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Garg D, Chopra P, Lee JWL, Tikhonov DS, Kumar S, Akcaalan O, Allum F, Boll R, Butler AA, Erk B, Gougoula E, Gruet SP, He L, Heathcote D, Jones E, Kazemi MM, Lahl J, Lemmens AK, Liu Z, Loru D, Maclot S, Mason R, Merrick J, Müller E, Mullins T, Papadopoulou CC, Passow C, Peschel J, Plach M, Ramm D, Robertson P, Rompotis D, Simao A, Steber AL, Tajalli A, Tul-Noor A, Vadassery N, Vinklárek IS, Techert S, Küpper J, Rijs AM, Rolles D, Brouard M, Bari S, Eng-Johnsson P, Vallance C, Burt M, Manschwetus B, Schnell M. Ultrafast dynamics of fluorene initiated by highly intense laser fields. Phys Chem Chem Phys 2024. [PMID: 38958416 DOI: 10.1039/d3cp05063g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/04/2024]
Abstract
We present an investigation of the ultrafast dynamics of the polycyclic aromatic hydrocarbon fluorene initiated by an intense femtosecond near-infrared laser pulse (810 nm) and probed by a weak visible pulse (405 nm). Using a multichannel detection scheme (mass spectra, electron and ion velocity-map imaging), we provide a full disentanglement of the complex dynamics of the vibronically excited parent molecule, its excited ionic states, and fragments. We observed various channels resulting from the strong-field ionization regime. In particular, we observed the formation of the unstable tetracation of fluorene, above-threshold ionization features in the photoelectron spectra, and evidence of ubiquitous secondary fragmentation. We produced a global fit of all observed time-dependent photoelectron and photoion channels. This global fit includes four parent ions extracted from the mass spectra, 15 kinetic-energy-resolved ionic fragments extracted from ion velocity map imaging, and five photoelectron channels obtained from electron velocity map imaging. The fit allowed for the extraction of 60 lifetimes of various metastable photoinduced intermediates.
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Affiliation(s)
- Diksha Garg
- Deutsches Elektronen-Synchrotron DESY, Hamburg, Germany.
- Department of Physics, Universität Hamburg, Hamburg, Germany
| | - Pragya Chopra
- Deutsches Elektronen-Synchrotron DESY, Hamburg, Germany.
- Institute of Physical Chemistry, Christian-Albrechts-Universität zu Kiel, Kiel, Germany
| | - Jason W L Lee
- Deutsches Elektronen-Synchrotron DESY, Hamburg, Germany.
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford, UK
| | | | - Sonu Kumar
- Deutsches Elektronen-Synchrotron DESY, Hamburg, Germany.
- Department of Physics, Universität Hamburg, Hamburg, Germany
| | | | - Felix Allum
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford, UK
| | | | - Alexander A Butler
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford, UK
| | - Benjamin Erk
- Deutsches Elektronen-Synchrotron DESY, Hamburg, Germany.
| | - Eva Gougoula
- Deutsches Elektronen-Synchrotron DESY, Hamburg, Germany.
| | | | - Lanhai He
- Center for Free-Electron Laser Science CFEL, Deutsches Elektronen-Synchrotron DESY, Germany
| | - David Heathcote
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford, UK
| | - Ellen Jones
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford, UK
| | - Mehdi M Kazemi
- Deutsches Elektronen-Synchrotron DESY, Hamburg, Germany.
| | - Jan Lahl
- Department of Physics, Lund University, Lund, Sweden
| | - Alexander K Lemmens
- Van't Hoff Institute for Molecular Sciences, University of Amsterdam, Amsterdam, The Netherlands
- FELIX Laboratory, Radboud University, Nijmegen, The Netherlands
| | - Zhihao Liu
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford, UK
| | - Donatella Loru
- Deutsches Elektronen-Synchrotron DESY, Hamburg, Germany.
| | | | - Robert Mason
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford, UK
| | - James Merrick
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford, UK
| | - Erland Müller
- Deutsches Elektronen-Synchrotron DESY, Hamburg, Germany.
| | - Terry Mullins
- Center for Free-Electron Laser Science CFEL, Deutsches Elektronen-Synchrotron DESY, Germany
- European XFEL, Schenefeld, Germany
| | | | | | | | - Marius Plach
- Department of Physics, Lund University, Lund, Sweden
| | - Daniel Ramm
- Deutsches Elektronen-Synchrotron DESY, Hamburg, Germany.
| | - Patrick Robertson
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford, UK
| | - Dimitrios Rompotis
- Deutsches Elektronen-Synchrotron DESY, Hamburg, Germany.
- European XFEL, Schenefeld, Germany
| | - Alcides Simao
- Deutsches Elektronen-Synchrotron DESY, Hamburg, Germany.
| | | | - Ayhan Tajalli
- Deutsches Elektronen-Synchrotron DESY, Hamburg, Germany.
| | - Atia Tul-Noor
- Deutsches Elektronen-Synchrotron DESY, Hamburg, Germany.
| | - Nidin Vadassery
- Center for Free-Electron Laser Science CFEL, Deutsches Elektronen-Synchrotron DESY, Germany
- Department of Chemistry, Universität Hamburg, Hamburg, Germany
| | - Ivo S Vinklárek
- Center for Free-Electron Laser Science CFEL, Deutsches Elektronen-Synchrotron DESY, Germany
| | - Simone Techert
- Deutsches Elektronen-Synchrotron DESY, Hamburg, Germany.
| | - Jochen Küpper
- Center for Free-Electron Laser Science CFEL, Deutsches Elektronen-Synchrotron DESY, Germany
- Department of Physics, Universität Hamburg, Hamburg, Germany
- Center for Ultrafast Imaging, Universität Hamburg, Hamburg, Germany
- Department of Chemistry, Universität Hamburg, Hamburg, Germany
| | - Anouk M Rijs
- Division of BioAnalytical Chemistry, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - Daniel Rolles
- J. R. Macdonald Laboratory, Department of Physics, Kansas State University, Manhattan, KS, USA
| | - Mark Brouard
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford, UK
| | - Sadia Bari
- Deutsches Elektronen-Synchrotron DESY, Hamburg, Germany.
- Zernike Institute for Advanced Materials, University of Groningen, Groningen, The Netherlands
| | | | - Claire Vallance
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford, UK
| | - Michael Burt
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford, UK
| | | | - Melanie Schnell
- Deutsches Elektronen-Synchrotron DESY, Hamburg, Germany.
- Institute of Physical Chemistry, Christian-Albrechts-Universität zu Kiel, Kiel, Germany
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2
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Chen J, Xing X, Rey-de-Castro R, Rabitz H. Ultrafast control of the LnF +/LnO + ratio from Ln(hfac) 3. Phys Chem Chem Phys 2024; 26:15850-15855. [PMID: 38682860 DOI: 10.1039/d4cp00337c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/01/2024]
Abstract
The photo-induced dissociative ionization of lanthanide complexes Ln(hfac)3 (Ln = Pr, Er, Yb) is studied using ultrafast shaped laser pulses in a time-of-flight (TOF) mass spectrometry setup. Various fluorine and Ln-containing mass fragments were observed, which can be interpreted by the photo-fragmentation mechanistic pathway involving C-C bond rotation processes proposed previously. A set of experiments used pulse shaping guided by closed-loop feedback control to identify pulses that optimize the ratio of LnF+/LnO+. In agreement with previous studies in which very little LnO+ was observed, broad pulses were found to maximize the LnF+/LnO+ ratio, which involves metal-ligand bond-breaking followed by bond rotation and bond rearrangement. In contrast, a transform limited (TL) pulse favored the formation of LnO+. Finally, the recently developed experimental control pulse slicing (CPS) technique was applied to elucidate the dynamics induced by fields that either maximize or minimize the LnF+/LnO+ ratio, which also indicates that longer laser pulses facilitate LnF+ formation during the C-C bond rotation dissociative-ionization process.
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Affiliation(s)
- Jiangchao Chen
- Department of Chemistry, Princeton University, Princeton, New Jersey 08544, USA.
| | - Xi Xing
- Department of Chemistry, Princeton University, Princeton, New Jersey 08544, USA.
| | | | - Herschel Rabitz
- Department of Chemistry, Princeton University, Princeton, New Jersey 08544, USA.
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3
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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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4
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Zhao X, Liu M. Excitation dynamics in molecule resolved by internuclear distance driven by the strong laser field. OPTICS EXPRESS 2024; 32:355-365. [PMID: 38175066 DOI: 10.1364/oe.503839] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/21/2023] [Accepted: 12/10/2023] [Indexed: 01/05/2024]
Abstract
Rydberg-state excitation of stretched model molecules subjected to near-infrared intense laser fields has been investigated based on a fully quantum model (QM) proposed recently and the numerical solutions of time-dependent Schrödinger equation (TDSE). Given the good agreement between QM and TDSE, it is found that, as the molecules are stretched, the electron tends to be trapped into low-lying Rydberg-states after its ionization from the core, which can be attributed to the shift of the ionization moments corresponding to maximum excitation populations. Moreover, the n-distribution is broadened for molecules with increasing internuclear distance, which results from the change of momentum distribution of emitted electrons. Analysis indicates that both of the above phenomena are closely related to the interference effect of electronic wave packets emitted from different nuclei. Our study provides a more comprehensive understanding of the molecular excitation in intense laser fields, as well as a means of possible applications to related experimental observations.
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5
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Casasús IM, Corrales ME, Murillo-Sánchez ML, Marggi Poullain S, de Oliveira N, Limão-Vieira P, Bañares L. Stark control of multiphoton ionization through Freeman resonances in alkyl iodides. J Chem Phys 2023; 159:074302. [PMID: 37581421 DOI: 10.1063/5.0161628] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2023] [Accepted: 07/31/2023] [Indexed: 08/16/2023] Open
Abstract
Multiphoton ionization (MPI) of alkyl iodides (RI, R = CnH2n+1, n = 1-4) has been investigated with femtosecond laser pulses centered at 800 and 400 nm along with photoelectron imaging detection. In addition, the ultraviolet (UV)-vacuum ultraviolet (VUV) absorption spectra of gas-phase RIs have been measured in the photon energy range of 5-11 eV using the VUV Fourier transform spectrometer at the VUV DESIRS beamline of the synchrotron SOLEIL facility. The use of high-laser-field strengths in matter-radiation interaction generates highly non-linear phenomena, such as the Stark shift effect, which distorts the potential energy surfaces of molecules by varying both the energy of electronic and rovibrational states and their ionization energies. The Stark shift can then generate resonances between intermediate states and an integer number of laser photons of a given wavelength, which are commonly known as Freeman resonances. Here, we study how the molecular structure of linear and branched alkyl iodides affects the UV-VUV absorption spectrum, the MPI process, and the generation of Freeman resonances. The obtained results reveal a dominant resonance in the experiments at 800 nm, which counter-intuitively appears at the same photoelectron kinetic energy in the whole alkyl iodide series. The ionization pathways of this resonance strongly involve the 6p(2E3/2) Rydberg state with different degrees of vibrational excitation, revealing an energy compensation effect as the R-chain complexity increases.
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Affiliation(s)
- Ignacio M Casasús
- Departamento de Química Física, Facultad de Ciencias Químicas, Universidad Complutense de Madrid, 28040 Madrid, Spain
| | - María E Corrales
- Departamento de Química Física, Facultad de Ciencias Químicas, Universidad Complutense de Madrid, 28040 Madrid, Spain
- Departamento de Química, Facultad de Ciencias, Módulo 13, Facultad de Ciencias, Universidad Autónoma de Madrid, 28049 Madrid, Spain
| | - Marta L Murillo-Sánchez
- Departamento de Química Física, Facultad de Ciencias Químicas, Universidad Complutense de Madrid, 28040 Madrid, Spain
| | - Sonia Marggi Poullain
- Departamento de Química Física, Facultad de Ciencias Químicas, Universidad Complutense de Madrid, 28040 Madrid, Spain
| | | | - Paulo Limão-Vieira
- Atomic and Molecular Collisions Laboratory, CEFITEC, Department of Physics, Universidade NOVA de Lisboa, 2829-516 Caparica, Portugal
| | - Luis Bañares
- Departamento de Química Física, Facultad de Ciencias Químicas, Universidad Complutense de Madrid, 28040 Madrid, Spain
- Instituto Madrileño de Estudios Avanzados en Nanociencia (IMDEA-Nanoscience), Cantoblanco, 28049 Madrid, Spain
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6
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Yang Y, Ren H, Zhang M, Zhou S, Mu X, Li X, Wang Z, Deng K, Li M, Ma P, Li Z, Hao X, Li W, Chen J, Wang C, Ding D. H 2 formation via non-Born-Oppenheimer hydrogen migration in photoionized ethane. Nat Commun 2023; 14:4951. [PMID: 37587115 PMCID: PMC10432507 DOI: 10.1038/s41467-023-40628-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Accepted: 08/03/2023] [Indexed: 08/18/2023] Open
Abstract
Neutral H2 formation via intramolecular hydrogen migration in hydrocarbon molecules plays a vital role in many chemical and biological processes. Here, employing cold target recoil ion momentum spectroscopy (COLTRIMS) and pump-probe technique, we find that the non-adiabatic coupling between the ground and excited ionic states of ethane through conical intersection leads to a significantly high yield of neutral H2 fragment. Based on the analysis of fingerprints that are sensitive to orbital symmetry and electronic state energies in the photoelectron momentum distributions, we tag the initial electronic population of both the ground and excited ionic states and determine the branching ratios of H2 formation channel from those two states. Incorporating theoretical simulation, we established the timescale of the H2 formation to be ~1300 fs. We provide a comprehensive characterization of H2 formation in ionic states of ethane mediated by conical intersection and reveals the significance of non-adiabatic coupling dynamics in the intramolecular hydrogen migration.
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Affiliation(s)
- Yizhang Yang
- Institute of Atomic and Molecular Physics and Jilin Provincial Key Laboratory of Applied Atomic and Molecular Spectroscopy, Jilin University, 130012, Changchun, China
| | - Hao Ren
- Institute of Theoretical Physics and Department of Physics, State Key Laboratory of Quantum Optics and Quantum Optics Devices, Collaborative Innovation Center of Extreme Optics, Shanxi University, 030006, Taiyuan, China
| | - Ming Zhang
- State Key Laboratory for Mesoscopic Physics and Frontiers Science Center for Nano-Optoelectronics, School of Physics, Peking University, 100871, Beijing, China
| | - Shengpeng Zhou
- Institute of Atomic and Molecular Physics and Jilin Provincial Key Laboratory of Applied Atomic and Molecular Spectroscopy, Jilin University, 130012, Changchun, China
| | - Xiangxu Mu
- State Key Laboratory for Mesoscopic Physics and Frontiers Science Center for Nano-Optoelectronics, School of Physics, Peking University, 100871, Beijing, China
| | - Xiaokai Li
- Institute of Atomic and Molecular Physics and Jilin Provincial Key Laboratory of Applied Atomic and Molecular Spectroscopy, Jilin University, 130012, Changchun, China
| | - Zhenzhen Wang
- Institute of Atomic and Molecular Physics and Jilin Provincial Key Laboratory of Applied Atomic and Molecular Spectroscopy, Jilin University, 130012, Changchun, China
| | - Ke Deng
- Institute of Atomic and Molecular Physics and Jilin Provincial Key Laboratory of Applied Atomic and Molecular Spectroscopy, Jilin University, 130012, Changchun, China
| | - Mingxuan Li
- Institute of Atomic and Molecular Physics and Jilin Provincial Key Laboratory of Applied Atomic and Molecular Spectroscopy, Jilin University, 130012, Changchun, China
| | - Pan Ma
- Institute of Atomic and Molecular Physics and Jilin Provincial Key Laboratory of Applied Atomic and Molecular Spectroscopy, Jilin University, 130012, Changchun, China
| | - Zheng Li
- State Key Laboratory for Mesoscopic Physics and Frontiers Science Center for Nano-Optoelectronics, School of Physics, Peking University, 100871, Beijing, China.
- Collaborative Innovation Center of Extreme Optics, Shanxi University, 030006, Taiyuan, Shanxi, China.
- Peking University Yangtze Delta Institute of Optoelectronics, 226010, Nantong, Jiangsu, China.
| | - Xiaolei Hao
- Institute of Theoretical Physics and Department of Physics, State Key Laboratory of Quantum Optics and Quantum Optics Devices, Collaborative Innovation Center of Extreme Optics, Shanxi University, 030006, Taiyuan, China.
| | - Weidong Li
- Shenzhen Key Laboratory of Ultraintense Laser and Advanced Material Technology, and College of Engineering Physics, Shenzhen Technology University, 518118, Shenzhen, China
| | - Jing Chen
- Shenzhen Key Laboratory of Ultraintense Laser and Advanced Material Technology, and College of Engineering Physics, Shenzhen Technology University, 518118, Shenzhen, China
- Hefei National Research Center for Physical Sciences at the Microscale and School of Physical Sciences, Department of Modern Physics, University of Science and Technology of China, 230026, Hefei, China
| | - Chuncheng Wang
- Institute of Atomic and Molecular Physics and Jilin Provincial Key Laboratory of Applied Atomic and Molecular Spectroscopy, Jilin University, 130012, Changchun, China.
| | - Dajun Ding
- Institute of Atomic and Molecular Physics and Jilin Provincial Key Laboratory of Applied Atomic and Molecular Spectroscopy, Jilin University, 130012, Changchun, China.
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7
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Tong J, Pan S, Jiang W, Han L, Xu Y, Zuo Z, Lu P, Gong X, Wu J. Identifying photoelectron releasing order in strong-field dissociative ionization of H 2. OPTICS EXPRESS 2023; 31:25467-25476. [PMID: 37710432 DOI: 10.1364/oe.495066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Accepted: 07/04/2023] [Indexed: 09/16/2023]
Abstract
Driven by intense laser fields, the outgoing photoelectrons in molecules possess a quiver motion, resulting in the rise of the effective ionization potential. The coupling of the field-dressed ionization potential with abundant molecular dynamics complicates the laser-molecule interactions. Here, we demonstrate an approach to resolve photoelectron releasing order in the dissociative and non-dissociative channels of multiphoton ionization driven by an orthogonally polarized two-color femtosecond laser pulse. The photoelectron kinetic energy releases and the regular nodes in the photoelectron angular distributions due to the participation of different continuum partial waves allow us to deduce the field-dressed ionization potential of various channels. It returns the ponderomotive energy experienced by the outgoing electron and reveals the corresponding photoionization instants within the laser pulse. Our results provide a route to explore the complex strong-field ionization dynamics of molecules using two-dimensional photoelectron momentum spectroscopy.
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8
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Yuan H, Yang Y, Guo F, Wang J, Chen J, Feng W, Cui Z. Effect of pulse duration on the above-threshold ionization of a hydrogen atom irradiated by a 400 nm intense laser. OPTICS EXPRESS 2023; 31:24213-24229. [PMID: 37475254 DOI: 10.1364/oe.495313] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2023] [Accepted: 06/26/2023] [Indexed: 07/22/2023]
Abstract
The photoelectron emission spectra generated by the interaction between ultrashort intense laser pulses and atoms can reveal the ultrafast dynamics of electrons. By using the numerical solution of the time-dependent Schrödinger equation in momentum space, the photoelectron emission spectra of atoms irradiated by 400 nm intense lasers with different durations of the pulse has been investigated. In the photoelectron emission spectrum, in addition to the above-threshold ionization peaks due to ionization interference in multiple cycles and the sideband peaks mainly due to the interference of ionized electrons at different moments along the rising edge of the laser pulse envelope, additional peaks of photoelectron emission whose intensity appears to oscillate with the increasing duration of the laser pulse can also be observed. Based on strong-field approximation and the population's analysis of the bound state, it is found that these photoelectron peaks originate from the ionization of the excited state and the oscillations of these peaks are due to the superposition of their peak energy positions with the sideband energy positions. Furthermore, it is demonstrated that the energy positions of the maximum intensity of the photoelectron emission spectra move towards the higher energy end as the duration of the driving laser pulse extends. This phenomenon can be attributed to the fact that the main moment of ionization of atoms changes with the increasing duration of the driving laser pulse, thus allowing the real-time ionization of atoms to be probed using photoelectron emission spectra.
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9
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Pan S, Hu C, Zhang W, Zhang Z, Zhou L, Lu C, Lu P, Ni H, Wu J, He F. Rabi oscillations in a stretching molecule. LIGHT, SCIENCE & APPLICATIONS 2023; 12:35. [PMID: 36732490 PMCID: PMC9894931 DOI: 10.1038/s41377-023-01075-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2022] [Revised: 01/07/2023] [Accepted: 01/09/2023] [Indexed: 05/06/2023]
Abstract
Rabi oscillation is an elementary laser-driven physical process in atoms and artificial atoms from solid-state systems, while it is rarely demonstrated in molecules. Here, we investigate the bond-length-dependent Rabi oscillations with varying Rabi frequencies in strong-laser-field dissociation of H2+. The coupling of the bond stretching and Rabi oscillations makes the nuclei gain different kinetic energies while the electron is alternatively absorbing and emitting photons. The resulting proton kinetic energy spectra show rich structures beyond the prediction of the Floquet theorem and the well-accepted resonant one-photon dissociation pathway. Our study shows that the laser-driven Rabi oscillations accompanied by nuclear motions are essential to understanding the bond-breaking mechanism and provide a time-resolved perspective to manipulate rich dynamics of the strong-laser-field dissociation of molecules.
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Affiliation(s)
- Shengzhe Pan
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai, 200241, China
| | - Chenxi Hu
- Key Laboratory for Laser Plasmas (Ministry of Education) and School of Physics and Astronomy, Collaborative Innovation Center of IFSA (CICIFSA), Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Wenbin Zhang
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai, 200241, China
| | - Zhaohan Zhang
- Key Laboratory for Laser Plasmas (Ministry of Education) and School of Physics and Astronomy, Collaborative Innovation Center of IFSA (CICIFSA), Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Lianrong Zhou
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai, 200241, China
| | - Chenxu Lu
- 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
| | - Hongcheng Ni
- 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
| | - Jian Wu
- 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.
- Chongqing Key Laboratory of Precision Optics, Chongqing Institute of East China Normal University, Chongqing, 401121, China.
- CAS Center for Excellence in Ultra-intense Laser Science, Shanghai, 201800, China.
| | - Feng He
- Key Laboratory for Laser Plasmas (Ministry of Education) and School of Physics and Astronomy, Collaborative Innovation Center of IFSA (CICIFSA), Shanghai Jiao Tong University, Shanghai, 200240, China.
- CAS Center for Excellence in Ultra-intense Laser Science, Shanghai, 201800, China.
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10
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Casasús IM, Corrales ME, Bañares L. Wavelength dependence of the multiphoton ionization of CH 3I by intense femtosecond laser pulses through Freeman resonances. Phys Chem Chem Phys 2022; 24:29616-29628. [PMID: 36449016 DOI: 10.1039/d2cp04308d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Multiphoton ionization (MPI) of methyl iodide, CH3I, has been investigated with the photoelectron imaging (PEI) technique, using high intensity femtosecond laser pulses at different central wavelengths. The use of high laser field strengths alters the way in which matter-radiation interaction takes place. This generates highly nonlinear phenomena, among which we can highlight the Stark shift effect. It can distort the potential energy surfaces of atoms and molecules, varying both the energy of electronic and rovibrational states of these systems and their ionization potentials. In this way, the Stark shift can generate resonances between intermediate states and an integer number of laser photons of a given wavelength, which would be absent in the low intensity regime. The main purpose of this work is the generation, detection and characterization of resonances produced by the Stark shift, commonly known as Freeman resonances, induced by multiphoton ionization of gas-phase CH3I at different laser wavelengths. The results obtained reveal that a multitude of resonances are induced in the ionization of CH3I in the range of intensities employed, involving several Rydberg states. Ionization pathways associated with different degrees of vibrational excitation in both the intermediate states and the molecular cation generated in each of the experiments are proposed.
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Affiliation(s)
- Ignacio M Casasús
- Departamento de Química Física, Facultad de Ciencias Químicas, Universidad Complutense de Madrid, 28040 Madrid, Spain.
| | - María E Corrales
- Departamento de Química Física, Facultad de Ciencias Químicas, Universidad Complutense de Madrid, 28040 Madrid, Spain.
| | - Luis Bañares
- Departamento de Química Física, Facultad de Ciencias Químicas, Universidad Complutense de Madrid, 28040 Madrid, Spain. .,Instituto Madrileño de Estudios Avanzados en Nanociencia (IMDEA Nanoscience), Cantoblanco, 28049 Madrid, Spain
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11
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Mayer N, Patchkovskii S, Morales F, Ivanov M, Smirnova O. Imprinting Chirality on Atoms Using Synthetic Chiral Light Fields. PHYSICAL REVIEW LETTERS 2022; 129:243201. [PMID: 36563267 DOI: 10.1103/physrevlett.129.243201] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Revised: 05/14/2022] [Accepted: 10/21/2022] [Indexed: 06/17/2023]
Abstract
Atoms are usually thought of as achiral objects. However, one can construct superpositions of atomic states that are chiral [1]. Here, we show how to excite such superpositions with tailored light fields both in the weak-field and strong-field regimes, using realistic laser parameters. First, we use time-dependent Schrödinger equation simulations to demonstrate the creation of a time-dependent bound chiral wave packet in sodium atoms. Second, we show how the time-dependent handedness of this wave packet can be probed by photoelectron circular dichroism, in spite of the central symmetry of the core potential. Third, we use time-dependent Schrödinger equation simulations to show how chirality can be directly imprinted on a photoelectron wave packet created by strong-field ionization and introduce an unambiguous chiral measure that allows us to characterize its handedness.
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Affiliation(s)
- Nicola Mayer
- Max-Born-Institute, Max-Born Strasse 2A, 12489 Berlin, Germany
| | | | - Felipe Morales
- Max-Born-Institute, Max-Born Strasse 2A, 12489 Berlin, Germany
| | - Misha Ivanov
- Max-Born-Institute, Max-Born Strasse 2A, 12489 Berlin, Germany
- Department of Physics, Humboldt University, Newtonstrasse 15, D-12489 Berlin, Germany
- Blackett Laboratory, Imperial College London, SW7 2AZ London, United Kingdom
| | - Olga Smirnova
- Max-Born-Institute, Max-Born Strasse 2A, 12489 Berlin, Germany
- Department of Physics, Technical University Berlin, 10623 Berlin, Germany
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12
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Oelmann JH, Heldt T, Guth L, Nauta J, Lackmann N, Wössner V, Kokh S, Pfeifer T, López-Urrutia JRC. Photoelectron tomography with an intra-cavity velocity-map imaging spectrometer at 100 MHz repetition rate. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2022; 93:123303. [PMID: 36586896 DOI: 10.1063/5.0104679] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Accepted: 11/16/2022] [Indexed: 06/17/2023]
Abstract
We present a compact velocity-map imaging (VMI) spectrometer for photoelectron imaging at 100 MHz repetition rate. Ultrashort pulses from a near-infrared frequency comb laser are amplified in a polarization-insensitive passive femtosecond enhancement cavity. In the focus, multi-photon ionization (MPI) of gas-phase atoms is studied tomographically by rotating the laser polarization. We demonstrate the functioning of the VMI spectrometer by reconstructing photoelectron angular momentum distributions from xenon MPI. Our intra-cavity VMI setup collects electron energy spectra at high rates, with the advantage of transferring the coherence of the cavity-stabilized femtosecond pulses to the electrons. In addition, the setup will allow studies of strong-field effects in nanometric tips.
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Affiliation(s)
- J-H Oelmann
- Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg, Germany
| | - T Heldt
- Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg, Germany
| | - L Guth
- Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg, Germany
| | - J Nauta
- Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg, Germany
| | - N Lackmann
- Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg, Germany
| | - V Wössner
- Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg, Germany
| | - S Kokh
- Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg, Germany
| | - T Pfeifer
- Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg, Germany
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13
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Brennecke S, Ranke M, Dimitriou A, Walther S, Prandolini MJ, Lein M, Frühling U. Control of Electron Wave Packets Close to the Continuum Threshold Using Near-Single-Cycle THz Waveforms. PHYSICAL REVIEW LETTERS 2022; 129:213202. [PMID: 36461977 DOI: 10.1103/physrevlett.129.213202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Accepted: 10/17/2022] [Indexed: 06/17/2023]
Abstract
The control of low-energy electrons by carrier-envelope-phase-stable near-single-cycle THz pulses is demonstrated. A femtosecond laser pulse is used to create a temporally localized wave packet through multiphoton absorption at a well defined phase of a synchronized THz field. By recording the photoelectron momentum distributions as a function of the time delay, we observe signatures of various regimes of dynamics, ranging from recollision-free acceleration to coherent electron-ion scattering induced by the THz field. The measurements are confirmed by three-dimensional time-dependent Schrödinger equation simulations. A classical trajectory model allows us to identify scattering phenomena analogous to strong-field photoelectron holography and high-order above-threshold ionization.
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Affiliation(s)
- Simon Brennecke
- Leibniz Universität Hannover, Institut für Theoretische Physik, Appelstraße 2, 30167 Hannover, Germany
| | - Martin Ranke
- Institut für Experimentalphysik, Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg, Germany
- The Hamburg Centre for Ultrafast Imaging (CUI), Luruper Chaussee 149, 22761 Hamburg, Germany
| | - Anastasios Dimitriou
- Institut für Experimentalphysik, Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg, Germany
- The Hamburg Centre for Ultrafast Imaging (CUI), Luruper Chaussee 149, 22761 Hamburg, Germany
- Institute of Nanoscience and Nanotechnology, NSR Demokritos, 15341 Agia Paraskevi, Athens, Greece
| | - Sophie Walther
- Institut für Experimentalphysik, Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg, Germany
- The Hamburg Centre for Ultrafast Imaging (CUI), Luruper Chaussee 149, 22761 Hamburg, Germany
| | - Mark J Prandolini
- Institut für Experimentalphysik, Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg, Germany
| | - Manfred Lein
- Leibniz Universität Hannover, Institut für Theoretische Physik, Appelstraße 2, 30167 Hannover, Germany
| | - Ulrike Frühling
- Institut für Experimentalphysik, Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg, Germany
- The Hamburg Centre for Ultrafast Imaging (CUI), Luruper Chaussee 149, 22761 Hamburg, Germany
- Deutsches Elektronen-Synchrotron, Notkestrasse 85, 22603 Hamburg, Germany
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14
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Ayuso D, Ordonez AF, Smirnova O. Ultrafast chirality: the road to efficient chiral measurements. Phys Chem Chem Phys 2022; 24:26962-26991. [PMID: 36342056 PMCID: PMC9673685 DOI: 10.1039/d2cp01009g] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Accepted: 07/20/2022] [Indexed: 08/20/2023]
Abstract
Today we are witnessing the electric-dipole revolution in chiral measurements. Here we reflect on its lessons and outcomes, such as the perspective on chiral measurements using the complementary principles of "chiral reagent" and "chiral observer", the hierarchy of scalar, vectorial and tensorial enantio-sensitive observables, the new properties of the chiro-optical response in the ultrafast and non-linear domains, and the geometrical magnetism associated with the chiral response in photoionization. The electric-dipole revolution is a landmark event. It has opened routes to extremely efficient enantio-discrimination with a family of new methods. These methods are governed by the same principles but work in vastly different regimes - from microwaves to optical light; they address all molecular degrees of freedom - electronic, vibrational and rotational, and use flexible detection schemes, i.e. detecting photons or electrons, making them applicable to different chiral phases, from gases to liquids to amorphous solids. The electric-dipole revolution has also enabled enantio-sensitive manipulation of chiral molecules with light. This manipulation includes exciting and controlling ultrafast helical currents in vibronic states of chiral molecules, enantio-sensitive control of populations in electronic, vibronic and rotational molecular states, and opens the way to efficient enantio-separation and enantio-sensitive trapping of chiral molecules. The word "perspective" has two meanings: an "outlook" and a "point of view". In this perspective article, we have tried to cover both meanings.
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Affiliation(s)
- David Ayuso
- Max-Born-Institut, 12489 Berlin, Germany
- Imperial College London, SW7 2AZ London, UK.
| | - Andres F Ordonez
- Max-Born-Institut, 12489 Berlin, Germany
- ICFO-Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, 08860 Barcelona, Spain.
| | - Olga Smirnova
- Max-Born-Institut, 12489 Berlin, Germany
- Technische Universität Berlin, 10623 Berlin, Germany.
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15
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Allum F, McManus J, Denby O, Burt M, Brouard M. Photoionization and Photofragmentation Dynamics of I 2 in Intense Laser Fields: A Velocity-Map Imaging Study. J Phys Chem A 2022; 126:8577-8587. [DOI: 10.1021/acs.jpca.2c04379] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Felix Allum
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford OX1 3TA, U.K
| | - Joseph McManus
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford OX1 3TA, U.K
| | - Oskar Denby
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford OX1 3TA, U.K
| | - Michael Burt
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford OX1 3TA, U.K
| | - Mark Brouard
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford OX1 3TA, U.K
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16
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Mayer N, Beaulieu S, Jiménez-Galán Á, Patchkovskii S, Kornilov O, Descamps D, Petit S, Smirnova O, Mairesse Y, Ivanov MY. Role of Spin-Orbit Coupling in High-Order Harmonic Generation Revealed by Supercycle Rydberg Trajectories. PHYSICAL REVIEW LETTERS 2022; 129:173202. [PMID: 36332250 DOI: 10.1103/physrevlett.129.173202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Revised: 07/26/2022] [Accepted: 09/08/2022] [Indexed: 06/16/2023]
Abstract
High-harmonic generation is typically thought of as a sub-laser-cycle process, with the electron's excursion in the continuum lasting a fraction of the optical cycle. However, it was recently suggested that long-lived Rydberg states can play a particularly important role in high harmonic generation by atoms driven by the combination of the counterrotating circularly polarized fundamental light field and its second harmonic. Here we report direct experimental evidence of very long and stable Rydberg trajectories contributing to high-harmonic generation in such fields. We track their dynamics inside the laser pulse using the spin-orbit evolution in the ionic core, utilizing the spin-orbit Larmor clock. We confirm their effect on harmonic emission both via microscopic simulations and by showing how this radiation can lead to a well-collimated macroscopic far-field signal. Our observations contrast sharply with the general view that long-lived Rydberg orbits should generate negligible contribution to the macroscopic far-field high harmonic response of the medium.
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Affiliation(s)
- N Mayer
- Max-Born-Institute, Max-Born Straße 2A, 12489 Berlin, Germany
| | - S Beaulieu
- Université de Bordeaux-CNRS-CEA, Centre Lasers Intenses et Applications (CELIA), UMR5107, F33405 Talence, France
| | - Á Jiménez-Galán
- Max-Born-Institute, Max-Born Straße 2A, 12489 Berlin, Germany
- Joint Attosecond Science Laboratory, National Research Council of Canada and University of Ottawa, Ottawa, Canada
| | - S Patchkovskii
- Max-Born-Institute, Max-Born Straße 2A, 12489 Berlin, Germany
| | - O Kornilov
- Max-Born-Institute, Max-Born Straße 2A, 12489 Berlin, Germany
| | - D Descamps
- Université de Bordeaux-CNRS-CEA, Centre Lasers Intenses et Applications (CELIA), UMR5107, F33405 Talence, France
| | - S Petit
- Université de Bordeaux-CNRS-CEA, Centre Lasers Intenses et Applications (CELIA), UMR5107, F33405 Talence, France
| | - O Smirnova
- Max-Born-Institute, Max-Born Straße 2A, 12489 Berlin, Germany
| | - Y Mairesse
- Université de Bordeaux-CNRS-CEA, Centre Lasers Intenses et Applications (CELIA), UMR5107, F33405 Talence, France
| | - M Y Ivanov
- Max-Born-Institute, Max-Born Straße 2A, 12489 Berlin, Germany
- Department of Physics, Humboldt University, Newtonstraße 15, D-12489 Berlin, Germany
- Blackett Laboratory, Imperial College London, SW7 2AZ London, United Kingdom
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17
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Yuan H, Yang Y, Guo F, Wang J, Cui Z. Influence of multiphoton resonance excitation on the above-threshold ionization of a hydrogen atom. OPTICS EXPRESS 2022; 30:19745-19756. [PMID: 36221742 DOI: 10.1364/oe.461582] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Accepted: 05/09/2022] [Indexed: 06/16/2023]
Abstract
The photo-electron emission of a hydrogen atom irradiated by an ultraviolet laser pulse is investigated by numerically solving the time-dependent Schrödinger equation in momentum space. A subpeak structure with high intensity is observed in the photo-electron emission spectrum, and the peak of the enhanced structure shifts to a higher energy as the laser intensity increases. Through the strong-field approximation and the analysis of the population of the bound state , it is found that this subpeak structure is generated from the interference between the ionized electrons from the ground state and the ionized electrons from the 2p state after the resonant transition from the ground state to the 2p state. Analyzing the change rule of the photo-electron emission spectrum can further deepen the understanding of the energy change of the dressed bound state for an atom irradiated by an intense laser pulse.
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18
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Lin K, Eckart S, Hartung A, Trabert D, Fehre K, Rist J, Schmidt LPH, Schöffler MS, Jahnke T, Kunitski M, Dörner R. Photoelectron energy peaks shift against the radiation pressure in strong-field ionization. SCIENCE ADVANCES 2022; 8:eabn7386. [PMID: 35333574 PMCID: PMC8956253 DOI: 10.1126/sciadv.abn7386] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Accepted: 02/02/2022] [Indexed: 06/14/2023]
Abstract
The photoelectric effect describes the ejection of an electron upon absorption of one or several photons. The kinetic energy of this electron is determined by the photon energy reduced by the binding energy of the electron and, if strong laser fields are involved, by the ponderomotive potential in addition. It has therefore been widely taken for granted that for atoms and molecules, the photoelectron energy does not depend on the electron's emission direction, but theoretical studies have questioned this since 1990. Here, we provide experimental evidence that the energies of photoelectrons emitted against the light propagation direction are shifted toward higher values, while those electrons that are emitted along the light propagation direction are shifted to lower values. We attribute the energy shift to a nondipole contribution to the ponderomotive potential that is due to the interaction of the moving electrons with the incident photons.
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Affiliation(s)
- Kang Lin
- Institut für Kernphysik, Goethe-Universität, Max-von-Laue-Str. 1, 60438 Frankfurt am Main, Germany
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200241, China
| | - Sebastian Eckart
- Institut für Kernphysik, Goethe-Universität, Max-von-Laue-Str. 1, 60438 Frankfurt am Main, Germany
| | - Alexander Hartung
- Institut für Kernphysik, Goethe-Universität, Max-von-Laue-Str. 1, 60438 Frankfurt am Main, Germany
| | - Daniel Trabert
- Institut für Kernphysik, Goethe-Universität, Max-von-Laue-Str. 1, 60438 Frankfurt am Main, Germany
| | - Kilian Fehre
- Institut für Kernphysik, Goethe-Universität, Max-von-Laue-Str. 1, 60438 Frankfurt am Main, Germany
| | - Jonas Rist
- Institut für Kernphysik, Goethe-Universität, Max-von-Laue-Str. 1, 60438 Frankfurt am Main, Germany
| | - Lothar Ph. H. Schmidt
- Institut für Kernphysik, Goethe-Universität, Max-von-Laue-Str. 1, 60438 Frankfurt am Main, Germany
| | - Markus S. Schöffler
- Institut für Kernphysik, Goethe-Universität, Max-von-Laue-Str. 1, 60438 Frankfurt am Main, Germany
| | | | - Maksim Kunitski
- Institut für Kernphysik, Goethe-Universität, Max-von-Laue-Str. 1, 60438 Frankfurt am Main, Germany
| | - Reinhard Dörner
- Institut für Kernphysik, Goethe-Universität, Max-von-Laue-Str. 1, 60438 Frankfurt am Main, Germany
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19
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Krebs BS, Tulsky V, Kazak L, Zabel M, Bauer D, Tiggesbäumker J. Phase-of-the-Phase Electron Momentum Spectroscopy on Single Metal Atoms in Helium Nanodroplets. J Phys Chem Lett 2022; 13:1526-1532. [PMID: 35133167 DOI: 10.1021/acs.jpclett.2c00110] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Magnesium atoms fully embedded in helium nanodroplets are exposed to two-color laser pulses, which trigger multiphoton above-threshold ionization (ATI). This allows exemplary study of the contribution of a dense, neutral, and finite medium on single electron propagation. The angular-resolved photoelectron spectra show striking differences with respect to results obtained on free atoms. Scattering of the individual Mg photoelectrons, when traversing the neutral helium environment, causes the angular distribution to become almost isotropic. Furthermore, the appearance of higher-energy electrons is observed, indicating the impact of the droplet on the concerted emission process. Phase-of-the-phase spectroscopy, however, reveals a marked loss in the 2ω-ω phase dependence of the electron signal. Taking into account sideband formation on a quantitative level, a Monte Carlo simulation which includes laser-assisted electron scattering can reproduce the experimental spectra and give insights into the strong-field-induced electron emission from disordered systems.
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Affiliation(s)
- Bennet S Krebs
- Institute of Physics, University of Rostock, 18059 Rostock, Germany
- Department "Life, Light and Matter", University of Rostock, 18059 Rostock, Germany
| | - Vasily Tulsky
- Institute of Physics, University of Rostock, 18059 Rostock, Germany
| | - Lev Kazak
- Institute of Physics, University of Rostock, 18059 Rostock, Germany
| | - Michael Zabel
- Institute of Physics, University of Rostock, 18059 Rostock, Germany
- Department "Life, Light and Matter", University of Rostock, 18059 Rostock, Germany
| | - Dieter Bauer
- Institute of Physics, University of Rostock, 18059 Rostock, Germany
| | - Josef Tiggesbäumker
- Institute of Physics, University of Rostock, 18059 Rostock, Germany
- Department "Life, Light and Matter", University of Rostock, 18059 Rostock, Germany
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20
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Kang Y, Pisanty E, Ciappina M, Lewenstein M, Figueira de Morisson Faria C, Maxwell AS. Conservation laws for electron vortices in strong-field ionisation. THE EUROPEAN PHYSICAL JOURNAL. D, ATOMIC, MOLECULAR, AND OPTICAL PHYSICS 2021; 75:199. [PMID: 34720728 PMCID: PMC8550503 DOI: 10.1140/epjd/s10053-021-00214-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Accepted: 04/27/2021] [Indexed: 06/13/2023]
Abstract
ABSTRACT We investigate twisted electrons with a well-defined orbital angular momentum, which have been ionised via a strong laser field. By formulating a new variant of the well-known strong field approximation, we are able to derive conservation laws for the angular momenta of twisted electrons in the cases of linear and circularly polarised fields. In the case of linear fields, we demonstrate that the orbital angular momentum of the twisted electron is determined by the magnetic quantum number of the initial bound state. The condition for the circular field can be related to the famous ATI peaks, and provides a new interpretation for this fundamental feature of photoelectron spectra. We find the length of the circular pulse to be a vital factor in this selection rule and, employing an effective frequency, we show that the photoelectron OAM emission spectra are sensitive to the parity of the number of laser cycles. This work provides the basic theoretical framework with which to understand the OAM of a photoelectron undergoing strong field ionisation.
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Affiliation(s)
- Yuxin Kang
- Department of Physics and Astronomy, University College London, Gower Street, London, WC1E 6BT UK
| | - Emilio Pisanty
- Max Born Institute for Nonlinear Optics and Short Pulse Spectroscopy, Max-Born-Straße 2A, 12489 Berlin, Germany
- ICFO - Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, Av. Carl Friedrich Gauss 3, 08860 Castelldefels (Barcelona), Spain
| | - Marcelo Ciappina
- ICFO - Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, Av. Carl Friedrich Gauss 3, 08860 Castelldefels (Barcelona), Spain
- Physics Program, Guangdong Technion – Israel Institute of Technology, Shantou, 515063 Guangdong China
- Technion – Israel Institute of Technology, 32000 Haifa, Israel
| | - Maciej Lewenstein
- ICFO - Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, Av. Carl Friedrich Gauss 3, 08860 Castelldefels (Barcelona), Spain
- ICREA, Pg. Lluís Companys 23, 08010 Barcelona, Spain
| | | | - Andrew S. Maxwell
- Department of Physics and Astronomy, University College London, Gower Street, London, WC1E 6BT UK
- ICFO - Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, Av. Carl Friedrich Gauss 3, 08860 Castelldefels (Barcelona), Spain
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21
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Angular dependence of the Wigner time delay upon tunnel ionization of H 2. Nat Commun 2021; 12:1697. [PMID: 33727546 PMCID: PMC7966791 DOI: 10.1038/s41467-021-21845-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Accepted: 02/16/2021] [Indexed: 11/08/2022] Open
Abstract
When a very strong light field is applied to a molecule an electron can be ejected by tunneling. In order to quantify the time-resolved dynamics of this ionization process, the concept of the Wigner time delay can be used. The properties of this process can depend on the tunneling direction relative to the molecular axis. Here, we show experimental and theoretical data on the Wigner time delay for tunnel ionization of H2 molecules and demonstrate its dependence on the emission direction of the electron with respect to the molecular axis. We find, that the observed changes in the Wigner time delay can be quantitatively explained by elongated/shortened travel paths of the emitted electrons, which occur due to spatial shifts of the electrons' birth positions after tunneling. Our work provides therefore an intuitive perspective towards the Wigner time delay in strong-field ionization.
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22
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Woźniak AP, Lesiuk M, Przybytek M, Efimov DK, Prauzner-Bechcicki JS, Mandrysz M, Ciappina M, Pisanty E, Zakrzewski J, Lewenstein M, Moszyński R. A systematic construction of Gaussian basis sets for the description of laser field ionization and high-harmonic generation. J Chem Phys 2021; 154:094111. [PMID: 33685145 DOI: 10.1063/5.0040879] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
A precise understanding of mechanisms governing the dynamics of electrons in atoms and molecules subjected to intense laser fields has a key importance for the description of attosecond processes such as the high-harmonic generation and ionization. From the theoretical point of view, this is still a challenging task, as new approaches to solve the time-dependent Schrödinger equation with both good accuracy and efficiency are still emerging. Until recently, the purely numerical methods of real-time propagation of the wavefunction using finite grids have been frequently and successfully used to capture the electron dynamics in small one- or two-electron systems. However, as the main focus of attoscience shifts toward many-electron systems, such techniques are no longer effective and need to be replaced by more approximate but computationally efficient ones. In this paper, we explore the increasingly popular method of expanding the wavefunction of the examined system into a linear combination of atomic orbitals and present a novel systematic scheme for constructing an optimal Gaussian basis set suitable for the description of excited and continuum atomic or molecular states. We analyze the performance of the proposed basis sets by carrying out a series of time-dependent configuration interaction calculations for the hydrogen atom in fields of intensity varying from 5 × 1013 W/cm2 to 5 × 1014 W/cm2. We also compare the results with the data obtained using Gaussian basis sets proposed previously by other authors.
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Affiliation(s)
| | - Michał Lesiuk
- Faculty of Chemistry, University of Warsaw, Pasteura 1, 02-093 Warsaw, Poland
| | - Michał Przybytek
- Faculty of Chemistry, University of Warsaw, Pasteura 1, 02-093 Warsaw, Poland
| | - Dmitry K Efimov
- Institute of Theoretical Physics, Jagiellonian University in Krakow, Łojasiewicza 11, 30-348 Kraków, Poland
| | - Jakub S Prauzner-Bechcicki
- Marian Smoluchowski Institute of Physics, Jagiellonian University in Krakow, Łojasiewicza 11, 30-348 Kraków, Poland
| | - Michał Mandrysz
- Institute of Theoretical Physics, Jagiellonian University in Krakow, Łojasiewicza 11, 30-348 Kraków, Poland
| | - Marcelo Ciappina
- ICFO-Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, Av. Carl Friedrich Gauss 3, 08860, Castelldefels, Barcelona, Spain
| | - Emilio Pisanty
- ICFO-Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, Av. Carl Friedrich Gauss 3, 08860, Castelldefels, Barcelona, Spain
| | - Jakub Zakrzewski
- Institute of Theoretical Physics, Jagiellonian University in Krakow, Łojasiewicza 11, 30-348 Kraków, Poland
| | - Maciej Lewenstein
- ICFO-Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, Av. Carl Friedrich Gauss 3, 08860, Castelldefels, Barcelona, Spain
| | - Robert Moszyński
- Faculty of Chemistry, University of Warsaw, Pasteura 1, 02-093 Warsaw, Poland
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23
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De Silva AHNC, Atri-Schuller D, Dubey S, Acharya BP, Romans KL, Foster K, Russ O, Compton K, Rischbieter C, Douguet N, Bartschat K, Fischer D. Using Circular Dichroism to Control Energy Transfer in Multiphoton Ionization. PHYSICAL REVIEW LETTERS 2021; 126:023201. [PMID: 33512178 DOI: 10.1103/physrevlett.126.023201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Revised: 10/26/2020] [Accepted: 12/17/2020] [Indexed: 06/12/2023]
Abstract
Chirality causes symmetry breaks in a large variety of natural phenomena ranging from particle physics to biochemistry. We investigate one of the simplest conceivable chiral systems, a laser-excited, oriented, effective one-electron Li target. Prepared in a polarized p state with |m|=1 in an optical trap, the atoms are exposed to co- and counterrotating circularly polarized femtosecond laser pulses. For a field frequency near the excitation energy of the oriented initial state, a strong circular dichroism is observed and the photoelectron energies are significantly affected by the helicity-dependent Autler-Townes splitting. Besides its fundamental relevance, this system is suited to create spin-polarized electron pulses with a reversible switch on a femtosecond timescale at an energy resolution of a few meV.
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Affiliation(s)
- A H N C De Silva
- Physics Department and LAMOR, Missouri University of Science & Technology, Rolla, Missouri 65409, USA
| | - D Atri-Schuller
- Department of Physics and Astronomy, Drake University, Des Moines, Iowa 50311, USA
| | - S Dubey
- Physics Department and LAMOR, Missouri University of Science & Technology, Rolla, Missouri 65409, USA
| | - B P Acharya
- Physics Department and LAMOR, Missouri University of Science & Technology, Rolla, Missouri 65409, USA
| | - K L Romans
- Physics Department and LAMOR, Missouri University of Science & Technology, Rolla, Missouri 65409, USA
| | - K Foster
- Physics Department and LAMOR, Missouri University of Science & Technology, Rolla, Missouri 65409, USA
| | - O Russ
- Physics Department and LAMOR, Missouri University of Science & Technology, Rolla, Missouri 65409, USA
| | - K Compton
- Physics Department and LAMOR, Missouri University of Science & Technology, Rolla, Missouri 65409, USA
| | - C Rischbieter
- Physics Department and LAMOR, Missouri University of Science & Technology, Rolla, Missouri 65409, USA
| | - N Douguet
- Department of Physics, Kennesaw State University, Kennesaw, Georgia 30144, USA
| | - K Bartschat
- Department of Physics and Astronomy, Drake University, Des Moines, Iowa 50311, USA
| | - D Fischer
- Physics Department and LAMOR, Missouri University of Science & Technology, Rolla, Missouri 65409, USA
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Kim YH, Ivanov IA, Hwang SI, Kim K, Nam CH, Kim KT. Attosecond streaking using a rescattered electron in an intense laser field. Sci Rep 2020; 10:22075. [PMID: 33328542 PMCID: PMC7745043 DOI: 10.1038/s41598-020-79034-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Accepted: 12/03/2020] [Indexed: 11/10/2022] Open
Abstract
When an atom or molecule is exposed to a strong laser field, an electron can tunnel out from the parent ion and moves along a specific trajectory. This ultrafast electron motion is sensitive to a variation of the laser field. Thus, it can be used as a fast temporal gate for the temporal characterization of the laser field. Here, we demonstrate a new type of attosecond streaking wherein a rescattered electron trajectory is manipulated by an ultrashort laser pulse. The vector potential of the laser pulse is directly recorded in the photoelectron spectra of the rescattered electron. In contrast to high harmonic generation methods, our approach has no directional ambiguity in space, leading to complete in situ temporal characterization. In addition, it provides timing information on ionization and re-scattering events. Therefore, our approach can be a useful tool for the investigation of strong-field processes triggered by rescattering, such as non-sequential double ionization and laser-induced electron diffraction.
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Affiliation(s)
- Yang Hwan Kim
- Center for Relativistic Laser Science, Institute for Basic Science, Gwangju, 61005, Korea
- Department of Physics and Photon Science, Gwangju Institute of Science and Technology, Gwangju, 61005, Korea
| | - Igor A Ivanov
- Center for Relativistic Laser Science, Institute for Basic Science, Gwangju, 61005, Korea
| | - Sung In Hwang
- Center for Relativistic Laser Science, Institute for Basic Science, Gwangju, 61005, Korea
| | - Kyungseung Kim
- Center for Relativistic Laser Science, Institute for Basic Science, Gwangju, 61005, Korea
| | - Chang Hee Nam
- Center for Relativistic Laser Science, Institute for Basic Science, Gwangju, 61005, Korea
- Department of Physics and Photon Science, Gwangju Institute of Science and Technology, Gwangju, 61005, Korea
| | - Kyung Taec Kim
- Center for Relativistic Laser Science, Institute for Basic Science, Gwangju, 61005, Korea.
- Department of Physics and Photon Science, Gwangju Institute of Science and Technology, Gwangju, 61005, Korea.
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25
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Hishikawa A, Matsuda A, Fushitani M. Ultrafast Reaction Imaging and Control by Ultrashort Intense Laser Pulses. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 2020. [DOI: 10.1246/bcsj.20200158] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Akiyoshi Hishikawa
- Research Center for Materials Science, Nagoya University, Nagoya, Aichi 464-8602, Japan
- Department of Chemistry, Graduate School of Science, Nagoya University, Nagoya, Aichi 464-8602, Japan
| | - Akitaka Matsuda
- Department of Chemistry, Graduate School of Science, Nagoya University, Nagoya, Aichi 464-8602, Japan
| | - Mizuho Fushitani
- Department of Chemistry, Graduate School of Science, Nagoya University, Nagoya, Aichi 464-8602, Japan
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26
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27
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Kelbg M, Zabel M, Krebs B, Kazak L, Meiwes-Broer KH, Tiggesbäumker J. Temporal Development of a Laser-Induced Helium Nanoplasma Measured through Auger Emission and Above-Threshold Ionization. PHYSICAL REVIEW LETTERS 2020; 125:093202. [PMID: 32915628 DOI: 10.1103/physrevlett.125.093202] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/17/2019] [Revised: 04/14/2020] [Accepted: 07/23/2020] [Indexed: 06/11/2023]
Abstract
Femtosecond pump-probe electron and ion spectroscopy is applied to study the development of a helium nanoplasma up to the nanosecond timescale. Electrons, bound by the deep confining mean-field potential, are elevated toward the vacuum level in the nanoplasma expansion. Subsequent electron recombination gives rise to transitions between He^{+} states, resulting in autoionization. The time-resolved analysis of the energy transfer to quasifree electrons reveals a transient depletion of the Auger emission, which allows for a temporal gate to map the distribution of delocalized electrons in the developing mean field. Furthermore, we trace the recombination of delocalized electrons near the vacuum level into highly excited Rydberg states. Transient above-threshold ionization is introduced as a diagnostic tool to resolve the dynamics. Thus, the development of the electron distribution in the nanoplasma mean-field potential can be monitored via the features observed in the emission spectra.
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Affiliation(s)
- M Kelbg
- Institut für Physik, Universität Rostock, 18059 Rostock, Germany
| | - M Zabel
- Institut für Physik, Universität Rostock, 18059 Rostock, Germany
| | - B Krebs
- Institut für Physik, Universität Rostock, 18059 Rostock, Germany
| | - L Kazak
- Institut für Physik, Universität Rostock, 18059 Rostock, Germany
| | - K-H Meiwes-Broer
- Institut für Physik, Universität Rostock, 18059 Rostock, Germany and Department "Life, Light, and Matter," Universität Rostock, 18059 Rostock, Germany
| | - J Tiggesbäumker
- Institut für Physik, Universität Rostock, 18059 Rostock, Germany and Department "Life, Light, and Matter," Universität Rostock, 18059 Rostock, Germany
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28
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Chen J, Xing X, Rey-de-Castro R, Rabitz H. Ultrafast Photofragmentation of Ln(hfac) 3 with a Proposed Mechanism for forming High Mass Fluorinated Products. Sci Rep 2020; 10:7066. [PMID: 32341431 PMCID: PMC7184609 DOI: 10.1038/s41598-020-64015-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Accepted: 04/09/2020] [Indexed: 11/27/2022] Open
Abstract
The photo-induced dissociative-ionization of lanthanide complexes Ln(hfac)3 (Ln = Pr, Er, Yb) is studied using intense ultrafast transform limited (TL) and linearly chirped laser pulses in a time-of-flight (TOF) mass spectrometry setup. Various fluorine and Ln-containing high-mass fragments were observed in this experiment, including the molecular parent ion, which have not been seen with previous studies relying on relatively long-duration laser pulses (i.e., ns or longer). These new high-mass observations provide important formerly missing information for deducing a set of photo-fragmentation mechanistic pathways for Ln(hfac)3. An overall ultrafast control mechanism is proposed by combining insights from earlier studies and the fragments observed in this research to result in three main distinct photo-fragmentation processes: (a) ligand-metal charge transfer, (b) CF3 elimination, and (c) C-C bond rotation processes. We conclude that ultrafast dissociative-ionization could be a promising technique for generating high-mass fragments for potential use in material science applications.
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Affiliation(s)
- Jiangchao Chen
- Department of Chemistry, Princeton University, Princeton, New Jersey, 08544, USA
| | - Xi Xing
- Department of Chemistry, Princeton University, Princeton, New Jersey, 08544, USA
| | | | - Herschel Rabitz
- Department of Chemistry, Princeton University, Princeton, New Jersey, 08544, USA.
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29
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Nauta J, Oelmann JH, Ackermann A, Knauer P, Pappenberger R, Borodin A, Muhammad IS, Ledwa H, Pfeifer T, Crespo López-Urrutia JR. 100 MHz frequency comb for low-intensity multi-photon studies: intra-cavity velocity-map imaging of xenon. OPTICS LETTERS 2020; 45:2156-2159. [PMID: 32287180 DOI: 10.1364/ol.389327] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Accepted: 03/06/2020] [Indexed: 06/11/2023]
Abstract
We raise the power from a commercial 10 W frequency comb inside an enhancement cavity and perform multi-photon ionization of gas-phase atoms at 100 MHz for the first time, to the best of our knowledge. An intra-cavity velocity-map-imaging setup collects electron-energy spectra of xenon at rates several orders of magnitude higher than those of conventional laser systems. Consequently, we can use much lower intensities ${\sim}{{10}^{12}} \;{\rm W}/{{\rm cm}^2} $∼1012W/cm2 without increasing acquisition times above just a few seconds. The high rate and coherence of the stabilized femtosecond pulses are known to be transferred to the actively stabilized cavity and will allow studying purely perturbative multi-photon effects, paving the road towards a new field of precision tests in nonlinear physics.
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30
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Shu Z, Liu M, Hu S, Chen J. Molecular Rydberg-state excitation in laser pulses: bandwidth and orbital symmetry. OPTICS EXPRESS 2020; 28:11165-11174. [PMID: 32403633 DOI: 10.1364/oe.390564] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Accepted: 03/24/2020] [Indexed: 06/11/2023]
Abstract
We have performed a comparison study of the Rydberg-state excitation of model molecules (1πg and 1πu states) in different laser fields by the approaches of time-dependent Schrödinger equation and a fully quantum-mechanical model, and both simulations show good accordance. It is found that the peak structure of the Rydberg-state population vs laser intensity becomes pronounced for longer laser pulses due to the stronger interference effect between the subwave packets released in different optical cycles, and the locations of the intensity-dependent peaks closely satisfy the multi-photon resonant transition condition. In addition, it is demonstrated that the populations of the Rydberg states possessing the identical parity oscillate in an inverse manner with increasing laser intensity for different initial states (1πg and 1πu), and the aforementioned distinct phenomenon is attributed to the additional phase introduced by the symmetry of 1πg state with respect to that of 1πu state.
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31
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Jiang WC, Chen SG, Peng LY, Burgdörfer J. Two-Electron Interference in Strong-Field Ionization of He by a Short Intense Extreme Ultraviolet Laser Pulse. PHYSICAL REVIEW LETTERS 2020; 124:043203. [PMID: 32058759 DOI: 10.1103/physrevlett.124.043203] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Indexed: 06/10/2023]
Abstract
Double ionization of helium by a single intense (above 10^{18} W/cm^{2}) linearly polarized extreme ultraviolet laser pulse is studied by numerically solving the full-dimensional time-dependent Schrödinger equation. For the laser intensities well beyond the perturbative limit, novel gridlike interference fringes are found in the correlated energy spectrum of the two photoelectrons. The interference can be traced to the multitude of two-electron wave packets emitted at different ionization times. A semianalytical model for the dressed two-photon double ionization is shown to qualitatively account for the interference patterns in the joint energy spectrum. Similar signatures of interferences between transient induced time-delayed ionization bursts are expected for other atomic and molecular multielectron systems.
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Affiliation(s)
- Wei-Chao Jiang
- College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, China
- State Key Laboratory for Mesoscopic Physics and Collaborative Innovation Center of Quantum Matter, School of Physics, Peking University, Beijing 100871, China
- Institute for Theoretical Physics, Vienna University of Technology, Wiedner Hauptstraße 8-10, A-1040 Vienna, Austria, EU
| | - Si-Ge Chen
- State Key Laboratory for Mesoscopic Physics and Collaborative Innovation Center of Quantum Matter, School of Physics, Peking University, Beijing 100871, China
| | - Liang-You Peng
- State Key Laboratory for Mesoscopic Physics and Collaborative Innovation Center of Quantum Matter, School of Physics, Peking University, Beijing 100871, China
- Beijing Academy of Quantum Information Sciences, Beijing 100193, China
| | - Joachim Burgdörfer
- Institute for Theoretical Physics, Vienna University of Technology, Wiedner Hauptstraße 8-10, A-1040 Vienna, Austria, EU
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32
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Huang X, Zhang Q, Xu S, Fu X, Han X, Cao W, Lu P. Coulomb focusing in retrapped ionization with near-circularly polarized laser field. OPTICS EXPRESS 2019; 27:38116-38124. [PMID: 31878583 DOI: 10.1364/oe.27.038116] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2019] [Accepted: 11/28/2019] [Indexed: 06/10/2023]
Abstract
The full three-dimensional photoelectron momentum distributions of argon are measured in intense near-circularly polarized laser fields. We observed that the transverse momentum distribution of ejected electrons by 410-nm near-circularly polarized field is unexpectedly narrowed with increasing laser intensity, which is contrary to the conventional rules predicted by adiabatic theory. By analyzing the momentum-resolved angular momentum distribution measured experimentally and the corresponding trajectories of ejected electrons semiclassically, the narrowing can be attributed to a temporary trapping and thereby focusing of a photoelectron by the atomic potential in a quasibound state. With the near-circularly polarized laser field, the strong Coulomb interaction with the rescattering electrons is avoided, thus the Coulomb focusing in the retrapped process is highlighted. We believe that these findings will facilitate understanding and steering electron dynamics in the Coulomb coupled system.
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33
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Hu S, Hao X, Lv H, Liu M, Yang T, Xu H, Jin M, Ding D, Li Q, Li W, Becker W, Chen J. Quantum dynamics of atomic Rydberg excitation in strong laser fields. OPTICS EXPRESS 2019; 27:31629-31643. [PMID: 31684393 DOI: 10.1364/oe.27.031629] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2019] [Accepted: 09/19/2019] [Indexed: 06/10/2023]
Abstract
Neutral atoms have been observed to survive intense laser pulses in high Rydberg states with surprisingly large probability. Only with this Rydberg-state excitation (RSE) included is the picture of intense-laser-atom interaction complete. Various mechanisms have been proposed to explain the underlying physics. However, neither one can explain all the features observed in experiments and in time-dependent Schrödinger equation (TDSE) simulations. Here we propose a fully quantum-mechanical model based on the strong-field approximation (SFA). It well reproduces the intensity dependence of RSE obtained by the TDSE, which exhibits a series of modulated peaks. They are due to recapture of the liberated electron and the fact that the pertinent probability strongly depends on the position and the parity of the Rydberg state. We also present measurements of RSE in xenon at 800 nm, which display the peak structure consistent with the calculations.
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34
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Zhang L, Miao Z, Zheng W, Zhong X, Wu C. Nonresonant multiphoton ionization of xenon atoms by femtosecond laser pulses. Chem Phys 2019. [DOI: 10.1016/j.chemphys.2019.04.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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35
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Xu L, Fu L. Multichannel Interference in Resonancelike Enhancement of High-Order Above-Threshold Ionization. PHYSICAL REVIEW LETTERS 2019; 122:253202. [PMID: 31347865 DOI: 10.1103/physrevlett.122.253202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Revised: 03/21/2019] [Indexed: 06/10/2023]
Abstract
The intensity-dependent resonancelike enhancement phenomenon in the high-order above-threshold ionization spectrum is a typical quantum effect for atoms or molecules in an intense laser field, which has not been well understood. The calculations of the time-dependent Schrödinger equation (TDSE) are in remarkable agreement with the experimental data, but they cannot clarify the contributions of the bound states. The semiclassical approach of strong field approximation, in which no excited states are involved, can obtain a similar phenomenon, but the laser intensities of enhanced regions predicted by the strong field approximation are inconsistent with the results of the TDSE. In this Letter, a new fully quantum model is established from the TDSE without any excited states. Two types of enhanced structures, unimodal and multimodal structures, are found in the results of the TDSE and model. In addition, the calculations of the model reproduce the key features of the results of the TDSE. It shows that the excited states are not the key factor in the resonancelike enhancements in our calculated system, since there are no excited states in our model. Based on the calculations of our model, we show that such resonancelike enhancements are caused by the constructive interference of different momentum transfer channels. Last, the Fano-like line shapes are also discussed for the features of multichannel interference.
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Affiliation(s)
- Long Xu
- Graduate School of China Academy of Engineering Physics, No. 10 Xibeiwang East Road, Haidian District, Beijing, 100193, China
| | - Libin Fu
- Graduate School of China Academy of Engineering Physics, No. 10 Xibeiwang East Road, Haidian District, Beijing, 100193, China
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36
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Wang C, Li X, Xiao XR, Yang Y, Luo S, Yu X, Xu X, Peng LY, Gong Q, Ding D. Accurate in situ Measurement of Ellipticity Based on Subcycle Ionization Dynamics. PHYSICAL REVIEW LETTERS 2019; 122:013203. [PMID: 31012706 DOI: 10.1103/physrevlett.122.013203] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2018] [Indexed: 06/09/2023]
Abstract
Elliptically polarized laser pulses (EPLPs) are widely applied in many fields of ultrafast sciences, but the ellipticity (ϵ) has never been in situ measured in the interaction zone of the laser focus. In this Letter, we propose and realize a robust scheme to retrieve the ϵ by temporally overlapping two identical counterrotating EPLPs. The combined linearly electric field is coherently controlled to ionize Xe atoms by varying the phase delay between the two EPLPs. The electron spectra of the above-threshold ionization and the ion yield are sensitively modulated by the phase delay. We demonstrate that these modulations can be used to accurately determine ϵ of the EPLP. We show that the present method is highly reliable and is applicable in a wide range of laser parameters. The accurate retrieval of ϵ offers a better characterization of a laser pulse, promising a more delicate and quantitative control of the subcycle dynamics in many strong field processes.
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Affiliation(s)
- Chuncheng Wang
- Institute of Atomic and Molecular Physics, Jilin University, Changchun 130012, China
| | - Xiaokai Li
- Institute of Atomic and Molecular Physics, Jilin University, Changchun 130012, China
| | - Xiang-Ru Xiao
- State Key Laboratory for Mesoscopic Physics and Collaborative Innovation Center of Quantum Matter, School of Physics, Peking University, Beijing 100871, China
| | - Yizhang Yang
- Institute of Atomic and Molecular Physics, Jilin University, Changchun 130012, China
| | - Sizuo Luo
- Institute of Atomic and Molecular Physics, Jilin University, Changchun 130012, China
| | - Xitao Yu
- Institute of Atomic and Molecular Physics, Jilin University, Changchun 130012, China
| | - Xinpeng Xu
- Institute of Atomic and Molecular Physics, Jilin University, Changchun 130012, China
| | - Liang-You Peng
- State Key Laboratory for Mesoscopic Physics and Collaborative Innovation Center of Quantum Matter, School of Physics, Peking University, Beijing 100871, China
- Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan, Shanxi 030006, China
- Beijing Academy of Quantum Information Sciences, West Bld. #3, No. 10 Xibeiwang East Rd., Haidian District, Beijing 100193, China
| | - Qihuang Gong
- State Key Laboratory for Mesoscopic Physics and Collaborative Innovation Center of Quantum Matter, School of Physics, Peking University, Beijing 100871, China
- Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan, Shanxi 030006, China
- Beijing Academy of Quantum Information Sciences, West Bld. #3, No. 10 Xibeiwang East Rd., Haidian District, Beijing 100193, China
| | - Dajun Ding
- Institute of Atomic and Molecular Physics, Jilin University, Changchun 130012, China
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37
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Xu L, Dong H, Fu L. Frequency-resolved photon-electronic spectroscopy for excited state population detection. OPTICS LETTERS 2018; 43:5725-5728. [PMID: 30499978 DOI: 10.1364/ol.43.005725] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Accepted: 10/19/2018] [Indexed: 06/09/2023]
Abstract
Atomic excitation to excited states in a strong laser field is the key to high-order harmonic generation below the ionization threshold, yet it remains unclear mainly due to the lack of proper detection methods. We propose a frequency-resolved photon-electron spectroscopy technique to reconstruct a population of excited states with the second delayed laser pulse. The technique utilizes Fourier transformation to separate ionization from different excited states to different positions on the spectrum. With the advantage of separation, we provide a scheme to reconstruct populations on different excited states after the first pulse. The scheme is validated by a high-precision population reconstruction of helium and hydrogen atoms.
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38
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Jiang WC, Burgdörfer J. Dynamic interference as signature of atomic stabilization. OPTICS EXPRESS 2018; 26:19921-19931. [PMID: 30119311 DOI: 10.1364/oe.26.019921] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2018] [Accepted: 07/04/2018] [Indexed: 06/08/2023]
Abstract
We study the ionization of atoms by very intense linearly polarized pulse with moderately high frequency by numerically solving the time-dependent Schrödinger equation (TDSE). In this regime, the photon energy exceeds the ionization potential allowing for one-photon ionization which is, however, strongly influenced by strong nonlinear photon-atom interactions. We find that the onset of atomic stabilization can be monitored by the appearance of a dynamic interference pattern in the photoelectron spectrum.
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39
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Tan J, Zhou Y, Li M, He M, Liu Y, Lu P. Accurate measurement of laser intensity using photoelectron interference in strong-field tunneling ionization. OPTICS EXPRESS 2018; 26:20063-20075. [PMID: 30119322 DOI: 10.1364/oe.26.020063] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2018] [Accepted: 06/25/2018] [Indexed: 06/08/2023]
Abstract
Accurate determination of laser intensity is of fundamental importance to study various phenomena in intense laser-atom/molecule interactions. We theoretically demonstrate a scheme to measure laser intensity by examining the holographic structure originating from the interference between the direct and near-forward rescattering electrons in strong-field tunneling ionization. By adding a weak second-harmonic field with polarization orthogonal to the strong fundamental driving field, the interference pattern oscillates with the changing relative phases of the two-color fields. Interestingly, the amplitude of this oscillation in the photoelectron momentum spectrum depends on the parallel momentum. With the quantum-orbit analysis, we show that the amplitude of the oscillation minimizes when the time difference between the recollision and ionization of near-forward rescattering electron is half cycle of the fundamental driving field. This enables us to measure accurately the laser intensity by seeking the minimum of the oscillation amplitude. Moreover, we show that this minimum can be determined without scanning the relative phases, instead, by just monitoring the interference patterns for two relative phases. This facilitates the application of our scheme in experiment.
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40
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Schell F, Boguslavskiy AE, Schulz CP, Patchkovskii S, Vrakking MJJ, Stolow A, Mikosch J. Sequential and direct ionic excitation in the strong-field ionization of 1-butene molecules. Phys Chem Chem Phys 2018; 20:14708-14717. [PMID: 29774327 DOI: 10.1039/c7cp08195b] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We study the Strong-Field Ionization (SFI) of the hydrocarbon 1-butene as a function of wavelength using photoion-photoelectron covariance and coincidence spectroscopy. We observe a striking transition in the fragment-associated photoelectron spectra: from a single Above Threshold Ionization (ATI) progression for photon energies less than the cation D0-D1 gap to two ATI progressions for a photon energy greater than this gap. For the first case, electronically excited cations are created by SFI populating the ground cationic state D0, followed by sequential post-ionization excitation. For the second case, direct sub-cycle SFI to the D1 excited cation state contributes significantly. Our experiments access ionization dynamics in a regime where strong-field and resonance-enhanced processes can interplay.
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Affiliation(s)
- Felix Schell
- Max-Born-Institut, Max-Born-Strasse 2A, 12489 Berlin, Germany.
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41
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Li B, Hu S, Shu Z, He X, Chen J. Resonance-like enhancement in high-order above threshold ionization of atoms and molecules in intense laser fields. OPTICS EXPRESS 2018; 26:13012-13019. [PMID: 29801334 DOI: 10.1364/oe.26.013012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2018] [Accepted: 04/30/2018] [Indexed: 06/08/2023]
Abstract
We investigate the high-order above-threshold ionization (HATI) of atoms (Ar and Xe) and molecules (N2 and O2) subjected to strong laser fields by numerically solving time-dependent Schrödinger equation. It is demonstrated that resonance-like enhancement of groups of adjacent peaks in photoelectron spectrum of HATI is observed for Ar, Xe, and N2, while this peculiar phenomenon is absent for O2, which is in agreement with experimental observation [ Phys. Rev. A88, 021401 (2013)]. In addition, analysis indicates that resonance-like enhancement in HATI spectra of atoms and molecules is closely related to excitation of the high-lying excited states.
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42
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Ning QC, Saalmann U, Rost JM. Electron Dynamics Driven by Light-Pulse Derivatives. PHYSICAL REVIEW LETTERS 2018; 120:033203. [PMID: 29400507 DOI: 10.1103/physrevlett.120.033203] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2017] [Indexed: 06/07/2023]
Abstract
We demonstrate that ultrashort pulses carry the possibility for a new regime of light-matter interaction with nonadiabatic electron processes sensitive to the envelope derivative of the light pulse. A standard single pulse with its two peaks in the derivative separated by the width of the pulse acts in this regime like a traditional double pulse. The two ensuing nonadiabatic ionization bursts have slightly different ionization amplitudes. This difference is due to the redistribution of continuum electron energy during the bursts, negligible in standard photoionization. A time-dependent close-coupling approach based on cycle-averaged potentials in the Kramers-Henneberger reference frame permits a detailed understanding of light-pulse derivative-driven electron dynamics.
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Affiliation(s)
- Qi-Cheng Ning
- Max Planck Institute for the Physics of Complex Systems, Nöthnitzer Straße 38, 01187 Dresden, Germany
| | - Ulf Saalmann
- Max Planck Institute for the Physics of Complex Systems, Nöthnitzer Straße 38, 01187 Dresden, Germany
| | - Jan M Rost
- Max Planck Institute for the Physics of Complex Systems, Nöthnitzer Straße 38, 01187 Dresden, Germany
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Brée C, Hofmann M, Demircan A, Morgner U, Kosareva O, Savel'ev A, Husakou A, Ivanov M, Babushkin I. Symmetry Breaking and Strong Persistent Plasma Currents via Resonant Destabilization of Atoms. PHYSICAL REVIEW LETTERS 2017; 119:243202. [PMID: 29286725 DOI: 10.1103/physrevlett.119.243202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2017] [Indexed: 06/07/2023]
Abstract
The ionization rate of an atom in a strong optical field can be resonantly enhanced by the presence of long-living atomic levels (so-called Freeman resonances). This process is most prominent in the multiphoton ionization regime, meaning that the ionization event takes many optical cycles. Nevertheless, here, we show that these resonances can lead to rapid subcycle-scale plasma buildup at the resonant values of the intensity in the pump pulse. The fast buildup can break the cycle-to-cycle symmetry of the ionization process, resulting in the generation of persistent macroscopic plasma currents which remain after the end of the pulse. This, in turn, gives rise to a broadband radiation of unusual spectral structure, forming a comb from terahertz to visible. This radiation contains fingerprints of the attosecond electron dynamics in Rydberg states during ionization.
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Affiliation(s)
- C Brée
- Weierstrass Institute, Mohrenstrasse 39, 10117 Berlin, Germany
| | - M Hofmann
- Virtimo AG, Münzstrasse 5, 10178 Berlin, Germany
| | - A Demircan
- Institute for Quantum Optics, Leibniz Universität Hannover, Welfengarten 1, 30167 Hannover, Germany
- Hannover Centre for optical Technologies, Nienburger Strasse 17, 30167 Hannover, Germany
| | - U Morgner
- Institute for Quantum Optics, Leibniz Universität Hannover, Welfengarten 1, 30167 Hannover, Germany
- Hannover Centre for optical Technologies, Nienburger Strasse 17, 30167 Hannover, Germany
| | - O Kosareva
- Physics Faculty, Lomonosov Moscow State University, Leninskie gory 1-62, 119991 Moscow, Russia
| | - A Savel'ev
- Physics Faculty, Lomonosov Moscow State University, Leninskie gory 1-62, 119991 Moscow, Russia
| | - A Husakou
- Max Born Institute, Max Born Strasse 2a, 12489 Berlin, Germany
| | - M Ivanov
- Max Born Institute, Max Born Strasse 2a, 12489 Berlin, Germany
| | - I Babushkin
- Institute for Quantum Optics, Leibniz Universität Hannover, Welfengarten 1, 30167 Hannover, Germany
- Max Born Institute, Max Born Strasse 2a, 12489 Berlin, Germany
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Forbes R, Boguslavskiy AE, Wilkinson I, Underwood JG, Stolow A. Excited state wavepacket dynamics in NO 2 probed by strong-field ionization. J Chem Phys 2017; 147:054305. [PMID: 28789534 DOI: 10.1063/1.4996461] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We present an experimental femtosecond time-resolved study of the 399 nm excited state dynamics of nitrogen dioxide using channel-resolved above threshold ionization (CRATI) as the probe process. This method relies on photoelectron-photoion coincidence and covariance to correlate the strong-field photoelectron spectrum with ionic fragments, which label the channel. In all ionization channels observed, we report apparent oscillations in the ion and photoelectron yields as a function of pump-probe delay. Further, we observe the presence of a persistent, time-invariant above threshold ionization comb in the photoelectron spectra associated with most ionization channels at long time delays. These observations are interpreted in terms of single-pump-photon excitation to the first excited electronic X̃ 2A1 state and multi-pump-photon excitations to higher-lying states. The short time delay (<100 fs) dynamics in the fragment channels show multi-photon pump signatures of higher-lying neutral state dynamics, in data sets recorded with higher pump intensities. As expected for pumping NO2 at 399 nm, non-adiabatic coupling was seen to rapidly re-populate the ground state following excitation to the first excited electronic state, within 200 fs. Subsequent intramolecular vibrational energy redistribution results in the spreading of the ground state vibrational wavepacket into the asymmetric stretch coordinate, allowing the wavepacket to explore nuclear geometries in the asymptotic region of the ground state potential energy surface. Signatures of the vibrationally "hot" ground state wavepacket were observed in the CRATI spectra at longer time delays. This study highlights the complex and sometimes competing phenomena that can arise in strong-field ionization probing of excited state molecular dynamics.
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Affiliation(s)
- Ruaridh Forbes
- Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT, United Kingdom
| | - Andrey E Boguslavskiy
- National Research Council of Canada, 100 Sussex Drive, Ottawa, Ontario K1A 0R6, Canada
| | - Iain Wilkinson
- National Research Council of Canada, 100 Sussex Drive, Ottawa, Ontario K1A 0R6, Canada
| | - Jonathan G Underwood
- Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT, United Kingdom
| | - Albert Stolow
- National Research Council of Canada, 100 Sussex Drive, Ottawa, Ontario K1A 0R6, Canada
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45
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Bunjac A, Popović DB, Simonović NS. Resonant dynamic Stark shift as a tool in strong-field quantum control: calculation and application for selective multiphoton ionization of sodium. Phys Chem Chem Phys 2017; 19:19829-19836. [PMID: 28718483 DOI: 10.1039/c7cp02146a] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A method for determining the resonant dynamic Stark shift (RDSS), based on wave-packet calculations of the populations of quantum states, is presented. It is almost insensitive to variations of the laser pulse profile, and this feature ensures generality in applications. This method is used to determine an RDSS data set for 3s → nl (n ≤ 6) transitions in sodium induced by laser pulses with peak intensities up to 7.9 × 1012 W cm-2 and wavelengths in the range from 455.6 to 1139 nm. The data are applied to analyze the photoelectron spectra (electron yield versus excess energy) of the sodium atom interacting with 800 nm laser radiation. Substructures observed in the experimentally measured spectra are successfully reproduced and related to the resonantly enhanced multiphoton ionization via specific (P and F) intermediate states.
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Affiliation(s)
- A Bunjac
- Institute of Physics, University of Belgrade, P.O. Box 57, 11001 Belgrade, Serbia.
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Jochim B, Siemering R, Zohrabi M, Voznyuk O, Mahowald JB, Schmitz DG, Betsch KJ, Berry B, Severt T, Kling NG, Burwitz TG, Carnes KD, Kling MF, Ben-Itzhak I, Wells E, de Vivie-Riedle R. The importance of Rydberg orbitals in dissociative ionization of small hydrocarbon molecules in intense laser fields. Sci Rep 2017; 7:4441. [PMID: 28667335 PMCID: PMC5493692 DOI: 10.1038/s41598-017-04638-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2017] [Accepted: 05/18/2017] [Indexed: 11/10/2022] Open
Abstract
Much of our intuition about strong-field processes is built upon studies of diatomic molecules, which typically have electronic states that are relatively well separated in energy. In polyatomic molecules, however, the electronic states are closer together, leading to more complex interactions. A combined experimental and theoretical investigation of strong-field ionization followed by hydrogen elimination in the hydrocarbon series C2D2, C2D4 and C2D6 reveals that the photofragment angular distributions can only be understood when the field-dressed orbitals rather than the field-free orbitals are considered. Our measured angular distributions and intensity dependence show that these field-dressed orbitals can have strong Rydberg character for certain orientations of the molecule relative to the laser polarization and that they may contribute significantly to the hydrogen elimination dissociative ionization yield. These findings suggest that Rydberg contributions to field-dressed orbitals should be routinely considered when studying polyatomic molecules in intense laser fields.
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Affiliation(s)
- Bethany Jochim
- J.R. Macdonald Laboratory, Department of Physics, Kansas State University, Manhattan, KS 66506, USA
| | - R Siemering
- Department für Chemie, Ludwig-Maximilians-Universität München, Butenandt-Strasse 11, D-81377, München, Germany
| | - M Zohrabi
- J.R. Macdonald Laboratory, Department of Physics, Kansas State University, Manhattan, KS 66506, USA
| | - O Voznyuk
- Department of Physics, Augustana University, Sioux Falls, SD 57197, USA
| | - J B Mahowald
- Department of Physics, Augustana University, Sioux Falls, SD 57197, USA
| | - D G Schmitz
- Department of Physics, Augustana University, Sioux Falls, SD 57197, USA
| | - K J Betsch
- J.R. Macdonald Laboratory, Department of Physics, Kansas State University, Manhattan, KS 66506, USA
| | - Ben Berry
- J.R. Macdonald Laboratory, Department of Physics, Kansas State University, Manhattan, KS 66506, USA
| | - T Severt
- J.R. Macdonald Laboratory, Department of Physics, Kansas State University, Manhattan, KS 66506, USA
| | - Nora G Kling
- J.R. Macdonald Laboratory, Department of Physics, Kansas State University, Manhattan, KS 66506, USA.,Department für Physik, Ludwig-Maximilians-Universität München, Am Coulombwall 1, D-85748, Garching, Germany
| | - T G Burwitz
- Department of Physics, Augustana University, Sioux Falls, SD 57197, USA
| | - K D Carnes
- J.R. Macdonald Laboratory, Department of Physics, Kansas State University, Manhattan, KS 66506, USA
| | - M F Kling
- J.R. Macdonald Laboratory, Department of Physics, Kansas State University, Manhattan, KS 66506, USA.,Department für Physik, Ludwig-Maximilians-Universität München, Am Coulombwall 1, D-85748, Garching, Germany
| | - I Ben-Itzhak
- J.R. Macdonald Laboratory, Department of Physics, Kansas State University, Manhattan, KS 66506, USA
| | - E Wells
- Department of Physics, Augustana University, Sioux Falls, SD 57197, USA.
| | - R de Vivie-Riedle
- Department für Chemie, Ludwig-Maximilians-Universität München, Butenandt-Strasse 11, D-81377, München, Germany.
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Mi Y, Camus N, Fechner L, Laux M, Moshammer R, Pfeifer T. Electron-Nuclear Coupling through Autoionizing States after Strong-Field Excitation of H_{2} Molecules. PHYSICAL REVIEW LETTERS 2017; 118:183201. [PMID: 28524692 DOI: 10.1103/physrevlett.118.183201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Indexed: 06/07/2023]
Abstract
Channel-selective electron emission from strong-field photoionization of H_{2} molecules is experimentally investigated by using ultrashort laser pulses and a reaction microscope. The electron momenta and energy spectra in coincidence with bound and dissociative ionization channels are compared. Surprisingly, we observed an enhancement of the photoelectron yield in the low-energy region for the bound ionization channel. By further investigation of asymmetrical electron emission using two-color laser pulses, this enhancement is understood as the population of the autoionizing states of H_{2} molecules in which vibrational energy is transferred to electronic energy. This general mechanism provides access to the vibrational-state distribution of molecular ions produced in a strong-field interaction.
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Affiliation(s)
- Yonghao Mi
- Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg, Germany
| | - Nicolas Camus
- Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg, Germany
| | - Lutz Fechner
- Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg, Germany
| | - Martin Laux
- Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg, Germany
| | - Robert Moshammer
- Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg, Germany
| | - Thomas Pfeifer
- Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg, Germany
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Gong X, Lin C, He F, Song Q, Lin K, Ji Q, Zhang W, Ma J, Lu P, Liu Y, Zeng H, Yang W, Wu J. Energy-Resolved Ultrashort Delays of Photoelectron Emission Clocked by Orthogonal Two-Color Laser Fields. PHYSICAL REVIEW LETTERS 2017; 118:143203. [PMID: 28430519 DOI: 10.1103/physrevlett.118.143203] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2016] [Indexed: 06/07/2023]
Abstract
A phase-controlled orthogonal two-color (OTC) femtosecond laser pulse is employed to probe the time delay of photoelectron emission in the strong-field ionization of atoms. The OTC field spatiotemporally steers the emission dynamics of the photoelectrons and meanwhile allows us to unambiguously distinguish the main and sideband peaks of the above-threshold ionization spectrum. The relative phase shift between the main and sideband peaks, retrieved from the phase-of-phase of the photoelectron spectrum as a function of the laser phase, gradually decreases with increasing electron energy, and becomes zero for the fast electron which is mainly produced by the rescattering process. Furthermore, a Freeman resonance delay of 140±40 attoseconds between photoelectrons emitted via the 4f and 5p Rydberg states of argon is observed.
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Affiliation(s)
- Xiaochun Gong
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200062, China
| | - Cheng Lin
- Department of Physics, College of Science, Shantou University, Shantou, Guangdong 515063, China
| | - Feng He
- Key Laboratory of Laser Plasmas (Ministry of Education) and Department of Physics and Astronomy, Collaborative Innovation Center for IFSA (CICIFSA), Shanghai Jiao Tong University, Shanghai 200240, China
| | - Qiying Song
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200062, China
| | - Kang Lin
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200062, China
| | - Qinying Ji
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200062, China
| | - Wenbin Zhang
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200062, China
| | - Junyang Ma
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200062, China
| | - Peifen Lu
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200062, China
| | - Yunquan Liu
- Department of Physics and State Key Laboratory for Mesoscopic Physics, Peking University, Beijing 100871, China
| | - Heping Zeng
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200062, China
| | - Weifeng Yang
- Department of Physics, College of Science, Shantou University, Shantou, Guangdong 515063, China
| | - Jian Wu
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200062, China
- Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan, Shanxi 030006, China
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Hüter O, Temps F. Note: Energy calibration of a femtosecond photoelectron imaging detector with correction for the ponderomotive shift of atomic ionization energies. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2017; 88:046101. [PMID: 28456263 DOI: 10.1063/1.4979799] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Femtosecond photoelectron imaging spectroscopy is a powerful technique for following state-resolved molecular transformations in complex coupled potential energy landscapes. To avoid unwanted nonlinear side-effects, the employed laser pulse energies are usually reduced to minimal values. However, the energy calibration of the photoelectron imaging detector is ideally performed using multi-photon above-threshold ionization of suitable atomic species, for which rather high laser intensities are required. In this work, we show that the calibration spectra of xenon obtained with high laser pulse energies cannot be directly used for the evaluation of molecular photoelectron spectra recorded using low-energy laser pulses. The reason is the intensity-dependent AC Stark shift of the atomic ionization energies to larger values, which in turn leads to a corresponding decrease of the photoelectron kinetic energies. We present a simple procedure to quantify this so-called ponderomotive shift and calculate the theoretically expected un-shifted photoelectron energies.
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Affiliation(s)
- O Hüter
- Institute of Physical Chemistry, Christian-Albrechts-University Kiel, Olshausenstr. 40, 24098 Kiel, Germany
| | - F Temps
- Institute of Physical Chemistry, Christian-Albrechts-University Kiel, Olshausenstr. 40, 24098 Kiel, Germany
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50
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Channel-specific photoelectron angular distribution in laboratory and molecular frames for dissociative ionization of methanol in intense ultraviolet laser fields. Chem Phys Lett 2017. [DOI: 10.1016/j.cplett.2017.01.043] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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