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Yang S, Liu X, Zhang H, Song X, Zuo R, Meier T, Yang W. Sub-cycle strong-field tunneling dynamics in solids. OPTICS EXPRESS 2024; 32:15862-15869. [PMID: 38859226 DOI: 10.1364/oe.521207] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2024] [Accepted: 03/27/2024] [Indexed: 06/12/2024]
Abstract
Tunneling ionization is a crucial process in the interaction between strong laser fields and matter which initiates numerous nonlinear phenomena including high-order harmonic generation, photoelectron holography, etc. Both adiabatic and nonadiabatic tunneling ionization are well understood in atomic systems. However, the tunneling dynamics in solids, especially nonadiabatic tunneling, has not yet been fully understood. Here, we study the sub-cycle resolved strong-field tunneling dynamics in solids via a complex saddle-point method. We compare the instantaneous momentum at the moment of tunneling and the tunneling distances over a range of Keldysh parameters. Our results demonstrate that for nonadiabatic tunneling, tunneling ionization away from Γ point is possible. When this happens the electron has a nonzero initial velocity when it emerges in the conduction band. Moreover, consistent with atomic tunneling, a reduced tunneling distance as compared to the quasi-static case is found. Our results provide remarkable insight into the basic physics governing the sub-cycle electron tunneling dynamics with significant implications for understanding subsequent strong-field nonlinear phenomena in solids.
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2
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Peng Y, Che J, Zhang F, Xie X, Xin G, Chen Y. Response time of an electron inside a molecule to light in strong-field ionization. OPTICS EXPRESS 2024; 32:12734-12746. [PMID: 38571088 DOI: 10.1364/oe.516390] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2023] [Accepted: 03/13/2024] [Indexed: 04/05/2024]
Abstract
We study ionization of aligned H2+ in strong elliptically polarized laser fields numerically and analytically. The calculated offset angle in photoelectron momentum distribution is several degrees larger for the molecule than a model atom with similar ionization potential at diverse laser parameters. Using a strong-field model that considers the properties of multi-center and single-center Coulomb potentials, we are able to quantitatively reproduce this angle difference between the molecule and the atom. Further analyses based on this model show that the response time of electron to light which is encoded in the offset angle and is manifested as the time spent in tunneling ionization, is about 15 attoseconds longer for the molecule than the atom. This time difference is further enlarged when increasing the internuclear distance of the molecule.
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3
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Wu J, Che J, Zhang F, Chen C, Li W, Xin G, Chen Y. Two-color attosecond chronoscope. OPTICS EXPRESS 2023; 31:21038-21047. [PMID: 37381213 DOI: 10.1364/oe.494098] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Accepted: 05/29/2023] [Indexed: 06/30/2023]
Abstract
We study ionization of atoms in strong orthogonal two-color (OTC) laser fields numerically and analytically. The calculated photoelectron momentum distribution shows two typical structures: a rectangular-like one and a shoulder-like one, the positions of which depend on the laser parameters. Using a strong-field model which allows us to quantitatively evaluate the Coulomb effect, we show that these two structures arise from attosecond response of electron inside an atom to light in OTC-induced photoemission. Some simple mappings between the locations of these structures and response time are derived. Through these mappings, we are able to establish a two-color attosecond chronoscope for timing electron emission, which is essential for OTC-based precise manipulation.
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4
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Xiao Z, Quan W, Yu S, Lai X, Liu X, Wei Z, Chen J. Nonadiabatic strong field ionization of noble gas atoms in elliptically polarized laser pulses. OPTICS EXPRESS 2022; 30:14873-14885. [PMID: 35473221 DOI: 10.1364/oe.454846] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2022] [Accepted: 04/03/2022] [Indexed: 06/14/2023]
Abstract
We present theoretically obtained photoelectron momentum distributions (PMDs) for the strong field ionization of argon in an elliptically polarized laser field at a central wavelength of 400 nm. Three different theoretical approaches, namely, a numerical solution of the time-dependent Schrödinger equation (TDSE), a nonadiabatic model, and a classical-trajectory Monte Carlo (CTMC) model are adopted in our calculations. From the TDSE calculations, it is found that the attoclock offset angle (most probable electron emission angles with respect to the minor axis of the laser's polarization ellipse) in the PMD increases with rising ATI order. While this result cannot be reproduced by the CTMC model, the nonadiabatic model achieves good agreement with the TDSE result. Analysis shows that the nonadiabatic corrections of the photoelectron initial momentum distribution (in both longitudinal and transverse directions with respect to the tunneling direction) and nonadiabatic correction of the tunneling exit are responsible for the ATI order-dependent angular shift.
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5
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Ortmann L, AlShafey A, Staudte A, Landsman AS. Tracking the Ionization Site in Neutral Molecules. PHYSICAL REVIEW LETTERS 2021; 127:213201. [PMID: 34860111 DOI: 10.1103/physrevlett.127.213201] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Revised: 09/19/2021] [Accepted: 10/15/2021] [Indexed: 06/13/2023]
Abstract
When a diatomic molecule is exposed to intense light, the valence electron may tunnel from a higher potential (corresponding to an upfield atom) due to the suppressed internuclear barrier. This process is known as ionization enhancement and is a key mechanism in strong field ionization of molecules. Alternatively, the bound electron wave function can evolve adiabatically in the laser field, resulting in ionization from the downfield atom. Here, we introduce a method to quantify the relative contribution of these two processes. Applying this method to experimentally measured electron momenta distributions following strong field ionization of N_{2} with infrared laser light, we find approximately a 2∶1 ratio of electrons ionized from a downfield atom, relative to upfield. This suggests that the bound state wave function largely adapts adiabatically to the changing laser field, although the nonadiabatic process of ionization enhancement still contributes even in neutral molecules. Our method can be applied to any diatomic neutral molecule to better understand the evolution of the initially bound electron wave packet and hence the nature of the molecular ionization process.
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Affiliation(s)
- L Ortmann
- Max Planck Institute for the Physics of Complex Systems, Nöthnitzer Straße 38, D-01187 Dresden, Germany
- Department of Physics, The Ohio State University, Columbus, Ohio 43210, USA
| | - A AlShafey
- Department of Physics, The Ohio State University, Columbus, Ohio 43210, USA
| | - A Staudte
- Joint Attosecond Science Lab of the National Research Council and the University of Ottawa, Ottawa, Ontario K1A 0R6, Canada
| | - A S Landsman
- Department of Physics, The Ohio State University, Columbus, Ohio 43210, USA
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6
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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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7
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Li C, Chen K, Guan M, Wang X, Zhou X, Zhai F, Dai J, Li Z, Sun Z, Meng S, Liu K, Dai Q. Extreme nonlinear strong-field photoemission from carbon nanotubes. Nat Commun 2019; 10:4891. [PMID: 31653837 PMCID: PMC6814826 DOI: 10.1038/s41467-019-12797-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2019] [Accepted: 09/27/2019] [Indexed: 11/09/2022] Open
Abstract
Strong-field photoemission produces attosecond (10-18 s) electron pulses that are synchronized to the waveform of the incident light. This nonlinear photoemission lies at the heart of current attosecond technologies. Here we report a new nonlinear photoemission behaviour-the nonlinearity in strong-field regime sharply increases (approaching 40th power-law scaling), making use of sub-nanometric carbon nanotubes and 800 nm pulses. As a result, the carrier-envelope phase sensitive photoemission current shows a greatly improved modulation depth of up to 100% (with a total modulation current up to 2 nA). The calculations reveal that the behaviour is an interplay of valence band optical-field emission with charge interaction, and the nonlinear dynamics can be tunable by changing the bandgap of carbon nanotubes. The extreme nonlinear photoemission offers a new means of producing extreme temporal-spatial resolved electron pulses, and provides a new design philosophy for attosecond electronics and photonics.
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Affiliation(s)
- Chi Li
- Division of Nanophotonics, CAS Key Laboratory of Standardization and Measurement for Nanotechnology, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing, 100190, China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Ke Chen
- Division of Nanophotonics, CAS Key Laboratory of Standardization and Measurement for Nanotechnology, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing, 100190, China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Mengxue Guan
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Science, Beijing, 100190, China
| | - Xiaowei Wang
- Department of Physics, National University of Defense Technology, Changsha, 410073, China
| | - Xu Zhou
- School of Physics, Academy for Advanced Interdisciplinary Studies, Collaborative Innovation Center of Quantum Matter, Peking University, Beijing, 100871, China
| | - Feng Zhai
- Department of Physics, Zhejiang Normal University, Jinhua, 321004, China
| | - Jiayu Dai
- Department of Physics, National University of Defense Technology, Changsha, 410073, China
| | - Zhenjun Li
- Division of Nanophotonics, CAS Key Laboratory of Standardization and Measurement for Nanotechnology, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing, 100190, China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Zhipei Sun
- Department of Electronics and Nanoengineering, Aalto University, Tietotie 3, FI-02150, Finland
- QTF Centre of Excellence, Department of Applied Physics, Aalto University, FI-00076, Aalto, Finland
| | - Sheng Meng
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Science, Beijing, 100190, China.
| | - Kaihui Liu
- School of Physics, Academy for Advanced Interdisciplinary Studies, Collaborative Innovation Center of Quantum Matter, Peking University, Beijing, 100871, China.
| | - Qing Dai
- Division of Nanophotonics, CAS Key Laboratory of Standardization and Measurement for Nanotechnology, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing, 100190, China.
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing, 100049, China.
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8
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Han M, Ge P, Fang Y, Yu X, Guo Z, Ma X, Deng Y, Gong Q, Liu Y. Unifying Tunneling Pictures of Strong-Field Ionization with an Improved Attoclock. PHYSICAL REVIEW LETTERS 2019; 123:073201. [PMID: 31491089 DOI: 10.1103/physrevlett.123.073201] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Indexed: 06/10/2023]
Abstract
We demonstrate a novel attoclock, in which we add a perturbative linearly polarized light field at 400 nm to calibrate the attoclock constructed by an intense circularly polarized field at 800 nm. This approach can be directly implemented to analyze the recent hot and controversial topics involving strong-field tunneling ionization. The generally accepted picture is that tunneling ionization is instantaneous and that the tunneling probability synchronizes with the laser electric field. Alternatively, recently it was described in the Wigner picture that tunneling ionization would occur with a certain of time delay. We unify the two seemingly opposite viewpoints within one theoretical framework, i.e., the strong-field approximation (SFA). We illustrate that both the instantaneous tunneling picture and the Wigner time delay picture that are derived from the SFA can interpret the measurement well. Our results show that the finite tunneling delay will accompany nonzero exit longitudinal momenta. This is not the case for the instantaneous tunneling picture, where the most probable exit longitudinal momentum would be zero.
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Affiliation(s)
- Meng Han
- State Key Laboratory for Mesoscopic Physics and Collaborative Innovation Center of Quantum Matter, School of Physics, Peking University, Beijing 100871, China
| | - Peipei Ge
- State Key Laboratory for Mesoscopic Physics and Collaborative Innovation Center of Quantum Matter, School of Physics, Peking University, Beijing 100871, China
| | - Yiqi Fang
- State Key Laboratory for Mesoscopic Physics and Collaborative Innovation Center of Quantum Matter, School of Physics, Peking University, Beijing 100871, China
| | - Xiaoyang Yu
- State Key Laboratory for Mesoscopic Physics and Collaborative Innovation Center of Quantum Matter, School of Physics, Peking University, Beijing 100871, China
| | - Zhenning Guo
- State Key Laboratory for Mesoscopic Physics and Collaborative Innovation Center of Quantum Matter, School of Physics, Peking University, Beijing 100871, China
| | - Xueyan Ma
- State Key Laboratory for Mesoscopic Physics and Collaborative Innovation Center of Quantum Matter, School of Physics, Peking University, Beijing 100871, China
| | - Yongkai Deng
- State Key Laboratory for Mesoscopic Physics and Collaborative Innovation Center of Quantum Matter, School of Physics, Peking University, Beijing 100871, China
| | - Qihuang Gong
- State Key Laboratory for Mesoscopic Physics and Collaborative Innovation Center of Quantum Matter, School of Physics, Peking University, Beijing 100871, China
- Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan, Shanxi 030006, China
- Beijing Academy of Quantum Information Sciences, Beijing 100193, China
| | - Yunquan Liu
- State Key Laboratory for Mesoscopic Physics and Collaborative Innovation Center of Quantum Matter, School of Physics, Peking University, Beijing 100871, China
- Center for Applied Physics and Technology, HEDPS, Peking University, Beijing 100871, China
- Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan, Shanxi 030006, China
- Beijing Academy of Quantum Information Sciences, Beijing 100193, China
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9
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Yuan M. Direct probing of tunneling time in strong-field ionization processes by time-dependent wave packets. OPTICS EXPRESS 2019; 27:6502-6511. [PMID: 30876234 DOI: 10.1364/oe.27.006502] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Accepted: 02/09/2019] [Indexed: 06/09/2023]
Abstract
We propose a straightforward approach to directly probe the tunneling time by observing the transition of photoelectron wave packets in strong-field ionization processes, where Coulomb potentials do not affect the results. A circularly polarized laser pulse is used to avoid the impact of scattering electrons on the direct ionization electrons, and a pure transmission photoelectron wave packet can be obtained. Then, a positive tunneling time is extracted. The results demonstrate that the tunneling time is dominated mainly by the laser frequency in some laser intensity range. At the same time, we also investigate the tunneling time by analyzing the instantaneous ionization rate, and the consentaneous results are obtained.
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10
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Wang R, Zhang Q, Li D, Xu S, Cao P, Zhou Y, Cao W, Lu P. Identification of tunneling and multiphoton ionization in intermediate Keldysh parameter regime. OPTICS EXPRESS 2019; 27:6471-6482. [PMID: 30876249 DOI: 10.1364/oe.27.006471] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2018] [Accepted: 02/06/2019] [Indexed: 06/09/2023]
Abstract
Quantitative identification of tunneling ionization (TI) and multiphoton ionization (MPI) with Keldysh parameter γ in intermediate regime is of great importance to better understand various ionization-triggered strong-field phenomena. We theoretically demonstrate that the numerical observable ionization delay time is a more reliable indicator for characterizing the transition from TI to MPI under different laser parameters. Using non-linear iterative curve fitting algorithm (NICFA), the detected time-dependent probability current of ionized electrons can be decoupled into weighted TI and MPI portions. This enables us to confirm that the observed plateau-like structure in ionization delay time picture at the intermediate γ originates from the competition between TI and MPI processes. A hybrid quantum and classical approach (HQCA) is developed to evaluate the weights of TI and MPI electrons in good agreement with NICFA result. Moreover, the well separated TI and MPI electrons using HQCA are further propagated classically for mapping their final momentum, which well reproduces the experimental or ab-initio numerical calculated signatures of ionized electron momentum distribution in a rather broad γ regime.
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11
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Liu K, Luo S, Li M, Li Y, Feng Y, Du B, Zhou Y, Lu P, Barth I. Detecting and Characterizing the Nonadiabaticity of Laser-Induced Quantum Tunneling. PHYSICAL REVIEW LETTERS 2019; 122:053202. [PMID: 30822014 DOI: 10.1103/physrevlett.122.053202] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/27/2018] [Indexed: 06/09/2023]
Abstract
The nonadiabaticity of quantum tunneling through an evolving barrier is relevant to resolving laser-driven dynamics of atoms and molecules at an attosecond timescale. Here, we propose and demonstrate a novel scheme to detect the nonadiabatic behavior of tunnel ionization studied in an attoclock configuration, without counting on the laser intensity calibration or the modeling of the Coulomb effect. In our scheme, the degree of nonadiabaticity for tunneling scenarios in elliptically polarized laser fields can be steered continuously simply with the pulse ellipticity, while the critical instantaneous vector potentials remain identical. We observe the characteristic feature of the measured photoelectron momentum distributions, which matches the distinctive prediction of nonadiabatic theories. In particular, our experiments demonstrate that the nonadiabatic initial transverse momentum at the tunnel exit is approximately proportional to the instantaneous effective Keldysh parameters in the tunneling regime, as predicted theoretically by Ohmi, Tolstikhin, and Morishita [Phys. Rev. A 92, 043402 (2015)PLRAAN1050-294710.1103/PhysRevA.92.043402]. Our study clarifies a long-standing controversy over the validation of the adiabatic approximation and will substantially advance studies of laser-induced ultrafast dynamics in experiments.
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Affiliation(s)
- Kunlong Liu
- Wuhan National Laboratory for Optoelectronics and School of Physics, Huazhong University of Science and Technology, Wuhan 430074, China
- Max-Planck-Institut für Mikrostrukturphysik, Weinberg 2, 06120 Halle (Saale), Germany
| | - Siqiang Luo
- Wuhan National Laboratory for Optoelectronics and School of Physics, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Min Li
- Wuhan National Laboratory for Optoelectronics and School of Physics, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Yang Li
- Wuhan National Laboratory for Optoelectronics and School of Physics, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Yudi Feng
- Wuhan National Laboratory for Optoelectronics and School of Physics, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Baojie Du
- Wuhan National Laboratory for Optoelectronics and School of Physics, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Yueming Zhou
- Wuhan National Laboratory for Optoelectronics and School of Physics, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Peixiang Lu
- Wuhan National Laboratory for Optoelectronics and School of Physics, Huazhong University of Science and Technology, Wuhan 430074, China
- Hubei Key Laboratory of Optical Information and Pattern Recognition, Wuhan Institute of Technology, Wuhan 430205, China
| | - Ingo Barth
- Max-Planck-Institut für Mikrostrukturphysik, Weinberg 2, 06120 Halle (Saale), Germany
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12
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Bray AW, Eckart S, Kheifets AS. Keldysh-Rutherford Model for the Attoclock. PHYSICAL REVIEW LETTERS 2018; 121:123201. [PMID: 30296152 DOI: 10.1103/physrevlett.121.123201] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Indexed: 06/08/2023]
Abstract
We demonstrate a clear similarity between attoclock offset angles and Rutherford scattering angles taking the Keldysh tunneling width as the impact parameter and the vector potential of the driving pulse as the asymptotic velocity. This simple model is tested against the solution of the time-dependent Schrödinger equation using hydrogenic and screened (Yukawa) potentials of equal binding energy. We observe a smooth transition from a hydrogenic to "hard-zero" intensity dependence of the offset angle with variation of the Yukawa screening parameter. Additionally, we make a comparison with the attoclock offset angles for various noble gases obtained with the classical-trajectory Monte Carlo method. In all cases we find a close correspondence between the model predictions and numerical calculations. This suggests a largely Coulombic origin of the attoclock offset angle and casts further doubt on its interpretation in terms of a finite tunneling time.
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Affiliation(s)
- Alexander W Bray
- Research School of Physics and Engineering, The Australian National University, Canberra, Australian Capital Territory 0200, Australia
| | - Sebastian Eckart
- Institut für Kernphysik, Goethe-Universität, Max-von-Laue-Straße 1, 60438 Frankfurt, Germany
| | - Anatoli S Kheifets
- Research School of Physics and Engineering, The Australian National University, Canberra, Australian Capital Territory 0200, Australia
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13
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Tan J, Zhou Y, Li M, He M, Liu Y, Lu P. Accurate measurement of laser intensity using photoelectron interference in strong-field tunneling ionization. OPTICS EXPRESS 2018; 26:20063-20075. [PMID: 30119322 DOI: 10.1364/oe.26.020063] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2018] [Accepted: 06/25/2018] [Indexed: 06/08/2023]
Abstract
Accurate determination of laser intensity is of fundamental importance to study various phenomena in intense laser-atom/molecule interactions. We theoretically demonstrate a scheme to measure laser intensity by examining the holographic structure originating from the interference between the direct and near-forward rescattering electrons in strong-field tunneling ionization. By adding a weak second-harmonic field with polarization orthogonal to the strong fundamental driving field, the interference pattern oscillates with the changing relative phases of the two-color fields. Interestingly, the amplitude of this oscillation in the photoelectron momentum spectrum depends on the parallel momentum. With the quantum-orbit analysis, we show that the amplitude of the oscillation minimizes when the time difference between the recollision and ionization of near-forward rescattering electron is half cycle of the fundamental driving field. This enables us to measure accurately the laser intensity by seeking the minimum of the oscillation amplitude. Moreover, we show that this minimum can be determined without scanning the relative phases, instead, by just monitoring the interference patterns for two relative phases. This facilitates the application of our scheme in experiment.
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14
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Ultrafast Mid-IR Laser Pulses Generation via Chirp Manipulated Optical Parametric Amplification. APPLIED SCIENCES-BASEL 2018. [DOI: 10.3390/app8050744] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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15
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Gallmann L, Jordan I, Wörner HJ, Castiglioni L, Hengsberger M, Osterwalder J, Arrell CA, Chergui M, Liberatore E, Rothlisberger U, Keller U. Photoemission and photoionization time delays and rates. STRUCTURAL DYNAMICS (MELVILLE, N.Y.) 2017; 4:061502. [PMID: 29308414 PMCID: PMC5732014 DOI: 10.1063/1.4997175] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2017] [Accepted: 11/02/2017] [Indexed: 05/20/2023]
Abstract
Ionization and, in particular, ionization through the interaction with light play an important role in fundamental processes in physics, chemistry, and biology. In recent years, we have seen tremendous advances in our ability to measure the dynamics of photo-induced ionization in various systems in the gas, liquid, or solid phase. In this review, we will define the parameters used for quantifying these dynamics. We give a brief overview of some of the most important ionization processes and how to resolve the associated time delays and rates. With regard to time delays, we ask the question: how long does it take to remove an electron from an atom, molecule, or solid? With regard to rates, we ask the question: how many electrons are emitted in a given unit of time? We present state-of-the-art results on ionization and photoemission time delays and rates. Our review starts with the simplest physical systems: the attosecond dynamics of single-photon and tunnel ionization of atoms in the gas phase. We then extend the discussion to molecular gases and ionization of liquid targets. Finally, we present the measurements of ionization delays in femto- and attosecond photoemission from the solid-vacuum interface.
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Affiliation(s)
- L Gallmann
- Department of Physics, Institute of Quantum Electronics, ETH Zurich, 8093 Zurich, Switzerland
| | - I Jordan
- Laboratorium für Physikalische Chemie, ETH Zürich, Vladimir-Prelog-Weg 2, 8093 Zurich, Switzerland
| | - H J Wörner
- Laboratorium für Physikalische Chemie, ETH Zürich, Vladimir-Prelog-Weg 2, 8093 Zurich, Switzerland
| | - L Castiglioni
- Department of Physics, University of Zurich, 8057 Zürich, Switzerland
| | - M Hengsberger
- Department of Physics, University of Zurich, 8057 Zürich, Switzerland
| | - J Osterwalder
- Department of Physics, University of Zurich, 8057 Zürich, Switzerland
| | - C A Arrell
- Laboratoire de Spectroscopie Ultrarapide (LSU), and Lausanne Centre for Ultrafast Science (LACUS), ISIC-FSB, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
| | - M Chergui
- Laboratoire de Spectroscopie Ultrarapide (LSU), and Lausanne Centre for Ultrafast Science (LACUS), ISIC-FSB, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
| | - E Liberatore
- Laboratory of Computational Chemistry and Biochemistry, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
| | - U Rothlisberger
- Laboratory of Computational Chemistry and Biochemistry, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
| | - U Keller
- Department of Physics, Institute of Quantum Electronics, ETH Zurich, 8093 Zurich, Switzerland
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16
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Bircher MP, Liberatore E, Browning NJ, Brickel S, Hofmann C, Patoz A, Unke OT, Zimmermann T, Chergui M, Hamm P, Keller U, Meuwly M, Woerner HJ, Vaníček J, Rothlisberger U. Nonadiabatic effects in electronic and nuclear dynamics. STRUCTURAL DYNAMICS (MELVILLE, N.Y.) 2017; 4:061510. [PMID: 29376108 PMCID: PMC5760266 DOI: 10.1063/1.4996816] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2017] [Accepted: 10/19/2017] [Indexed: 05/25/2023]
Abstract
Due to their very nature, ultrafast phenomena are often accompanied by the occurrence of nonadiabatic effects. From a theoretical perspective, the treatment of nonadiabatic processes makes it necessary to go beyond the (quasi) static picture provided by the time-independent Schrödinger equation within the Born-Oppenheimer approximation and to find ways to tackle instead the full time-dependent electronic and nuclear quantum problem. In this review, we give an overview of different nonadiabatic processes that manifest themselves in electronic and nuclear dynamics ranging from the nonadiabatic phenomena taking place during tunnel ionization of atoms in strong laser fields to the radiationless relaxation through conical intersections and the nonadiabatic coupling of vibrational modes and discuss the computational approaches that have been developed to describe such phenomena. These methods range from the full solution of the combined nuclear-electronic quantum problem to a hierarchy of semiclassical approaches and even purely classical frameworks. The power of these simulation tools is illustrated by representative applications and the direct confrontation with experimental measurements performed in the National Centre of Competence for Molecular Ultrafast Science and Technology.
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Affiliation(s)
- Martin P Bircher
- Laboratory of Computational Chemistry and Biochemistry, Institut des Sciences et Ingénierie Chimiques, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Elisa Liberatore
- Laboratory of Computational Chemistry and Biochemistry, Institut des Sciences et Ingénierie Chimiques, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Nicholas J Browning
- Laboratory of Computational Chemistry and Biochemistry, Institut des Sciences et Ingénierie Chimiques, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Sebastian Brickel
- Department of Chemistry, University of Basel, Klingelbergstrasse 80, CH-4056 Basel, Switzerland
| | | | - Aurélien Patoz
- Laboratory of Theoretical Physical Chemistry, Institut des Sciences et Ingénierie Chimiques, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Oliver T Unke
- Department of Chemistry, University of Basel, Klingelbergstrasse 80, CH-4056 Basel, Switzerland
| | - Tomáš Zimmermann
- Laboratory of Theoretical Physical Chemistry, Institut des Sciences et Ingénierie Chimiques, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Majed Chergui
- Laboratoire de Spectroscopie Ultrarapide (LSU) and Lausanne Centre for Ultrafast Science (LACUS), Institut des Sciences et Ingénierie Chimiques, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Peter Hamm
- Department of Chemistry, University of Zurich, Zürich, Switzerland
| | - Ursula Keller
- Physics Department, ETH Zurich, CH-8093 Zurich, Switzerland
| | - Markus Meuwly
- Department of Chemistry, University of Basel, Klingelbergstrasse 80, CH-4056 Basel, Switzerland
| | - Hans-Jakob Woerner
- Laboratorium für Physikalische Chemie, ETH Zürich, CH-8093 Zürich, Switzerland
| | - Jiří Vaníček
- Laboratory of Theoretical Physical Chemistry, Institut des Sciences et Ingénierie Chimiques, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Ursula Rothlisberger
- Laboratory of Computational Chemistry and Biochemistry, Institut des Sciences et Ingénierie Chimiques, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
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17
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Yuan M, Xin P, Chu T, Liu H. Exploring tunneling time by instantaneous ionization rate in strong-field ionization. OPTICS EXPRESS 2017; 25:23493-23501. [PMID: 29041649 DOI: 10.1364/oe.25.023493] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Accepted: 09/08/2017] [Indexed: 06/07/2023]
Abstract
A quantum approach is presented to investigate tunneling time by supervising the instantaneous ionization rate. We find that the ionization rate peak appearance lags behind the maximum of electric field intensity for a linearly polarized pulse. This time delay interval can be taken to characterize the tunneling time. In addition, if an atom with anisotropic electronic distribution is exposed to a circular polarized pulse, the tunneling time can also be measured and defined as the time difference between the instant of the largest ionization rate and the moment when the electric field points in the maximum of the bound electron density.
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18
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Zhao R, Sarwono YP, Zhang RQ. Tunneling lifetimes of electrons escaping from atoms under a static electric field. J Chem Phys 2017; 147:064109. [PMID: 28810789 DOI: 10.1063/1.4994937] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The tunneling lifetime of an electron escaping from an atom is calculated using a projected Green's function method, combining with the radial potential of the atom which is obtained from density functional theory. Results of the calculated electron tunneling lifetimes in model systems such as a quantum dot are shown to be comparable with other theoretical studies. For the first time, we have obtained the tunneling lifetimes of electrons escaping from a series of atoms (He, Ne, Ar, Kr, H, Li, Na, K) under a static electric field. Dependent on both the barrier width/height and the bound strength of the ground state electron, the calculated tunneling lifetime under a static electric field spans from femtosecond level to picosecond level, consistent with the attosecond-level results in experiments using a time-dependent external field.
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Affiliation(s)
- Rundong Zhao
- Beijing Computational Science Research Center, Beijing, China
| | | | - Rui-Qin Zhang
- Department of Physics and Materials Science, City University of Hong Kong, Hong Kong, China
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19
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Camus N, Yakaboylu E, Fechner L, Klaiber M, Laux M, Mi Y, Hatsagortsyan KZ, Pfeifer T, Keitel CH, Moshammer R. Experimental Evidence for Quantum Tunneling Time. PHYSICAL REVIEW LETTERS 2017; 119:023201. [PMID: 28753333 DOI: 10.1103/physrevlett.119.023201] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2017] [Indexed: 06/07/2023]
Abstract
The first hundred attoseconds of the electron dynamics during strong field tunneling ionization are investigated. We quantify theoretically how the electron's classical trajectories in the continuum emerge from the tunneling process and test the results with those achieved in parallel from attoclock measurements. An especially high sensitivity on the tunneling barrier is accomplished here by comparing the momentum distributions of two atomic species of slightly deviating atomic potentials (argon and krypton) being ionized under absolutely identical conditions with near-infrared laser pulses (1300 nm). The agreement between experiment and theory provides clear evidence for a nonzero tunneling time delay and a nonvanishing longitudinal momentum of the electron at the "tunnel exit."
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Affiliation(s)
- Nicolas Camus
- Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg, Germany
| | - Enderalp Yakaboylu
- Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg, Germany
| | - Lutz Fechner
- Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg, Germany
| | - Michael Klaiber
- Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg, Germany
| | - Martin Laux
- Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg, Germany
| | - Yonghao Mi
- Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg, Germany
| | | | - Thomas Pfeifer
- Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg, Germany
| | - Christoph H Keitel
- Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg, Germany
| | - Robert Moshammer
- Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg, Germany
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20
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Tian J, Wang X, Eberly JH. Numerical Detector Theory for the Longitudinal Momentum Distribution of the Electron in Strong Field Ionization. PHYSICAL REVIEW LETTERS 2017; 118:213201. [PMID: 28598667 DOI: 10.1103/physrevlett.118.213201] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2016] [Indexed: 06/07/2023]
Abstract
The lack of analytical solutions for the exit momentum in the laser-driven tunneling theory is a well-recognized problem in strong field physics. Theoretical studies of electron momentum distributions in the neighborhood of the tunneling exit depend heavily on ad hoc assumptions. In this Letter, we apply a new numerical method to study the exiting electron's longitudinal momentum distribution under intense short-pulse laser excitation. We present the first realizations of the dynamic behavior of an electron near the so-called tunneling exit region without adopting a tunneling approximation.
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Affiliation(s)
- Justin Tian
- Department of Physics and Astronomy, University of Rochester, Rochester, New York 14627, USA
| | - Xu Wang
- Graduate School, China Academy of Engineering Physics, Beijing 100193, China
| | - J H Eberly
- Department of Physics and Astronomy, University of Rochester, Rochester, New York 14627, USA
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21
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Hao X, Shu Z, Li W, Hu S, Chen J. Quantitative identification of different strong-field ionization channels in the transition regime. OPTICS EXPRESS 2016; 24:25250-25257. [PMID: 27828463 DOI: 10.1364/oe.24.025250] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
We make a quantitative investigation on the tunneling and multi-photon channels in the transition regime from Keldysh parameter γ < 1 to γ > 1 by numerically solving the time-dependent Schrödinger equation (TDSE). A method is proposed to separate the contributions of those ionization channels based on the characteristics of the current. By analysing the dependence of the ionization rate on the Keldysh parameter γ, we identify a field independent transition point at γ ≈ 2, which is different from the well-accepted consensus of γ ≈ 1, from adiabatic to nonadiabatic regime.
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22
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Quan W, Yuan M, Yu S, Xu S, Chen Y, Wang Y, Sun R, Xiao Z, Gong C, Hua L, Lai X, Liu X, Chen J. Laser intensity determination using nonadiabatic tunneling ionization of atoms in close-to-circularly polarized laser fields. OPTICS EXPRESS 2016; 24:23248-23259. [PMID: 27828389 DOI: 10.1364/oe.24.023248] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
We conceive an improved procedure to determine the laser intensity with the momentum distributions from nonadiabatic tunneling ionization of atoms in the close-to-circularly polarized laser fields. The measurements for several noble gas atoms are in accordance with the semiclassical calculations, where the nonadiabatic effect and the influence of Coulomb potential are included. Furthermore, the high-order above-threshold ionization spectrum in linearly polarized laser fields for Ar is measured and compared with the numerical calculation of the time-dependent Schrödinger equation in the single-active-electron approximation to test the accuracy of the calibrated laser intensity.
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23
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Unraveling nonadiabatic ionization and Coulomb potential effect in strong-field photoelectron holography. Sci Rep 2016; 6:28392. [PMID: 27329071 PMCID: PMC4916607 DOI: 10.1038/srep28392] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2016] [Accepted: 06/02/2016] [Indexed: 11/08/2022] Open
Abstract
Strong field photoelectron holography has been proposed as a means for interrogating the spatial and temporal information of electrons and ions in a dynamic system. After ionization, part of the electron wave packet may directly go to the detector (the reference wave), while another part may be driven back and scatters off the ion(the signal wave). The interference hologram of the two waves may be used to extract target information embedded in the collision process. Unlike conventional optical holography, however, propagation of the electron wave packet is affected by the Coulomb potential as well as by the laser field. In addition, electrons are emitted over the whole laser pulse duration, thus multiple interferences may occur. In this work, we used a generalized quantum-trajectory Monte Carlo method to investigate the effect of Coulomb potential and the nonadiabatic subcycle ionization on the photoelectron hologram. We showed that photoelectron hologram can be well described only when the effect of nonadiabatic ionization is accounted for, and Coulomb potential can be neglected only in the tunnel ionization regime. Our results help paving the way for establishing photoelectron holography for probing spatial and dynamic properties of atoms and molecules.
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24
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Zimmermann T, Mishra S, Doran BR, Gordon DF, Landsman AS. Tunneling Time and Weak Measurement in Strong Field Ionization. PHYSICAL REVIEW LETTERS 2016; 116:233603. [PMID: 27341232 DOI: 10.1103/physrevlett.116.233603] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2015] [Indexed: 06/06/2023]
Abstract
Tunneling delays represent a hotly debated topic, with many conflicting definitions and little consensus on when and if such definitions accurately describe the physical observables. Here, we relate these different definitions to distinct experimental observables in strong field ionization, finding that two definitions, Larmor time and Bohmian time, are compatible with the attoclock observable and the resonance lifetime of a bound state, respectively. Both of these definitions are closely connected to the theory of weak measurement, with Larmor time being the weak measurement value of tunneling time and Bohmian trajectory corresponding to the average particle trajectory, which has been recently reconstructed using weak measurement in a two-slit experiment [S. Kocsis, B. Braverman, S. Ravets, M. J. Stevens, R. P. Mirin, L. K. Shalm, and A. M. Steinberg, Science 332, 1170 (2011)]. We demonstrate a big discrepancy in strong field ionization between the Bohmian and weak measurement values of tunneling time, and we suggest this arises because the tunneling time is calculated for a small probability postselected ensemble of electrons. Our results have important implications for the interpretation of experiments in attosecond science, suggesting that tunneling is unlikely to be an instantaneous process.
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Affiliation(s)
- Tomáš Zimmermann
- Seminar for Applied Mathematics, ETH Zurich, CH-8093 Zurich, Switzerland
- Physics Department, ETH Zurich, CH-8093 Zurich, Switzerland
| | - Siddhartha Mishra
- Seminar for Applied Mathematics, ETH Zurich, CH-8093 Zurich, Switzerland
| | - Brent R Doran
- Department of Mathematics, ETH Zurich, CH-8093 Zurich, Switzerland
| | - Daniel F Gordon
- Radiation and Acceleration Physics Section, Naval Research Laboratory, Washington, D.C. 20375, USA
| | - Alexandra S Landsman
- Seminar for Applied Mathematics, ETH Zurich, CH-8093 Zurich, Switzerland
- Physics Department, ETH Zurich, CH-8093 Zurich, Switzerland
- Max Planck Institute for the Physics of Complex Systems, D-01187 Dresden, Germany
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25
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Geng JW, Xiong WH, Xiao XR, Peng LY, Gong Q. Nonadiabatic Electron Dynamics in Orthogonal Two-Color Laser Fields with Comparable Intensities. PHYSICAL REVIEW LETTERS 2015; 115:193001. [PMID: 26588375 DOI: 10.1103/physrevlett.115.193001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2015] [Indexed: 06/05/2023]
Abstract
We theoretically investigate the nonadiabatic subcycle electron dynamics in orthogonally polarized two-color laser fields with comparable intensities. The photoelectron dynamics is simulated by exact solution to the 3D time-dependent Schrödinger equation, and also by two other semiclassical methods, i.e., the quantum trajectory Monte Carlo simulation and the Coulomb-corrected strong field approximation. Through these methods, we identify the underlying mechanisms of the subcycle electron dynamics and find that both the nonadiabatic effects and the Coulomb potential play very important roles. The contribution of the nonadiabatic effects manifest in two aspects, i.e., the nonadiabatic ionization rate and the nonzero initial velocities at the tunneling exit. The Coulomb potential has a different impact on the electrons' trajectories for different relative phases between the two pulses.
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Affiliation(s)
- Ji-Wei Geng
- State Key Laboratory for Mesoscopic Physics and Department of Physics, Peking University, Beijing 100871, China
| | - Wei-Hao Xiong
- State Key Laboratory for Mesoscopic Physics and Department of Physics, Peking University, Beijing 100871, China
| | - Xiang-Ru Xiao
- State Key Laboratory for Mesoscopic Physics and Department of Physics, Peking University, Beijing 100871, China
| | - Liang-You Peng
- State Key Laboratory for Mesoscopic Physics and Department of Physics, Peking University, Beijing 100871, China
- Collaborative Innovation Center of Quantum Matter, Beijing 100871, China
| | - Qihuang Gong
- State Key Laboratory for Mesoscopic Physics and Department of Physics, Peking University, Beijing 100871, China
- Collaborative Innovation Center of Quantum Matter, Beijing 100871, China
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26
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Klaiber M, Hatsagortsyan KZ, Keitel CH. Tunneling dynamics in multiphoton ionization and attoclock calibration. PHYSICAL REVIEW LETTERS 2015; 114:083001. [PMID: 25768761 DOI: 10.1103/physrevlett.114.083001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2014] [Indexed: 06/04/2023]
Abstract
The intermediate domain of strong-field ionization between the tunneling and multiphoton regimes is investigated using the strong-field approximation and the imaginary-time method. An intuitive model for the dynamics is developed which describes the ionization process within a nonadiabatic tunneling picture with a coordinate dependent electron energy during the under-the-barrier motion. The nonadiabatic effects in the elliptically polarized laser field induce a transversal momentum shift of the tunneled electron wave packet at the tunnel exit and a delayed appearance in the continuum as well as a shift of the tunneling exit towards the ionic core. The latter significantly modifies the Coulomb focusing during the electron excursion in the laser field after exiting the ionization tunnel. We show that nonadiabatic effects are especially large when the Coulomb field of the ionic core is taken into account during the under-the-barrier motion. The simple man model modified with these nonadiabatic corrections provides an intuitive background for exact theories and has direct implications for the calibration of the attoclock technique.
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Affiliation(s)
- Michael Klaiber
- Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg, Germany
| | | | - Christoph H Keitel
- Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg, Germany
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27
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Krause P, Schlegel HB. Strong-field ionization rates of linear polyenes simulated with time-dependent configuration interaction with an absorbing potential. J Chem Phys 2014; 141:174104. [DOI: 10.1063/1.4900576] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Pascal Krause
- Department of Chemistry, Wayne State University, Detroit, Michigan 48202-3489, USA
| | - H. Bernhard Schlegel
- Department of Chemistry, Wayne State University, Detroit, Michigan 48202-3489, USA
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28
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Boge R, Heuser S, Sabbar M, Lucchini M, Gallmann L, Cirelli C, Keller U. Revealing the time-dependent polarization of ultrashort pulses with sub-cycle resolution. OPTICS EXPRESS 2014; 22:26967-26975. [PMID: 25401846 DOI: 10.1364/oe.22.026967] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
We report on the first experiments characterizing the complete time-dependent 2D vector potential of a few-cycle laser pulse. The instantaneous amplitude and orientation of the electric field is determined with sub-cycle resolution, directly giving access to the polarization state of the pulse at any instant in time. This is achieved by performing an attosecond streaking experiment using a reaction microscope, where the full pulse characterization is performed directly in the target region.
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29
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Sabbar M, Heuser S, Boge R, Lucchini M, Gallmann L, Cirelli C, Keller U. Combining attosecond XUV pulses with coincidence spectroscopy. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2014; 85:103113. [PMID: 25362377 DOI: 10.1063/1.4898017] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Here we present a successful combination of an attosecond beamline with a COLTRIMS apparatus, which we refer to as AttoCOLTRIMS. The setup provides either single attosecond pulses or attosecond pulse trains for extreme ultraviolet-infrared pump-probe experiments. We achieve full attosecond stability by using an active interferometer stabilization. The capability of the setup is demonstrated by means of two measurements, which lie at the heart of the COLTRIMS detector: firstly, we resolve the rotating electric field vector of an elliptically polarized few-cycle infrared laser field by attosecond streaking exploiting the access to the 3D momentum space of the charged particles. Secondly, we show streaking measurements on different atomic species obtained simultaneously in a single measurement making use of the advantage of measuring ions and electrons in coincidence. Both of these studies demonstrate the potential of the AttoCOLTRIMS for attosecond science.
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Affiliation(s)
- M Sabbar
- Department of Physics, ETH Zurich, 8093 Zurich, Switzerland
| | - S Heuser
- Department of Physics, ETH Zurich, 8093 Zurich, Switzerland
| | - R Boge
- Department of Physics, ETH Zurich, 8093 Zurich, Switzerland
| | - M Lucchini
- Department of Physics, ETH Zurich, 8093 Zurich, Switzerland
| | - L Gallmann
- Department of Physics, ETH Zurich, 8093 Zurich, Switzerland
| | - C Cirelli
- Department of Physics, ETH Zurich, 8093 Zurich, Switzerland
| | - U Keller
- Department of Physics, ETH Zurich, 8093 Zurich, Switzerland
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30
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Landsman AS, Hofmann C, Pfeiffer AN, Cirelli C, Keller U. Unified approach to probing Coulomb effects in tunnel ionization for any ellipticity of laser light. PHYSICAL REVIEW LETTERS 2013; 111:263001. [PMID: 24483793 DOI: 10.1103/physrevlett.111.263001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2013] [Indexed: 06/03/2023]
Abstract
We present experimental data that show significant deviations from theoretical predictions for the location of the center of the electron momenta distribution at low values of ellipticity ε of laser light. We show that these deviations are caused by significant Coulomb focusing along the minor axis of polarization, something that is normally neglected in the analysis of electron dynamics, even in cases where the Coulomb correction is otherwise taken into account. By investigating ellipticity-resolved electron momenta distributions in the plane of polarization, we show that Coulomb focusing predominates at lower values of ellipticity of laser light, while Coulomb asymmetry becomes important at higher values, showing that these two complementary phenomena can be used to probe long-range Coulomb interaction at all polarizations of laser light. Our results suggest that both the breakdown of Coulomb focusing and the onset of Coulomb asymmetry are linked to the disappearance of Rydberg states with increasing ellipticity.
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Affiliation(s)
- A S Landsman
- Physics Department, ETH Zurich, CH-8093 Zurich, Switzerland
| | - C Hofmann
- Physics Department, ETH Zurich, CH-8093 Zurich, Switzerland
| | - A N Pfeiffer
- Physics Department, ETH Zurich, CH-8093 Zurich, Switzerland
| | - C Cirelli
- Physics Department, ETH Zurich, CH-8093 Zurich, Switzerland
| | - U Keller
- Physics Department, ETH Zurich, CH-8093 Zurich, Switzerland
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