1
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Larsen KA, Borne K, Obaid R, Kamalov A, Liu Y, Cheng X, James J, Driver T, Li K, Liu Y, Sakdinawat A, David C, Wolf TJA, Cryan JP, Walter P, Lin MF. Compact single-shot soft X-ray photon spectrometer for free-electron laser diagnostics. OPTICS EXPRESS 2023; 31:35822-35834. [PMID: 38017746 DOI: 10.1364/oe.502105] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/12/2023] [Accepted: 09/20/2023] [Indexed: 11/30/2023]
Abstract
The photon spectrum from free-electron laser (FEL) light sources offers valuable information in time-resolved experiments and machine optimization in the spectral and temporal domains. We have developed a compact single-shot photon spectrometer to diagnose soft X-ray spectra. The spectrometer consists of an array of off-axis Fresnel zone plates (FZP) that act as transmission-imaging gratings, a Ce:YAG scintillator, and a microscope objective to image the scintillation target onto a two-dimensional imaging detector. This spectrometer operates in segmented energy ranges which covers tens of electronvolts for each absorption edge associated with several atomic constituents: carbon, nitrogen, oxygen, and neon. The spectrometer's performance is demonstrated at a repetition rate of 120 Hz, but our detection scheme can be easily extended to 200 kHz spectral collection by employing a fast complementary metal oxide semiconductor (CMOS) line-scan camera to detect the light from the scintillator. This compact photon spectrometer provides an opportunity for monitoring the spectrum downstream of an endstation in a limited space environment with sub-electronvolt energy resolution.
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2
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Keefer D, Cavaletto SM, Rouxel JR, Garavelli M, Yong H, Mukamel S. Ultrafast X-Ray Probes of Elementary Molecular Events. Annu Rev Phys Chem 2023; 74:73-97. [PMID: 37093660 DOI: 10.1146/annurev-physchem-062322-051532] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/25/2023]
Abstract
Elementary events that determine photochemical outcomes and molecular functionalities happen on the femtosecond and subfemtosecond timescales. Among the most ubiquitous events are the nonadiabatic dynamics taking place at conical intersections. These facilitate ultrafast, nonradiative transitions between electronic states in molecules that can outcompete slower relaxation mechanisms such as fluorescence. The rise of ultrafast X-ray sources, which provide intense light pulses with ever-shorter durations and larger observation bandwidths, has fundamentally revolutionized our spectroscopic capabilities to detect conical intersections. Recent theoretical studies have demonstrated an entirely new signature emerging once a molecule traverses a conical intersection, giving detailed insights into the coupled nuclear and electronic motions that underlie, facilitate, and ultimately determine the ultrafast molecular dynamics. Following a summary of current sources and experiments, we survey these techniques and provide a unified overview of their capabilities. We discuss their potential to dramatically increase our understanding of ultrafast photochemistry.
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Affiliation(s)
- Daniel Keefer
- Department of Chemistry and Department of Physics and Astronomy, University of California, Irvine, California, USA; ,
| | - Stefano M Cavaletto
- Department of Chemistry and Department of Physics and Astronomy, University of California, Irvine, California, USA; ,
- Current affiliation: Department of Physics and Astronomy, Aarhus University, Aarhus, Denmark
| | - Jérémy R Rouxel
- Université de Lyon, UJM-Saint-Etienne, IOGS, Laboratoire Hubert Curien, UMR CNRS 5516, Saint-Etienne, France
| | - Marco Garavelli
- Dipartimento di Chimica Industriale, Università degli Studi di Bologna, Bologna, Italy
| | - Haiwang Yong
- Department of Chemistry and Department of Physics and Astronomy, University of California, Irvine, California, USA; ,
| | - Shaul Mukamel
- Department of Chemistry and Department of Physics and Astronomy, University of California, Irvine, California, USA; ,
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3
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Fouda AEA, Koulentianos D, Young L, Doumy G, Ho PJ. Resonant double-core excitations with ultrafast, intense X-ray pulses. Mol Phys 2022. [DOI: 10.1080/00268976.2022.2133749] [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]
Affiliation(s)
- Adam E. A. Fouda
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, IL, USA
| | - Dimitris Koulentianos
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, IL, USA
| | - Linda Young
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, IL, USA
- Department of Physics and James Franck Institute, The University of Chicago, Chicago, IL, USA
| | - Gilles Doumy
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, IL, USA
| | - Phay J. Ho
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, IL, USA
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4
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Straub M, Ding T, Rebholz M, Borisova GD, Magunia A, Lindenblatt H, Meister S, Trost F, Wang Y, Palutke S, Braune M, Düsterer S, Treusch R, Greene CH, Moshammer R, Pfeifer T, Ott C. Differential Measurement of Electron Ejection after Two-Photon Two-Electron Excitation of Helium. PHYSICAL REVIEW LETTERS 2022; 129:183204. [PMID: 36374686 DOI: 10.1103/physrevlett.129.183204] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2022] [Accepted: 10/04/2022] [Indexed: 06/16/2023]
Abstract
We report the measurement of the photoelectron angular distribution of two-photon single-ionization near the 2p^{2} ^{1}D^{e} double-excitation resonance in helium, benchmarking the fundamental nonlinear interaction of two photons with two correlated electrons. This observation is enabled by the unique combination of intense extreme ultraviolet pulses, delivered at the high-repetition-rate free-electron laser in Hamburg (FLASH), ionizing a jet of cryogenically cooled helium atoms in a reaction microscope. The spectral structure of the intense self-amplified spontaneous emission free-electron laser pulses has been resolved on a single-shot level to allow for post selection of pulses, leading to an enhanced spectral resolution, and introducing a new experimental method. The measured angular distribution is directly compared to state-of-the-art theory based on multichannel quantum defect theory and the streamlined R-matrix method. These results and experimental methodology open a promising route for exploring fundamental interactions of few photons with few electrons in general.
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Affiliation(s)
- Michael Straub
- Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, D-69117 Heidelberg, Germany
| | - Thomas Ding
- Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, D-69117 Heidelberg, Germany
| | - Marc Rebholz
- Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, D-69117 Heidelberg, Germany
| | - Gergana D Borisova
- Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, D-69117 Heidelberg, Germany
| | - Alexander Magunia
- Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, D-69117 Heidelberg, Germany
| | - Hannes Lindenblatt
- Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, D-69117 Heidelberg, Germany
| | - Severin Meister
- Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, D-69117 Heidelberg, Germany
| | - Florian Trost
- Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, D-69117 Heidelberg, Germany
| | - Yimeng Wang
- Department of Physics and Astronomy, Purdue University, West Lafayette, Indiana 47907, USA
| | - Steffen Palutke
- Deutsches Elektronen Synchroton DESY, Notkestrasse 85, D-22607 Hamburg, Germany
| | - Markus Braune
- Deutsches Elektronen Synchroton DESY, Notkestrasse 85, D-22607 Hamburg, Germany
| | - Stefan Düsterer
- Deutsches Elektronen Synchroton DESY, Notkestrasse 85, D-22607 Hamburg, Germany
| | - Rolf Treusch
- Deutsches Elektronen Synchroton DESY, Notkestrasse 85, D-22607 Hamburg, Germany
| | - Chris H Greene
- Department of Physics and Astronomy, Purdue University, West Lafayette, Indiana 47907, USA
| | - Robert Moshammer
- Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, D-69117 Heidelberg, Germany
| | - Thomas Pfeifer
- Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, D-69117 Heidelberg, Germany
| | - Christian Ott
- Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, D-69117 Heidelberg, Germany
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5
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Artificial intelligence for online characterization of ultrashort X-ray free-electron laser pulses. Sci Rep 2022; 12:17809. [PMID: 36280680 PMCID: PMC9592592 DOI: 10.1038/s41598-022-21646-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Accepted: 09/28/2022] [Indexed: 11/24/2022] Open
Abstract
X-ray free-electron lasers (XFELs) as the world’s brightest light sources provide ultrashort X-ray pulses with a duration typically in the order of femtoseconds. Recently, they have approached and entered the attosecond regime, which holds new promises for single-molecule imaging and studying nonlinear and ultrafast phenomena such as localized electron dynamics. The technological evolution of XFELs toward well-controllable light sources for precise metrology of ultrafast processes has been, however, hampered by the diagnostic capabilities for characterizing X-ray pulses at the attosecond frontier. In this regard, the spectroscopic technique of photoelectron angular streaking has successfully proven how to non-destructively retrieve the exact time–energy structure of XFEL pulses on a single-shot basis. By using artificial intelligence techniques, in particular convolutional neural networks, we here show how this technique can be leveraged from its proof-of-principle stage toward routine diagnostics even at high-repetition-rate XFELs, thus enhancing and refining their scientific accessibility in all related disciplines.
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6
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Walter P, Osipov T, Lin MF, Cryan J, Driver T, Kamalov A, Marinelli A, Robinson J, Seaberg MH, Wolf TJA, Aldrich J, Brown N, Champenois EG, Cheng X, Cocco D, Conder A, Curiel I, Egger A, Glownia JM, Heimann P, Holmes M, Johnson T, Lee L, Li X, Moeller S, Morton DS, Ng ML, Ninh K, O’Neal JT, Obaid R, Pai A, Schlotter W, Shepard J, Shivaram N, Stefan P, Van X, Wang AL, Wang H, Yin J, Yunus S, Fritz D, James J, Castagna JC. The time-resolved atomic, molecular and optical science instrument at the Linac Coherent Light Source. JOURNAL OF SYNCHROTRON RADIATION 2022; 29:957-968. [PMID: 35787561 PMCID: PMC9255571 DOI: 10.1107/s1600577522004283] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Accepted: 04/21/2022] [Indexed: 06/15/2023]
Abstract
The newly constructed time-resolved atomic, molecular and optical science instrument (TMO) is configured to take full advantage of both linear accelerators at SLAC National Accelerator Laboratory, the copper accelerator operating at a repetition rate of 120 Hz providing high per-pulse energy as well as the superconducting accelerator operating at a repetition rate of about 1 MHz providing high average intensity. Both accelerators power a soft X-ray free-electron laser with the new variable-gap undulator section. With this flexible light source, TMO supports many experimental techniques not previously available at LCLS and will have two X-ray beam focus spots in line. Thereby, TMO supports atomic, molecular and optical, strong-field and nonlinear science and will also host a designated new dynamic reaction microscope with a sub-micrometer X-ray focus spot. The flexible instrument design is optimized for studying ultrafast electronic and molecular phenomena and can take full advantage of the sub-femtosecond soft X-ray pulse generation program.
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Affiliation(s)
- Peter Walter
- SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025, USA
| | - Timur Osipov
- SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025, USA
| | - Ming-Fu Lin
- SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025, USA
| | - James Cryan
- SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025, USA
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025, USA
| | - Taran Driver
- SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025, USA
| | - Andrei Kamalov
- SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025, USA
| | - Agostino Marinelli
- SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025, USA
| | - Joe Robinson
- SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025, USA
| | - Matthew H. Seaberg
- SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025, USA
| | - Thomas J. A. Wolf
- SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025, USA
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025, USA
| | - Jeff Aldrich
- SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025, USA
| | - Nolan Brown
- SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025, USA
| | - Elio G. Champenois
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025, USA
| | - Xinxin Cheng
- SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025, USA
| | - Daniele Cocco
- SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025, USA
| | - Alan Conder
- SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025, USA
| | - Ivan Curiel
- SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025, USA
| | - Adam Egger
- SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025, USA
| | - James M. Glownia
- SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025, USA
| | - Philip Heimann
- SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025, USA
| | - Michael Holmes
- SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025, USA
| | - Tyler Johnson
- SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025, USA
| | - Lance Lee
- SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025, USA
| | - Xiang Li
- SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025, USA
| | - Stefan Moeller
- SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025, USA
| | - Daniel S. Morton
- SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025, USA
| | - May Ling Ng
- SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025, USA
| | - Kayla Ninh
- SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025, USA
| | - Jordan T. O’Neal
- SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025, USA
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025, USA
| | - Razib Obaid
- SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025, USA
| | - Allen Pai
- SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025, USA
| | - William Schlotter
- SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025, USA
| | - Jackson Shepard
- SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025, USA
| | - Niranjan Shivaram
- SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025, USA
| | - Peter Stefan
- SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025, USA
| | - Xiong Van
- SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025, USA
| | - Anna Li Wang
- SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025, USA
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025, USA
| | - Hengzi Wang
- SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025, USA
| | - Jing Yin
- SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025, USA
| | - Sameen Yunus
- SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025, USA
| | - David Fritz
- SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025, USA
| | - Justin James
- SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025, USA
| | - Jean-Charles Castagna
- SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025, USA
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7
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Sparapassi G, Cavaletto SM, Tollerud J, Montanaro A, Glerean F, Marciniak A, Giusti F, Mukamel S, Fausti D. Transient measurement of phononic states with covariance-based stochastic spectroscopy. LIGHT, SCIENCE & APPLICATIONS 2022; 11:44. [PMID: 35228519 PMCID: PMC8885707 DOI: 10.1038/s41377-022-00727-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Revised: 01/17/2022] [Accepted: 01/26/2022] [Indexed: 05/09/2023]
Abstract
We present a novel approach to transient Raman spectroscopy, which combines stochastic probe pulses and a covariance-based detection to measure stimulated Raman signals in alpha-quartz. A coherent broadband pump is used to simultaneously impulsively excite a range of different phonon modes, and the phase, amplitude, and energy of each mode are independently recovered as a function of the pump-probe delay by a noisy-probe and covariance-based analysis. Our experimental results and the associated theoretical description demonstrate the feasibility of 2D-Raman experiments based on the stochastic-probe schemes, with new capabilities not available in equivalent mean-value-based 2D-Raman techniques. This work unlocks the gate for nonlinear spectroscopies to capitalize on the information hidden within the noise and overlooked by a mean-value analysis.
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Affiliation(s)
- Giorgia Sparapassi
- Physics Department, University of Trieste, Trieste, Italy
- Elettra-Sincrotrone Trieste S.C.p.A., Trieste, Italy
| | - Stefano M Cavaletto
- Department of Chemistry and Department of Physics & Astronomy, University of California, Irvine, CA, USA
| | - Jonathan Tollerud
- Optical Sciences Centre, Swinburne University, Melbourne, Australia.
| | - Angela Montanaro
- Physics Department, University of Trieste, Trieste, Italy
- Elettra-Sincrotrone Trieste S.C.p.A., Trieste, Italy
| | - Filippo Glerean
- Physics Department, University of Trieste, Trieste, Italy
- Elettra-Sincrotrone Trieste S.C.p.A., Trieste, Italy
| | - Alexandre Marciniak
- Physics Department, University of Trieste, Trieste, Italy
- Elettra-Sincrotrone Trieste S.C.p.A., Trieste, Italy
| | - Fancesca Giusti
- Physics Department, University of Trieste, Trieste, Italy
- Elettra-Sincrotrone Trieste S.C.p.A., Trieste, Italy
| | - Shaul Mukamel
- Department of Chemistry and Department of Physics & Astronomy, University of California, Irvine, CA, USA
| | - Daniele Fausti
- Physics Department, University of Trieste, Trieste, Italy.
- Elettra-Sincrotrone Trieste S.C.p.A., Trieste, Italy.
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8
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Yang M, Sissay A, Chen M, Lopata K. Intruder Peak-Free Transient Inner-Shell Spectra Using Real-Time Simulations. J Chem Theory Comput 2022; 18:992-1002. [PMID: 35025498 DOI: 10.1021/acs.jctc.1c00079] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Real-time methods are convenient for simulating core-level absorption spectra but suffer from nonphysical intruder peaks when using atom-centered basis sets. In transient absorption spectra, these peaks exhibit highly nonphysical time-dependent modulations in their energies and oscillator strengths. In this paper, we address the origins of these intruder peaks and propose a straightforward and effective solution based on a filtered dipole operator. In combination with real-time time-dependent density functional theory (RT-TDDFT), we demonstrate how to compute intruder-free attosecond transient X-ray absorption spectra for the aminophenol (C6H7NO) oxygen and nitrogen K-edges and the α-quartz (SiO2) silicon L-edge. Without filtering, the computed spectra are qualitatively wrong. This procedure is suitable for both static and transient inner-shell spectroscopy studies and can easily be implemented in a range of real-time methodologies.
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Affiliation(s)
- Mengqi Yang
- Department of Chemistry, Louisiana State University, Baton Rouge, Louisiana 70803, United States
| | - Adonay Sissay
- Department of Chemistry, Louisiana State University, Baton Rouge, Louisiana 70803, United States
| | - Min Chen
- Department of Chemistry, Louisiana State University, Baton Rouge, Louisiana 70803, United States
| | - Kenneth Lopata
- Department of Chemistry, Louisiana State University, Baton Rouge, Louisiana 70803, United States.,Center for Computation and Technology, Louisiana State University, Baton Rouge, Louisiana 70803, United States
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9
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Walter P, Kamalov A, Gatton A, Driver T, Bhogadi D, Castagna JC, Cheng X, Shi H, Obaid R, Cryan J, Helml W, Ilchen M, Coffee RN. Multi-resolution electron spectrometer array for future free-electron laser experiments. JOURNAL OF SYNCHROTRON RADIATION 2021; 28:1364-1376. [PMID: 34475285 DOI: 10.1107/s1600577521007700] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Accepted: 07/28/2021] [Indexed: 06/13/2023]
Abstract
The design of an angular array of electron time-of-flight (eToF) spectrometers is reported, intended for non-invasive spectral, temporal, and polarization characterization of single shots of high-repetition rate, quasi-continuous, short-wavelength free-electron lasers (FELs) such as the LCLS II at SLAC. This array also enables angle-resolved, high-resolution eToF spectroscopy to address a variety of scientific questions on ultrafast and nonlinear light-matter interactions at FELs. The presented device is specifically designed for the time-resolved atomic, molecular and optical science endstation (TMO) at LCLS II. In its final version, the spectrometer comprises up to 20 eToF spectrometers aligned to collect electrons from the interaction point, which is defined by the intersection of the incoming FEL radiation and a gaseous target. The full composition involves 16 spectrometers forming a circular equiangular array in the plane normal to the X-ray propagation and four spectrometers at 54.7° angle relative to the principle linear X-ray polarization axis with orientations in the forward and backward direction of the light propagation. The spectrometers are capable of independent and minimally chromatic electrostatic lensing and retardation, in order to enable simultaneous angle-resolved photo- and Auger-Meitner electron spectroscopy with high energy resolution. They are designed to ensure an energy resolution of 0.25 eV across an energy window of up to 75 eV, which can be individually centered via the adjustable retardation to cover the full range of electron kinetic energies relevant to soft X-ray methods, 0-2 keV. The full spectrometer array will enable non-invasive and online spectral-polarimetry measurements, polarization-sensitive attoclock spectroscopy for characterizing the full time-energy structure of SASE or seeded LCLS II pulses, and support emerging trends in molecular-frame spectroscopy measurements.
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Affiliation(s)
- Peter Walter
- SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025, USA
| | - Andrei Kamalov
- SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025, USA
| | - Averell Gatton
- SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025, USA
| | - Taran Driver
- The Stanford PULSE Institute, 2575 Sand Hill Road, Menlo Park, CA 94025, USA
| | - Dileep Bhogadi
- SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025, USA
| | - Jean Charles Castagna
- SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025, USA
| | - Xianchao Cheng
- SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025, USA
| | - Hongliang Shi
- SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025, USA
| | - Razib Obaid
- SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025, USA
| | - James Cryan
- SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025, USA
| | - Wolfram Helml
- Technische Universität Dortmund, Maria-Goeppert-Mayer-Strasse 2, 44227 Dortmund, Germany
| | - Markus Ilchen
- European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
| | - Ryan N Coffee
- SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025, USA
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10
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Fouda AEA, Ho PJ. Site-specific generation of excited state wavepackets with high-intensity attosecond x rays. J Chem Phys 2021; 154:224111. [PMID: 34241215 DOI: 10.1063/5.0050891] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
High-intensity attosecond x rays can produce coherent superpositions of valence-excited states through two-photon Raman transitions. The broad-bandwidth, high-field nature of the pulses results in a multitude of accessible excited states. Multiconfigurational quantum chemistry with the time-dependent Schrödinger equation is used to examine population transfer dynamics in stimulated x-ray Raman scattering of the nitric oxide oxygen and nitrogen K-edges. Two pulse schemes initiate wavepackets of different characters and demonstrate how chemical differences between core-excitation pathways affect the dynamics. The population transfer to valence-excited states is found to be sensitive to the electronic structure and pulse conditions, highlighting complexities attributed to the Rabi frequency. The orthogonally polarized two-color-pulse setup has increased selectivity while facilitating longer, less intense pulses than the one-pulse setup. Population transfer in the 1s → Rydberg region is more effective but less selective at the nitrogen K-edge; the selectivity is reduced by double core-excited states. Result interpretation is aided by resonant inelastic x-ray scattering maps.
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Affiliation(s)
- Adam E A Fouda
- Chemical Sciences and Engineering Division, Argonne National Laboratory, 9700 S Cass Avenue, Lemont, Illinois 60439, USA
| | - Phay J Ho
- Chemical Sciences and Engineering Division, Argonne National Laboratory, 9700 S Cass Avenue, Lemont, Illinois 60439, USA
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11
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Fuller FD, Loukianov A, Takanashi T, You D, Li Y, Ueda K, Fransson T, Yabashi M, Katayama T, Weng TC, Alonso-Mori R, Bergmann U, Jan Kern, Yachandra VK, Wernet P, Yano J. Resonant X-ray emission spectroscopy from broadband stochastic pulses at an X-ray free electron laser. Commun Chem 2021; 4:84. [PMID: 35291552 PMCID: PMC8920481 DOI: 10.1038/s42004-021-00512-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Accepted: 04/21/2021] [Indexed: 01/27/2023] Open
Abstract
Hard X-ray spectroscopy is an element specific probe of electronic state, but signals are weak and require intense light to study low concentration samples. Free electron laser facilities offer the highest intensity X-rays of any available light source. The light produced at such facilities is stochastic, with spikey, broadband spectra that change drastically from shot to shot. Here, using aqueous ferrocyanide, we show that the resonant X-ray emission (RXES) spectrum can be inferred by correlating for each shot the fluorescence intensity from the sample with spectra of the fluctuating, self-amplified spontaneous emission (SASE) source. We obtain resolved narrow and chemically rich information in core-to-valence transitions of the pre-edge region at the Fe K-edge. Our approach avoids monochromatization, provides higher photon flux to the sample, and allows non-resonant signals like elastic scattering to be simultaneously recorded. The spectra obtained match well with spectra measured using a monochromator. We also show that inaccurate measurements of the stochastic light spectra reduce the measurement efficiency of our approach.
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Affiliation(s)
| | | | | | | | - Yiwen Li
- Tohoku University, Sendai, Miyagi Japan
| | | | | | | | - Tetsuo Katayama
- RIKEN SPring-8 Center, Sayo, Hyogo Japan
- Japan Synchrotron Radiation Research Institute, Sayo, Hyogo Japan
| | - Tsu-Chien Weng
- School of Physical Science and Technology, ShanghaiTech University, Shanghai, China
| | | | | | - Jan Kern
- Lawrence Berkeley National Laboratory, Berkeley, CA USA
| | | | | | - Junko Yano
- Lawrence Berkeley National Laboratory, Berkeley, CA USA
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12
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Liekhus-Schmaltz CE, Ho PJ, Weakly RB, Aquila A, Schoenlein RW, Khalil M, Govind N. Ultrafast x-ray pump x-ray probe transient absorption spectroscopy: A computational study and proposed experiment probing core-valence electronic correlations in solvated complexes. J Chem Phys 2021; 154:214107. [PMID: 34240961 DOI: 10.1063/5.0047381] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Femtosecond x-ray pump-x-ray probe experiments are currently possible at free electron lasers such as the linac coherent light source, which opens new opportunities for studying solvated transition metal complexes. In order to make the most effective use of these kinds of experiments, it is necessary to determine which chemical properties an x-ray probe pulse will measure. We have combined electron cascade calculations and excited-state time-dependent density functional theory calculations to predict the initial state prepared by an x-ray pump and the subsequent x-ray probe spectra at the Fe K-edge in the solvated model transition metal complex, K4FeII(CN)6. We find several key spectral features that report on the ligand-field splitting and the 3p and 3d electron interactions. We then show how these features could be measured in an experiment.
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Affiliation(s)
| | - Phay J Ho
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - Robert B Weakly
- Department of Chemistry, University of Washington, Seattle, Washington 98195, USA
| | - Andrew Aquila
- LCLS, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - Robert W Schoenlein
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - Munira Khalil
- Department of Chemistry, University of Washington, Seattle, Washington 98195, USA
| | - Niranjan Govind
- Physical and Computational Sciences Directorate, Pacific Northwest National Laboratory, Richland, Washington 99352, USA
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13
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Cavaletto SM, Keefer D, Rouxel JR, Aleotti F, Segatta F, Garavelli M, Mukamel S. Unveiling the spatial distribution of molecular coherences at conical intersections by covariance X-ray diffraction signals. Proc Natl Acad Sci U S A 2021; 118:e2105046118. [PMID: 34050030 PMCID: PMC8179141 DOI: 10.1073/pnas.2105046118] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
The outcomes and timescales of molecular nonadiabatic dynamics are decisively impacted by the quantum coherences generated at localized molecular regions. In time-resolved X-ray diffraction imaging, these coherences create distinct signatures via inelastic photon scattering, but they are buried under much stronger background elastic features. Here, we exploit the rich dynamical information encoded in the inelastic patterns, which we reveal by frequency-dispersed covariance ultrafast powder X-ray diffraction of stochastic X-ray free-electron laser pulses. This is demonstrated for the photoisomerization of azobenzene involving the passage through a conical intersection, where the nuclear wave packet branches and explores different quantum pathways. Snapshots of the coherence dynamics are obtained at high frequency shifts, not accessible with conventional diffraction measurements. These provide access to the timing and to the confined spatial distribution of the valence electrons directly involved in the conical intersection passage. This study can be extended to full three-dimensional imaging of conical intersections with ultrafast X-ray and electron diffraction.
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Affiliation(s)
- Stefano M Cavaletto
- Department of Chemistry, University of California, Irvine, CA 92697
- Department of Physics & Astronomy, University of California, Irvine, CA 92697
| | - Daniel Keefer
- Department of Chemistry, University of California, Irvine, CA 92697
- Department of Physics & Astronomy, University of California, Irvine, CA 92697
| | - Jérémy R Rouxel
- Department of Chemistry, University of California, Irvine, CA 92697
- Department of Physics & Astronomy, University of California, Irvine, CA 92697
- University Lyon, UJM-Saint-Étienne, CNRS, Graduate School Optics Institute, Laboratoire Hubert Curien UMR 5516, Saint-Étienne 42023, France
| | - Flavia Aleotti
- Dipartimento di Chimica Industriale, Università degli Studi di Bologna, 40136 Bologna, Italy
| | - Francesco Segatta
- Dipartimento di Chimica Industriale, Università degli Studi di Bologna, 40136 Bologna, Italy
| | - Marco Garavelli
- Dipartimento di Chimica Industriale, Università degli Studi di Bologna, 40136 Bologna, Italy
| | - Shaul Mukamel
- Department of Chemistry, University of California, Irvine, CA 92697;
- Department of Physics & Astronomy, University of California, Irvine, CA 92697
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14
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Li S, Driver T, Alexander O, Cooper B, Garratt D, Marinelli A, Cryan JP, Marangos JP. Time-resolved pump-probe spectroscopy with spectral domain ghost imaging. Faraday Discuss 2021; 228:488-501. [PMID: 33625412 DOI: 10.1039/d0fd00122h] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
An atomic-level picture of molecular and bulk processes, such as chemical bonding and charge transfer, necessitates an understanding of the dynamical evolution of these systems. On the ultrafast timescales associated with nuclear and electronic motion, the temporal behaviour of a system is often interrogated in a 'pump-probe' scheme. Here, an initial 'pump' pulse triggers dynamics through photoexcitation, and after a carefully controlled delay a 'probe' pulse initiates projection of the instantaneous state of the evolving system onto an informative measurable quantity, such as electron binding energy. In this paper, we apply spectral ghost imaging to a pump-probe time-resolved experiment at an X-ray free-electron laser (XFEL) facility, where the observable is spectral absorption in the X-ray regime. By exploiting the correlation present in the shot-to-shot fluctuations in the incoming X-ray pulses and measured electron kinetic energies, we show that spectral ghost imaging can be applied to time-resolved pump-probe measurements. In the experiment presented, interpretation of the measurement is simplified because spectral ghost imaging separates the overlapping contributions to the photoelectron spectrum from the pump and probe pulse.
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Affiliation(s)
- Siqi Li
- Accelerator Research Division, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - Taran Driver
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, USA and Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - Oliver Alexander
- Quantum Optics and Laser Science Group, Blackett Laboratory, Imperial College London, London, SW7 2BW, UK
| | - Bridgette Cooper
- Atomic, Molecular, Optical and Positron Physics Group, Department of Physics and Astronomy, University College London, Gower Street, London, WC1E 6BT, UK
| | - Douglas Garratt
- Quantum Optics and Laser Science Group, Blackett Laboratory, Imperial College London, London, SW7 2BW, UK
| | - Agostino Marinelli
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, USA and Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - James P Cryan
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, USA and Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - Jonathan P Marangos
- Quantum Optics and Laser Science Group, Blackett Laboratory, Imperial College London, London, SW7 2BW, UK
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15
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Madjet MEA, Ali E, Carignano M, Vendrell O, Chakraborty HS. Ultrafast Transfer and Transient Entrapment of Photoexcited Mg Electron in Mg@C_{60}. PHYSICAL REVIEW LETTERS 2021; 126:183002. [PMID: 34018762 DOI: 10.1103/physrevlett.126.183002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2020] [Revised: 02/12/2021] [Accepted: 03/26/2021] [Indexed: 06/12/2023]
Abstract
Electron relaxation is studied in endofullerene Mg@C_{60} after an initial localized photoexcitation in Mg by nonadiabatic molecular dynamics simulations. Two approaches to the electronic structure of the excited electronic states are used: (i) an independent particle approximation based on a density-functional theory description of molecular orbitals and (ii) a configuration-interaction description of the many-body effects. Both methods exhibit similar relaxation times, leading to an ultrafast decay and charge transfer from Mg to C_{60} within tens of femtoseconds. Method (i) further elicits a transient trap of the transferred electron that can delay the electron-hole recombination. Results shall motivate experiments to probe these ultrafast processes by two-photon transient absorption or photoelectron spectroscopy in gas phase, in solution, or as thin films.
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Affiliation(s)
- Mohamed El-Amine Madjet
- Max-Planck-Institut für Physik komplexer Systeme, Nöthnitzer Straße 38, 01187 Dresden, Germany
- Department of Natural Sciences, D. L. Hubbard Center for Innovation, Northwest Missouri State University, Maryville, Missouri 64468, USA
| | - Esam Ali
- Department of Natural Sciences, D. L. Hubbard Center for Innovation, Northwest Missouri State University, Maryville, Missouri 64468, USA
| | - Marcelo Carignano
- Department of Biomedical Engineering, Northwestern University, Evanston, Illinois 60208, USA
| | - Oriol Vendrell
- Theoretical Chemistry, Institute of Physical Chemistry and Centre for Advanced Materials, Heidelberg University, Im Neuenheimer Feld 229 and 225, 69120 Heidelberg, Germany
| | - Himadri S Chakraborty
- Department of Natural Sciences, D. L. Hubbard Center for Innovation, Northwest Missouri State University, Maryville, Missouri 64468, USA
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16
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Géneaux R, Chang HT, Schwartzberg AM, Marroux HJB. Source noise suppression in attosecond transient absorption spectroscopy by edge-pixel referencing. OPTICS EXPRESS 2021; 29:951-960. [PMID: 33726320 DOI: 10.1364/oe.412117] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Accepted: 12/01/2020] [Indexed: 06/12/2023]
Abstract
Attosecond transient absorption spectroscopy (ATAS) is used to observe photoexcited dynamics with outstanding time resolution. The main experimental challenge of this technique is that high-harmonic generation sources show significant instabilities, resulting in sub-par sensitivity when compared to other techniques. This paper proposes edge-pixel referencing as a means to suppress this noise. Two approaches are introduced: the first is deterministic and uses a correlation analysis, while the second relies on singular value decomposition. Each method is demonstrated and quantified on a noisy measurement taken on WS2 and results in a fivefold increase in sensitivity. The combination of the two methods ensures the fidelity of the procedure and can be implemented on live data collection but also on existing datasets. The results show that edge-referencing methods bring the sensitivity of ATAS near the detector noise floor. An implementation of the post-processing code is provided to the reader.
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17
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Suresh MI, Russell PSJ, Tani F. Covariance spectroscopy of molecular gases using fs pulse bursts created by modulational instability in gas-filled hollow-core fiber. OPTICS EXPRESS 2020; 28:34328-34336. [PMID: 33182905 DOI: 10.1364/oe.405767] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Accepted: 10/20/2020] [Indexed: 05/24/2023]
Abstract
We present a technique that uses noisy broadband pulse bursts generated by modulational instability to probe nonlinear processes, including infrared-inactive Raman transitions, in molecular gases. These processes imprint correlations between different regions of the noisy spectrum, which can be detected by acquiring single shot spectra and calculating the Pearson correlation coefficient between the different frequency components. Numerical simulations verify the experimental measurements and are used to further understand the system and discuss methods to improve the signal strength and the spectral resolution of the technique.
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18
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Chen M, Lopata K. First-Principles Simulations of X-ray Transient Absorption for Probing Attosecond Electron Dynamics. J Chem Theory Comput 2020; 16:4470-4478. [PMID: 32470295 PMCID: PMC7467644 DOI: 10.1021/acs.jctc.0c00122] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
X-ray transient absorption spectroscopy (XTAS) is a promising technique for measuring electron dynamics in molecules and solids with attosecond time resolutions. In XTAS, the elemental specificity and spatial locality of core-to-valence X-ray absorption is exploited to relate modulations in the time-resolved absorption spectra to local electron density variations around particular atoms. However, interpreting these absorption modulations and frequency shifts as a function of the time delay in terms of dynamics can be challenging. In this paper, we present a first-principles study of attosecond XTAS in a selection of simple molecules based on real-time time-dependent density functional theory (RT-TDDFT) with constrained DFT to emulate the state of the system following the interaction with a ultraviolet pump laser. In general, there is a decrease in the optical density and a blue shift in the frequency with increasing electron density around the absorbing atom. In carbon monoxide (CO), modulations in the O K-edge occur at the frequency of the valence electron dynamics, while for dioxygen (O2) they occur at twice the frequency, due to the indistinguishability of the oxygen atoms. In 4-aminophenol (H2NC6H4OH), likewise, there is a decrease in the optical density and a blue shift in the frequency for the oxygen and nitrogen K-edges with increasing charge density on the O and N, respectively. Similar effects are observed in the nitrogen K-edge for a long-range charge-transfer excitation in a benzene (C6H6)-tetracyanoethylene (C6N4; TCNE) dimer but with weaker modulations due to the delocalization of the charge across the entire TCNE molecule. Additionally, in all cases, there are pre-edge features corresponding to core transitions to depopulated orbitals. These potentially offer a background-free signal that only appears in pumped molecules.
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Affiliation(s)
- Min Chen
- Department of Chemistry, Louisiana State University, Baton Rouge, Louisiana 70803, United States
| | - Kenneth Lopata
- Department of Chemistry, Louisiana State University, Baton Rouge, Louisiana 70803, United States.,Center for Computation and Technology, Louisiana State University, Baton Rouge, Louisiana 70803, United States
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19
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Zheng X, Liu J, Doumy G, Young L, Cheng L. Hetero-site Double Core Ionization Energies with Sub-electronvolt Accuracy from Delta-Coupled-Cluster Calculations. J Phys Chem A 2020; 124:4413-4426. [DOI: 10.1021/acs.jpca.0c00901] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Xuechen Zheng
- Department of Chemistry, The Johns Hopkins University, Baltimore, Maryland 21218, United States
| | - Junzi Liu
- Department of Chemistry, The Johns Hopkins University, Baltimore, Maryland 21218, United States
| | - Gilles Doumy
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
| | - Linda Young
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
| | - Lan Cheng
- Department of Chemistry, The Johns Hopkins University, Baltimore, Maryland 21218, United States
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