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V Grafenstein K, Foerster FM, Haberstroh F, Campbell D, Irshad F, Salgado FC, Schilling G, Travac E, Weiße N, Zepf M, Döpp A, Karsch S. Laser-accelerated electron beams at 1 GeV using optically-induced shock injection. Sci Rep 2023; 13:11680. [PMID: 37468564 DOI: 10.1038/s41598-023-38805-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Accepted: 07/14/2023] [Indexed: 07/21/2023] Open
Abstract
In recent years, significant progress has been made in laser wakefield acceleration (LWFA), both regarding the increase in electron energy, charge and stability as well as the reduction of bandwidth of electron bunches. Simultaneous optimization of these parameters is, however, still the subject of an ongoing effort in the community to reach sufficient beam quality for next generation's compact accelerators. In this report, we show the design of slit-shaped gas nozzles providing centimeter-long supersonic gas jets that can be used as targets for the acceleration of electrons to the GeV regime. In LWFA experiments at the Centre for Advanced Laser Applications, we show that electron bunches are accelerated to [Formula: see text] using these nozzles. The electron bunches were injected into the laser wakefield via a laser-machined density down-ramp using hydrodynamic optical-field-ionization and subsequent plasma expansion on a ns-timescale. This injection method provides highly controllable quasi-monoenergetic electron beams with high charge around [Formula: see text], low divergence of [Formula: see text], and a relatively small energy spread of around [Formula: see text] at [Formula: see text]. In contrast to capillaries and gas cells, the scheme allows full plasma access for injection, probing or guiding in order to further improve the energy and quality of LWFA beams.
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Affiliation(s)
- K V Grafenstein
- Ludwig-Maximilians-Universität München, Centre for Advanced Laser Applications, 85748, Garching, Germany.
| | - F M Foerster
- Ludwig-Maximilians-Universität München, Centre for Advanced Laser Applications, 85748, Garching, Germany
| | - F Haberstroh
- Ludwig-Maximilians-Universität München, Centre for Advanced Laser Applications, 85748, Garching, Germany
| | - D Campbell
- Ludwig-Maximilians-Universität München, Centre for Advanced Laser Applications, 85748, Garching, Germany
- Department of Physics, University of Strathclyde, Glasgow, G4 0NG, UK
| | - F Irshad
- Ludwig-Maximilians-Universität München, Centre for Advanced Laser Applications, 85748, Garching, Germany
| | - F C Salgado
- Friedrich-Schiller-Universität Jena, Institut für Optik und Quantenelektronik, 07743, Jena, Germany
- Helmholtz-Institut Jena, 07743, Jena, Germany
| | - G Schilling
- Ludwig-Maximilians-Universität München, Centre for Advanced Laser Applications, 85748, Garching, Germany
| | - E Travac
- Ludwig-Maximilians-Universität München, Centre for Advanced Laser Applications, 85748, Garching, Germany
| | - N Weiße
- Ludwig-Maximilians-Universität München, Centre for Advanced Laser Applications, 85748, Garching, Germany
| | - M Zepf
- Friedrich-Schiller-Universität Jena, Institut für Optik und Quantenelektronik, 07743, Jena, Germany
- Helmholtz-Institut Jena, 07743, Jena, Germany
| | - A Döpp
- Ludwig-Maximilians-Universität München, Centre for Advanced Laser Applications, 85748, Garching, Germany
- Max Planck Institut für Quantenoptik, 85748, Garching, Germany
| | - S Karsch
- Ludwig-Maximilians-Universität München, Centre for Advanced Laser Applications, 85748, Garching, Germany.
- Max Planck Institut für Quantenoptik, 85748, Garching, Germany.
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Lei Y, Shayeganrad G, Wang H, Sakakura M, Yu Y, Wang L, Kliukin D, Skuja L, Svirko Y, Kazansky PG. Efficient ultrafast laser writing with elliptical polarization. LIGHT, SCIENCE & APPLICATIONS 2023; 12:74. [PMID: 36918535 PMCID: PMC10015004 DOI: 10.1038/s41377-023-01098-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2022] [Revised: 01/27/2023] [Accepted: 02/06/2023] [Indexed: 05/25/2023]
Abstract
Photosensitivity in nature is commonly associated with stronger light absorption. It is also believed that artificial optical anisotropy to be the strongest when created by light with linear polarization. Contrary to intuition, ultrafast laser direct writing with elliptical polarization in silica glass, while nonlinear absorption is about 2.5 times weaker, results in form birefringence about twice that of linearly polarized light. Moreover, a larger concentration of anisotropic nanopores created by elliptically polarized light pulses is observed. The phenomenon is interpreted in terms of enhanced interaction of circularly polarized light with a network of randomly oriented bonds and hole polarons in silica glass, as well as efficient tunneling ionization produced by circular polarization. Applications to multiplexed optical data storage and birefringence patterning in silica glass are demonstrated.
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Affiliation(s)
- Yuhao Lei
- Optoelectronics Research Centre, University of Southampton, Southampton, SO17 1BJ, UK.
| | | | - Huijun Wang
- Optoelectronics Research Centre, University of Southampton, Southampton, SO17 1BJ, UK
| | - Masaaki Sakakura
- Optoelectronics Research Centre, University of Southampton, Southampton, SO17 1BJ, UK
| | - Yanhao Yu
- Optoelectronics Research Centre, University of Southampton, Southampton, SO17 1BJ, UK
| | - Lei Wang
- Optoelectronics Research Centre, University of Southampton, Southampton, SO17 1BJ, UK
| | - Dmitrii Kliukin
- Optoelectronics Research Centre, University of Southampton, Southampton, SO17 1BJ, UK
| | - Linards Skuja
- Institute of Solid State Physics, University of Latvia, 8 Kengaraga Strasse, Riga, LV-1063, Latvia
| | - Yuri Svirko
- Institute of Photonics, Department of Physics and Mathematics, University of Eastern Finland, FI-80101, Joensuu, Finland
| | - Peter G Kazansky
- Optoelectronics Research Centre, University of Southampton, Southampton, SO17 1BJ, UK.
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3
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López S, García A, Rueda D, Oliva E. 3D modelling of cavity-free lasing in nitrogen plasma filaments. OPTICS EXPRESS 2023; 31:8479-8493. [PMID: 36859962 DOI: 10.1364/oe.478100] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Accepted: 12/28/2022] [Indexed: 06/18/2023]
Abstract
In this article we show results on cavity-free lasing in nitrogen filaments using our 3D, time-dependent Maxwell-Bloch code, Dagon. This code was previously used to model plasma-based soft X-ray lasers and it has been adapted to model lasing in nitrogen plasma filaments. In order to assess the predictive capabilities of the code, we have conducted several benchmarks against experimental and 1D modelling results. Afterwards, we study the amplification of an externally seeded UV beam in nitrogen plasma filaments. Our results show that the phase of the amplified beam carries information about the temporal dynamics of amplification and collisional processes inside the plasma, along with information about the spatial structure of the amplified beam and the active region of the filament. We thus conclude that measuring the phase of an UV probe beam, in combination with 3D Maxwell-Bloch modelling, might be an excellent method for diagnosing electron density value and gradients, mean ionization, density of N2+ ions and the magnitude of collisional processes inside these filaments.
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4
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Xu K, Liu M, Arbab MH. Broadband terahertz time-domain polarimetry based on air plasma filament emissions and spinning electro-optic sampling in GaP. APPLIED PHYSICS LETTERS 2022; 120:181107. [PMID: 35539361 PMCID: PMC9068238 DOI: 10.1063/5.0087127] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Accepted: 04/19/2022] [Indexed: 05/25/2023]
Abstract
We report on a time-domain polarimetry (TDP) system for generating and detecting broadband terahertz (THz) waves of different polarization angles. We generate THz waves from two-color laser filaments and determine their polarization states with a detection bandwidth of up to 8 THz using a spinning gallium phosphide crystal. The polarization of THz emission can be controlled by adjusting the position and tilt angle of the β-barium borate crystal. We characterize the precision of this system for polarimetric measurements at fixed time delay to be 1.6 ° and 1.9 ° for complete time-domain waveforms. We also demonstrate the feasibility of our TDP system by measuring broadband optical properties of anisotropic samples in both transmission and reflection geometries. The THz-TDP technique can be easily integrated in conventional THz time-domain spectroscopy setups using nonlinear crystal detectors.
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Affiliation(s)
- Kuangyi Xu
- Department of Biomedical Engineering, State University of New York at Stony Brook, Stony Brook, New York 11794, USA
| | - Mengkun Liu
- Department of Physics and Astronomy, State University of New York at Stony Brook, Stony Brook, New York 11794, USA
| | - M. Hassan Arbab
- Department of Biomedical Engineering, State University of New York at Stony Brook, Stony Brook, New York 11794, USA
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5
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Sun S, Gu B, Mukamel S. Polariton ring currents and circular dichroism of Mg-porphyrin in a chiral cavity. Chem Sci 2022; 13:1037-1048. [PMID: 35211270 PMCID: PMC8790894 DOI: 10.1039/d1sc04341b] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2021] [Accepted: 12/21/2021] [Indexed: 01/17/2023] Open
Abstract
By placing Mg-porphyrin molecules in a chiral optical cavity, time reversal symmetry is broken, and polariton ring currents can be generated with linearly polarized light, resulting in a circular dichroism signal. Since the electronic state degeneracy in the molecule is lifted by the formation of chiral polaritons, this signal is one order of magnitude stronger than the bare molecule signal induced by circularly polarized light. Enantiomer-selective photochemical processes in chiral optical cavities is an intriguing future possibility. Placing aromatic molecules in a chiral optical cavity can break time-reversal symmetry and generate polariton ring currents with a linearly polarized pump. Such currents can be probed by circular dichroism, with one order of magnitude enhancement.![]()
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Affiliation(s)
- Shichao Sun
- Department of Chemistry and Department of Physics & Astronomy, University of California Irvine USA
| | - Bing Gu
- Department of Chemistry and Department of Physics & Astronomy, University of California Irvine USA
| | - Shaul Mukamel
- Department of Chemistry and Department of Physics & Astronomy, University of California Irvine USA
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6
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Xu QY, Yang ZJ, He YL, Gao FY, Lu HZ, Guo J. Ultrafast attosecond-magnetic-field generation of the charge migration process based on HeH 2+ and H 2 + electronically excited by circularly polarized laser pulses. OPTICS EXPRESS 2021; 29:32312-32324. [PMID: 34615305 DOI: 10.1364/oe.438264] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Accepted: 09/17/2021] [Indexed: 06/13/2023]
Abstract
The ultrafast process by the electron in molecular ions from one site or region to another that has come to be known as charge migration (CM), which is of fundamental importance to photon induced chemical or physical reactions. In this work, we study the electron current and ultrafast magnetic-field generation based on CM process of oriented asymmetric (HeH2+) and symmetric (H2 +) molecular ions. Calculated results show that they are ascribed to quantum interference of electronic states for these molecular ions under intense circularly polarized (CP) laser pulses. The two scenarios of (i) resonance excitation and (ii) direct ionization are considered through appropriately utilizing designed laser pulses. By comparison, the magnetic field induced by the scenario (i) is stronger than that of scenario (ii) for molecular ions. However, the scheme (ii) is very sensitive to the helicity of CP field, which is opposite to the scenario (i). Moreover, the magnetic field generated by H2 + is stronger than that by HeH2+ through scenario (i). Our findings provide a guiding principle for producing ultrafast magnetic fields in molecular systems for future research in ultrafast magneto-optics.
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7
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Symmetries and Selection Rules of the Spectra of Photoelectrons and High-Order Harmonics Generated by Field-Driven Atoms and Molecules. Symmetry (Basel) 2021. [DOI: 10.3390/sym13091566] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Using the strong-field approximation we systematically investigate the selection rules for high-order harmonic generation and the symmetry properties of the angle-resolved photoelectron spectra for various atomic and molecular targets exposed to one-component and two-component laser fields. These include bicircular fields and orthogonally polarized two-color fields. The selection rules are derived directly from the dynamical symmetries of the driving field. Alternatively, we demonstrate that they can be obtained using the conservation of the projection of the total angular momentum on the quantization axis. We discuss how the harmonic spectra of atomic targets depend on the type of the ground state or, for molecular targets, on the pertinent molecular orbital. In addition, we briefly discuss some properties of the high-order harmonic spectra generated by a few-cycle laser field. The symmetry properties of the angle-resolved photoelectron momentum distribution are also determined by the dynamical symmetry of the driving field. We consider the first two terms in a Born series expansion of the T matrix, which describe the direct and the rescattered electrons. Dynamical symmetries involving time translation generate rotational symmetries obeyed by both terms. However, those that involve time reversal generate reflection symmetries that are only observed by the direct electrons. Finally, we explain how the symmetry properties, imposed by the dynamical symmetry of the driving field, are altered for molecular targets.
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8
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Armstrong GSJ, Khokhlova MA, Labeye M, Maxwell AS, Pisanty E, Ruberti M. Dialogue on analytical and ab initio methods in attoscience. THE EUROPEAN PHYSICAL JOURNAL. D, ATOMIC, MOLECULAR, AND OPTICAL PHYSICS 2021; 75:209. [PMID: 34720730 PMCID: PMC8550504 DOI: 10.1140/epjd/s10053-021-00207-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Accepted: 06/18/2021] [Indexed: 06/13/2023]
Abstract
The perceived dichotomy between analytical and ab initio approaches to theory in attosecond science is often seen as a source of tension and misconceptions. This Topical Review compiles the discussions held during a round-table panel at the 'Quantum Battles in Attoscience' cecam virtual workshop, to explore the sources of tension and attempt to dispel them. We survey the main theoretical tools of attoscience-covering both analytical and numerical methods-and we examine common misconceptions, including the relationship between ab initio approaches and the broader numerical methods, as well as the role of numerical methods in 'analytical' techniques. We also evaluate the relative advantages and disadvantages of analytical as well as numerical and ab initio methods, together with their role in scientific discovery, told through the case studies of two representative attosecond processes: non-sequential double ionisation and resonant high-harmonic generation. We present the discussion in the form of a dialogue between two hypothetical theoreticians, a numericist and an analytician, who introduce and challenge the broader opinions expressed in the attoscience community.
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Affiliation(s)
- Gregory S. J. Armstrong
- Centre for Theoretical Atomic, Molecular, and Optical Physics, Queen’s University Belfast, Belfast, BT7 1NN UK
| | - Margarita A. Khokhlova
- Max Born Institute for Nonlinear Optics and Short Pulse Spectroscopy, Max-Born-Straße 2A, 12489 Berlin, Germany
- Department of Physics, Imperial College London, South Kensington Campus, London, SW7 2AZ UK
| | - Marie Labeye
- CNRS, PASTEUR, Département de chimie, Ecole Normale Supérieure, PSL University, Sorbonne Université, 75005 Paris, France
| | - Andrew S. Maxwell
- Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, 08860 Castelldefels (Barcelona), Spain
- 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
- Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, 08860 Castelldefels (Barcelona), Spain
| | - Marco Ruberti
- Department of Physics, Imperial College London, South Kensington Campus, London, SW7 2AZ UK
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9
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Hofmann C, Bray A, Koch W, Ni H, Shvetsov-Shilovski NI. Quantum battles in attoscience: tunnelling. THE EUROPEAN PHYSICAL JOURNAL. D, ATOMIC, MOLECULAR, AND OPTICAL PHYSICS 2021; 75:208. [PMID: 34720729 PMCID: PMC8550434 DOI: 10.1140/epjd/s10053-021-00224-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Accepted: 07/06/2021] [Indexed: 05/29/2023]
Abstract
ABSTRACT What is the nature of tunnelling? This yet unanswered question is as pertinent today as it was at the dawn of quantum mechanics. This article presents a cross section of current perspectives on the interpretation, computational modelling, and numerical investigation of tunnelling processes in attosecond physics as debated in the Quantum Battles in Attoscience virtual workshop 2020. GRAPHIC ABSTRACT
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Affiliation(s)
- Cornelia Hofmann
- Department of Physics and Astronomy, University College London, Gower Street, London, WC1E 6BT UK
| | - Alexander Bray
- Research School of Physics, The Australian National University, Canberra, ACT 0200 Australia
| | - Werner Koch
- Weizmann Institute of Science, Rehovot, Israel
| | - Hongcheng Ni
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai, 200241 China
- Institute for Theoretical Physics, Vienna University of Technology, 1040 Vienna, Austria
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10
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He T, Zhang Y, Zhao JJ, Wang X, Shen Z, Jin Z, Yan TM, Jiang Y. Third-order harmonic generation in a bi-chromatic elliptical laser field. OPTICS EXPRESS 2021; 29:21936-21946. [PMID: 34265969 DOI: 10.1364/oe.427232] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Accepted: 06/16/2021] [Indexed: 06/13/2023]
Abstract
The low-order harmonic generation induced by a strong laser field produces a bright, ultrashort, supercontinuum radiation ranging from the terahertz to ultraviolet band. By controlling the phase-delay and ellipticity of the bi-chromatic laser fields, the third harmonic generation is experimentally and theoretically investigated for elucidating the mechanism of the low-order harmonics. The third harmonic generation is found to be strongly suppressed in the counter-rotating bi-chromatic laser field due to the selection rule for harmonic emissions. The continuum-continuum transition in the strong field approximation is extended to explain the third harmonic generation as a function of the phase delay and ellipticity of the bi-chromatic laser fields. Compared with the semi-classical photocurrent model, the continuum-continuum transition on the basis of quantum-mechanical treatment achieves better agreement with the experimental observations. Our work indicates that the overlapping in continuum states via different quantum paths of a single electron plays a role in low-order harmonics generation under elliptical bi-chromatic laser fields.
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11
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Song Q, Yuan X, Hu S, Huang J, Zhong H, Lin Q, Wang H, Lu X, Zheng M, Cai Y, Zeng X, Xu S. Enhance terahertz radiation and its polarization- control with two paralleled filaments pumped by two-color femtosecond laser fields. OPTICS EXPRESS 2021; 29:22659-22666. [PMID: 34266024 DOI: 10.1364/oe.427896] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Accepted: 06/22/2021] [Indexed: 06/13/2023]
Abstract
We present experimentally an obvious enhancement of the terahertz (THz) radiation with two paralleled filaments pumped by two-color laser fields for a full use of a high laser power, compared with single filament. By mapping the 3-dimensional electric trajectories of generated THz fields with a (111) ZnTe crystal, we observe that the total THz polarization from two filaments can be manipulated by varying the time delay between the two orthogonally polarized pumps, which agrees well with the simulations under the photocurrent model. Notably, the power and spectrum of the THz field almost keep unchanged while manipulating the ellipticity of the THz polarization, which is important for a polarization-controllable THz source.
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12
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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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13
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Ellipticity of High-Order Harmonics Generated by Aligned Homonuclear Diatomic Molecules Exposed to an Orthogonal Two-Color Laser Field. PHOTONICS 2020. [DOI: 10.3390/photonics7040110] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
We investigate emission rate and ellipticity of high-order harmonics generated exposing a homonuclear diatomic molecule, aligned in the laser-field polarization plane, to a strong orthogonally polarized two-color (OTC) laser field. The linearly polarized OTC-field components have frequencies rω and sω, where r and s are integers. Using the molecular strong-field approximation with dressed initial state and undressed final state, we calculate the harmonic emission rate and harmonic ellipticity for frequency ratios 1:2 and 1:3. The obtained quantities depend strongly on the relative phase between the laser-field components. We show that with the OTC field it is possible to generate elliptically polarized high-energy harmonics with high emission rate. To estimate the relative phase for which the emission rate is maximal we use the simple man’s model. In the harmonic spectra as a function of the molecular orientation there are two types of minima, one connected with the symmetry of the molecular orbital and the other one due to destructive interference between different contributions to the recombination matrix element, where we take into account that the electron can be ionized and recombine at the same or different atomic centers. We derive a condition for the interference minima. These minima are blurred in the OTC field except in the cases where the highest occupied molecular orbital is modeled using only s or only p orbitals in the linear combination of the atomic orbitals. This allows us to use the interference minima to assess which atomic orbitals are dominant in a particular molecular orbital. Finally, we show that the harmonic ellipticity, presented in false colors in the molecular-orientation angle vs. harmonic-order plane, can be large in particular regions of this plane. These regions are bounded by the curves determined by the condition that the harmonic ellipticity is approximately zero, which is determined by the minima of the T-matrix contributions parallel and perpendicular to the fundamental component of the OTC field.
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14
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Jerigova M, Lorenc D, Velic D. Two-color symmetry breaking in laser-based secondary neutral mass spectrometry. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2020; 34:e8828. [PMID: 32396682 DOI: 10.1002/rcm.8828] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2019] [Revised: 04/06/2020] [Accepted: 05/07/2020] [Indexed: 06/11/2023]
Abstract
RATIONALE An alternative method of analysis for laser-based secondary neutral mass spectrometry is introduced. METHODS By mixing a fundamental 1240 nm wavelength of the near-infrared laser field with an intensity of 1 × 1015 W/cm2 with its second harmonic generation wavelength of 620 nm, control is attained over the ion yield in secondary neutral mass spectrometry for a native silver surface and a surface covered with silver nanoparticles. RESULTS The ion yields of selected species in the mass spectra, such as a C2 H4 O2 surfactant fragment ion and the Ag ion, are enhanced or suppressed by a factor of 8 or 23, respectively, in comparison with single color post-ionization. In addition, a significant suppression of ion fragmentation is demonstrated for both the silver sample and silver nanoparticles. Periodic variation of the ion yield with a modulation depth of 4% is observed depending upon the relative phase between the fundamental and second harmonic generated fields. These variations are explained in terms of tunneling ionization with symmetry-broken fields. CONCLUSIONS An additional degree of freedom in a form of additional second color is introduced in laser-based secondary neutral mass spectrometry. Ion yield control is extended in a form of symmetry-broken fields.
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Affiliation(s)
- Monika Jerigova
- International Laser Centre, Ilkovicova 3, Bratislava, 841 04, Slovakia
- Faculty of Natural Sciences, Comenius University, Ilkovicova 6, Bratislava, 842 15, Slovakia
| | - Dusan Lorenc
- International Laser Centre, Ilkovicova 3, Bratislava, 841 04, Slovakia
- Faculty of Natural Sciences, Comenius University, Ilkovicova 6, Bratislava, 842 15, Slovakia
| | - Dusan Velic
- International Laser Centre, Ilkovicova 3, Bratislava, 841 04, Slovakia
- Faculty of Natural Sciences, Comenius University, Ilkovicova 6, Bratislava, 842 15, Slovakia
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15
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Miao B, Feder L, Shrock JE, Goffin A, Milchberg HM. Optical Guiding in Meter-Scale Plasma Waveguides. PHYSICAL REVIEW LETTERS 2020; 125:074801. [PMID: 32857573 DOI: 10.1103/physrevlett.125.074801] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Revised: 07/05/2020] [Accepted: 07/20/2020] [Indexed: 06/11/2023]
Abstract
We demonstrate a new highly tunable technique for generating meter-scale low density plasma waveguides. Such guides can enable laser-driven electron acceleration to tens of GeV in a single stage. Plasma waveguides are imprinted in hydrogen gas by optical field ionization induced by two time-separated Bessel beam pulses: The first pulse, a J_{0} beam, generates the core of the waveguide, while the delayed second pulse, here a J_{8} or J_{16} beam, generates the waveguide cladding, enabling wide control of the guide's density, depth, and mode confinement. We demonstrate guiding of intense laser pulses over hundreds of Rayleigh lengths with on-axis plasma densities as low as N_{e0}∼5×10^{16} cm^{-3}.
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Affiliation(s)
- B Miao
- Institute for Research in Electronics and Applied Physics University of Maryland, College Park, Maryland 20742, USA
| | - L Feder
- Institute for Research in Electronics and Applied Physics University of Maryland, College Park, Maryland 20742, USA
| | - J E Shrock
- Institute for Research in Electronics and Applied Physics University of Maryland, College Park, Maryland 20742, USA
| | - A Goffin
- Institute for Research in Electronics and Applied Physics University of Maryland, College Park, Maryland 20742, USA
| | - H M Milchberg
- Institute for Research in Electronics and Applied Physics University of Maryland, College Park, Maryland 20742, USA
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16
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Setting the photoelectron clock through molecular alignment. Nat Commun 2020; 11:2546. [PMID: 32439923 PMCID: PMC7242449 DOI: 10.1038/s41467-020-16270-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Accepted: 04/16/2020] [Indexed: 11/09/2022] Open
Abstract
The interaction of strong laser fields with matter intrinsically provides a powerful tool for imaging transient dynamics with an extremely high spatiotemporal resolution. Here, we study strong-field ionisation of laser-aligned molecules, and show a full real-time picture of the photoelectron dynamics in the combined action of the laser field and the molecular interaction. We demonstrate that the molecule has a dramatic impact on the overall strong-field dynamics: it sets the clock for the emission of electrons with a given rescattering kinetic energy. This result represents a benchmark for the seminal statements of molecular-frame strong-field physics and has strong impact on the interpretation of self-diffraction experiments. Furthermore, the resulting encoding of the time-energy relation in molecular-frame photoelectron momentum distributions shows the way of probing the molecular potential in real-time, and accessing a deeper understanding of electron transport during strong-field interactions. Interaction of strong laser fields with matter provides powerful tools to image transient dynamics with high spatiotemporal resolution. The authors investigate strong-field ionisation of laser-aligned molecules showing the effect of molecular alignment on the photoelectron dynamics and the resulting influence of the molecular frame in imaging experiments.
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17
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Atomic, Molecular and Cluster Science with the Reaction Microscope Endstation at FLASH2. APPLIED SCIENCES-BASEL 2020. [DOI: 10.3390/app10082953] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The reaction microscope (REMI) endstation for atomic and molecular science at the free-electron laser FLASH2 at DESY in Hamburg is presented together with a brief overview of results recently obtained. The REMI allows coincident detection of electrons and ions that emerge from atomic or molecular fragmentation reactions in the focus of the extreme-ultraviolet (XUV) free-electron laser (FEL) beam. A large variety of target species ranging from atoms and molecules to small clusters can be injected with a supersonic gas-jet into the FEL focus. Their ionization and fragmentation dynamics can be studied either under single pulse conditions, or for double pulses as a function of their time delay by means of FEL-pump–FEL-probe schemes and also in combination with a femtosecond infrared (IR) laser. In a recent upgrade, the endstation was further extended by a light source based on high harmonic generation (HHG), which is now available for upcoming FEL/HHG pump–probe experiments.
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18
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Brennecke S, Eicke N, Lein M. Gouy's Phase Anomaly in Electron Waves Produced by Strong-Field Ionization. PHYSICAL REVIEW LETTERS 2020; 124:153202. [PMID: 32357055 DOI: 10.1103/physrevlett.124.153202] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2019] [Revised: 03/17/2020] [Accepted: 03/31/2020] [Indexed: 06/11/2023]
Abstract
Ionization of atoms by strong laser fields produces photoelectron momentum distributions that exhibit modulations due to the interference of outgoing electron trajectories. For a faithful modeling, it is essential to include previously overlooked phase shifts occurring when trajectories pass through focal points. Such phase shifts are known as Gouy's phase anomaly in optics or as Maslov phases in semiclassical theory. Because of Coulomb focusing in three dimensions, one out of two trajectories in photoelectron holography goes through a focal point as it crosses the symmetry axis in momentum space. In addition, there exist observable Maslov phases already in two dimensions. Clustering algorithms enable us to implement a semiclassical model with the correct preexponential factor that affects both the weight and the phase of each trajectory. We also derive a simple rule to relate two-dimensional and three-dimensional models for linear polarization. It explains the shifted interference fringes and weaker high-energy yield in three dimensions. The results are in excellent agreement with solutions of the time-dependent Schrödinger equation.
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Affiliation(s)
- Simon Brennecke
- Leibniz Universität Hannover, Institut für Theoretische Physik, Appelstraße 2, 30167 Hannover, Germany
| | - Nicolas Eicke
- Leibniz Universität Hannover, Institut für Theoretische Physik, Appelstraße 2, 30167 Hannover, Germany
| | - Manfred Lein
- Leibniz Universität Hannover, Institut für Theoretische Physik, Appelstraße 2, 30167 Hannover, Germany
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19
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Ma Y, Seipt D, Hussein AE, Hakimi S, Beier NF, Hansen SB, Hinojosa J, Maksimchuk A, Nees J, Krushelnick K, Thomas AGR, Dollar F. Polarization-Dependent Self-Injection by Above Threshold Ionization Heating in a Laser Wakefield Accelerator. PHYSICAL REVIEW LETTERS 2020; 124:114801. [PMID: 32242688 DOI: 10.1103/physrevlett.124.114801] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2019] [Revised: 12/20/2019] [Accepted: 02/20/2020] [Indexed: 06/11/2023]
Abstract
We report on the experimental observation of a decreased self-injection threshold by using laser pulses with circular polarization in laser wakefield acceleration experiments in a nonpreformed plasma, compared to the usually employed linear polarization. A significantly higher electron beam charge was also observed for circular polarization compared to linear polarization over a wide range of parameters. Theoretical analysis and quasi-3D particle-in-cell simulations reveal that the self-injection and hence the laser wakefield acceleration is polarization dependent and indicate a different injection mechanism for circularly polarized laser pulses, originating from larger momentum gain by electrons during above threshold ionization. This enables electrons to meet the trapping condition more easily, and the resulting higher plasma temperature was confirmed via spectroscopy of the XUV plasma emission.
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Affiliation(s)
- Y Ma
- Gérard Mourou Center for Ultrafast Optical Science, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - D Seipt
- Gérard Mourou Center for Ultrafast Optical Science, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - A E Hussein
- Gérard Mourou Center for Ultrafast Optical Science, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - S Hakimi
- Department of Physics and Astronomy, University of California, Irvine, California 92697, USA
| | - N F Beier
- Department of Physics and Astronomy, University of California, Irvine, California 92697, USA
| | - S B Hansen
- Sandia National Laboratories, Albuquerque, New Mexico 87185, USA
| | - J Hinojosa
- Gérard Mourou Center for Ultrafast Optical Science, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - A Maksimchuk
- Gérard Mourou Center for Ultrafast Optical Science, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - J Nees
- Gérard Mourou Center for Ultrafast Optical Science, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - K Krushelnick
- Gérard Mourou Center for Ultrafast Optical Science, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - A G R Thomas
- Gérard Mourou Center for Ultrafast Optical Science, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - F Dollar
- Department of Physics and Astronomy, University of California, Irvine, California 92697, USA
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20
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Danylo R, Zhang X, Fan Z, Zhou D, Lu Q, Zhou B, Liang Q, Zhuang S, Houard A, Mysyrowicz A, Oliva E, Liu Y. Formation Dynamics of Excited Neutral Nitrogen Molecules inside Femtosecond Laser Filaments. PHYSICAL REVIEW LETTERS 2019; 123:243203. [PMID: 31922877 DOI: 10.1103/physrevlett.123.243203] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2019] [Indexed: 06/10/2023]
Abstract
Nitrogen molecules are promoted to excited neutral states during femtosecond laser pulse filamentary propagation in atmosphere, leading to a characteristic UV fluorescence. Using a laser-induced fluorescence depletion technique, we measure the formation dynamics of these excited neutral nitrogen molecules with femtosecond time resolution. We find that the excited neutral molecules are formed in an unexpected ultrafast timescale of ∼4 ps at 1 bar and ∼120 ps at 30 mbar pressure. From this observation we deduce that the excitation of neutral N_{2} occurs via multiple collisions with hot free electrons. Numerical simulations based on rate equations reproduce well this ultrafast formation time and its dependence on gas pressure, and thus support this interpretation.
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Affiliation(s)
- Rostyslav Danylo
- Engineering Research Center of Optical Instrument and System, The Ministry of Education; Shanghai Key Lab of Modern Optical System, University of Shanghai for Science and Technology, 516, Jungong Road, 200093 Shanghai, China
| | - Xiang Zhang
- Engineering Research Center of Optical Instrument and System, The Ministry of Education; Shanghai Key Lab of Modern Optical System, University of Shanghai for Science and Technology, 516, Jungong Road, 200093 Shanghai, China
| | - Zhengquan Fan
- Engineering Research Center of Optical Instrument and System, The Ministry of Education; Shanghai Key Lab of Modern Optical System, University of Shanghai for Science and Technology, 516, Jungong Road, 200093 Shanghai, China
| | - Dongjie Zhou
- Engineering Research Center of Optical Instrument and System, The Ministry of Education; Shanghai Key Lab of Modern Optical System, University of Shanghai for Science and Technology, 516, Jungong Road, 200093 Shanghai, China
| | - Qi Lu
- Engineering Research Center of Optical Instrument and System, The Ministry of Education; Shanghai Key Lab of Modern Optical System, University of Shanghai for Science and Technology, 516, Jungong Road, 200093 Shanghai, China
| | - Bin Zhou
- Engineering Research Center of Optical Instrument and System, The Ministry of Education; Shanghai Key Lab of Modern Optical System, University of Shanghai for Science and Technology, 516, Jungong Road, 200093 Shanghai, China
| | - Qingqing Liang
- Engineering Research Center of Optical Instrument and System, The Ministry of Education; Shanghai Key Lab of Modern Optical System, University of Shanghai for Science and Technology, 516, Jungong Road, 200093 Shanghai, China
| | - Songlin Zhuang
- Engineering Research Center of Optical Instrument and System, The Ministry of Education; Shanghai Key Lab of Modern Optical System, University of Shanghai for Science and Technology, 516, Jungong Road, 200093 Shanghai, China
| | - Aurélien Houard
- Laboratoire d'Optique Appliquée, ENSTA Paris, Ecole Polytechnique, CNRS, Institut Polytechnique de Paris, 828 Boulevard des Maréchaux, 91762 Palaiseau cedex, France
| | - André Mysyrowicz
- Laboratoire d'Optique Appliquée, ENSTA Paris, Ecole Polytechnique, CNRS, Institut Polytechnique de Paris, 828 Boulevard des Maréchaux, 91762 Palaiseau cedex, France
| | - Eduardo Oliva
- Departamento de Ingeniería Energética, ETSI Industriales, Universidad Politécnica de Madrid, E-28006 Madrid, Spain
- Instituto de Fusión Nuclear "Guillermo Velarde", Universidad Politécnica de Madrid, 28006 Madrid, Spain
| | - Yi Liu
- Engineering Research Center of Optical Instrument and System, The Ministry of Education; Shanghai Key Lab of Modern Optical System, University of Shanghai for Science and Technology, 516, Jungong Road, 200093 Shanghai, China
- Laboratoire d'Optique Appliquée, ENSTA Paris, Ecole Polytechnique, CNRS, Institut Polytechnique de Paris, 828 Boulevard des Maréchaux, 91762 Palaiseau cedex, France
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21
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Amini K, Biegert J, Calegari F, Chacón A, Ciappina MF, Dauphin A, Efimov DK, Figueira de Morisson Faria C, Giergiel K, Gniewek P, Landsman AS, Lesiuk M, Mandrysz M, Maxwell AS, Moszyński R, Ortmann L, Antonio Pérez-Hernández J, Picón A, Pisanty E, Prauzner-Bechcicki J, Sacha K, Suárez N, Zaïr A, Zakrzewski J, Lewenstein M. Symphony on strong field approximation. REPORTS ON PROGRESS IN PHYSICS. PHYSICAL SOCIETY (GREAT BRITAIN) 2019; 82:116001. [PMID: 31226696 DOI: 10.1088/1361-6633/ab2bb1] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
This paper has been prepared by the Symphony collaboration (University of Warsaw, Uniwersytet Jagielloński, DESY/CNR and ICFO) on the occasion of the 25th anniversary of the 'simple man's models' which underlie most of the phenomena that occur when intense ultrashort laser pulses interact with matter. The phenomena in question include high-harmonic generation (HHG), above-threshold ionization (ATI), and non-sequential multielectron ionization (NSMI). 'Simple man's models' provide both an intuitive basis for understanding the numerical solutions of the time-dependent Schrödinger equation and the motivation for the powerful analytic approximations generally known as the strong field approximation (SFA). In this paper we first review the SFA in the form developed by us in the last 25 years. In this approach the SFA is a method to solve the TDSE, in which the non-perturbative interactions are described by including continuum-continuum interactions in a systematic perturbation-like theory. In this review we focus on recent applications of the SFA to HHG, ATI and NSMI from multi-electron atoms and from multi-atom molecules. The main novel part of the presented theory concerns generalizations of the SFA to: (i) time-dependent treatment of two-electron atoms, allowing for studies of an interplay between electron impact ionization and resonant excitation with subsequent ionization; (ii) time-dependent treatment in the single active electron approximation of 'large' molecules and targets which are themselves undergoing dynamics during the HHG or ATI processes. In particular, we formulate the general expressions for the case of arbitrary molecules, combining input from quantum chemistry and quantum dynamics. We formulate also theory of time-dependent separable molecular potentials to model analytically the dynamics of realistic electronic wave packets for molecules in strong laser fields. We dedicate this work to the memory of Bertrand Carré, who passed away in March 2018 at the age of 60.
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Affiliation(s)
- Kasra Amini
- Faculty of Chemistry, University of Warsaw, Pasteura 1, 02-093 Warsaw, Poland. ICFO-Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, 08860 Castelldefels (Barcelona), Spain
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22
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23
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Zhang C, Huang CK, Marsh KA, Clayton CE, Mori WB, Joshi C. Ultrafast optical field-ionized gases-A laboratory platform for studying kinetic plasma instabilities. SCIENCE ADVANCES 2019; 5:eaax4545. [PMID: 32047856 PMCID: PMC6984967 DOI: 10.1126/sciadv.aax4545] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/25/2019] [Accepted: 08/02/2019] [Indexed: 06/10/2023]
Abstract
Kinetic instabilities arising from anisotropic electron velocity distributions are ubiquitous in ionospheric, cosmic, and terrestrial plasmas, yet there are only a handful of experiments that purport to validate their theory. It is known that optical field ionization of atoms using ultrashort laser pulses can generate plasmas with known anisotropic electron velocity distributions. Here, we show that following the ionization but before collisions thermalize the electrons, the plasma undergoes two-stream, filamentation, and Weibel instabilities that isotropize the electron distributions. The polarization-dependent frequency and growth rates of these kinetic instabilities, measured using Thomson scattering of a probe laser, agree well with the kinetic theory and simulations. Thus, we have demonstrated an easily deployable laboratory platform for studying kinetic instabilities in plasmas.
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Affiliation(s)
- Chaojie Zhang
- Department of Electrical and Computer Engineering, University of California Los Angeles, Los Angeles, CA 90095, USA
| | - Chen-Kang Huang
- Department of Electrical and Computer Engineering, University of California Los Angeles, Los Angeles, CA 90095, USA
| | - Ken A. Marsh
- Department of Electrical and Computer Engineering, University of California Los Angeles, Los Angeles, CA 90095, USA
| | - Chris E. Clayton
- Department of Electrical and Computer Engineering, University of California Los Angeles, Los Angeles, CA 90095, USA
| | - Warren B. Mori
- Department of Electrical and Computer Engineering, University of California Los Angeles, Los Angeles, CA 90095, USA
- Department of Physics and Astronomy, University of California Los Angeles, Los Angeles, CA 90095, USA
| | - Chan Joshi
- Department of Electrical and Computer Engineering, University of California Los Angeles, Los Angeles, CA 90095, USA
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24
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Akagi H, Otobe T, Itakura R. Deformation of an inner valence molecular orbital in ethanol by an intense laser field. SCIENCE ADVANCES 2019; 5:eaaw1885. [PMID: 31114805 PMCID: PMC6524975 DOI: 10.1126/sciadv.aaw1885] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Accepted: 04/02/2019] [Indexed: 06/09/2023]
Abstract
Valence molecular orbitals play a crucial role in chemical reactions. Here, we reveal that an intense laser field deforms an inner valence orbital (10a') in the ethanol molecule. We measure the recoil-frame photoelectron angular distribution (RFPAD), which corresponds to the orientation dependence of the ionization probability of the orbital, using photoelectron-photoion coincidence momentum imaging with a circularly polarized laser pulse. Ab initio simulations show that the orbital deformation depends strongly on the laser field direction and that the measured RFPAD cannot be reproduced without taking the orbital deformation into account. Our findings suggest that the laser-induced orbital deformation occurs before electron emission on a suboptical cycle time scale.
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25
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Dnestryan AI, Tolstikhin OI, Madsen LB, Jensen F. Structure factors for tunneling ionization rates of molecules: General grid-based methodology and convergence studies. J Chem Phys 2018; 149:164107. [DOI: 10.1063/1.5046902] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Andrey I. Dnestryan
- Moscow Institute of Physics and Technology, Dolgoprudny 141700, Russia
- National Research University Higher School of Economics, Moscow 101000, Russia
| | | | - Lars Bojer Madsen
- Department of Physics and Astronomy, Aarhus University, 8000 Aarhus C, Denmark
| | - Frank Jensen
- Department of Chemistry, Aarhus University, 8000 Aarhus C, Denmark
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26
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Eckart S, Fehre K, Eicke N, Hartung A, Rist J, Trabert D, Strenger N, Pier A, Schmidt LPH, Jahnke T, Schöffler MS, Lein M, Kunitski M, Dörner R. Direct Experimental Access to the Nonadiabatic Initial Momentum Offset upon Tunnel Ionization. PHYSICAL REVIEW LETTERS 2018; 121:163202. [PMID: 30387676 DOI: 10.1103/physrevlett.121.163202] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2018] [Revised: 08/16/2018] [Indexed: 06/08/2023]
Abstract
We report on the nonadiabatic offset of the initial electron momentum distribution in the plane of polarization upon single ionization of argon by strong field tunneling and show how to experimentally control the degree of nonadiabaticity. Two-color counter- and corotating fields (390 and 780 nm) are compared to show that the nonadiabatic offset strongly depends on the temporal evolution of the laser electric field. We introduce a simple method for the direct access to the nonadiabatic offset using two-color counter- and corotating fields. Further, for a single-color circularly polarized field at 780 nm, we show that the radius of the experimentally observed donutlike distribution increases for increasing momentum in the light propagation direction. Our observed initial momentum offsets are well reproduced by the strong-field approximation. A mechanistic picture is introduced that links the measured nonadiabatic offset to the magnetic quantum number of virtually populated intermediate states.
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Affiliation(s)
- S Eckart
- Institut für Kernphysik, Goethe-Universität, Max-von-Laue-Str. 1, 60438 Frankfurt, Germany
| | - K Fehre
- Institut für Kernphysik, Goethe-Universität, Max-von-Laue-Str. 1, 60438 Frankfurt, Germany
| | - N Eicke
- Institut für Theoretische Physik, Leibniz Universität Hannover, Appelstr. 2, 30167 Hannover, Germany
| | - A Hartung
- Institut für Kernphysik, Goethe-Universität, Max-von-Laue-Str. 1, 60438 Frankfurt, Germany
| | - J Rist
- Institut für Kernphysik, Goethe-Universität, Max-von-Laue-Str. 1, 60438 Frankfurt, Germany
| | - D Trabert
- Institut für Kernphysik, Goethe-Universität, Max-von-Laue-Str. 1, 60438 Frankfurt, Germany
| | - N Strenger
- Institut für Kernphysik, Goethe-Universität, Max-von-Laue-Str. 1, 60438 Frankfurt, Germany
| | - A Pier
- Institut für Kernphysik, Goethe-Universität, Max-von-Laue-Str. 1, 60438 Frankfurt, Germany
| | - L Ph H Schmidt
- Institut für Kernphysik, Goethe-Universität, Max-von-Laue-Str. 1, 60438 Frankfurt, Germany
| | - T Jahnke
- Institut für Kernphysik, Goethe-Universität, Max-von-Laue-Str. 1, 60438 Frankfurt, Germany
| | - M S Schöffler
- Institut für Kernphysik, Goethe-Universität, Max-von-Laue-Str. 1, 60438 Frankfurt, Germany
| | - M Lein
- Institut für Theoretische Physik, Leibniz Universität Hannover, Appelstr. 2, 30167 Hannover, Germany
| | - M Kunitski
- Institut für Kernphysik, Goethe-Universität, Max-von-Laue-Str. 1, 60438 Frankfurt, Germany
| | - R Dörner
- Institut für Kernphysik, Goethe-Universität, Max-von-Laue-Str. 1, 60438 Frankfurt, Germany
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27
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Ultrafast Dynamics of High-Harmonic Generation in Terms of Complex Floquet Spectral Analysis. Symmetry (Basel) 2018. [DOI: 10.3390/sym10080313] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
We studied the high-harmonic generation (HHG) of a two-level-system (TLS) driven by an intense monochromatic phase-locked laser based on complex spectral analysis with the Floquet method. In contrast with phenomenological approaches, this analysis deals with the whole process as a coherent quantum process based on microscopic dynamics. We have obtained the time-frequency resolved spectrum of spontaneous HHG single-photon emission from an excited TLS driven by a laser field. Characteristic spectral features of the HHG, such as the plateau and cutoff, are reproduced by the present model. Because the emitted high-harmonic photon is represented as a superposition of different frequencies, the Fano profile appears in the long-time spectrum as a result of the quantum interference of the emitted photon. We reveal that the condition of the quantum interference depends on the initial phase of the driving laser field. We have also clarified that the change in spectral features from the short-time regime to the long-time regime is attributed to the interference between the interference from the Floquet resonance states and the dressed radiation field.
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28
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Shalloo RJ, Arran C, Corner L, Holloway J, Jonnerby J, Walczak R, Milchberg HM, Hooker SM. Hydrodynamic optical-field-ionized plasma channels. Phys Rev E 2018; 97:053203. [PMID: 29906935 DOI: 10.1103/physreve.97.053203] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2018] [Indexed: 11/07/2022]
Abstract
We present experiments and numerical simulations which demonstrate that fully ionized, low-density plasma channels could be formed by hydrodynamic expansion of plasma columns produced by optical field ionization. Simulations of the hydrodynamic expansion of plasma columns formed in hydrogen by an axicon lens show the generation of 200 mm long plasma channels with axial densities of order n_{e}(0)=1×10^{17}cm^{-3} and lowest-order modes of spot size W_{M}≈40μm. These simulations show that the laser energy required to generate the channels is modest: of order 1 mJ per centimeter of channel. The simulations are confirmed by experiments with a spherical lens which show the formation of short plasma channels with 1.5×10^{17}cm^{-3}≲n_{e}(0)≲1×10^{18}cm^{-3} and 61μm≳W_{M}≳33μm. Low-density plasma channels of this type would appear to be well suited as multi-GeV laser-plasma accelerator stages capable of long-term operation at high pulse repetition rates.
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Affiliation(s)
- R J Shalloo
- John Adams Institute for Accelerator Science and Department of Physics, University of Oxford, Denys Wilkinson Building, Keble Road, Oxford OX1 3RH, United Kingdom
| | - C Arran
- John Adams Institute for Accelerator Science and Department of Physics, University of Oxford, Denys Wilkinson Building, Keble Road, Oxford OX1 3RH, United Kingdom
| | - L Corner
- John Adams Institute for Accelerator Science and Department of Physics, University of Oxford, Denys Wilkinson Building, Keble Road, Oxford OX1 3RH, United Kingdom
| | - J Holloway
- John Adams Institute for Accelerator Science and Department of Physics, University of Oxford, Denys Wilkinson Building, Keble Road, Oxford OX1 3RH, United Kingdom
| | - J Jonnerby
- John Adams Institute for Accelerator Science and Department of Physics, University of Oxford, Denys Wilkinson Building, Keble Road, Oxford OX1 3RH, United Kingdom
| | - R Walczak
- John Adams Institute for Accelerator Science and Department of Physics, University of Oxford, Denys Wilkinson Building, Keble Road, Oxford OX1 3RH, United Kingdom
| | - H M Milchberg
- Institute for Research in Electronics and Applied Physics, University of Maryland, College Park, Maryland 20742, USA
| | - S M Hooker
- John Adams Institute for Accelerator Science and Department of Physics, University of Oxford, Denys Wilkinson Building, Keble Road, Oxford OX1 3RH, United Kingdom
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Tag El-Din Kamal M, Sedik EWS, Talaat H. Variation of the Intersection Point of the Potential Surface Crossing Induced by the Laser Phase Along the Reaction Path in Ion-Molecule Reactions: Application To Li+ + CH4. J STRUCT CHEM+ 2018. [DOI: 10.1134/s0022476618010043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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30
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Xie X, Wang T, Yu S, Lai X, Roither S, Kartashov D, Baltuška A, Liu X, Staudte A, Kitzler M. Disentangling Intracycle Interferences in Photoelectron Momentum Distributions Using Orthogonal Two-Color Laser Fields. PHYSICAL REVIEW LETTERS 2017; 119:243201. [PMID: 29286743 DOI: 10.1103/physrevlett.119.243201] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2017] [Indexed: 06/07/2023]
Abstract
We use orthogonally polarized two-color (OTC) laser pulses to separate quantum paths in the multiphoton ionization of Ar atoms. Our OTC pulses consist of 400 and 800 nm light at a relative intensity ratio of 10∶1. We find a hitherto unobserved interference in the photoelectron momentum distribution, which exhibits a strong dependence on the relative phase of the OTC pulse. Analysis of model calculations reveals that the interference is caused by quantum pathways from nonadjacent quarter cycles.
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Affiliation(s)
- Xinhua Xie
- Photonics Institute, Technische Universität Wien, 1040 Vienna, Austria
| | - Tian Wang
- Joint Laboratory for Attosecond Science of the National Research Council and the University of Ottawa, Ottawa, Ontario K1A 0R6, Canada
| | - ShaoGang Yu
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, China
| | - XuanYang Lai
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, China
| | - Stefan Roither
- Photonics Institute, Technische Universität Wien, 1040 Vienna, Austria
| | - Daniil Kartashov
- Photonics Institute, Technische Universität Wien, 1040 Vienna, Austria
| | - Andrius Baltuška
- Photonics Institute, Technische Universität Wien, 1040 Vienna, Austria
| | - XiaoJun Liu
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, China
| | - André Staudte
- Joint Laboratory for Attosecond Science of the National Research Council and the University of Ottawa, Ottawa, Ontario K1A 0R6, Canada
| | - Markus Kitzler
- Photonics Institute, Technische Universität Wien, 1040 Vienna, Austria
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31
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Martiskainen H, Moiseyev N. Adiabatic perturbation theory for atoms and molecules in the low-frequency regime. J Chem Phys 2017; 147:224101. [DOI: 10.1063/1.5001866] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Affiliation(s)
- Hanna Martiskainen
- Physics Department, Technion–Israel Institute of Technology, Haifa 32000, Israel
| | - Nimrod Moiseyev
- Physics Department, Technion–Israel Institute of Technology, Haifa 32000, Israel
- Schulich Faculty of Chemistry, Technion–Israel Institute of Technology, Haifa 32000, Israel
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32
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Nisoli M, Decleva P, Calegari F, Palacios A, Martín F. Attosecond Electron Dynamics in Molecules. Chem Rev 2017; 117:10760-10825. [DOI: 10.1021/acs.chemrev.6b00453] [Citation(s) in RCA: 261] [Impact Index Per Article: 37.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Affiliation(s)
- Mauro Nisoli
- Department
of Physics, Politecnico di Milano, 20133 Milano, Italy
- Institute for Photonics and Nanotechnologies, IFN-CNR, 20133 Milano, Italy
| | - Piero Decleva
- Dipartimento
di Scienze Chimiche e Farmaceutiche, Universitá di Trieste and IOM- CNR, 34127 Trieste, Italy
| | - Francesca Calegari
- Institute for Photonics and Nanotechnologies, IFN-CNR, 20133 Milano, Italy
- Center for Free-Electron Laser Science, DESY, 22607 Hamburg, Germany
- Department
of Physics, University of Hamburg, 20355 Hamburg, Germany
| | - Alicia Palacios
- Departamento
de Química, Módulo 13, Universidad Autónoma de Madrid, 28049 Madrid, Spain
| | - Fernando Martín
- Departamento
de Química, Módulo 13, Universidad Autónoma de Madrid, 28049 Madrid, Spain
- Instituto Madrileño de Estudios Avanzados en Nanociencia, 28049 Madrid, Spain
- Condensed
Matter Physics Center (IFIMAC), Universidad Autónoma de Madrid, 28049 Madrid, Spain
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33
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Chelkowski S, Bandrauk AD. Photon momentum transfer in photoionisation: unexpected breakdown of the dipole approximation. Mol Phys 2017. [DOI: 10.1080/00268976.2017.1321155] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
- Szczepan Chelkowski
- Département de Chimie, Faculté des Sciences, Université de Sherbrooke , Sherbrooke, Canada
| | - André D. Bandrauk
- Département de Chimie, Faculté des Sciences, Université de Sherbrooke , Sherbrooke, Canada
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34
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Talaat H, Sedik EWS, Tag El-Din Kamal M. Variation of potential energy surface height and bound state depth induced by laser phase along the reaction path in atom-molecule reactions: Application to Li + CH4 → LiH + CH3. RUSSIAN JOURNAL OF PHYSICAL CHEMISTRY B 2017. [DOI: 10.1134/s1990793117010122] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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35
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Schütte B, Ye P, Patchkovskii S, Austin DR, Brahms C, Strüber C, Witting T, Ivanov MY, Tisch JWG, Marangos JP. Strong-field ionization of clusters using two-cycle pulses at 1.8 μm. Sci Rep 2016; 6:39664. [PMID: 28009012 PMCID: PMC5180105 DOI: 10.1038/srep39664] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2016] [Accepted: 11/24/2016] [Indexed: 11/23/2022] Open
Abstract
The interaction of intense laser pulses with nanoscale particles leads to the production of high-energy electrons, ions, neutral atoms, neutrons and photons. Up to now, investigations have focused on near-infrared to X-ray laser pulses consisting of many optical cycles. Here we study strong-field ionization of rare-gas clusters (103 to 105 atoms) using two-cycle 1.8 μm laser pulses to access a new interaction regime in the limit where the electron dynamics are dominated by the laser field and the cluster atoms do not have time to move significantly. The emission of fast electrons with kinetic energies exceeding 3 keV is observed using laser pulses with a wavelength of 1.8 μm and an intensity of 1 × 1015 W/cm2, whereas only electrons below 500 eV are observed at 800 nm using a similar intensity and pulse duration. Fast electrons are preferentially emitted along the laser polarization direction, showing that they are driven out from the cluster by the laser field. In addition to direct electron emission, an electron rescattering plateau is observed. Scaling to even longer wavelengths is expected to result in a highly directional current of energetic electrons on a few-femtosecond timescale.
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Affiliation(s)
- Bernd Schütte
- Department of Physics, Imperial College London, South Kensington Campus, London SW7 2AZ, UK
| | - Peng Ye
- Department of Physics, Imperial College London, South Kensington Campus, London SW7 2AZ, UK
| | | | - Dane R. Austin
- Department of Physics, Imperial College London, South Kensington Campus, London SW7 2AZ, UK
| | - Christian Brahms
- Department of Physics, Imperial College London, South Kensington Campus, London SW7 2AZ, UK
| | - Christian Strüber
- Department of Physics, Imperial College London, South Kensington Campus, London SW7 2AZ, UK
| | - Tobias Witting
- Department of Physics, Imperial College London, South Kensington Campus, London SW7 2AZ, UK
| | - Misha Yu. Ivanov
- Department of Physics, Imperial College London, South Kensington Campus, London SW7 2AZ, UK
- Max-Born-Institut, Max-Born-Strasse 2A, 12489 Berlin, Germany
| | - John W. G. Tisch
- Department of Physics, Imperial College London, South Kensington Campus, London SW7 2AZ, UK
| | - Jon P. Marangos
- Department of Physics, Imperial College London, South Kensington Campus, London SW7 2AZ, UK
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36
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Xiao XR, Wang MX, Xiong WH, Peng LY. Efficient time-sampling method in Coulomb-corrected strong-field approximation. Phys Rev E 2016; 94:053310. [PMID: 27967194 DOI: 10.1103/physreve.94.053310] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2016] [Indexed: 11/07/2022]
Abstract
One of the main goals of strong-field physics is to understand the complex structures formed in the momentum plane of the photoelectron. For this purpose, different semiclassical methods have been developed to seek an intuitive picture of the underlying mechanism. The most popular ones are the quantum trajectory Monte Carlo (QTMC) method and the Coulomb-corrected strong-field approximation (CCSFA), both of which take the classical action into consideration and can describe the interference effect. The CCSFA is more widely applicable in a large range of laser parameters due to its nonadiabatic nature in treating the initial tunneling dynamics. However, the CCSFA is much more time consuming than the QTMC method because of the numerical solution to the saddle-point equations. In the present work, we present a time-sampling method to overcome this disadvantage. Our method is as efficient as the fast QTMC method and as accurate as the original treatment in CCSFA. The performance of our method is verified by comparing the results of these methods with that of the exact solution to the time-dependent Schrödinger equation.
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Affiliation(s)
- Xiang-Ru Xiao
- State Key Laboratory for Mesoscopic Physics and School of Physics, Peking University, Beijing 100871, China
| | - Mu-Xue Wang
- State Key Laboratory for Mesoscopic Physics and School of Physics, Peking University, Beijing 100871, China
| | - Wei-Hao Xiong
- State Key Laboratory for Mesoscopic Physics and School of Physics, Peking University, Beijing 100871, China
| | - Liang-You Peng
- State Key Laboratory for Mesoscopic Physics and School of Physics, Peking University, Beijing 100871, China.,Collaborative Innovation Center of Quantum Matter, Beijing 100871, China
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37
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Keil T, Popruzhenko SV, Bauer D. Laser-Driven Recollisions under the Coulomb Barrier. PHYSICAL REVIEW LETTERS 2016; 117:243003. [PMID: 28009212 DOI: 10.1103/physrevlett.117.243003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/12/2016] [Indexed: 06/06/2023]
Abstract
Photoelectron spectra obtained from the ab initio solution of the time-dependent Schrödinger equation can be in striking disagreement with predictions by the strong-field approximation (SFA), not only at low energy but also around twice the ponderomotive energy where the transition from the direct to the rescattered electrons is expected. In fact, the relative enhancement of the ionization probability compared to the SFA in this regime can be several orders of magnitude. We show for which laser and target parameters such an enhancement occurs and for which the SFA prediction is qualitatively good. The enhancement is analyzed in terms of the Coulomb-corrected action along analytic quantum orbits in the complex-time plane, taking soft recollisions under the Coulomb barrier into account. These recollisions in complex time and space prevent a separation into sub-barrier motion up to the "tunnel exit" and subsequent classical dynamics. Instead, the entire quantum path up to the detector determines the ionization probability.
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Affiliation(s)
- Th Keil
- Institut für Physik, Universität Rostock, 18051 Rostock, Germany
| | - S V Popruzhenko
- National Research Nuclear University MEPhI, Kashirskoe shosse 31, 115409 Moscow, Russia
| | - D Bauer
- Institut für Physik, Universität Rostock, 18051 Rostock, Germany
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38
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Frank Y, Zigler A, Henis Z. Atomic kinetics of matter irradiated by intense laser fields. Phys Rev E 2016; 94:033209. [PMID: 27739737 DOI: 10.1103/physreve.94.033209] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2015] [Indexed: 11/07/2022]
Abstract
The atomic kinetics of solid density low-Z material under an intense oscillating laser field is presented. The transient behavior of the average ionization and the heating mechanism is analyzed. Temporal oscillations in excited configurations populations caused by the laser field oscillations are demonstrated. These phenomena present a method for creating short, 1-100 fs, monochromatic but incoherent x-ray pulses and for measuring basic atomic rates.
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Affiliation(s)
- Yechiel Frank
- Racah Institute of Physics, Hebrew University, Jerusalem 91904, Israel.,Soreq Research Center, Yavne 81800, Israel
| | - Arie Zigler
- Racah Institute of Physics, Hebrew University, Jerusalem 91904, Israel
| | - Zohar Henis
- Racah Institute of Physics, Hebrew University, Jerusalem 91904, Israel.,Soreq Research Center, Yavne 81800, Israel
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39
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Calvert JE, Xu H, Palmer AJ, Glover RD, Laban DE, Tong XM, Kheifets AS, Bartschat K, Litvinyuk IV, Kielpinski D, Sang RT. The interaction of excited atoms and few-cycle laser pulses. Sci Rep 2016; 6:34101. [PMID: 27666403 PMCID: PMC5035976 DOI: 10.1038/srep34101] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2016] [Accepted: 09/07/2016] [Indexed: 11/26/2022] Open
Abstract
This work describes the first observations of the ionisation of neon in a metastable atomic state utilising a strong-field, few-cycle light pulse. We compare the observations to theoretical predictions based on the Ammosov-Delone-Krainov (ADK) theory and a solution to the time-dependent Schrödinger equation (TDSE). The TDSE provides better agreement with the experimental data than the ADK theory. We optically pump the target atomic species and measure the ionisation rate as the a function of different steady-state populations in the fine structure of the target state which shows significant ionisation rate dependence on populations of spin-polarised states. The physical mechanism for this effect is unknown.
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Affiliation(s)
- J E Calvert
- Australian Attosecond Science Facility and Centre for Quantum Dynamics, Griffith University, Brisbane, Queensland 4111, Australia
| | - Han Xu
- Australian Attosecond Science Facility and Centre for Quantum Dynamics, Griffith University, Brisbane, Queensland 4111, Australia
| | - A J Palmer
- Australian Attosecond Science Facility and Centre for Quantum Dynamics, Griffith University, Brisbane, Queensland 4111, Australia
| | - R D Glover
- Institute for Atomic and Nuclear Physics, University of Liege, Liege 4000, Belgium
| | - D E Laban
- Australian Attosecond Science Facility and Centre for Quantum Dynamics, Griffith University, Brisbane, Queensland 4111, Australia
| | - X M Tong
- Graduate School of Pure and Applied Sciences, and Center for Computational Science, University of Tsukuba, Tsukuba, 305-8571, Japan
| | - A S Kheifets
- Research School of Physics and Engineering, The Australian National University, Canberra ACT 0200, Australia
| | - K Bartschat
- Australian Attosecond Science Facility and Centre for Quantum Dynamics, Griffith University, Brisbane, Queensland 4111, Australia.,Department of Physics and Astronomy, Drake University, Des Moines, IA 50311, USA
| | - I V Litvinyuk
- Australian Attosecond Science Facility and Centre for Quantum Dynamics, Griffith University, Brisbane, Queensland 4111, Australia
| | - D Kielpinski
- Australian Attosecond Science Facility and Centre for Quantum Dynamics, Griffith University, Brisbane, Queensland 4111, Australia
| | - R T Sang
- Australian Attosecond Science Facility and Centre for Quantum Dynamics, Griffith University, Brisbane, Queensland 4111, Australia
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40
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41
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Momentum Distribution of Near-Zero-Energy Photoelectrons in the Strong-Field Tunneling Ionization in the Long Wavelength Limit. Sci Rep 2015; 5:11473. [PMID: 26081971 PMCID: PMC4469979 DOI: 10.1038/srep11473] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2014] [Accepted: 05/18/2015] [Indexed: 11/16/2022] Open
Abstract
We investigate the ionization dynamics of Argon atoms irradiated by an ultrashort intense laser of a wavelength up to 3100 nm, addressing the momentum distribution of the photoelectrons with near-zero-energy. We find a surprising accumulation in the momentum distribution corresponding to meV energy and a “V”-like structure at the slightly larger transverse momenta. Semiclassical simulations indicate the crucial role of the Coulomb attraction between the escaping electron and the remaining ion at an extremely large distance. Tracing back classical trajectories, we find the tunneling electrons born in a certain window of the field phase and transverse velocity are responsible for the striking accumulation. Our theoretical results are consistent with recent meV-resolved high-precision measurements.
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42
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Yuan KJ, Chelkowski S, Bandrauk AD. Molecular photoelectron angular distribution rotations in multi-photon resonant ionization of H2+ by circularly polarized ultraviolet laser pulses. J Chem Phys 2015; 142:144304. [DOI: 10.1063/1.4917419] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Kai-Jun Yuan
- Laboratoire de Chimie Théorique, Faculté des Sciences, Université de Sherbrooke, Sherbrooke, Québec J1K 2R1, Canada
| | - Szczepan Chelkowski
- Laboratoire de Chimie Théorique, Faculté des Sciences, Université de Sherbrooke, Sherbrooke, Québec J1K 2R1, Canada
| | - André D. Bandrauk
- Laboratoire de Chimie Théorique, Faculté des Sciences, Université de Sherbrooke, Sherbrooke, Québec J1K 2R1, Canada
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43
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Ge XL, Du H, Guo J, Liu XS. Quantum control of electron wave packet during high harmonic process of H2(+) in a combination of a circularly polarized laser field and a Terahertz field. OPTICS EXPRESS 2015; 23:8837-8844. [PMID: 25968721 DOI: 10.1364/oe.23.008837] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
By solving a two-dimensional time-dependent Schrödinger equation we investigate high harmonic generation (HHG) and isolated attosecond pulse generation for the H2+ molecular ion in a circularly polarized laser pulse combined with a Terahertz (THz) field. The harmonic intensity can be greatly enhanced and a continuum spectrum can be obtained when a THz field is added. The HHG process is studied by the semi-classical three-step model and the time-frequency analysis. Our studies show that only short trajectories contribute to HHG. Furthermore, we present the temporal evolution of the probability density of electron wave packet, which perfectly shows a clear picture of the electron's two-time recombination when a THz field is added, and it is the main mechanism of HHG. By superposing the harmonics in the range of 216-249 eV, an isolated attosecond pulse with a duration of about 69 attoseconds can be generated.
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44
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Mitryukovskiy S, Liu Y, Ding P, Houard A, Couairon A, Mysyrowicz A. Plasma luminescence from femtosecond filaments in air: evidence for impact excitation with circularly polarized light pulses. PHYSICAL REVIEW LETTERS 2015; 114:063003. [PMID: 25723217 DOI: 10.1103/physrevlett.114.063003] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2014] [Indexed: 06/04/2023]
Abstract
Filaments produced in air by intense femtosecond laser pulses emit UV luminescence from excited N(2) and N(2)(+) molecules. We report on a strong dependence at high intensities (I≥1.4×10(14) W/cm(2)) of this luminescence with the polarization state of the incident laser pulses. We attribute this effect to the onset of new impact excitation channels from energetic electrons produced with circularly polarized laser pulses above a threshold laser intensity.
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Affiliation(s)
- Sergey Mitryukovskiy
- Laboratoire d'Optique Appliquée, ENSTA/CNRS/Ecole Polytechnique, 828, Boulevard des Maréchaux, Palaiseau F-91762, France
| | - Yi Liu
- Laboratoire d'Optique Appliquée, ENSTA/CNRS/Ecole Polytechnique, 828, Boulevard des Maréchaux, Palaiseau F-91762, France
| | - Pengji Ding
- Laboratoire d'Optique Appliquée, ENSTA/CNRS/Ecole Polytechnique, 828, Boulevard des Maréchaux, Palaiseau F-91762, France
| | - Aurélien Houard
- Laboratoire d'Optique Appliquée, ENSTA/CNRS/Ecole Polytechnique, 828, Boulevard des Maréchaux, Palaiseau F-91762, France
| | - Arnaud Couairon
- Centre de Physique Théorique, Ecole Polytechnique, CNRS, Palaiseau F-91128, France
| | - André Mysyrowicz
- Laboratoire d'Optique Appliquée, ENSTA/CNRS/Ecole Polytechnique, 828, Boulevard des Maréchaux, Palaiseau F-91762, France
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45
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Lu C, Zhang S, Yao Y, Xu S, Jia T, Ding J, Sun Z. Effect of two-color laser pulse intensity ratio on intense terahertz generation. RSC Adv 2015. [DOI: 10.1039/c4ra12556h] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
We theoretically demonstrate the effect of the intensity ratio of the two-color laser field on the terahertz generation based on a transient photocurrent model.
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Affiliation(s)
- Chenhui Lu
- State Key Laboratory of Precision Spectroscopy
- Department of Physics
- East China Normal University
- Shanghai 200062
- People's Republic of China
| | - Shian Zhang
- State Key Laboratory of Precision Spectroscopy
- Department of Physics
- East China Normal University
- Shanghai 200062
- People's Republic of China
| | - Yunhua Yao
- State Key Laboratory of Precision Spectroscopy
- Department of Physics
- East China Normal University
- Shanghai 200062
- People's Republic of China
| | - Shuwu Xu
- State Key Laboratory of Precision Spectroscopy
- Department of Physics
- East China Normal University
- Shanghai 200062
- People's Republic of China
| | - Tianqing Jia
- State Key Laboratory of Precision Spectroscopy
- Department of Physics
- East China Normal University
- Shanghai 200062
- People's Republic of China
| | - Jingxin Ding
- State Key Laboratory of Precision Spectroscopy
- Department of Physics
- East China Normal University
- Shanghai 200062
- People's Republic of China
| | - Zhenrong Sun
- State Key Laboratory of Precision Spectroscopy
- Department of Physics
- East China Normal University
- Shanghai 200062
- People's Republic of China
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46
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Smeenk CTL, Arissian L, Sokolov AV, Spanner M, Lee KF, Staudte A, Villeneuve DM, Corkum PB. Alignment dependent enhancement of the photoelectron cutoff for multiphoton ionization of molecules. PHYSICAL REVIEW LETTERS 2014; 112:253001. [PMID: 25014807 DOI: 10.1103/physrevlett.112.253001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/14/2013] [Indexed: 06/03/2023]
Abstract
The multiphoton ionization rate of molecules depends on the alignment of the molecular axis with respect to the ionizing laser polarization. By studying molecular frame photoelectron angular distributions from N(2), O(2), and benzene, we illustrate how the angle-dependent ionization rate affects the photoelectron cutoff energy. We find alignment can enhance the high energy cutoff of the photoelectron spectrum when probing along a nodal plane or when ionization is otherwise suppressed. This is supported by calculations using a tunneling model with a single ion state.
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Affiliation(s)
- C T L Smeenk
- JASLab, University of Ottawa and National Research Council, 100 Sussex Drive, Ottawa, Canada K1A 0R6
| | - L Arissian
- Department of Electrical and Computer Engineering, University of New Mexico, Albuquerque, New Mexico 87131, USA
| | - A V Sokolov
- Department of Physics, Texas A & M University, College Station 77843, Texas, USA
| | - M Spanner
- JASLab, University of Ottawa and National Research Council, 100 Sussex Drive, Ottawa, Canada K1A 0R6
| | - K F Lee
- JASLab, University of Ottawa and National Research Council, 100 Sussex Drive, Ottawa, Canada K1A 0R6 and Department of Physics, Texas A & M University, College Station 77843, Texas, USA
| | - A Staudte
- JASLab, University of Ottawa and National Research Council, 100 Sussex Drive, Ottawa, Canada K1A 0R6
| | - D M Villeneuve
- JASLab, University of Ottawa and National Research Council, 100 Sussex Drive, Ottawa, Canada K1A 0R6
| | - P B Corkum
- JASLab, University of Ottawa and National Research Council, 100 Sussex Drive, Ottawa, Canada K1A 0R6
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47
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Li S, Jones RR. Ionization of excited atoms by intense single-cycle THz pulses. PHYSICAL REVIEW LETTERS 2014; 112:143006. [PMID: 24765954 DOI: 10.1103/physrevlett.112.143006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2013] [Indexed: 06/03/2023]
Abstract
We have employed intense, single-cycle THz pulses to explore strong-field ionization of low-lying Na Rydberg states in the low-frequency limit. At the largest fields used, F≃430 kV/cm, electrons with energies up to 60 eV are created. The field ionization threshold is greater than expected for adiabatic "over-the-barrier" ionization and is found to scale as n-3. In addition, for a given field amplitude, higher energy electrons are produced during the ionization of the most tightly bound states. These observations can be attributed to the suppression of scattering from the nonhydrogenic ion core, the long times required for Rydberg electrons to escape over the barrier in the field-dressed Coulomb potential, and the failure, in the single-cycle limit, of the standard prediction for electron energy transfer in an oscillating field. The latter, in particular, holds important implications for future strong-field experiments involving the interaction of ground-state atoms and molecules with true single-cycle laser fields.
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Affiliation(s)
- Sha Li
- Department of Physics, University of Virginia, Charlottesville, Virginia 22904, USA
| | - R R Jones
- Department of Physics, University of Virginia, Charlottesville, Virginia 22904, USA
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48
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Sowlati-Hashjin S, Matta CF. The chemical bond in external electric fields: Energies, geometries, and vibrational Stark shifts of diatomic molecules. J Chem Phys 2013; 139:144101. [DOI: 10.1063/1.4820487] [Citation(s) in RCA: 82] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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49
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Chang BY, Shin S, Palacios A, Martín F, Sola IR. Two-Pulse Control of Large-Amplitude Vibrations in H2+. Chemphyschem 2013; 14:1405-12. [DOI: 10.1002/cphc.201201078] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2012] [Revised: 02/18/2013] [Indexed: 11/07/2022]
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50
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Guo L, Han SS, Liu X, Cheng Y, Xu ZZ, Fan J, Chen J, Chen SG, Becker W, Blaga CI, DiChiara AD, Sistrunk E, Agostini P, DiMauro LF. Scaling of the low-energy structure in above-threshold ionization in the tunneling regime: theory and experiment. PHYSICAL REVIEW LETTERS 2013; 110:013001. [PMID: 23383786 DOI: 10.1103/physrevlett.110.013001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2012] [Indexed: 06/01/2023]
Abstract
A calculation of the second-order (rescattering) term in the S-matrix expansion of above-threshold ionization is presented for the case when the binding potential is the unscreened Coulomb potential. Technical problems related to the divergence of the Coulomb scattering amplitude are avoided in the theory by considering the depletion of the atomic ground state due to the applied laser field, which is well defined and does not require the introduction of a screening constant. We focus on the low-energy structure, which was observed in recent experiments with a midinfrared wavelength laser field. Both the spectra and, in particular, the observed scaling versus the Keldysh parameter and the ponderomotive energy are reproduced. The theory provides evidence that the origin of the structure lies in the long-range Coulomb interaction.
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Affiliation(s)
- L Guo
- Key Laboratory for Quantum Optics and Center for Cold Atom Physics, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800, China
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