gothenburg, Sweden
| | - Måns Wallner
- University of Gothenburg, Department of Physics, Origovgen 6B, SE-412 58, Gothenburg, Sweden
| | - Richard J Squibb
- University of Gothenburg, Department of Physics, Origovgen 6B, SE-412 58, Gothenburg, Sweden
| | - Rafael C Couto
- Division of Theoretical Chemistry and Biology, School of Engineering Sciences in Chemistry, Biotechnology and Health, KTH Royal Institute of Technology, SE-106 91, Stockholm, Sweden
| | - Leif Karlsson
- Uppsala University, Department of Physics and Astronomy, Box 516, SE-751 20, Uppsala, Sweden
| | - Gunnar Nyman
- University of Gothenburg, Department of Chemistry and Molecular Biology, Kemigården 4, SE-412 96, Gothenburg, Sweden
| | - Majdi Hochlaf
- Universite Gustave Eiffel, COSYS/IMSE, 5 Bd Descartes 77454, Champs sur Marne, France
| | - John H D Eland
- Oxford University, Department of Chemistry, Physical and Theoretical Chemistry Laboratory, South Parks Road, Oxford, OX1 3QZ, UK
| | - Hans Ågren
- Uppsala University, Department of Physics and Astronomy, Box 516, SE-751 20, Uppsala, Sweden
| | - Raimund Feifel
- University of Gothenburg, Department of Physics, Origovgen 6B, SE-412 58, Gothenburg, Sweden.
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20
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Keefer D, Cavaletto SM, Rouxel JR, Garavelli M, Yong H, Mukamel S. Ultrafast X-Ray Probes of Elementary Molecular Events. Annu Rev Phys Chem 2023; 74:73-97. [PMID: 37093660 DOI: 10.1146/annurev-physchem-062322-051532] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/25/2023]
Abstract
Elementary events that determine photochemical outcomes and molecular functionalities happen on the femtosecond and subfemtosecond timescales. Among the most ubiquitous events are the nonadiabatic dynamics taking place at conical intersections. These facilitate ultrafast, nonradiative transitions between electronic states in molecules that can outcompete slower relaxation mechanisms such as fluorescence. The rise of ultrafast X-ray sources, which provide intense light pulses with ever-shorter durations and larger observation bandwidths, has fundamentally revolutionized our spectroscopic capabilities to detect conical intersections. Recent theoretical studies have demonstrated an entirely new signature emerging once a molecule traverses a conical intersection, giving detailed insights into the coupled nuclear and electronic motions that underlie, facilitate, and ultimately determine the ultrafast molecular dynamics. Following a summary of current sources and experiments, we survey these techniques and provide a unified overview of their capabilities. We discuss their potential to dramatically increase our understanding of ultrafast photochemistry.
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Affiliation(s)
- Daniel Keefer
- Department of Chemistry and Department of Physics and Astronomy, University of California, Irvine, California, USA; ,
| | - Stefano M Cavaletto
- Department of Chemistry and Department of Physics and Astronomy, University of California, Irvine, California, USA; ,
- Current affiliation: Department of Physics and Astronomy, Aarhus University, Aarhus, Denmark
| | - Jérémy R Rouxel
- Université de Lyon, UJM-Saint-Etienne, IOGS, Laboratoire Hubert Curien, UMR CNRS 5516, Saint-Etienne, France
| | - Marco Garavelli
- Dipartimento di Chimica Industriale, Università degli Studi di Bologna, Bologna, Italy
| | - Haiwang Yong
- Department of Chemistry and Department of Physics and Astronomy, University of California, Irvine, California, USA; ,
| | - Shaul Mukamel
- Department of Chemistry and Department of Physics and Astronomy, University of California, Irvine, California, USA; ,
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21
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Zhang P, Hoang VH, Wang C, Luu TT, Svoboda V, Le AT, Wörner HJ. Effects of Autoionizing Resonances on Wave-Packet Dynamics Studied by Time-Resolved Photoelectron Spectroscopy. PHYSICAL REVIEW LETTERS 2023; 130:153201. [PMID: 37115860 DOI: 10.1103/physrevlett.130.153201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Accepted: 02/23/2023] [Indexed: 06/19/2023]
Abstract
We report a combined experimental and theoretical study on the effect of autoionizing resonances in time-resolved photoelectron spectroscopy. The coherent excitation of N_{2} by ∼14.15 eV extreme-ultraviolet photons prepares a superposition of three dominant adjacent vibrational levels (v^{'}=14-16) in the valence b^{'} ^{1}Σ_{u}^{+} state, which are probed by the absorption of two or three near-infrared photons (800 nm). The superposition manifests itself as coherent oscillations in the measured photoelectron spectra. A quantum-mechanical simulation confirms that two autoionizing Rydberg states converging to the excited A ^{2}Π_{u} and B ^{2}Σ_{u}^{+} N_{2}^{+} cores are accessed by the resonant absorption of near-infrared photons. We show that these resonances apply different filters to the observation of the vibrational wave packet, which results in different phases and amplitudes of the oscillating photoelectron signal depending on the nature of the autoionizing resonance. This work clarifies the importance of resonances in time-resolved photoelectron spectroscopy and particularly reveals the phase of vibrational quantum beats as a powerful observable for characterizing the properties of such resonances.
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Affiliation(s)
- Pengju Zhang
- Laboratory for Physical Chemistry, ETH Zürich, Vladimir-Prelog-Weg 2, 8093 Zürich, Switzerland
| | - Van-Hung Hoang
- Department of Physics, Missouri University of Science and Technology, Rolla, Missouri 65409, USA
- Department of Physics, Kansas State University, Manhattan, Kansas 66506, USA
| | - Chuncheng Wang
- Laboratory for Physical Chemistry, ETH Zürich, Vladimir-Prelog-Weg 2, 8093 Zürich, Switzerland
| | - Tran Trung Luu
- Laboratory for Physical Chemistry, ETH Zürich, Vladimir-Prelog-Weg 2, 8093 Zürich, Switzerland
- Department of Physics, The University of Hong Kong, Pokfulam Road, SAR Hong Kong, People's Republic of China
| | - Vít Svoboda
- Laboratory for Physical Chemistry, ETH Zürich, Vladimir-Prelog-Weg 2, 8093 Zürich, Switzerland
| | - Anh-Thu Le
- Department of Physics, Missouri University of Science and Technology, Rolla, Missouri 65409, USA
- Department of Physics, University of Connecticut, 196A Auditorium Road, Unit 3046, Storrs, Connecticut 06269, USA
| | - Hans Jakob Wörner
- Laboratory for Physical Chemistry, ETH Zürich, Vladimir-Prelog-Weg 2, 8093 Zürich, Switzerland
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22
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Folorunso AS, Mauger F, Hamer KA, Jayasinghe DD, Wahyutama IS, Ragains JR, Jones RR, DiMauro LF, Gaarde MB, Schafer KJ, Lopata K. Attochemistry Regulation of Charge Migration. J Phys Chem A 2023; 127:1894-1900. [PMID: 36791088 PMCID: PMC9986869 DOI: 10.1021/acs.jpca.3c00568] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Abstract
Charge migration (CM) is a coherent attosecond process that involves the movement of localized holes across a molecule. To determine the relationship between a molecule's structure and the CM dynamics it exhibits, we perform systematic studies of para-functionalized bromobenzene molecules (X-C6H4-R) using real-time time-dependent density functional theory. We initiate valence-electron dynamics by emulating rapid strong-field ionization leading to a localized hole on the bromine atom. The resulting CM, which takes on the order of 1 fs, occurs via an X localized → C6H4 delocalized → R localized mechanism. Interestingly, the hole contrast on the acceptor functional group increases with increasing electron-donating strength. This trend is well-described by the Hammett σ value of the group, which is a commonly used metric for quantifying the effect of functionalization on the chemical reactivity of benzene derivatives. These results suggest that simple attochemistry principles and a density-based picture can be used to predict and understand CM.
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Affiliation(s)
| | | | | | | | | | | | - Robert R Jones
- Department of Physics, University of Virginia, Charlottesville, Virginia 22904, United States
| | - Louis F DiMauro
- Department of Physics, The Ohio State University, Columbus, Ohio 43210, United States
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23
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Camper A, Ferré A, Blanchet V, Descamps D, Lin N, Petit S, Lucchese R, Salières P, Ruchon T, Mairesse Y. Quantum-Path-Resolved Attosecond High-Harmonic Spectroscopy. PHYSICAL REVIEW LETTERS 2023; 130:083201. [PMID: 36898107 DOI: 10.1103/physrevlett.130.083201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Accepted: 12/08/2022] [Indexed: 06/18/2023]
Abstract
Strong-field ionization of molecules releases electrons which can be accelerated and driven back to recombine with their parent ion, emitting high-order harmonics. This ionization also initiates attosecond electronic and vibrational dynamics in the ion, evolving during the electron travel in the continuum. Revealing this subcycle dynamics from the emitted radiation usually requires advanced theoretical modeling. We show that this can be avoided by resolving the emission from two families of electronic quantum paths in the generation process. The corresponding electrons have the same kinetic energy, and thus the same structural sensitivity, but differ by the travel time between ionization and recombination-the pump-probe delay in this attosecond self-probing scheme. We measure the harmonic amplitude and phase in aligned CO_{2} and N_{2} molecules and observe a strong influence of laser-induced dynamics on two characteristic spectroscopic features: a shape resonance and multichannel interference. This quantum-path-resolved spectroscopy thus opens wide prospects for the investigation of ultrafast ionic dynamics, such as charge migration.
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Affiliation(s)
- Antoine Camper
- Université Paris-Saclay, CEA, CNRS, LIDYL, 91191 Gif-sur-Yvette, France
- Department of Physics, University of Oslo, Sem Sælandsvei 24, 0371 Oslo, Norway
| | - Amélie Ferré
- Aix Marseille Université, CNRS, LP3, 13288, Marseille, France
| | | | | | - Nan Lin
- Université Paris-Saclay, CEA, CNRS, LIDYL, 91191 Gif-sur-Yvette, France
- Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, 201800 Shanghai, China
| | - Stéphane Petit
- Université de Bordeaux-CNRS-CEA, CELIA, UMR5107 Talence, France
| | - Robert Lucchese
- Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - Pascal Salières
- Université Paris-Saclay, CEA, CNRS, LIDYL, 91191 Gif-sur-Yvette, France
| | - Thierry Ruchon
- Université Paris-Saclay, CEA, CNRS, LIDYL, 91191 Gif-sur-Yvette, France
| | - Yann Mairesse
- Université de Bordeaux-CNRS-CEA, CELIA, UMR5107 Talence, France
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24
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Stewart GA, Hoerner P, Debrah DA, Lee SK, Schlegel HB, Li W. Attosecond Imaging of Electronic Wave Packets. PHYSICAL REVIEW LETTERS 2023; 130:083202. [PMID: 36898109 DOI: 10.1103/physrevlett.130.083202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Accepted: 11/22/2022] [Indexed: 06/18/2023]
Abstract
An electronic wave packet has significant spatial evolution besides its temporal evolution, due to the delocalized nature of composing electronic states. The spatial evolution was not previously accessible to experimental investigations at the attosecond timescale. A phase-resolved two-electron-angular-streaking method is developed to image the shape of the hole density of an ultrafast spin-orbit wave packet in the krypton cation. Furthermore, the motion of an even faster wave packet in the xenon cation is captured for the first time: An electronic hole is refilled 1.2 fs after it is produced, and the hole filling is observed on the opposite side where the hole is born.
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Affiliation(s)
- Gabriel A Stewart
- Department of Chemistry, Wayne State University, Detroit, Michigan 48202, USA
| | - Paul Hoerner
- Department of Chemistry, Wayne State University, Detroit, Michigan 48202, USA
| | - Duke A Debrah
- Department of Chemistry, Wayne State University, Detroit, Michigan 48202, USA
| | - Suk Kyoung Lee
- Department of Chemistry, Wayne State University, Detroit, Michigan 48202, USA
| | - H Bernhard Schlegel
- Department of Chemistry, Wayne State University, Detroit, Michigan 48202, USA
| | - Wen Li
- Department of Chemistry, Wayne State University, Detroit, Michigan 48202, USA
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25
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Moitra T, Konecny L, Kadek M, Rubio A, Repisky M. Accurate Relativistic Real-Time Time-Dependent Density Functional Theory for Valence and Core Attosecond Transient Absorption Spectroscopy. J Phys Chem Lett 2023; 14:1714-1724. [PMID: 36757216 PMCID: PMC9940299 DOI: 10.1021/acs.jpclett.2c03599] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2022] [Accepted: 02/03/2023] [Indexed: 06/18/2023]
Abstract
First principles theoretical modeling of out-of-equilibrium processes observed in attosecond pump-probe transient absorption spectroscopy (TAS) triggering pure electron dynamics remains a challenging task, especially for heavy elements and/or core excitations containing fingerprints of scalar and spin-orbit relativistic effects. To address this, we formulate a methodology for simulating TAS within the relativistic real-time, time-dependent density functional theory (RT-TDDFT) framework, for both the valence and core energy regimes. Especially for TAS, full four-component (4c) RT simulations are feasible but computationally demanding. Therefore, in addition to the 4c approach, we also introduce the atomic mean-field exact two-component (amfX2C) Hamiltonian accounting for one- and two-electron picture-change corrections within RT-TDDFT. amfX2C preserves the accuracy of the parent 4c method at a fraction of its computational cost. Finally, we apply the methodology to study valence and near-L2,3-edge TAS processes of experimentally relevant systems and provide additional physical insights using relativistic nonequilibrium response theory.
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Affiliation(s)
- Torsha Moitra
- Hylleraas
Centre for Quantum Molecular Sciences, Department of Chemistry, UiT The Arctic University of Norway, 9037 Tromsø, Norway
| | - Lukas Konecny
- Hylleraas
Centre for Quantum Molecular Sciences, Department of Chemistry, UiT The Arctic University of Norway, 9037 Tromsø, Norway
- Max
Planck Institute for the Structure and Dynamics of Matter, Center for Free Electron Laser Science, Luruper Chaussee 149, 22761 Hamburg, Germany
| | - Marius Kadek
- Hylleraas
Centre for Quantum Molecular Sciences, Department of Chemistry, UiT The Arctic University of Norway, 9037 Tromsø, Norway
- Department
of Physics, Northeastern University, Boston, Massachusetts 02115, United States
- Algorithmiq
Ltd., Kanavakatu 3C, FI-00160 Helsinki, Finland
| | - Angel Rubio
- Max
Planck Institute for the Structure and Dynamics of Matter, Center for Free Electron Laser Science, Luruper Chaussee 149, 22761 Hamburg, Germany
- Center
for Computational Quantum Physics (CCQ), The Flatiron Institute, 162 Fifth Avenue, New York New York 10010, United States
- Nano-Bio
Spectroscopy Group, Departamento de Física de Materiales, Universidad del País Vasco, 20018 San Sebastian, Spain
| | - Michal Repisky
- Hylleraas
Centre for Quantum Molecular Sciences, Department of Chemistry, UiT The Arctic University of Norway, 9037 Tromsø, Norway
- Department
of Physical and Theoretical Chemistry, Faculty of Natural Sciences, Comenius University, 84104 Bratislava, Slovakia
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26
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Investigation of the Spatio-Temporal Characteristics of High-Order Harmonic Generation Using a Bohmian Trajectory Scheme. Symmetry (Basel) 2023. [DOI: 10.3390/sym15030581] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/25/2023] Open
Abstract
High-order harmonic generation of atoms irradiated by an ultrashort laser pulse was calculated by numerically solving the time-dependent Schrödinger equation and the Bohmian trajectory scheme. The harmonic spectra with the two schemes are quantitatively consistent. Using the wavelet behavior of the Bohmian trajectory, the spatio-temporal features of harmonic emission from different energy regions are analyzed. It is found that the spatio-temporal distribution of the harmonic well revealed the physical mechanism of harmonic generation. This method will contribute to the understanding of harmonic emission mechanisms in complex systems, which include many atoms.
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27
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Chordiya K, Despré V, Nagyillés B, Zeller F, Diveki Z, Kuleff AI, Kahaly MU. Photo-ionization initiated differential ultrafast charge migration: impacts of molecular symmetries and tautomeric forms. Phys Chem Chem Phys 2023; 25:4472-4480. [PMID: 36317562 DOI: 10.1039/d2cp02681c] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Photo-ionization induced ultrafast electron dynamics is considered as a precursor for the slower nuclear dynamics associated with molecular dissociation. Here, using the ab initio multielectron wave-packet propagation method, we study the overall many-electron dynamics, triggered by ionizing the outer-valence orbitals of different tautomers for a prototype molecule with more than one symmetry element. From the time evolution of the initially created averaged hole density of each system, we identify distinctly different charge dynamics responses in the tautomers. We observe that the keto form shows a charge migration direction away from the nitrogen bonded with hydrogen, while in enol-U - away from oxygen bonded to hydrogen. Additionally, the dynamics following the ionization of molecular orbitals with different symmetries reveals that a' orbitals show a fast and highly delocalized charge density in comparison to a'' symmetry. These observations indicate why different tautomers respond differently to an XUV ionization, and might explain the subsequent different fragmentation pathways. An experimental schematics allowing the detection and reconstruction of such charge dynamics is also proposed. Although the present study uses a simple, prototypical bio-relevant molecule, it reveals the explicit role of molecular symmetry and tautomerism in the ionization-triggered charge migration that controls many ultrafast physical, chemical, and biological processes, making tautomeric forms a promising tool of molecular design for desired charge migration.
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Affiliation(s)
- Kalyani Chordiya
- ELI-ALPS, ELI-HU Non-Profit Ltd., Wolfgang Sandner utca 3., Szeged, H-6728, Hungary. .,Institute of Physics, University of Szeged, Dóm tér 9, H-6720, Szeged, Hungary
| | - Victor Despré
- Theoretische Chemie, Universität Heidelberg, Im Neuenheimer Feld 229, D-69120, Heidelberg, Germany.
| | - Balázs Nagyillés
- ELI-ALPS, ELI-HU Non-Profit Ltd., Wolfgang Sandner utca 3., Szeged, H-6728, Hungary. .,Institute of Physics, University of Szeged, Dóm tér 9, H-6720, Szeged, Hungary
| | - Felix Zeller
- Theoretische Chemie, Universität Heidelberg, Im Neuenheimer Feld 229, D-69120, Heidelberg, Germany.
| | - Zsolt Diveki
- ELI-ALPS, ELI-HU Non-Profit Ltd., Wolfgang Sandner utca 3., Szeged, H-6728, Hungary.
| | - Alexander I Kuleff
- ELI-ALPS, ELI-HU Non-Profit Ltd., Wolfgang Sandner utca 3., Szeged, H-6728, Hungary. .,Theoretische Chemie, Universität Heidelberg, Im Neuenheimer Feld 229, D-69120, Heidelberg, Germany.
| | - Mousumi Upadhyay Kahaly
- ELI-ALPS, ELI-HU Non-Profit Ltd., Wolfgang Sandner utca 3., Szeged, H-6728, Hungary. .,Institute of Physics, University of Szeged, Dóm tér 9, H-6720, Szeged, Hungary
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28
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Yong H, Keefer D, Mukamel S. Novel Ultrafast Molecular Imaging Based on the Combination of X-ray and Electron Diffraction. J Phys Chem A 2023; 127:835-841. [PMID: 36650121 DOI: 10.1021/acs.jpca.2c08024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Recent development of X-ray free-electron lasers and megaelectronvolt radio-frequency electron guns have made ultrafast X-ray and electron diffraction measurements possible, thereby capturing chemical dynamics with atomic-spatial and femtosecond-temporal resolutions. We present a unified formulation of standard homodyne-detected and heterodyne-detected signals for both techniques. Noting that X-rays scatter from molecular electrons while electrons scatter from both molecular electrons and nuclei, we show how the two diffraction signals can be combined to reveal novel chemical information that is unavailable by solely using each technique alone. By subtracting the homodyne-detected X-ray and electron diffraction signals, a mixed electronic-nuclear interference in electron diffraction can be identified with a self-heterodyne nature for the direct imaging of attosecond electron dynamics where the scattering off molecular nuclei serves as a local oscillator for the scattering off molecular electrons. By subtracting heterodyne-detected X-ray and electron diffraction, the purely nuclear charge density can be singled out.
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Affiliation(s)
- Haiwang Yong
- Department of Chemistry, University of California, Irvine, California92697, United States.,Department of Physics and Astronomy, University of California, Irvine, California92697, United States
| | - Daniel Keefer
- Department of Chemistry, University of California, Irvine, California92697, United States.,Department of Physics and Astronomy, University of California, Irvine, California92697, United States
| | - Shaul Mukamel
- Department of Chemistry, University of California, Irvine, California92697, United States.,Department of Physics and Astronomy, University of California, Irvine, California92697, United States
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29
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Waters MDJ, Casanova JT, Wörner HJ. Ultrafast dissociation of nitromethane from the 3p Rydberg state. Mol Phys 2023. [DOI: 10.1080/00268976.2022.2164749] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Affiliation(s)
- Max D. J. Waters
- Laboratory of Physical Chemistry, ETH Zürich, Zürich, Switzerland
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30
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Woźniak AP, Lewenstein M, Moszyński R. Exploring the attosecond laser-driven electron dynamics in the hydrogen molecule with different real-time time-dependent configuration interaction approaches. ADVANCES IN QUANTUM CHEMISTRY 2023. [DOI: 10.1016/bs.aiq.2023.01.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/05/2023]
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31
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Flórez-Angarita MF, Pérez-Torres JF. Photoionization of Oriented HD( 1Σ +) Yields Vibrating HD +( 2Σ +) with Charge Breathing and Small Charge Transfer. J Phys Chem A 2022; 126:8918-8929. [DOI: 10.1021/acs.jpca.2c05050] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Affiliation(s)
| | - J. F. Pérez-Torres
- Universidad Industrial de Santander, carrera 27 calle 9, 680002Bucaramanga, Colombia
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32
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Schnappinger T, Jadoun D, Gudem M, Kowalewski M. Time-resolved X-ray and XUV based spectroscopic methods for nonadiabatic processes in photochemistry. Chem Commun (Camb) 2022; 58:12763-12781. [PMID: 36317595 PMCID: PMC9671098 DOI: 10.1039/d2cc04875b] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2022] [Accepted: 10/21/2022] [Indexed: 11/03/2023]
Abstract
The photochemistry of numerous molecular systems is influenced by conical intersections (CIs). These omnipresent nonadiabatic phenomena provide ultra-fast radiationless relaxation channels by creating degeneracies between electronic states and decide over the final photoproducts. In their presence, the Born-Oppenheimer approximation breaks down, and the timescales of the electron and nuclear dynamics become comparable. Due to the ultra-fast dynamics and the complex interplay between nuclear and electronic degrees of freedom, the direct experimental observation of nonadiabatic processes close to CIs remains challenging. In this article, we give a theoretical perspective on novel spectroscopic techniques capable of observing clear signatures of CIs. We discuss methods that are based on ultra-short laser pulses in the extreme ultraviolet and X-ray regime, as their spectral and temporal resolution allow for resolving the ultra-fast dynamics near CIs.
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Affiliation(s)
- Thomas Schnappinger
- Department of Physics, Stockholm University, Albanova University Centre, SE-106 91 Stockholm, Sweden.
| | - Deependra Jadoun
- Department of Physics, Stockholm University, Albanova University Centre, SE-106 91 Stockholm, Sweden.
| | - Mahesh Gudem
- Department of Physics, Stockholm University, Albanova University Centre, SE-106 91 Stockholm, Sweden.
| | - Markus Kowalewski
- Department of Physics, Stockholm University, Albanova University Centre, SE-106 91 Stockholm, Sweden.
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33
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Schaap BH, Smorenburg PW, Luiten OJ. Isolated attosecond X-ray pulses from superradiant thomson scattering by a relativistic chirped electron mirror. Sci Rep 2022; 12:19727. [PMID: 36396752 PMCID: PMC9672037 DOI: 10.1038/s41598-022-24288-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2022] [Accepted: 11/14/2022] [Indexed: 11/18/2022] Open
Abstract
AbstractTime-resolved investigation of electron dynamics relies on the generation of isolated attosecond pulses in the (soft) X-ray regime. Thomson scattering is a source of high energy radiation of increasing prevalence in modern labs, complementing large scale facilities like undulators and X-ray free electron lasers. We propose a scheme to generate isolated attosecond X-ray pulses based on Thomson scattering by colliding microbunched electrons on a chirped laser pulse. The electrons collectively act as a relativistic chirped mirror, which superradiantly reflects the laser pulse into a single localized beat. As such, this technique extends chirped pulse compression, developed for radar and applied in optics, to the X-ray regime. In this paper we theoretically show that, by using this approach, attosecond soft X-ray pulses with GW peak power can be generated from pC electron bunches at tens of MeV electron beam energy. While we propose the generation of few cycle X-ray pulses on a table-top system, the theory is universally scalable over the electromagnetic spectrum.
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34
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Yong H, Sun S, Gu B, Mukamel S. Attosecond Charge Migration in Molecules Imaged by Combined X-ray and Electron Diffraction. J Am Chem Soc 2022; 144:20710-20716. [DOI: 10.1021/jacs.2c07997] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Affiliation(s)
- Haiwang Yong
- Department of Chemistry, University of California, Irvine, California92697, United States
- Department of Physics and Astronomy, University of California, Irvine, California92697, United States
| | - Shichao Sun
- Department of Chemistry, University of California, Irvine, California92697, United States
- Department of Physics and Astronomy, University of California, Irvine, California92697, United States
| | - Bing Gu
- Department of Chemistry, University of California, Irvine, California92697, United States
- Department of Physics and Astronomy, University of California, Irvine, California92697, United States
| | - Shaul Mukamel
- Department of Chemistry, University of California, Irvine, California92697, United States
- Department of Physics and Astronomy, University of California, Irvine, California92697, United States
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35
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Kobayashi Y, Leone SR. Characterizing coherences in chemical dynamics with attosecond time-resolved x-ray absorption spectroscopy. J Chem Phys 2022; 157:180901. [DOI: 10.1063/5.0119942] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Coherence can drive wave-like motion of electrons and nuclei in photoexcited systems, which can yield fast and efficient ways to exert materials’ functionalities beyond the thermodynamic limit. The search for coherent phenomena has been a central topic in chemical physics although their direct characterization is often elusive. Here, we highlight recent advances in time-resolved x-ray absorption spectroscopy (tr-XAS) to investigate coherent phenomena, especially those that utilize the eminent light source of isolated attosecond pulses. The unparalleled time and state sensitivities of tr-XAS in tandem with the unique element specificity render the method suitable to study valence electronic dynamics in a wide variety of materials. The latest studies have demonstrated the capabilities of tr-XAS to characterize coupled electronic–structural coherence in small molecules and coherent light–matter interactions of core-excited excitons in solids. We address current opportunities and challenges in the exploration of coherent phenomena, with potential applications for energy- and bio-related systems, potential crossings, strongly driven solids, and quantum materials. With the ongoing developments in both theory and light sources, tr-XAS holds great promise for revealing the role of coherences in chemical dynamics.
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Affiliation(s)
- Yuki Kobayashi
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
- Department of Applied Physics, Stanford University, Stanford, California 94305, USA
- Department of Chemistry, University of California, Berkeley, California 94720, USA
| | - Stephen R. Leone
- Department of Chemistry, University of California, Berkeley, California 94720, USA
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
- Department of Physics, University of California, Berkeley, California 94720, USA
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36
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Tong J, Liu X, Dong W, Jiang W, Zhu M, Xu Y, Zuo Z, Lu P, Gong X, Song X, Yang W, Wu J. Probing Resonant Photoionization Time Delay by Self-Referenced Molecular Attoclock. PHYSICAL REVIEW LETTERS 2022; 129:173201. [PMID: 36332237 DOI: 10.1103/physrevlett.129.173201] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Revised: 03/28/2022] [Accepted: 09/23/2022] [Indexed: 06/16/2023]
Abstract
Attosecond time-resolved electron tunneling dynamics have been investigated by using attosecond angular streaking spectroscopy, where a clock reference to the laser field vector is required in atomic strong-field ionization and the situation becomes complicated in molecules. Here we reveal a resonant ionization process via a transient state by developing an electron-tunneling-site-resolved molecular attoclock in Ar-Kr^{+}. Two distinct deflection angles are observed in the photoelectron angular distribution in the molecular frame, corresponding to the direct and resonant ionization pathways. We find the electron is temporally trapped in the Coulomb potential wells of the Ar-Kr^{+} before finally releasing into the continuum when the electron tunnels through the internal barrier. By utilizing the direct tunneling ionization as a self-referenced arm of the attoclock, the time delay of the electron trapped in the resonant state is revealed to be 3.50±0.04 fs. Our results give an impetus to exploring the ultrafast electron dynamics in complex systems and also endow a semiclassical presentation of the electron trapping dynamics in a quantum resonant state.
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Affiliation(s)
- Jihong Tong
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200241, China
| | - Xiwang Liu
- School of Science and Center for Theoretical Physics, Hainan University, Haikou 570288, China
| | - Wenhui Dong
- Department of Physics, College of Science, Shantou University, Shantou, Guangdong 515063, China
| | - Wenyu Jiang
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200241, China
| | - Ming Zhu
- School of Science and Center for Theoretical Physics, Hainan University, Haikou 570288, China
| | - Yidan Xu
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200241, China
| | - Zitan Zuo
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200241, China
| | - Peifen Lu
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200241, China
| | - Xiaochun Gong
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200241, China
- Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan, Shanxi 030006, China
| | - Xiaohong Song
- School of Science and Center for Theoretical Physics, Hainan University, Haikou 570288, China
| | - Weifeng Yang
- School of Science and Center for Theoretical Physics, Hainan University, Haikou 570288, China
| | - Jian Wu
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200241, China
- Chongqing Key Laboratory of Precision Optics, Chongqing Institute of East China Normal University, Chongqing 401121, China
- Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan, Shanxi 030006, China
- CAS Center for Excellence in Ultra-intense Laser Science, Shanghai 201800, China
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37
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Dey D, Kuleff AI, Worth GA. Quantum Interference Paves the Way for Long-Lived Electronic Coherences. PHYSICAL REVIEW LETTERS 2022; 129:173203. [PMID: 36332247 DOI: 10.1103/physrevlett.129.173203] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Revised: 06/02/2022] [Accepted: 09/12/2022] [Indexed: 06/16/2023]
Abstract
The creation and dynamical fate of a coherent superposition of electronic states generated in a polyatomic molecule by broadband ionization with extreme ultraviolet pulses is studied using the multiconfiguration time-dependent Hartree method together with an ionization continuum model Hamiltonian. The electronic coherence between the hole states usually lasts until the nuclear dynamics leads to decoherence. A key goal of attosecond science is to control the electronic motion and design laser control schemes to retain this coherence for longer timescales. Here, we investigate this possibility using time-delayed pulses and show how this opens up the prospect of coherent control of charge migration phenomenon.
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Affiliation(s)
- Diptesh Dey
- Department of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, United Kingdom
| | - Alexander I Kuleff
- Theoretische Chemie, PCI, Universität Heidelberg, Im Neuenheimer Feld 229, D-69120 Heidelberg, Germany
| | - Graham A Worth
- Department of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, United Kingdom
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38
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Matselyukh DT, Despré V, Golubev NV, Kuleff AI, Wörner HJ. Decoherence and Revival in Attosecond Charge Migration Driven by Non-adiabatic Dynamics. NATURE PHYSICS 2022; 18:1206-1213. [PMID: 36524215 PMCID: PMC7613930 DOI: 10.1038/s41567-022-01690-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Accepted: 06/24/2022] [Indexed: 06/17/2023]
Abstract
Attosecond charge migration is a periodic evolution of the charge density at specific sites of a molecule on a time scale defined by the energy intervals between the electronic states involved. Here, we report the observation of charge migration in neutral silane (SiH4) in 690 as, its decoherence within 15 fs, and its revival after 40-50 fs, using X-ray attosecond transient absorption spectroscopy. We observe the migration of charge as pairs of quantum beats with a characteristic spectral phase in the transient spectrum, in agreement with theory. The decay and revival of the degree of electronic coherence is found to be a result of both adiabatic and non-adiabatic dynamics in the populated Rydberg and valence states. The experimental results are supported by fully quantum-mechanical ab-initio calculations that include both electronic and nuclear dynamics, which additionally support the experimental evidence that conical intersections can mediate the transfer of electronic coherence from an initial superposition state to another one involving a different lower-lying state.
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Affiliation(s)
| | - Victor Despré
- Theoretische Chemie, Physikalisch-Chemisches Institut (PCI), Universität Heidelberg, 69120 Heidelberg, Germany
| | - Nikolay V. Golubev
- Laboratory of Theoretical Physical Chemistry, Institut des Sciences et Ingénierie Chimiques, EPF Lausanne, 1015 Lausanne, Switzerland
| | - Alexander I. Kuleff
- Theoretische Chemie, Physikalisch-Chemisches Institut (PCI), Universität Heidelberg, 69120 Heidelberg, Germany
| | - Hans Jakob Wörner
- Laboratorium für Physikalische Chemie, ETH Zürich, 8093 Zürich, Switzerland
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39
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Yan JZ, Zhao SS, Lan WD, Li SY, Zhou SS, Chen JG, Zhang JY, Yang YJ. Calculation of high-order harmonic generation of atoms and molecules by combining time series prediction and neural networks. OPTICS EXPRESS 2022; 30:35444-35456. [PMID: 36258495 DOI: 10.1364/oe.470495] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2022] [Accepted: 08/26/2022] [Indexed: 06/16/2023]
Abstract
High-order harmonic generation (HHG) from the interaction of ultra-intense laser pulses with atoms is an important tabletop short-wave coherent light source. Accurate quantum simulations of it present large computational difficulties due to multi-electron multidimensional effects. In this paper, the time-dependent response of hydrogen atoms is calculated using a time-series prediction scheme, the HHG spectrum is reconstructed very accurately. The accuracy of the forecasting is further improved by using a neural network scheme. This scheme is also applied to the simulation of the harmonic emission on multi-electron systems, and the applicability of the scheme is confirmed by the harmonic calculation of complex systems. This method is expected to simulate the nonlinear dynamic process of multi-electron atoms and molecules irradiated by intense laser pulses quickly and accurately.
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40
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Ruberti M, Patchkovskii S, Averbukh V. Quantum coherence in molecular photoionization. Phys Chem Chem Phys 2022; 24:19673-19686. [PMID: 35946491 DOI: 10.1039/d2cp01562e] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The study of onset and decay, as well as control of ultrafast quantum coherence in many-electron systems is in the focus of interest of attosecond physics. Interpretation of attosecond experiments detecting the ultrafast quantum coherence requires application of advanced theoretical and computational tools combining many-electron theory, description of the electronic continuum, including in the strong laser field scenario, as well as nuclear dynamics theory. This perspective reviews the recent theoretical advances in understanding the attosecond dynamics of quantum coherence in photoionized molecular systems and outlines possible future directions of theoretical and experimental study of coherence and entanglement in the attosecond regime.
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Affiliation(s)
- Marco Ruberti
- Imperial College London, Department of Physics, South Kensington Campus, London SW7 2AZ, UK.
| | | | - Vitali Averbukh
- Imperial College London, Department of Physics, South Kensington Campus, London SW7 2AZ, UK.
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41
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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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42
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Tsai MS, Liang AY, Tsai CL, Lai PW, Lin MW, Chen MC. Nonlinear compression toward high-energy single-cycle pulses by cascaded focus and compression. SCIENCE ADVANCES 2022; 8:eabo1945. [PMID: 35921417 PMCID: PMC9348793 DOI: 10.1126/sciadv.abo1945] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Accepted: 06/21/2022] [Indexed: 05/31/2023]
Abstract
The advancement of contemporary ultrafast science requires reliable sources to provide high-energy few-cycle light pulses. Through experiments and simulations, we demonstrate an arrangement of pulse postcompression, referred to as cascaded focus and compression (CASCADE), for generating millijoule-level, single-cycle pulses in a compact fashion. CASCADE is realized by a series of foci in matter, whereas pulse compression is provided immediately after each focus to maintain a high efficiency of spectral broadening. By implementing four stages of CASCADE in argon cells, we achieve 50-fold compression of millijoule-level pulses at 1030 nanometers from 157 to 3.1 femtoseconds, with an output pulse energy of 0.98 millijoules and a transmission efficiency of 73%. When driving high harmonic generation, these single-cycle pulses enable the creation of a carrier-envelope phase-dependent extreme ultraviolet continuum with energies extending up to 180 electron volts, providing isolated attosecond pulses at the output.
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Affiliation(s)
- Ming-Shian Tsai
- Institute of Photonics Technologies, National Tsing Hua University, Hsinchu 300044, Taiwan
| | - An-Yuan Liang
- Institute of Photonics Technologies, National Tsing Hua University, Hsinchu 300044, Taiwan
| | - Chia-Lun Tsai
- Institute of Photonics Technologies, National Tsing Hua University, Hsinchu 300044, Taiwan
| | - Po-Wei Lai
- Institute of Nuclear Engineering and Science, National Tsing Hua University, Hsinchu 300044, Taiwan
| | - Ming-Wei Lin
- Institute of Nuclear Engineering and Science, National Tsing Hua University, Hsinchu 300044, Taiwan
| | - Ming-Chang Chen
- Institute of Photonics Technologies, National Tsing Hua University, Hsinchu 300044, Taiwan
- Department of Physics, National Tsing Hua University, Hsinchu 300044, Taiwan
- Frontier Research Center on Fundamental and Applied Sciences of Matters, National Tsing Hua University, Hsinchu, Taiwan
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43
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Li H, Gong X, Ni H, Lu P, Luo X, Wen J, Yang Y, Qian X, Sun Z, Wu J. Light-Induced Ultrafast Molecular Dynamics: From Photochemistry to Optochemistry. J Phys Chem Lett 2022; 13:5881-5893. [PMID: 35730581 PMCID: PMC9251772 DOI: 10.1021/acs.jpclett.2c01119] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
By precisely controlling the waveform of ultrashort laser fields, electronic and nuclear motions in molecules can be steered on extremely short time scales, even in the attosecond regime. This new research field, termed "optochemistry", presents the light field in the time-frequency domain and opens new avenues for tailoring molecular reactions beyond photochemistry. This Perspective summarizes the ultrafast laser techniques employed in recent years for manipulating the molecular reactions based on waveform control of intense ultrashort laser pulses, where the chemical reactions can take place in isolated molecules, clusters, and various nanosystems. The underlying mechanisms for the coherent control of molecular dynamics are explicitly explored. Challenges and opportunities coexist in the field of optochemistry. Advanced technologies and theoretical modeling are still being pursued, with great prospects for controlling chemical reactions with unprecedented spatiotemporal precision.
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Affiliation(s)
- Hui Li
- State
Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200241, China
| | - Xiaochun Gong
- State
Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200241, China
| | - Hongcheng Ni
- State
Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200241, China
| | - Peifen Lu
- State
Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200241, China
| | - Xiao Luo
- School
of Chemistry and Molecular Engineering, East China Normal University, Shanghai 200241, China
| | - Jin Wen
- State
Key Laboratory for Modification of Chemical Fibers and Polymer Materials,
College of Materials Science and Engineering, Donghua University, Shanghai 201620, China
| | - Youjun Yang
- State
Key Laboratory of Bioreactor Engineering, Shanghai Key Laboratory
of Chemical Biology, School of Pharmacy, East China University of Science and Technology, Shanghai 200237, China
| | - Xuhong Qian
- State
Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200241, China
- School
of Chemistry and Molecular Engineering, East China Normal University, Shanghai 200241, China
| | - Zhenrong Sun
- State
Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200241, China
| | - Jian Wu
- State
Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200241, China
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Danilov D, Tran T, Bearpark MJ, Marangos JP, Worth GA, Robb MA. How electronic superpositions drive nuclear motion following the creation of a localized hole in the glycine radical cation. J Chem Phys 2022; 156:244114. [DOI: 10.1063/5.0093780] [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
In this work, we have studied the nuclear and electron dynamics in the glycine cation starting from localized hole states using the quantum Ehrenfest method. The nuclear dynamics is controlled both by the initial gradient and by the instantaneous gradient that results from the oscillatory electron dynamics (charge migration). We have used the Fourier transform (FT) of the spin densities to identify the “normal modes” of the electron dynamics. We observe an isomorphic relationship between the electron dynamics normal modes and the nuclear dynamics, seen in the vibrational normal modes. The FT spectra obtained this way show bands that are characteristic of the energy differences between the adiabatic hole states. These bands contain individual peaks that are in one-to-one correspondence with atom pair (+·) ↔ (·+) resonances, which, in turn, stimulate nuclear motion involving the atom pair. With such understanding, we anticipate “designer” coherent superpositions that can drive nuclear motion in a particular direction.
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Affiliation(s)
- Don Danilov
- Department of Chemistry, Imperial College London, Molecular Sciences Research Hub, 82 Wood Lane, W12 0BZ London, United Kingdom
| | - Thierry Tran
- Department of Chemistry, Imperial College London, Molecular Sciences Research Hub, 82 Wood Lane, W12 0BZ London, United Kingdom
- Department of Chemistry, University College London, 20 Gordon St., WC1H 0AJ London, United Kingdom
| | - Michael J. Bearpark
- Department of Chemistry, Imperial College London, Molecular Sciences Research Hub, 82 Wood Lane, W12 0BZ London, United Kingdom
| | - Jon P. Marangos
- Department of Physics, Imperial College London, Blackett Lab, Prince Consort Road, SW7 2BW London, United Kingdom
| | - Graham A. Worth
- Department of Chemistry, University College London, 20 Gordon St., WC1H 0AJ London, United Kingdom
| | - Michael A. Robb
- Department of Chemistry, Imperial College London, Molecular Sciences Research Hub, 82 Wood Lane, W12 0BZ London, United Kingdom
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Zinchenko KS, Ardana-Lamas F, Utrio Lanfaloni V, Pertot Y, Luu TT, Wörner HJ. Energy scaling of carrier-envelope-phase-stable sub-two-cycle pulses at 1.76 µm from hollow-core-fiber compression to 1.9 mJ. OPTICS EXPRESS 2022; 30:22376-22387. [PMID: 36224936 DOI: 10.1364/oe.457477] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Accepted: 04/28/2022] [Indexed: 06/16/2023]
Abstract
We present the energy scaling of a sub-two-cycle (10.4 fs) carrier-envelope-phase-stable light source centered at 1.76 µm to 1.9 mJ pulse energy. The light source is based on an optimized spectral-broadening scheme in a hollow-core fiber and a consecutive pulse compression with bulk material. This is, to our knowledge, the highest pulse energy reported to date from this type of sources. We demonstrate the application of this improved source to the generation of bright water-window soft-X-ray high harmonics. Combined with the short pulse duration, this source paves the way to the attosecond time-resolved water-window spectroscopy of complex molecules in aqueous solutions.
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High-Harmonic Generation Using a Single Dielectric Nanostructure. PHOTONICS 2022. [DOI: 10.3390/photonics9060427] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/10/2022]
Abstract
High-harmonic generation (HHG) from solids is a novel method used to emanate coherent extreme-ultraviolet (EUV) pulses. The efficiency of plasmonic HHG can be improved by enhancing the field of nanostructures. However, the nanostructures used for plasmonic HHG have a limitation owing to the damage caused by the amplified field. This study presents a single conical sapphire nanostructure used as a compact HHG emitter that generates high-order harmonics with wavelengths up to approximately 60 nm without causing severe damage. We compare the structure with a gold-layered conical sapphire structure and a bulk sapphire. The conical sapphire structure has a higher damage threshold and reusability for EUV generation even though it has a lower HHG intensity than that of the gold-layered conical sapphire structure because of the lower intensity enhancement. The measured signal intensity of the high-order harmonics in the EUV band from the conical sapphire structure is ten times higher than that of the bulk sapphire. The results confirm the possibility of creating a compact EUV light source for nanoscale applications.
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Roscam Abbing SDC, Kolkowski R, Zhang ZY, Campi F, Lötgering L, Koenderink AF, Kraus PM. Extreme-Ultraviolet Shaping and Imaging by High-Harmonic Generation from Nanostructured Silica. PHYSICAL REVIEW LETTERS 2022; 128:223902. [PMID: 35714263 DOI: 10.1103/physrevlett.128.223902] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Accepted: 04/26/2022] [Indexed: 06/15/2023]
Abstract
Coherent extreme-ultraviolet pulses from high-harmonic generation have ample applications in attosecond science, lensless imaging, and industrial metrology. However, tailoring complex spatial amplitude, phase, and polarization properties of extreme-ultraviolet pulses is made nontrivial by the lack of efficient optical elements. Here, we have overcome this limitation through nanoengineered solid samples, which enable direct control over amplitude and phase patterns of nonlinearly generated extreme-ultraviolet pulses. We demonstrate experimental configurations and emitting structures that yield spatially patterned beam profiles, increased conversion efficiencies, and tailored polarization states. Furthermore, we use the emitted patterns to reconstruct height profiles, probe the near-field confinement in nanostructures below the diffraction limit of the fundamental radiation, and to image complex structures through coherent diffractive emission from these structures. Our results pave the way for introducing sub-fundamental-wavelength resolution imaging, direct manipulation of beams through nanoengineered samples, and metrology of nanostructures into the extreme-ultraviolet spectral range.
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Affiliation(s)
| | - Radoslaw Kolkowski
- Center for Nanophotonics, AMOLF, Science Park 104, 1098XG Amsterdam, Netherlands
- Optics and Photonics Group, Department of Applied Physics, Aalto University, P.O. Box 13500, FI-00076 Aalto, Finland
| | - Zhuang-Yan Zhang
- Advanced Research Center for Nanolithography (ARCNL), Science Park 106, 1098XG Amsterdam, Netherlands
| | - Filippo Campi
- Advanced Research Center for Nanolithography (ARCNL), Science Park 106, 1098XG Amsterdam, Netherlands
| | - Lars Lötgering
- Advanced Research Center for Nanolithography (ARCNL), Science Park 106, 1098XG Amsterdam, Netherlands
| | - A Femius Koenderink
- Center for Nanophotonics, AMOLF, Science Park 104, 1098XG Amsterdam, Netherlands
| | - Peter M Kraus
- Advanced Research Center for Nanolithography (ARCNL), Science Park 106, 1098XG Amsterdam, Netherlands
- Department of Physics and Astronomy, and LaserLaB, Vrije Universiteit, De Boelelaan 1081, 1081HV Amsterdam, Netherlands
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Borrego-Varillas R, Lucchini M, Nisoli M. Attosecond spectroscopy for the investigation of ultrafast dynamics in atomic, molecular and solid-state physics. REPORTS ON PROGRESS IN PHYSICS. PHYSICAL SOCIETY (GREAT BRITAIN) 2022; 85:066401. [PMID: 35294930 DOI: 10.1088/1361-6633/ac5e7f] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Accepted: 03/16/2022] [Indexed: 06/14/2023]
Abstract
Since the first demonstration of the generation of attosecond pulses (1 as = 10-18s) in the extreme-ultraviolet spectral region, several measurement techniques have been introduced, at the beginning for the temporal characterization of the pulses, and immediately after for the investigation of electronic and nuclear ultrafast dynamics in atoms, molecules and solids with unprecedented temporal resolution. The attosecond spectroscopic tools established in the last two decades, together with the development of sophisticated theoretical methods for the interpretation of the experimental outcomes, allowed to unravel and investigate physical processes never observed before, such as the delay in photoemission from atoms and solids, the motion of electrons in molecules after prompt ionization which precede any notable nuclear motion, the temporal evolution of the tunneling process in dielectrics, and many others. This review focused on applications of attosecond techniques to the investigation of ultrafast processes in atoms, molecules and solids. Thanks to the introduction and ongoing developments of new spectroscopic techniques, the attosecond science is rapidly moving towards the investigation, understanding and control of coupled electron-nuclear dynamics in increasingly complex systems, with ever more accurate and complete investigation techniques. Here we will review the most common techniques presenting the latest results in atoms, molecules and solids.
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Affiliation(s)
- Rocío Borrego-Varillas
- Institute for Photonics and Nanotechnologies (IFN), Consiglio Nazionale delle Ricerche (CNR), Piazza Leonardo da Vinci 32, 20133 Milano, Italy
| | - Matteo Lucchini
- Institute for Photonics and Nanotechnologies (IFN), Consiglio Nazionale delle Ricerche (CNR), Piazza Leonardo da Vinci 32, 20133 Milano, Italy
- Department of Physics, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano, Italy
| | - Mauro Nisoli
- Institute for Photonics and Nanotechnologies (IFN), Consiglio Nazionale delle Ricerche (CNR), Piazza Leonardo da Vinci 32, 20133 Milano, Italy
- Department of Physics, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano, Italy
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Schlegel HB, Hoerner P, Li W. Ionization of HCCI Neutral and Cations by Strong Laser Fields Simulated With Time Dependent Configuration Interaction. Front Chem 2022; 10:866137. [PMID: 35548678 PMCID: PMC9081608 DOI: 10.3389/fchem.2022.866137] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2022] [Accepted: 03/24/2022] [Indexed: 12/05/2022] Open
Abstract
Strong field ionization of neutral iodoacetylene (HCCI) can produce a coherent superposition of the X and A cations. This superposition results in charge migration between the CC π orbital and the iodine π-type lone pair which can be monitored by strong field ionization with short, intense probe pulses. Strong field ionization of the X and A states of HCCI cation was simulated with time-dependent configuration interaction using singly ionized configurations and singly excited, singly ionized configurations (TD-CISD-IP) and an absorbing boundary. Studies with static fields were used to obtain the 3-dimensional angular dependence of instantaneous ionization rates by strong fields and the orbitals involved in producing the cations and dications. The frequency of charge oscillation is determined by the energy separation of the X and A states; this separation can change depending on the direction and strength of the field. Furthermore, fields along the molecular axis can cause extensive mixing between the field-free X and A configurations. For coherent superpositions of the X and A states, the charge oscillations are characterized by two frequencies-the driving frequency of the laser field of the probe pulse and the intrinsic frequency due to the energy separation between the X and A states. For linear and circularly polarized pulses, the ionization rates show marked differences that depend on the polarization direction of the pulse, the carrier envelope phase and initial phase of the superposition. Varying the initial phase of the superposition at the beginning of the probe pulse is analogous to changing the delay between the pump and probe pulses. The charge oscillation in the coherent superposition of the X and A states results in maxima and minima in the ionization yield as a function of the superposition phase.
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López Peña HA, Shusterman JM, Ampadu Boateng D, Lao KU, Tibbetts KM. Coherent Control of Molecular Dissociation by Selective Excitation of Nuclear Wave Packets. Front Chem 2022; 10:859095. [PMID: 35449589 PMCID: PMC9016217 DOI: 10.3389/fchem.2022.859095] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Accepted: 03/18/2022] [Indexed: 11/20/2022] Open
Abstract
We report on pump-probe control schemes to manipulate fragmentation product yields in p-nitrotoluene (PNT) cation. Strong field ionization of PNT prepares the parent cation in the ground electronic state, with coherent vibrational excitation along two normal modes: the C–C–N–O torsional mode at 80 cm−1 and the in-plane ring-stretching mode at 650 cm−1. Both vibrational wave packets are observed as oscillations in parent and fragment ion yields in the mass spectrum upon optical excitation. Excitation with 650 nm selectively fragments the PNT cation into C7H7+, whereas excitation with 400 nm selectively produces C5H5+ and C3H3+. In both cases the ion yield oscillations result from torsional wave packet excitation, but 650 and 400 nm excitation produce oscillations with opposite phases. Ab initio calculations of the ground and excited electronic potential energy surfaces of PNT cation along the C–C–N–O dihedral angle reveal that 400 nm excitation accesses an allowed transition from D0 to D6 at 0° dihedral angle, whereas 650 nm excitation accesses a strongly allowed transition from D0 to D4 at a dihedral angle of 90°. This ability to access different electronic excited states at different locations along the potential energy surface accounts for the selective fragmentation observed with different probe wavelengths. The ring-stretching mode, only observed using 800 nm excitation, is attributed to a D0 to D2 transition at a geometry with 90° dihedral angle and elongated C–N bond length. Collectively, these results demonstrate that strong field ionization induces multimode coherent excitation and that the vibrational wave packets can be excited with specific photon energies at different points on their potential energy surfaces to induce selective fragmentation.
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