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Tong J, Liu X, Dong W, Jiang W, Zhu M, Xu Y, Zuo Z, Lu P, Gong X, Song X, Yang W, Wu J. Probing Resonant Photoionization Time Delay by Self-Referenced Molecular Attoclock. PHYSICAL REVIEW LETTERS 2022; 129:173201. [PMID: 36332237 DOI: 10.1103/physrevlett.129.173201] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Revised: 03/28/2022] [Accepted: 09/23/2022] [Indexed: 06/16/2023]
Abstract
Attosecond time-resolved electron tunneling dynamics have been investigated by using attosecond angular streaking spectroscopy, where a clock reference to the laser field vector is required in atomic strong-field ionization and the situation becomes complicated in molecules. Here we reveal a resonant ionization process via a transient state by developing an electron-tunneling-site-resolved molecular attoclock in Ar-Kr^{+}. Two distinct deflection angles are observed in the photoelectron angular distribution in the molecular frame, corresponding to the direct and resonant ionization pathways. We find the electron is temporally trapped in the Coulomb potential wells of the Ar-Kr^{+} before finally releasing into the continuum when the electron tunnels through the internal barrier. By utilizing the direct tunneling ionization as a self-referenced arm of the attoclock, the time delay of the electron trapped in the resonant state is revealed to be 3.50±0.04 fs. Our results give an impetus to exploring the ultrafast electron dynamics in complex systems and also endow a semiclassical presentation of the electron trapping dynamics in a quantum resonant state.
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Affiliation(s)
- Jihong Tong
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200241, China
| | - Xiwang Liu
- School of Science and Center for Theoretical Physics, Hainan University, Haikou 570288, China
| | - Wenhui Dong
- Department of Physics, College of Science, Shantou University, Shantou, Guangdong 515063, China
| | - Wenyu Jiang
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200241, China
| | - Ming Zhu
- School of Science and Center for Theoretical Physics, Hainan University, Haikou 570288, China
| | - Yidan Xu
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200241, China
| | - Zitan Zuo
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200241, China
| | - Peifen Lu
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200241, China
| | - Xiaochun Gong
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200241, China
- Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan, Shanxi 030006, China
| | - Xiaohong Song
- School of Science and Center for Theoretical Physics, Hainan University, Haikou 570288, China
| | - Weifeng Yang
- School of Science and Center for Theoretical Physics, Hainan University, Haikou 570288, China
| | - Jian Wu
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200241, China
- Chongqing Key Laboratory of Precision Optics, Chongqing Institute of East China Normal University, Chongqing 401121, China
- Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan, Shanxi 030006, China
- CAS Center for Excellence in Ultra-intense Laser Science, Shanghai 201800, China
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2
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Ge P, Fang Y, Guo Z, Ma X, Yu X, Han M, Wu C, Gong Q, Liu Y. Probing the Spin-Orbit Time Delay of Multiphoton Ionization of Kr by Bicircular Fields. PHYSICAL REVIEW LETTERS 2021; 126:223001. [PMID: 34152168 DOI: 10.1103/physrevlett.126.223001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Accepted: 05/06/2021] [Indexed: 06/13/2023]
Abstract
We study multiphoton ionization of Kr atoms by circular 400-nm laser fields and probe its photoelectron circular dichroism with the weak corotating and counterrotating circular fields at 800 nm. The unusual momentum- and energy-resolved photoelectron circular dichroisms from the ^{2}P_{1/2} ionic state are observed as compared with those from ^{2}P_{3/2} ionic state. We identify an anomalous ionization enhancement at sidebands related to the ^{2}P_{1/2} ionic state on photoelectron momentum distribution when switching the relative helicity of the two fields from corotating to counterrotating. By performing the two-color intensity-continuously-varying experiments and the pump-probe experiment, we find a specific mixed-photon populated resonant transition channel in counterrotating fields that contributes to the ionization enhancement. We then probe the time delay between the two spin-orbit coupled ionic states (^{2}P_{1/2} and ^{2}P_{3/2}) using bicircular fields and reveal that the resonant transition has an insignificant effect on the relative spin-orbit time delay.
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Affiliation(s)
- Peipei Ge
- State Key Laboratory for Mesoscopic Physics and Frontiers Science Center for Nano-optoelectronics, School of Physics, Peking University, Beijing 100871, China
| | - Yiqi Fang
- State Key Laboratory for Mesoscopic Physics and Frontiers Science Center for Nano-optoelectronics, School of Physics, Peking University, Beijing 100871, China
| | - Zhenning Guo
- State Key Laboratory for Mesoscopic Physics and Frontiers Science Center for Nano-optoelectronics, School of Physics, Peking University, Beijing 100871, China
| | - Xueyan Ma
- State Key Laboratory for Mesoscopic Physics and Frontiers Science Center for Nano-optoelectronics, School of Physics, Peking University, Beijing 100871, China
| | - Xiaoyang Yu
- State Key Laboratory for Mesoscopic Physics and Frontiers Science Center for Nano-optoelectronics, School of Physics, Peking University, Beijing 100871, China
| | - Meng Han
- State Key Laboratory for Mesoscopic Physics and Frontiers Science Center for Nano-optoelectronics, School of Physics, Peking University, Beijing 100871, China
| | - Chengyin Wu
- State Key Laboratory for Mesoscopic Physics and Frontiers Science Center for Nano-optoelectronics, School of Physics, Peking University, Beijing 100871, China
- Collaborative Innovation Center of Quantum Matter, Beijing 100871, China
- Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan, Shanxi 030006, China
| | - Qihuang Gong
- State Key Laboratory for Mesoscopic Physics and Frontiers Science Center for Nano-optoelectronics, School of Physics, Peking University, Beijing 100871, China
- Collaborative Innovation Center of Quantum Matter, Beijing 100871, China
- Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan, Shanxi 030006, China
| | - Yunquan Liu
- State Key Laboratory for Mesoscopic Physics and Frontiers Science Center for Nano-optoelectronics, School of Physics, Peking University, Beijing 100871, China
- Collaborative Innovation Center of Quantum Matter, Beijing 100871, China
- Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan, Shanxi 030006, China
- Center for Applied Physics and Technology, HEDPS, Peking University, Beijing 100871, China
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Angle-dependent electron-electron correlation in the single ionization of H 2 in strong laser fields. Sci Rep 2018; 8:14933. [PMID: 30297785 PMCID: PMC6175880 DOI: 10.1038/s41598-018-33015-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2018] [Accepted: 09/11/2018] [Indexed: 11/29/2022] Open
Abstract
The one-photon ionization and tunneling ionization of H2 exposed to strong XUV and infrared laser pulses are studied by numerically simulating the four-dimensional time-dependent Schrödinger equation, which includes two-electron dynamics for arbitrary angle between the molecular axis and the laser polarization direction. In the one-photon single ionization of H2, one electron escapes fast and the other bound electron is not disturbed but remains in coherent superposition of two electronic states of \documentclass[12pt]{minimal}
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\begin{document}$${{\bf{H}}}_{{\bf{2}}}^{{\boldsymbol{+}}}$$\end{document}H2+. In another case, under the irradiation of strong infrared laser pulses, one electron tunnels through the laser-dressed Coulomb barrier, and the other bound electron has enough time to adapt to the potential of \documentclass[12pt]{minimal}
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\begin{document}$${{\bf{H}}}_{{\bf{2}}}^{{\boldsymbol{+}}}$$\end{document}H2+ and thus is prone to transfer to the ground electronic state of \documentclass[12pt]{minimal}
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\begin{document}$${{\bf{H}}}_{{\bf{2}}}^{{\boldsymbol{+}}}$$\end{document}H2+. In the intermediate regime, between the one photon and tunneling regimes, this electron-electron correlation depends strongly on the laser frequency, laser intensity and on the angle between laser polarization and the molecular axis.
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Song X, Shi G, Zhang G, Xu J, Lin C, Chen J, Yang W. Attosecond Time Delay of Retrapped Resonant Ionization. PHYSICAL REVIEW LETTERS 2018; 121:103201. [PMID: 30240251 DOI: 10.1103/physrevlett.121.103201] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Revised: 07/10/2018] [Indexed: 06/08/2023]
Abstract
A recent ultrafast pump-probe technique has allowed measurement of time delays during photoemission in a variety of systems ranging from atoms and molecules to solids with unprecedented temporal resolution. However, identifying the underlying physics is still a challenge especially in complicated multichannel above-threshold ionization (ATI) experiments. Here we demonstrate that the time delays of different ionization pathways in ATI can be clearly resolved and extracted with a semiclassical statistical method. The remarkable phase shift of near threshold photoelectrons can be attributed to a temporary retrapping of a photoelectron by the atomic potential in a quasibound state after emerging in the continuum state. This continuum-bound-continuum scattering manifests as a new resonant effect in strong-field photoemission. Our results unify the seemingly opposing quantum Eisenbud-Wigner-Smith time delay and classical Coulomb-induced time delay by highlighting the same physical picture, which holds promise for an intuitive interpretation of time-resolved fundamental electronic processes in strong-field experiments and epistemological reexamination of the quantum-classical correspondence.
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Affiliation(s)
- Xiaohong Song
- Department of Physics, College of Science, Shantou University, Shantou, Guangdong 515063, China
| | - Guangluo Shi
- Department of Physics, College of Science, Shantou University, Shantou, Guangdong 515063, China
| | - Guojun Zhang
- Department of Physics, College of Science, Shantou University, Shantou, Guangdong 515063, China
| | - Jingwen Xu
- Department of Physics, College of Science, Shantou University, Shantou, Guangdong 515063, China
| | - Cheng Lin
- Department of Physics, College of Science, Shantou University, Shantou, Guangdong 515063, China
| | - Jing Chen
- Key Laboratory of High Energy Density Physics Simulation, Center for Applied Physics and Technology, Peking University, Beijing 100084, China
- Institute of Applied Physics and Computational Mathematics, P.O. Box 8009, Beijing 100088, China
- Collaborative Innovation Center of Inertial Fusion Sciences and Applications, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Weifeng Yang
- Department of Physics, College of Science, Shantou University, Shantou, Guangdong 515063, China
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Attosecond Time Delay in Photoionization of Noble-Gas and Halogen Atoms. APPLIED SCIENCES-BASEL 2018. [DOI: 10.3390/app8030322] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Ultrafast processes are now accessible on the attosecond time scale due to the availability of ultrashort XUV laser pulses. Noble-gas and halogen atoms remain important targets due to their giant dipole resonance and Cooper minimum. Here, we calculate photoionization cross section, asymmetry parameter and Wigner time delay using the time-dependent local-density approximation (TDLDA), which includes the electron correlation effects. Our results are consistent with experimental data and other theoretical calculations. The asymmetry parameter provides an extra layer of access to the phase information of the photoionization processes. We find that halogen atoms bear a strong resemblance on cross section, asymmetry parameter and time delay to their noble-gas neighbors. Our predicted time delay should provide a guidance for future experiments on those atoms and related molecules.
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Gong X, Lin C, He F, Song Q, Lin K, Ji Q, Zhang W, Ma J, Lu P, Liu Y, Zeng H, Yang W, Wu J. Energy-Resolved Ultrashort Delays of Photoelectron Emission Clocked by Orthogonal Two-Color Laser Fields. PHYSICAL REVIEW LETTERS 2017; 118:143203. [PMID: 28430519 DOI: 10.1103/physrevlett.118.143203] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2016] [Indexed: 06/07/2023]
Abstract
A phase-controlled orthogonal two-color (OTC) femtosecond laser pulse is employed to probe the time delay of photoelectron emission in the strong-field ionization of atoms. The OTC field spatiotemporally steers the emission dynamics of the photoelectrons and meanwhile allows us to unambiguously distinguish the main and sideband peaks of the above-threshold ionization spectrum. The relative phase shift between the main and sideband peaks, retrieved from the phase-of-phase of the photoelectron spectrum as a function of the laser phase, gradually decreases with increasing electron energy, and becomes zero for the fast electron which is mainly produced by the rescattering process. Furthermore, a Freeman resonance delay of 140±40 attoseconds between photoelectrons emitted via the 4f and 5p Rydberg states of argon is observed.
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Affiliation(s)
- Xiaochun Gong
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200062, China
| | - Cheng Lin
- Department of Physics, College of Science, Shantou University, Shantou, Guangdong 515063, China
| | - Feng He
- Key Laboratory of Laser Plasmas (Ministry of Education) and Department of Physics and Astronomy, Collaborative Innovation Center for IFSA (CICIFSA), Shanghai Jiao Tong University, Shanghai 200240, China
| | - Qiying Song
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200062, China
| | - Kang Lin
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200062, China
| | - Qinying Ji
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200062, China
| | - Wenbin Zhang
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200062, China
| | - Junyang Ma
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200062, China
| | - Peifen Lu
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200062, China
| | - Yunquan Liu
- Department of Physics and State Key Laboratory for Mesoscopic Physics, Peking University, Beijing 100871, China
| | - Heping Zeng
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200062, China
| | - Weifeng Yang
- Department of Physics, College of Science, Shantou University, Shantou, Guangdong 515063, China
| | - Jian Wu
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200062, China
- Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan, Shanxi 030006, China
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Ni H, Saalmann U, Rost JM. Tunneling Ionization Time Resolved by Backpropagation. PHYSICAL REVIEW LETTERS 2016; 117:023002. [PMID: 27447504 DOI: 10.1103/physrevlett.117.023002] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2016] [Indexed: 06/06/2023]
Abstract
We determine the ionization time in tunneling ionization by an elliptically polarized light pulse relative to its maximum. This is achieved by a full quantum propagation of the electron wave function forward in time, followed by a classical backpropagation to identify tunneling parameters, in particular, the fraction of electrons that has tunneled out. We find that the ionization time is close to zero for single active electrons in helium and in hydrogen if the fraction of tunneled electrons is large. We expect our analysis to be essential to quantify ionization times for correlated electron motion.
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Affiliation(s)
- Hongcheng Ni
- Max-Planck-Institut für Physik komplexer Systeme, Nöthnitzer Strasse 38, 01187 Dresden, Germany
| | - Ulf Saalmann
- Max-Planck-Institut für Physik komplexer Systeme, Nöthnitzer Strasse 38, 01187 Dresden, Germany
| | - Jan-Michael Rost
- Max-Planck-Institut für Physik komplexer Systeme, Nöthnitzer Strasse 38, 01187 Dresden, Germany
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Spectral phase measurement of a Fano resonance using tunable attosecond pulses. Nat Commun 2016; 7:10566. [PMID: 26887682 PMCID: PMC4759632 DOI: 10.1038/ncomms10566] [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: 09/29/2015] [Accepted: 12/24/2015] [Indexed: 01/30/2023] Open
Abstract
Electron dynamics induced by resonant absorption of light is of fundamental importance in nature and has been the subject of countless studies in many scientific areas. Above the ionization threshold of atomic or molecular systems, the presence of discrete states leads to autoionization, which is an interference between two quantum paths: direct ionization and excitation of the discrete state coupled to the continuum. Traditionally studied with synchrotron radiation, the probability for autoionization exhibits a universal Fano intensity profile as a function of excitation energy. However, without additional phase information, the full temporal dynamics cannot be recovered. Here we use tunable attosecond pulses combined with weak infrared radiation in an interferometric setup to measure not only the intensity but also the phase variation of the photoionization amplitude across an autoionization resonance in argon. The phase variation can be used as a fingerprint of the interactions between the discrete state and the ionization continua, indicating a new route towards monitoring electron correlations in time. Resonant absorption of light in atoms can lead to autoionization, whose probability exhibits a Fano intensity profile. Here, the authors use attosecond pulses and weak infrared radiation to study the phase variation of the photoionization amplitude across an autoionization resonance in argon.
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