1
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Lee Y, Oang KY, Kim D, Ihee H. A comparative review of time-resolved x-ray and electron scattering to probe structural dynamics. STRUCTURAL DYNAMICS (MELVILLE, N.Y.) 2024; 11:031301. [PMID: 38706888 PMCID: PMC11065455 DOI: 10.1063/4.0000249] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/15/2024] [Accepted: 04/10/2024] [Indexed: 05/07/2024]
Abstract
The structure of molecules, particularly the dynamic changes in structure, plays an essential role in understanding physical and chemical phenomena. Time-resolved (TR) scattering techniques serve as crucial experimental tools for studying structural dynamics, offering direct sensitivity to molecular structures through scattering signals. Over the past decade, the advent of x-ray free-electron lasers (XFELs) and mega-electron-volt ultrafast electron diffraction (MeV-UED) facilities has ushered TR scattering experiments into a new era, garnering significant attention. In this review, we delve into the basic principles of TR scattering experiments, especially focusing on those that employ x-rays and electrons. We highlight the variations in experimental conditions when employing x-rays vs electrons and discuss their complementarity. Additionally, cutting-edge XFELs and MeV-UED facilities for TR x-ray and electron scattering experiments and the experiments performed at those facilities are reviewed. As new facilities are constructed and existing ones undergo upgrades, the landscape for TR x-ray and electron scattering experiments is poised for further expansion. Through this review, we aim to facilitate the effective utilization of these emerging opportunities, assisting researchers in delving deeper into the intricate dynamics of molecular structures.
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Affiliation(s)
| | - Key Young Oang
- Radiation Center for Ultrafast Science, Korea Atomic Energy Research Institute (KAERI), Daejeon 34057, South Korea
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2
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Lu W, Nicoul M, Shymanovich U, Tarasevitch A, Horn-von Hoegen M, von der Linde D, Sokolowski-Tinten K. A modular table-top setup for ultrafast x-ray diffraction. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2024; 95:013002. [PMID: 38190494 DOI: 10.1063/5.0181132] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2023] [Accepted: 12/09/2023] [Indexed: 01/10/2024]
Abstract
We present a table-top setup for femtosecond time-resolved x-ray diffraction based on a Cu Kα (8.05 keV) laser driven plasma x-ray source. Due to its modular design, it provides high accessibility to its individual components (e.g., x-ray optics and sample environment). The Kα-yield of the source is optimized using a pre-pulse scheme. A magnifying multilayer x-ray mirror with Montel-Helios geometry is used to collect the emitted radiation, resulting in a quasi-collimated flux of more than 105 Cu Kα photons/pulse impinging on the sample under investigation at a repetition rate of 10 Hz. A gas ionization chamber detector is placed right after the x-ray mirror and used for the normalization of the diffraction signals, enabling the measurement of relative signal changes of less than 1% even at the given low repetition rate. Time-resolved diffraction experiments on laser-excited epitaxial Bi films serve as an example to demonstrate the capabilities of the setup. The setup can also be used for Debye-Scherrer type measurements on poly-crystalline samples.
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3
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He X, Yang DS. Nanoscale Energy Transport Dynamics across Nonbonded Solid-Molecule Interfaces and in Molecular Thin Films. J Phys Chem Lett 2023; 14:11457-11464. [PMID: 38085824 DOI: 10.1021/acs.jpclett.3c02673] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2023]
Abstract
Thermal conductance across a solid-solid interface requires an atomic- or molecular-level understanding, especially when a system is in a non-equilibrium state and/or consists of nanosized materials with prominent differences in structures, properties, and vibrational behaviors. Here, we report the lattice dynamics of graphite-supported molecular thin films of ethanol, whose layers exhibit in-plane hydrogen-bonded chains and out-of-plane van der Waals stacking with clear structural anisotropy. The direct structure-probing method of ultrafast electron diffraction reveals a surprising temperature difference of more than 400 K at pico- to sub-nanosecond times across the graphite-ethanol interface, yet the temporal behavior signifies a reasonably large thermal boundary conductance. This apparent conflict in a non-equilibrium condition can be resolved by considering the coupling of out-of-plane motions, instead of the commonly used temperature-based model, at transient times for energy transport across the interface separated by van der Waals interactions with mismatched unit sizes and no strong bonds. The importance of spatiotemporally resolved structural dynamics at the atomic or molecular level is emphasized.
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Affiliation(s)
- Xing He
- Department of Chemistry, University of Houston, Houston, Texas 77204, United States
| | - Ding-Shyue Yang
- Department of Chemistry, University of Houston, Houston, Texas 77204, United States
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4
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Mattern M, von Reppert A, Zeuschner SP, Herzog M, Pudell JE, Bargheer M. Concepts and use cases for picosecond ultrasonics with x-rays. PHOTOACOUSTICS 2023; 31:100503. [PMID: 37275326 PMCID: PMC10238750 DOI: 10.1016/j.pacs.2023.100503] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/17/2023] [Revised: 04/28/2023] [Accepted: 04/30/2023] [Indexed: 06/07/2023]
Abstract
This review discusses picosecond ultrasonics experiments using ultrashort hard x-ray probe pulses to extract the transient strain response of laser-excited nanoscopic structures from Bragg-peak shifts. This method provides direct, layer-specific, and quantitative information on the picosecond strain response for structures down to few-nm thickness. We model the transient strain using the elastic wave equation and express the driving stress using Grüneisen parameters stating that the laser-induced stress is proportional to energy density changes in the microscopic subsystems of the solid, i.e., electrons, phonons and spins. The laser-driven strain response can thus serve as an ultrafast proxy for local energy-density and temperature changes, but we emphasize the importance of the nanoscale morphology for an accurate interpretation due to the Poisson effect. The presented experimental use cases encompass ultrathin and opaque metal-heterostructures, continuous and granular nanolayers as well as negative thermal expansion materials, that each pose a challenge to established all-optical techniques.
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Affiliation(s)
- Maximilian Mattern
- Institut für Physik & Astronomie, Universität Potsdam, 14476 Potsdam, Germany
| | | | - Steffen Peer Zeuschner
- Institut für Physik & Astronomie, Universität Potsdam, 14476 Potsdam, Germany
- Helmholtz Zentrum Berlin, 12489 Berlin, Germany
| | - Marc Herzog
- Institut für Physik & Astronomie, Universität Potsdam, 14476 Potsdam, Germany
| | - Jan-Etienne Pudell
- Institut für Physik & Astronomie, Universität Potsdam, 14476 Potsdam, Germany
- Helmholtz Zentrum Berlin, 12489 Berlin, Germany
- European XFEL, 22869 Schenefeld, Germany
| | - Matias Bargheer
- Institut für Physik & Astronomie, Universität Potsdam, 14476 Potsdam, Germany
- Helmholtz Zentrum Berlin, 12489 Berlin, Germany
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5
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Madan I, Dias EJC, Gargiulo S, Barantani F, Yannai M, Berruto G, LaGrange T, Piazza L, Lummen TTA, Dahan R, Kaminer I, Vanacore GM, García de Abajo FJ, Carbone F. Charge Dynamics Electron Microscopy: Nanoscale Imaging of Femtosecond Plasma Dynamics. ACS NANO 2023; 17:3657-3665. [PMID: 36780289 PMCID: PMC9979644 DOI: 10.1021/acsnano.2c10482] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/20/2022] [Accepted: 01/27/2023] [Indexed: 06/18/2023]
Abstract
Understanding and actively controlling the spatiotemporal dynamics of nonequilibrium electron clouds is fundamental for the design of light and electron sources, high-power electronic devices, and plasma-based applications. However, electron clouds evolve in a complex collective fashion on the nanometer and femtosecond scales, producing electromagnetic screening that renders them inaccessible to existing optical probes. Here, we solve the long-standing challenge of characterizing the evolution of electron clouds generated upon irradiation of metallic structures using an ultrafast transmission electron microscope to record the charged plasma dynamics. Our approach to charge dynamics electron microscopy (CDEM) is based on the simultaneous detection of electron-beam acceleration and broadening with nanometer/femtosecond resolution. By combining experimental results with comprehensive microscopic theory, we provide a deep understanding of this highly out-of-equilibrium regime, including previously inaccessible intricate microscopic mechanisms of electron emission, screening by the metal, and collective cloud dynamics. Beyond the present specific demonstration, the here-introduced CDEM technique grants us access to a wide range of nonequilibrium electrodynamic phenomena involving the ultrafast evolution of bound and free charges on the nanoscale.
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Affiliation(s)
- Ivan Madan
- Institute
of Physics, École Polytechnique Fédérale
de Lausanne, Lausanne1015, Switzerland
| | - Eduardo J. C. Dias
- ICFO-Institut
de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, Castelldefels, Barcelona08860, Spain
| | - Simone Gargiulo
- Institute
of Physics, École Polytechnique Fédérale
de Lausanne, Lausanne1015, Switzerland
| | - Francesco Barantani
- Institute
of Physics, École Polytechnique Fédérale
de Lausanne, Lausanne1015, Switzerland
- Department
of Quantum Matter Physics, University of
Geneva, Geneva1211, Switzerland
| | - Michael Yannai
- Department
of Electrical and Computer Engineering, Technion Israel Institute of Technology, Haifa32000, Israel
| | - Gabriele Berruto
- Institute
of Physics, École Polytechnique Fédérale
de Lausanne, Lausanne1015, Switzerland
| | - Thomas LaGrange
- Institute
of Physics, École Polytechnique Fédérale
de Lausanne, Lausanne1015, Switzerland
| | - Luca Piazza
- Institute
of Physics, École Polytechnique Fédérale
de Lausanne, Lausanne1015, Switzerland
| | | | - Raphael Dahan
- Department
of Electrical and Computer Engineering, Technion Israel Institute of Technology, Haifa32000, Israel
| | - Ido Kaminer
- Department
of Electrical and Computer Engineering, Technion Israel Institute of Technology, Haifa32000, Israel
| | - Giovanni Maria Vanacore
- Institute
of Physics, École Polytechnique Fédérale
de Lausanne, Lausanne1015, Switzerland
- Department
of Materials Science, University of Milano-Bicocca, Milano20126, Italy
| | - F. Javier García de Abajo
- ICFO-Institut
de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, Castelldefels, Barcelona08860, Spain
- ICREA, Institució
Catalana de Recerca i Estudis Avançats, Barcelona08010, Spain
| | - Fabrizio Carbone
- Institute
of Physics, École Polytechnique Fédérale
de Lausanne, Lausanne1015, Switzerland
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6
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Zhang M, Guo Z, Mi X, Li Z, Liu Y. Ultrafast Imaging of Molecular Dynamics Using Ultrafast Low-Frequency Lasers, X-ray Free Electron Lasers, and Electron Pulses. J Phys Chem Lett 2022; 13:1668-1680. [PMID: 35147438 DOI: 10.1021/acs.jpclett.1c03916] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
The requirement of high space-time resolution and brightness is a great challenge for imaging atomic motion and making molecular movies. Important breakthroughs in ultrabright tabletop laser, X-ray, and electron sources have enabled the direct imaging of evolving molecular structures in chemical processes, and recent experimental advances in preparing ultrafast laser and electron pulses resulted in molecular imaging with femtosecond time resolution. This Perspective presents an overview of the versatile imaging methods of molecular dynamics. High-order harmonic generation imaging and photoelectron diffraction imaging are based on laser-induced ionization and rescattering processes. Coulomb explosion imaging retrieves molecular structural information by detecting the momentum vectors of fragmented ions. Diffraction imaging encodes molecular structural and electronic information in reciprocal space. We also present various applications of these ultrafast imaging methods in resolving laser-induced nuclear and electronic dynamics.
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Affiliation(s)
- Ming Zhang
- State Key Laboratory for Mesoscopic Physics and Collaborative Innovation Center of Quantum Matter, School of Physics, Peking University, Beijing 100871, China
| | - Zhengning Guo
- State Key Laboratory for Mesoscopic Physics and Collaborative Innovation Center of Quantum Matter, School of Physics, Peking University, Beijing 100871, China
| | - Xiaoyu Mi
- State Key Laboratory for Mesoscopic Physics and Collaborative Innovation Center of Quantum Matter, School of Physics, Peking University, Beijing 100871, China
| | - Zheng Li
- 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
- Yangtze Delta Institute of Optoelectronics, Peking University, Nantong 226010, China
| | - Yunquan Liu
- 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
- Center for Applied Physics and Technology, HEDPS, Peking University, Beijing 100871, China
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7
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Zhao HC, Xia H, Hu S, Lv YY, Zhao ZR, He J, Liang E, Ni G, Chen LY, Qiu XP, Zhou SM, Zhao HB. Large ultrafast-modulated Voigt effect in noncollinear antiferromagnet Mn 3Sn. Nat Commun 2021; 12:5266. [PMID: 34489461 PMCID: PMC8421456 DOI: 10.1038/s41467-021-25654-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Accepted: 08/18/2021] [Indexed: 11/15/2022] Open
Abstract
The time-resolved magneto-optical (MO) Voigt effect can be utilized to study the Néel order dynamics in antiferromagnetic (AFM) materials, but it has been limited for collinear AFM spin configuration. Here, we have demonstrated that in Mn3Sn with an inverse triangular spin structure, the quench of AFM order by ultrafast laser pulses can result in a large Voigt effect modulation. The modulated Voigt angle is significantly larger than the polarization rotation due to the crystal-structure related linear dichroism effect and the modulated MO Kerr angle arising from the ferroic ordering of cluster magnetic octupole. The AFM order quench time shows negligible change with increasing temperature approaching the Néel temperature (TN), in markedly contrast with the pronounced slowing-down demagnetization typically observed in conventional magnetic materials. This atypical behavior can be explained by the influence of weakened Dzyaloshinskii–Moriya interaction rather than the smaller exchange splitting on the diminished AFM order near TN. The temperature-insensitive ultrafast spin manipulation can pave the way for high-speed spintronic devices either working at a wide range of temperature or demanding spin switching near TN. Mn3Sn is an anti-ferromagnetic material which displays a large magneto-optical Kerr effect, despite lacking a ferromagnetic moment. Here, the authors show that likewise, Mn3Sn, also presents a particularly large magneto-optical Voigt signal, with a negligible change in the quench time over a wide temperature range.
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Affiliation(s)
- H C Zhao
- Key Laboratory of Micro and Nano Photonic Structures (Ministry of Education), and Shanghai Ultra-precision Optical Manufacturing Engineering Research Center, Department of Optical Science and Engineering, Fudan University, Shanghai, China
| | - H Xia
- Key Laboratory of Micro and Nano Photonic Structures (Ministry of Education), and Shanghai Ultra-precision Optical Manufacturing Engineering Research Center, Department of Optical Science and Engineering, Fudan University, Shanghai, China.,Department of Physics, Fudan University, Shanghai, China
| | - S Hu
- Shanghai Key Laboratory of Special Artificial Microstructure Materials and Technology and Pohl Institute of Solid State Physics and School of Physics Science and Engineering, Tongji University, Shanghai, China
| | - Y Y Lv
- Shanghai Key Laboratory of Special Artificial Microstructure Materials and Technology and Pohl Institute of Solid State Physics and School of Physics Science and Engineering, Tongji University, Shanghai, China
| | - Z R Zhao
- Key Laboratory of Micro and Nano Photonic Structures (Ministry of Education), and Shanghai Ultra-precision Optical Manufacturing Engineering Research Center, Department of Optical Science and Engineering, Fudan University, Shanghai, China
| | - J He
- Key Laboratory of Micro and Nano Photonic Structures (Ministry of Education), and Shanghai Ultra-precision Optical Manufacturing Engineering Research Center, Department of Optical Science and Engineering, Fudan University, Shanghai, China
| | - E Liang
- Key Laboratory of Micro and Nano Photonic Structures (Ministry of Education), and Shanghai Ultra-precision Optical Manufacturing Engineering Research Center, Department of Optical Science and Engineering, Fudan University, Shanghai, China
| | - G Ni
- Key Laboratory of Micro and Nano Photonic Structures (Ministry of Education), and Shanghai Ultra-precision Optical Manufacturing Engineering Research Center, Department of Optical Science and Engineering, Fudan University, Shanghai, China.
| | - L Y Chen
- Key Laboratory of Micro and Nano Photonic Structures (Ministry of Education), and Shanghai Ultra-precision Optical Manufacturing Engineering Research Center, Department of Optical Science and Engineering, Fudan University, Shanghai, China
| | - X P Qiu
- Shanghai Key Laboratory of Special Artificial Microstructure Materials and Technology and Pohl Institute of Solid State Physics and School of Physics Science and Engineering, Tongji University, Shanghai, China.
| | - S M Zhou
- Shanghai Key Laboratory of Special Artificial Microstructure Materials and Technology and Pohl Institute of Solid State Physics and School of Physics Science and Engineering, Tongji University, Shanghai, China.
| | - H B Zhao
- Key Laboratory of Micro and Nano Photonic Structures (Ministry of Education), and Shanghai Ultra-precision Optical Manufacturing Engineering Research Center, Department of Optical Science and Engineering, Fudan University, Shanghai, China. .,Shanghai Frontier Base of Intelligent Optoelectronics and Perception, Institute of Optoelectronics, Fudan University, Shanghai, China.
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8
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Mankowsky R, Sander M, Zerdane S, Vonka J, Bartkowiak M, Deng Y, Winkler R, Giorgianni F, Matmon G, Gerber S, Beaud P, Lemke HT. New insights into correlated materials in the time domain-combining far-infrared excitation with x-ray probes at cryogenic temperatures. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2021; 33:374001. [PMID: 34098537 DOI: 10.1088/1361-648x/ac08b5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Accepted: 06/02/2021] [Indexed: 06/12/2023]
Abstract
Modern techniques for the investigation of correlated materials in the time domain combine selective excitation in the THz frequency range with selective probing of coupled structural, electronic and magnetic degrees of freedom using x-ray scattering techniques. Cryogenic sample temperatures are commonly required to prevent thermal occupation of the low energy modes and to access relevant material ground states. Here, we present a chamber optimized for high-field THz excitation and (resonant) x-ray diffraction at sample temperatures between 5 and 500 K. Directly connected to the beamline vacuum and featuring both a Beryllium window and an in-vacuum detector, the chamber covers the full (2-12.7) keV energy range of the femtosecond x-ray pulses available at the Bernina endstation of the SwissFEL free electron laser. Successful commissioning experiments made use of the energy tunability to selectively track the dynamics of the structural, magnetic and orbital order of Ca2RuO4and Tb2Ti2O7at the Ru (2.96 keV) and Tb (7.55 keV)L-edges, respectively. THz field amplitudes up to 1.12 MV cm-1peak field were demonstrated and used to excite the samples at temperatures as low as 5 K.
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Affiliation(s)
| | | | | | - Jakub Vonka
- Paul Scherrer Institute, Villigen, Switzerland
| | | | - Yunpei Deng
- Paul Scherrer Institute, Villigen, Switzerland
| | - Rafael Winkler
- Eidgenössische Technische Hochschule Zürich, Zürich, Switzerland
| | | | - Guy Matmon
- Paul Scherrer Institute, Villigen, Switzerland
| | | | - Paul Beaud
- Paul Scherrer Institute, Villigen, Switzerland
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9
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Jana S, Muralidhar S, Åkerman J, Schüßler-Langeheine C, Pontius N. Using the photoinduced L 3 resonance shift in Fe and Ni as time reference for ultrafast experiments at low flux soft x-ray sources. STRUCTURAL DYNAMICS (MELVILLE, N.Y.) 2021; 8:044304. [PMID: 34395721 PMCID: PMC8357444 DOI: 10.1063/4.0000108] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Accepted: 07/05/2021] [Indexed: 06/13/2023]
Abstract
We study the optical-pump induced ultrafast transient change of x-ray absorption at L 3 absorption resonances of the transition metals Ni and Fe in the Fe0.5Ni0.5 alloy. We find the effect for both elements to occur simultaneously on a femtosecond timescale. This effect may hence be used as a handy cross correlation scheme, providing a time-zero reference for ultrafast optical-pump soft x-ray-probe measurement. The method benefits from a relatively simple experimental setup as the sample itself acts as time-reference tool. In particular, this technique works with low flux ultrafast soft x-ray sources. The measurements are compared to the cross correlation method introduced in an earlier publication.
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Affiliation(s)
- Somnath Jana
- Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, 12489 Berlin, Germany
| | - Shreyas Muralidhar
- Department of Physics, University of Gothenburg, 412 96 Gothenburg, Sweden
| | - Johan Åkerman
- Department of Physics, University of Gothenburg, 412 96 Gothenburg, Sweden
| | | | - Niko Pontius
- Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, 12489 Berlin, Germany
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10
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Bach N, Schäfer S. Ultrafast strain propagation and acoustic resonances in nanoscale bilayer systems. STRUCTURAL DYNAMICS (MELVILLE, N.Y.) 2021; 8:035101. [PMID: 34169119 PMCID: PMC8214470 DOI: 10.1063/4.0000079] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Accepted: 04/21/2021] [Indexed: 06/13/2023]
Abstract
Ultrafast structural probing has greatly enhanced our understanding of the coupling of atomic motion to electronic and phononic degrees-of-freedom in quasi-bulk materials. In bi- and multilayer model systems, additionally, spatially inhomogeneous relaxation channels are accessible, often governed by pronounced interfacial couplings and local excitations in confined geometries. Here, we systematically explore the key dependencies of the low-frequency acoustic phonon spectrum in an elastically mismatched metal/semiconductor bilayer system optically excited by femtosecond laser pulses. We track the spatiotemporal strain wave propagation in the heterostructure employing a discrete numerical linear chain simulation and access acoustic wave reflections and interfacial couplings with a phonon mode description based on a continuum mechanics model. Due to the interplay of elastic properties and mass densities of the two materials, acoustic resonance frequencies of the heterostructure significantly differ from breathing modes in monolayer films. For large acoustic mismatch, the spatial localization of phonon eigenmodes is derived from analytical approximations and can be interpreted as harmonic oscillations in decoupled mechanical resonators.
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Affiliation(s)
- N. Bach
- Institute of Physics, University of Oldenburg, 26129 Oldenburg, Germany
| | - S. Schäfer
- Institute of Physics, University of Oldenburg, 26129 Oldenburg, Germany
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11
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Subterahertz collective dynamics of polar vortices. Nature 2021; 592:376-380. [PMID: 33854251 DOI: 10.1038/s41586-021-03342-4] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Accepted: 02/08/2021] [Indexed: 02/02/2023]
Abstract
The collective dynamics of topological structures1-6 are of interest from both fundamental and applied perspectives. For example, studies of dynamical properties of magnetic vortices and skyrmions3,4 have not only deepened our understanding of many-body physics but also offered potential applications in data processing and storage7. Topological structures constructed from electrical polarization, rather than electron spin, have recently been realized in ferroelectric superlattices5,6, and these are promising for ultrafast electric-field control of topological orders. However, little is known about the dynamics underlying the functionality of such complex extended nanostructures. Here, using terahertz-field excitation and femtosecond X-ray diffraction measurements, we observe ultrafast collective polarization dynamics that are unique to polar vortices, with orders-of-magnitude higher frequencies and smaller lateral size than those of experimentally realized magnetic vortices3. A previously unseen tunable mode, hereafter referred to as a vortexon, emerges in the form of transient arrays of nanoscale circular patterns of atomic displacements, which reverse their vorticity on picosecond timescales. Its frequency is considerably reduced (softened) at a critical strain, indicating a condensation (freezing) of structural dynamics. We use first-principles-based atomistic calculations and phase-field modelling to reveal the microscopic atomic arrangements and corroborate the frequencies of the vortex modes. The discovery of subterahertz collective dynamics in polar vortices opens opportunities for electric-field-driven data processing in topological structures with ultrahigh speed and density.
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12
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Afshari M, Krumey P, Menn D, Nicoul M, Brinks F, Tarasevitch A, Sokolowski-Tinten K. Time-resolved diffraction with an optimized short pulse laser plasma X-ray source. STRUCTURAL DYNAMICS (MELVILLE, N.Y.) 2020; 7:014301. [PMID: 31934600 PMCID: PMC6941949 DOI: 10.1063/1.5126316] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2019] [Accepted: 12/16/2019] [Indexed: 06/07/2023]
Abstract
We present a setup for time-resolved X-ray diffraction based on a short pulse, laser-driven plasma X-ray source. The employed modular design provides high flexibility to adapt the setup to the specific requirements (e.g., X-ray optics and sample environment) of particular applications. The configuration discussed here has been optimized toward high angular/momentum resolution and uses K α -radiation (4.51 keV) from a Ti wire-target in combination with a toroidally bent crystal for collection, monochromatization, and focusing of the emitted radiation. 2 × 10 5 Ti-K α1 photons per pulse with10 - 4 relative bandwidth are delivered to the sample at a repetition rate of 10 Hz. This allows for the high dynamic range (104) measurements of transient changes in the rocking curves of materials as for example induced by laser-triggered strain waves.
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Affiliation(s)
- M Afshari
- Faculty of Physics and Center for Nanointegration Duisburg-Essen, University of Duisburg-Essen, Lotharstrasse 1, 47048 Duisburg, Germany
| | - P Krumey
- Faculty of Physics and Center for Nanointegration Duisburg-Essen, University of Duisburg-Essen, Lotharstrasse 1, 47048 Duisburg, Germany
| | - D Menn
- Faculty of Physics and Center for Nanointegration Duisburg-Essen, University of Duisburg-Essen, Lotharstrasse 1, 47048 Duisburg, Germany
| | - M Nicoul
- Faculty of Physics and Center for Nanointegration Duisburg-Essen, University of Duisburg-Essen, Lotharstrasse 1, 47048 Duisburg, Germany
| | - F Brinks
- Faculty of Physics and Center for Nanointegration Duisburg-Essen, University of Duisburg-Essen, Lotharstrasse 1, 47048 Duisburg, Germany
| | - A Tarasevitch
- Faculty of Physics and Center for Nanointegration Duisburg-Essen, University of Duisburg-Essen, Lotharstrasse 1, 47048 Duisburg, Germany
| | - K Sokolowski-Tinten
- Faculty of Physics and Center for Nanointegration Duisburg-Essen, University of Duisburg-Essen, Lotharstrasse 1, 47048 Duisburg, Germany
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13
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Burian M, Marmiroli B, Radeticchio A, Morello C, Naumenko D, Biasiol G, Amenitsch H. Picosecond pump-probe X-ray scattering at the Elettra SAXS beamline. JOURNAL OF SYNCHROTRON RADIATION 2020; 27:51-59. [PMID: 31868736 PMCID: PMC6927520 DOI: 10.1107/s1600577519015728] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Accepted: 11/20/2019] [Indexed: 06/10/2023]
Abstract
A new setup for picosecond pump-probe X-ray scattering at the Austrian SAXS beamline at Elettra-Sincrotrone Trieste is presented. A high-power/high-repetion-rate laser has been installed on-site, delivering UV/VIS/IR femtosecond-pulses in-sync with the storage ring. Data acquisition is achieved by gating a multi-panel detector, capable of discriminating the single X-ray pulse in the dark-gap of the Elettra hybrid filling mode. Specific aspects of laser- and detection-synchronization, on-line beam steering as well protocols for spatial and temporal overlap of laser and X-ray beam are also described. The capabilities of the setup are demonstrated by studying transient heat-transfer in an In/Al/GaAs superlattice structure and results are confirmed by theoretical calculations.
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Affiliation(s)
- Max Burian
- Institute of Inorganic Chemistry, Graz University of Technology, Stremayrgasse 9/V, 8010 Graz, Austria
| | - Benedetta Marmiroli
- Institute of Inorganic Chemistry, Graz University of Technology, Stremayrgasse 9/V, 8010 Graz, Austria
| | - Andrea Radeticchio
- Institute of Inorganic Chemistry, Graz University of Technology, Stremayrgasse 9/V, 8010 Graz, Austria
| | - Christian Morello
- Elettra-Sincrotrone Trieste SCpA, Strada Statale 14, km 163.5, Basovizza, TS 34149, Italy
| | - Denys Naumenko
- Institute of Inorganic Chemistry, Graz University of Technology, Stremayrgasse 9/V, 8010 Graz, Austria
| | - Giorgio Biasiol
- Laboratorio TASC, CNR-IOM at Area Science Park, Strada Statale 14, km 163.5, Basovizza, TS 34149, Italy
| | - Heinz Amenitsch
- Institute of Inorganic Chemistry, Graz University of Technology, Stremayrgasse 9/V, 8010 Graz, Austria
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14
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Maiuri M, Garavelli M, Cerullo G. Ultrafast Spectroscopy: State of the Art and Open Challenges. J Am Chem Soc 2019; 142:3-15. [DOI: 10.1021/jacs.9b10533] [Citation(s) in RCA: 96] [Impact Index Per Article: 19.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Affiliation(s)
- Margherita Maiuri
- IFN-CNR, Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, I-20133 Milano, Italy
| | - Marco Garavelli
- Dipartimento di Chimica Industriale, Università degli Studi di Bologna, Viale del Risorgimento 4, I-40136 Bologna, Italy
| | - Giulio Cerullo
- IFN-CNR, Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, I-20133 Milano, Italy
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15
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van Thor JJ. Advances and opportunities in ultrafast X-ray crystallography and ultrafast structural optical crystallography of nuclear and electronic protein dynamics. STRUCTURAL DYNAMICS (MELVILLE, N.Y.) 2019; 6:050901. [PMID: 31559317 PMCID: PMC6759419 DOI: 10.1063/1.5110685] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2019] [Accepted: 08/29/2019] [Indexed: 05/02/2023]
Abstract
Both nuclear and electronic dynamics contribute to protein function and need multiple and complementary techniques to reveal their ultrafast structural dynamics response. Real-space information obtained from the measurement of electron density dynamics by X-ray crystallography provides aspects of both, while the molecular physics of coherence parameters and frequency-frequency correlation needs spectroscopy methods. Ultrafast pump-probe applications of protein dynamics in crystals provide real-space information through direct X-ray crystallographic structure analysis or through structural optical crystallographic analysis. A discussion of methods of analysis using ultrafast macromolecular X-ray crystallography and ultrafast nonlinear structural optical crystallography is presented. The current and future high repetition rate capabilities provided by X-ray free electron lasers for ultrafast diffraction studies provide opportunities for optical control and optical selection of nuclear coherence which may develop to access higher frequency dynamics through improvements of sensitivity and time resolution to reveal coherence directly. Specific selection of electronic coherence requires optical probes, which can provide real-space structural information through photoselection of oriented samples and specifically in birefringent crystals. Ultrafast structural optical crystallography of photosynthetic energy transfer has been demonstrated, and the theory of two-dimensional structural optical crystallography has shown a method for accessing the structural selection of electronic coherence.
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Affiliation(s)
- Jasper J. van Thor
- Molecular Biophysics, Imperial College London, London SW7 2AZ, United Kingdom
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16
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Sander M, Bauer R, Kabanova V, Levantino M, Wulff M, Pfuetzenreuter D, Schwarzkopf J, Gaal P. Demonstration of a picosecond Bragg switch for hard X-rays in a synchrotron-based pump-probe experiment. JOURNAL OF SYNCHROTRON RADIATION 2019; 26:1253-1259. [PMID: 31274451 DOI: 10.1107/s1600577519005356] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Accepted: 04/18/2019] [Indexed: 06/09/2023]
Abstract
A benchmark experiment is reported that demonstrates the shortening of hard X-ray pulses in a synchrotron-based optical pump-X-ray probe measurement. The pulse-shortening device is a photoacoustic Bragg switch that reduces the temporal resolution of an incident X-ray pulse to approximately 7.5 ps. The Bragg switch is employed to monitor propagating sound waves in nanometer thin epitaxial films. From the experimental data, the pulse duration, diffraction efficiency and switching contrast of the device can be inferred. A detailed efficiency analysis shows that the switch can deliver up to 109 photons s-1 in high-repetition-rate synchrotron experiments.
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Affiliation(s)
- Mathias Sander
- European Sychrotron Radiation Facility, 71 Avenue des Martyrs, 38000 Grenoble, France
| | - Roman Bauer
- Tailored X-ray Products gGmbH, Berlin, Germany
| | - Victoria Kabanova
- European Sychrotron Radiation Facility, 71 Avenue des Martyrs, 38000 Grenoble, France
| | - Matteo Levantino
- European Sychrotron Radiation Facility, 71 Avenue des Martyrs, 38000 Grenoble, France
| | - Michael Wulff
- European Sychrotron Radiation Facility, 71 Avenue des Martyrs, 38000 Grenoble, France
| | | | - Jutta Schwarzkopf
- Leibniz-Institut für Kristallzüchtung, Max-Born-Strasse 2, 12489 Berlin, Germany
| | - Peter Gaal
- Tailored X-ray Products gGmbH, Berlin, Germany
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17
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Schoenlein R, Elsaesser T, Holldack K, Huang Z, Kapteyn H, Murnane M, Woerner M. Recent advances in ultrafast X-ray sources. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2019; 377:20180384. [PMID: 30929633 DOI: 10.1098/rsta.2018.0384] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
Over more than a century, X-rays have transformed our understanding of the fundamental structure of matter and have been an indispensable tool for chemistry, physics, biology, materials science and related fields. Recent advances in ultrafast X-ray sources operating in the femtosecond to attosecond regimes have opened an important new frontier in X-ray science. These advances now enable: (i) sensitive probing of structural dynamics in matter on the fundamental timescales of atomic motion, (ii) element-specific probing of electronic structure and charge dynamics on fundamental timescales of electronic motion, and (iii) powerful new approaches for unravelling the coupling between electronic and atomic structural dynamics that underpin the properties and function of matter. Most notable is the recent realization of X-ray free-electron lasers (XFELs) with numerous new XFEL facilities in operation or under development worldwide. Advances in XFELs are complemented by advances in synchrotron-based and table-top laser-plasma X-ray sources now operating in the femtosecond regime, and laser-based high-order harmonic XUV sources operating in the attosecond regime. This article is part of the theme issue 'Measurement of ultrafast electronic and structural dynamics with X-rays'.
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Affiliation(s)
- Robert Schoenlein
- 1 SLAC National Accelerator Laboratory , 2575 Sand Hill Road, Menlo Park, CA 94025 , USA
| | - Thomas Elsaesser
- 2 Max-Born-Institut für Nichtlineare Optik und Kurzzeitspektroskopie , 12489 Berlin , Germany
| | - Karsten Holldack
- 3 Helmholtz-Zentrum Berlin für Materialien und Energie GmbH , Albert-Einstein-Strasse 15, 12489 Berlin , Germany
| | - Zhirong Huang
- 1 SLAC National Accelerator Laboratory , 2575 Sand Hill Road, Menlo Park, CA 94025 , USA
| | - Henry Kapteyn
- 4 Department of Physics and JILA, University of Colorado , Boulder, CO 80309-0440 , USA
| | - Margaret Murnane
- 4 Department of Physics and JILA, University of Colorado , Boulder, CO 80309-0440 , USA
| | - Michael Woerner
- 2 Max-Born-Institut für Nichtlineare Optik und Kurzzeitspektroskopie , 12489 Berlin , Germany
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18
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Abstract
A review that summarizes the most recent technological developments in the field of ultrafast structural dynamics with focus on the use of ultrashort X-ray and electron pulses follows. Atomistic views of chemical processes and phase transformations have long been the exclusive domain of computer simulators. The advent of femtosecond (fs) hard X-ray and fs-electron diffraction techniques made it possible to bring such a level of scrutiny to the experimental area. The following review article provides a summary of the main ultrafast techniques that enabled the generation of atomically resolved movies utilizing ultrashort X-ray and electron pulses. Recent advances are discussed with emphasis on synchrotron-based methods, tabletop fs-X-ray plasma sources, ultrabright fs-electron diffractometers, and timing techniques developed to further improve the temporal resolution and fully exploit the use of intense and ultrashort X-ray free electron laser (XFEL) pulses.
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19
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Plech A, Krause B, Baumbach T, Zakharova M, Eon S, Girmen C, Buth G, Bracht H. Structural and Thermal Characterisation of Nanofilms by Time-Resolved X-ray Scattering. NANOMATERIALS 2019; 9:nano9040501. [PMID: 30939755 PMCID: PMC6523543 DOI: 10.3390/nano9040501] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Revised: 03/19/2019] [Accepted: 03/22/2019] [Indexed: 11/16/2022]
Abstract
High time resolution in scattering analysis of thin films allows for determination of thermal conductivity by transient pump-probe detection of dissipation of laser-induced heating, TDXTS. We describe an approach that analyses the picosecond-resolved lattice parameter reaction of a gold transducer layer on pulsed laser heating to determine the thermal conductivity of layered structures below the transducer. A detailed modeling of the cooling kinetics by a Laplace-domain approach allows for discerning effects of conductivity and thermal interface resistance as well as basic depth information. The thermal expansion of the clamped gold film can be calibrated to absolute temperature change and effects of plastic deformation are discriminated. The method is demonstrated on two extreme examples of phononic barriers, isotopically modulated silicon multilayers with very small acoustic impedance mismatch and silicon-molybdenum multilayers, which show a high resistivity.
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Affiliation(s)
- Anton Plech
- Institute for Photon Science and Synchrotron Radiation, Karlsruhe Institute of Technology, D-76021 Karlsruhe, Germany.
| | - Bärbel Krause
- Institute for Photon Science and Synchrotron Radiation, Karlsruhe Institute of Technology, D-76021 Karlsruhe, Germany.
| | - Tilo Baumbach
- Institute for Photon Science and Synchrotron Radiation, Karlsruhe Institute of Technology, D-76021 Karlsruhe, Germany.
- Laboratory for Applications of Synchrotron Radiation, Karlsruhe Institute of Technology, D-76021 Karlsruhe, Germany.
| | - Margarita Zakharova
- Institute of Microstructure Technology, Karlsruhe Institute of Technology, D-76021 Karlsruhe, Germany.
| | - Soizic Eon
- Institute of Materials Physics, University of Muenster, D-48149 Münster, Germany.
| | - Caroline Girmen
- Institute of Materials Physics, University of Muenster, D-48149 Münster, Germany.
| | - Gernot Buth
- Institute for Photon Science and Synchrotron Radiation, Karlsruhe Institute of Technology, D-76021 Karlsruhe, Germany.
| | - Hartmut Bracht
- Institute of Materials Physics, University of Muenster, D-48149 Münster, Germany.
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20
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Zeuschner SP, Parpiiev T, Pezeril T, Hillion A, Dumesnil K, Anane A, Pudell J, Willig L, Rössle M, Herzog M, von Reppert A, Bargheer M. Tracking picosecond strain pulses in heterostructures that exhibit giant magnetostriction. STRUCTURAL DYNAMICS (MELVILLE, N.Y.) 2019; 6:024302. [PMID: 31041360 PMCID: PMC6447272 DOI: 10.1063/1.5084140] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2018] [Accepted: 02/26/2019] [Indexed: 05/06/2023]
Abstract
We combine ultrafast X-ray diffraction (UXRD) and time-resolved Magneto-Optical Kerr Effect (MOKE) measurements to monitor the strain pulses in laser-excited TbFe2/Nb heterostructures. Spatial separation of the Nb detection layer from the laser excitation region allows for a background-free characterization of the laser-generated strain pulses. We clearly observe symmetric bipolar strain pulses if the excited TbFe2 surface terminates the sample and a decomposition of the strain wavepacket into an asymmetric bipolar and a unipolar pulse, if a SiO2 glass capping layer covers the excited TbFe2 layer. The inverse magnetostriction of the temporally separated unipolar strain pulses in this sample leads to a MOKE signal that linearly depends on the strain pulse amplitude measured through UXRD. Linear chain model simulations accurately predict the timing and shape of UXRD and MOKE signals that are caused by the strain reflections from multiple interfaces in the heterostructure.
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Affiliation(s)
| | - T Parpiiev
- Institut des Molécules et Matériaux du Mans (UMR CNRS 6283), Université du Maine, 72085 Le Mans Cedex, France
| | - T Pezeril
- Institut des Molécules et Matériaux du Mans (UMR CNRS 6283), Université du Maine, 72085 Le Mans Cedex, France
| | - A Hillion
- Institut Jean Lamour (UMR CNRS 7198), Université de Lorraine, 54000 Nancy, France
| | - K Dumesnil
- Institut Jean Lamour (UMR CNRS 7198), Université de Lorraine, 54000 Nancy, France
| | - A Anane
- Unité Mixte de Physique, CNRS, Thales, Univ. Paris-Sud, Université Paris-Saclay, 91767, Palaiseau, France
| | - J Pudell
- Institute of Physics and Astronomy, University of Potsdam, Karl-Liebknecht-Straße 24-25, 14476 Potsdam, Germany
| | - L Willig
- Institute of Physics and Astronomy, University of Potsdam, Karl-Liebknecht-Straße 24-25, 14476 Potsdam, Germany
| | - M Rössle
- Helmholtz-Zentrum Berlin, Wilhelm-Conrad-Röntgen-Campus, BESSY II, Albert-Einstein-Straße 15, 12489 Berlin, Germany
| | - M Herzog
- Institute of Physics and Astronomy, University of Potsdam, Karl-Liebknecht-Straße 24-25, 14476 Potsdam, Germany
| | - A von Reppert
- Institute of Physics and Astronomy, University of Potsdam, Karl-Liebknecht-Straße 24-25, 14476 Potsdam, Germany
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21
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Bach N, Domröse T, Feist A, Rittmann T, Strauch S, Ropers C, Schäfer S. Coulomb interactions in high-coherence femtosecond electron pulses from tip emitters. STRUCTURAL DYNAMICS (MELVILLE, N.Y.) 2019; 6:014301. [PMID: 30868085 PMCID: PMC6404915 DOI: 10.1063/1.5066093] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2018] [Accepted: 01/08/2019] [Indexed: 05/26/2023]
Abstract
Tip-based photoemission electron sources offer unique properties for ultrafast imaging, diffraction, and spectroscopy experiments with highly coherent few-electron pulses. Extending this approach to increased bunch-charges requires a comprehensive experimental study on Coulomb interactions in nanoscale electron pulses and their impact on beam quality. For a laser-driven Schottky field emitter, we assess the transverse and longitudinal electron pulse properties in an ultrafast transmission electron microscope at a high photoemission current density. A quantitative characterization of electron beam emittance, pulse duration, spectral bandwidth, and chirp is performed. Due to the cathode geometry, Coulomb interactions in the pulse predominantly occur in the direct vicinity to the tip apex, resulting in a well-defined pulse chirp and limited emittance growth. Strategies for optimizing electron source parameters are identified, enabling advanced ultrafast transmission electron microscopy approaches, such as phase-resolved imaging and holography.
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Affiliation(s)
- Nora Bach
- 4th Physical Institute - Solids and Nanostructures, University of Goettingen, Goettingen, Germany
| | - Till Domröse
- 4th Physical Institute - Solids and Nanostructures, University of Goettingen, Goettingen, Germany
| | - Armin Feist
- 4th Physical Institute - Solids and Nanostructures, University of Goettingen, Goettingen, Germany
| | - Thomas Rittmann
- 4th Physical Institute - Solids and Nanostructures, University of Goettingen, Goettingen, Germany
| | - Stefanie Strauch
- 4th Physical Institute - Solids and Nanostructures, University of Goettingen, Goettingen, Germany
| | - Claus Ropers
- 4th Physical Institute - Solids and Nanostructures, University of Goettingen, Goettingen, Germany
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22
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Hauf C, Hernandez Salvador AA, Holtz M, Woerner M, Elsaesser T. Phonon driven charge dynamics in polycrystalline acetylsalicylic acid mapped by ultrafast x-ray diffraction. STRUCTURAL DYNAMICS (MELVILLE, N.Y.) 2019; 6:014503. [PMID: 30868088 PMCID: PMC6404925 DOI: 10.1063/1.5079229] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Accepted: 01/14/2019] [Indexed: 05/17/2023]
Abstract
The coupled lattice and charge dynamics induced by phonon excitation in polycrystalline acetylsalicylic acid (aspirin) are mapped by femtosecond x-ray powder diffraction. The hybrid-mode character of the 0.9 ± 0.1 THz methyl rotation in the aspirin molecules is evident from collective charge relocations over distances of some 100 pm, much larger than the sub-picometer nuclear displacements. Oscillatory charge relocations around the methyl group generate a torque on the latter, thus coupling electronic and nuclear motions.
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Affiliation(s)
- Christoph Hauf
- Max-Born-Institut für Nichtlineare Optik und Kurzzeitspektroskopie, 12489 Berlin, Germany
| | | | - Marcel Holtz
- Max-Born-Institut für Nichtlineare Optik und Kurzzeitspektroskopie, 12489 Berlin, Germany
| | - Michael Woerner
- Max-Born-Institut für Nichtlineare Optik und Kurzzeitspektroskopie, 12489 Berlin, Germany
| | - Thomas Elsaesser
- Max-Born-Institut für Nichtlineare Optik und Kurzzeitspektroskopie, 12489 Berlin, Germany
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23
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Hsu WH, Masim FCP, Balčytis A, Huang HH, Yonezawa T, Kuchmizhak AA, Juodkazis S, Hatanaka K. Enhancement of X-ray emission from nanocolloidal gold suspensions under double-pulse excitation. BEILSTEIN JOURNAL OF NANOTECHNOLOGY 2018; 9:2609-2617. [PMID: 30416911 PMCID: PMC6204784 DOI: 10.3762/bjnano.9.242] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Accepted: 09/09/2018] [Indexed: 06/09/2023]
Abstract
Enhancement of X-ray emission was observed from a micro-jet of a nano-colloidal gold suspension in air under double-pulse excitation of ultrashort (40 fs) near-IR laser pulses. Temporal and spatial overlaps between the pre-pulse and the main pulse were optimized for the highest X-ray emission. The maximum X-ray intensity was obtained at a 1-7 ns delay of the main pulse irradiation after the pre-pulse irradiation with the micro-jet position shifted along the laser beam propagation. It was revealed that the volume around gold nanoparticles where the permittivity is near zero, ε ≈ 0, accounts for the strongest absorption, which leads to the effective enhancements of X-ray emission.
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Affiliation(s)
- Wei-Hung Hsu
- Research Center for Applied Sciences, Academia Sinica, Nankang, Taipei 11529, Taiwan
| | | | - Armandas Balčytis
- Centre for Micro-Photonics, Swinburne University of Technology, Hawthorn, VIC 3122, Australia
| | - Hsin-Hui Huang
- Research Center for Applied Sciences, Academia Sinica, Nankang, Taipei 11529, Taiwan
| | - Tetsu Yonezawa
- Division of Materials Science and Engineering, Faculty of Engineering, Hokkaido University, Sapporo, Hokkaido 0608628, Japan
| | - Aleksandr A Kuchmizhak
- School of Natural Sciences, Far Eastern Federal University (FEFU), Vladivostok 690041, Russia
- Institute of Automation and Control Processes, Far Eastern Branch, Russian Academy of Science, Vladivostok 690041, Russia
| | - Saulius Juodkazis
- Centre for Micro-Photonics, Swinburne University of Technology, Hawthorn, VIC 3122, Australia
- Melbourne Centre for Nanofabrication, the Victorian Node of the Australian National Fabrication Facility, Clayton 3168 VIC, Australia
| | - Koji Hatanaka
- Research Center for Applied Sciences, Academia Sinica, Nankang, Taipei 11529, Taiwan
- College of Engineering, Chang Gung University , Guishan, Taoyuan 33302, Taiwan
- Department of Materials Science and Engineering, National Dong-Hwa University, Shoufeng, Hualien 97401, Taiwan
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24
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Lemke HT, Breiby DW, Ejdrup T, Hammershøj P, Cammarata M, Khakhulin D, Rusteika N, Adachi SI, Koshihara S, Kuhlman TS, Mariager SO, Nielsen TN, Wulff M, Sølling TI, Harrit N, Feidenhans’l R, Nielsen MM. Tuning and Tracking of Coherent Shear Waves in Molecular Films. ACS OMEGA 2018; 3:9929-9933. [PMID: 31459121 PMCID: PMC6645282 DOI: 10.1021/acsomega.8b01400] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/20/2018] [Accepted: 08/13/2018] [Indexed: 06/10/2023]
Abstract
We have determined the time-dependent displacement fields in molecular sub-micrometer thin films as response to femtosecond and picosecond laser pulse heating by time-resolved X-ray diffraction. This method allows a direct absolute determination of the molecular displacements induced by electron-phonon interactions, which are crucial for, for example, charge transport in organic electronic devices. We demonstrate that two different modes of coherent shear motion can be photoexcited in a thin film of organic molecules by careful tuning of the laser penetration depth relative to the thickness of the film. The measured response of the organic film to impulse heating is explained by a thermoelastic model and reveals the spatially resolved displacement in the film. Thereby, information about the profile of the energy deposition in the film as well as about the mechanical interaction with the substrate material is obtained.
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Affiliation(s)
- Henrik Till Lemke
- Nano-Science Center and Department of
Chemistry, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen, Denmark
| | - Dag Werner Breiby
- Deparment of Physics, Norwegian
University of Science and Technology, Højskoleringen 5, 7491 Trondheim, Norway
| | - Tine Ejdrup
- Nano-Science Center and Department of
Chemistry, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen, Denmark
| | - Peter Hammershøj
- Nano-Science Center and Department of
Chemistry, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen, Denmark
| | - Marco Cammarata
- Department of Chemistry, University of
Copenhagen, Universitetsparken
5, 2100 Copenhagen, Denmark
| | - Dmitry Khakhulin
- Department of Chemistry, University of
Copenhagen, Universitetsparken
5, 2100 Copenhagen, Denmark
| | - Nerijus Rusteika
- Nano-Science Center and Department of
Chemistry, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen, Denmark
| | - Shin-Ichi Adachi
- Tokyo Institute of Technology, 2-12-1-H61 Oh-okayama, Meguro-ku, Tokyo 152-8551, Japan
| | - Shinya Koshihara
- Tokyo Institute of Technology, 2-12-1-H61 Oh-okayama, Meguro-ku, Tokyo 152-8551, Japan
| | - Thomas Scheby Kuhlman
- Nano-Science Center and Department of
Chemistry, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen, Denmark
| | - Simon Oddsson Mariager
- Nano-Science Center and Department of
Chemistry, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen, Denmark
| | - Thomas Nørskov Nielsen
- Nano-Science Center and Department of
Chemistry, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen, Denmark
| | - Michael Wulff
- ESRF—The European Synchrotron, CS40220, 38043 Grenoble Cedex 9, France
| | - Theis Ivan Sølling
- Nano-Science Center and Department of
Chemistry, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen, Denmark
| | - Niels Harrit
- Department of Chemistry, University of
Copenhagen, Universitetsparken
5, 2100 Copenhagen, Denmark
| | - Robert Feidenhans’l
- Nano-Science Center and Department of
Chemistry, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen, Denmark
| | - Martin Meedom Nielsen
- Department of Physics, Technical University
of Denmark, Fysikvej
307, 2800 Kgs. Lyngby, Denmark
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25
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Hauf C, Hernandez Salvador AA, Holtz M, Woerner M, Elsaesser T. Soft-mode driven polarity reversal in ferroelectrics mapped by ultrafast x-ray diffraction. STRUCTURAL DYNAMICS (MELVILLE, N.Y.) 2018; 5:024501. [PMID: 29657958 PMCID: PMC5889304 DOI: 10.1063/1.5026494] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2018] [Accepted: 03/26/2018] [Indexed: 05/17/2023]
Abstract
Quantum theory has linked microscopic currents and macroscopic polarizations of ferroelectrics, but the interplay of lattice excitations and charge dynamics on atomic length and time scales is an open problem. Upon phonon excitation in the prototypical ferroelectric ammonium sulfate [(NH4)2SO4], we determine transient charge density maps by femtosecond x-ray diffraction. A newly discovered low frequency-mode with a 3 ps period and sub-picometer amplitudes induces periodic charge relocations over some 100 pm, a hallmark of soft-mode behavior. The transient charge density allows for deriving the macroscopic polarization, showing a periodic reversal of polarity.
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Affiliation(s)
- Christoph Hauf
- Max-Born-Institut für Nichtlineare Optik und Kurzzeitspektroskopie, 12489 Berlin, Germany
| | | | - Marcel Holtz
- Max-Born-Institut für Nichtlineare Optik und Kurzzeitspektroskopie, 12489 Berlin, Germany
| | - Michael Woerner
- Max-Born-Institut für Nichtlineare Optik und Kurzzeitspektroskopie, 12489 Berlin, Germany
| | - Thomas Elsaesser
- Max-Born-Institut für Nichtlineare Optik und Kurzzeitspektroskopie, 12489 Berlin, Germany
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26
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Feist A, Rubiano da Silva N, Liang W, Ropers C, Schäfer S. Nanoscale diffractive probing of strain dynamics in ultrafast transmission electron microscopy. STRUCTURAL DYNAMICS (MELVILLE, N.Y.) 2018; 5:014302. [PMID: 29464187 PMCID: PMC5801750 DOI: 10.1063/1.5009822] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2017] [Accepted: 11/21/2017] [Indexed: 05/31/2023]
Abstract
The control of optically driven high-frequency strain waves in nanostructured systems is an essential ingredient for the further development of nanophononics. However, broadly applicable experimental means to quantitatively map such structural distortion on their intrinsic ultrafast time and nanometer length scales are still lacking. Here, we introduce ultrafast convergent beam electron diffraction with a nanoscale probe beam for the quantitative retrieval of the time-dependent local deformation gradient tensor. We demonstrate its capabilities by investigating the ultrafast acoustic deformations close to the edge of a single-crystalline graphite membrane. Tracking the structural distortion with a 28-nm/700-fs spatio-temporal resolution, we observe an acoustic membrane breathing mode with spatially modulated amplitude, governed by the optical near field structure at the membrane edge. Furthermore, an in-plane polarized acoustic shock wave is launched at the membrane edge, which triggers secondary acoustic shear waves with a pronounced spatio-temporal dependency. The experimental findings are compared to numerical acoustic wave simulations in the continuous medium limit, highlighting the importance of microscopic dissipation mechanisms and ballistic transport channels.
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Affiliation(s)
- Armin Feist
- 4th Physical Institute - Solids and Nanostructures, University of Göttingen, Göttingen, Germany
| | - Nara Rubiano da Silva
- 4th Physical Institute - Solids and Nanostructures, University of Göttingen, Göttingen, Germany
| | - Wenxi Liang
- Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan, China
| | | | - Sascha Schäfer
- 4th Physical Institute - Solids and Nanostructures, University of Göttingen, Göttingen, Germany
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27
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Biswas S, Husek J, Baker LR. Elucidating ultrafast electron dynamics at surfaces using extreme ultraviolet (XUV) reflection–absorption spectroscopy. Chem Commun (Camb) 2018; 54:4216-4230. [DOI: 10.1039/c8cc01745j] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Time-resolved XUV reflection–absorption spectroscopy probes core-to-valence transitions to reveal state-specific electron dynamics at surfaces.
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28
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Hamm P, Meuwly M, Johnson SL, Beaud P, Staub U. Perspective: THz-driven nuclear dynamics from solids to molecules. STRUCTURAL DYNAMICS (MELVILLE, N.Y.) 2017; 4:061601. [PMID: 29308420 PMCID: PMC5741436 DOI: 10.1063/1.4992050] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/26/2017] [Accepted: 11/14/2017] [Indexed: 06/07/2023]
Abstract
Recent years have seen dramatic developments in the technology of intense pulsed light sources in the THz frequency range. Since many dipole-active excitations in solids and molecules also lie in this range, there is now a tremendous potential to use these light sources to study linear and nonlinear dynamics in such systems. While several experimental investigations of THz-driven dynamics in solid-state systems have demonstrated a variety of interesting linear and nonlinear phenomena, comparatively few efforts have been made to drive analogous dynamics in molecular systems. In the present Perspective article, we discuss the similarities and differences between THz-driven dynamics in solid-state and molecular systems on both conceptual and practical levels. We also discuss the experimental parameters needed for these types of experiments and thereby provide design criteria for a further development of this new research branch. Finally, we present a few recent examples to illustrate the rich physics that may be learned from nonlinear THz excitations of phonons in solids as well as inter-molecular vibrations in liquid and gas-phase systems.
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Affiliation(s)
- Peter Hamm
- Department of Chemistry, University of Zurich, Zurich, Switzerland
| | - Markus Meuwly
- Department of Chemistry, University of Basel, Basel, Switzerland
| | - Steve L Johnson
- Institute for Quantum Electronics, ETH Zurich, Zurich, Switzerland
| | - Paul Beaud
- Paul Scherrer Institute, Villigen, Switzerland
| | - Urs Staub
- Paul Scherrer Institute, Villigen, Switzerland
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29
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Alarcos N, Cohen B, Ziółek M, Douhal A. Photochemistry and Photophysics in Silica-Based Materials: Ultrafast and Single Molecule Spectroscopy Observation. Chem Rev 2017; 117:13639-13720. [PMID: 29068670 DOI: 10.1021/acs.chemrev.7b00422] [Citation(s) in RCA: 84] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Silica-based materials (SBMs) are widely used in catalysis, photonics, and drug delivery. Their pores and cavities act as hosts of diverse guests ranging from classical dyes to drugs and quantum dots, allowing changes in the photochemical behavior of the confined guests. The heterogeneity of the guest populations as well as the confinement provided by these hosts affect the behavior of the formed hybrid materials. As a consequence, the observed reaction dynamics becomes significantly different and complex. Studying their photobehavior requires advanced laser-based spectroscopy and microscopy techniques as well as computational methods. Thanks to the development of ultrafast (spectroscopy and imaging) tools, we are witnessing an increasing interest of the scientific community to explore the intimate photobehavior of these composites. Here, we review the recent theoretical and ultrafast experimental studies of their photodynamics and discuss the results in comparison to those in homogeneous media. The discussion of the confined dynamics includes solvation and intra- and intermolecular proton-, electron-, and energy transfer events of the guest within the SBMs. Several examples of applications in photocatalysis, (photo)sensors, photonics, photovoltaics, and drug delivery demonstrate the vast potential of the SBMs in modern science and technology.
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Affiliation(s)
- Noemí Alarcos
- Departamento de Química Física, Facultad de Ciencias Ambientales y Bioquímica, and INAMOL, Universidad de Castilla-La Mancha , Avenida Carlos III, S.N., 45071 Toledo, Spain
| | - Boiko Cohen
- Departamento de Química Física, Facultad de Ciencias Ambientales y Bioquímica, and INAMOL, Universidad de Castilla-La Mancha , Avenida Carlos III, S.N., 45071 Toledo, Spain
| | - Marcin Ziółek
- Quantum Electronics Laboratory, Faculty of Physics, Adam Mickiewicz University , Umultowska 85, 61-614 Poznań, Poland
| | - Abderrazzak Douhal
- Departamento de Química Física, Facultad de Ciencias Ambientales y Bioquímica, and INAMOL, Universidad de Castilla-La Mancha , Avenida Carlos III, S.N., 45071 Toledo, Spain
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30
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Hsu WH, Masim FCP, Balčytis A, Juodkazis S, Hatanaka K. Dynamic position shifts of X-ray emission from a water film induced by a pair of time-delayed femtosecond laser pulses. OPTICS EXPRESS 2017; 25:24109-24118. [PMID: 29041357 DOI: 10.1364/oe.25.024109] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
Femtosecond double-pulsed laser excitation of a water film in air showed enhancements of X-ray intensity as compared with single pulse irradiation. The position of the highest yield of X-rays strongly depends on temporal separation between the pre-pulse and the main-pulse (energy ratios where ∼ 1 : 10). The strongest X-ray emission was observed at 10-15 ns delay of the main-pulse. Nanoscale roughening of water surface can account for the observation.
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31
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Holtz M, Hauf C, Weisshaupt J, Salvador AAH, Woerner M, Elsaesser T. Towards shot-noise limited diffraction experiments with table-top femtosecond hard x-ray sources. STRUCTURAL DYNAMICS (MELVILLE, N.Y.) 2017; 4:054304. [PMID: 28795079 PMCID: PMC5517321 DOI: 10.1063/1.4991355] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2017] [Accepted: 07/10/2017] [Indexed: 05/17/2023]
Abstract
Table-top laser-driven hard x-ray sources with kilohertz repetition rates are an attractive alternative to large-scale accelerator-based systems and have found widespread applications in x-ray studies of ultrafast structural dynamics. Hard x-ray pulses of 100 fs duration have been generated at the Cu K α wavelength with a photon flux of up to 109 photons per pulse into the full solid angle, perfectly synchronized to the sub-100-fs optical pulses from the driving laser system. Based on spontaneous x-ray emission, such sources display a particular noise behavior which impacts the sensitivity of x-ray diffraction experiments. We present a detailed analysis of the photon statistics and temporal fluctuations of the x-ray flux, together with experimental strategies to optimize the sensitivity of optical pump/x-ray probe experiments. We demonstrate measurements close to the shot-noise limit of the x-ray source.
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Affiliation(s)
- Marcel Holtz
- Max-Born-Institut für Nichtlineare Optik und Kurzzeitspektroskopie, 12489 Berlin, Germany
| | - Christoph Hauf
- Max-Born-Institut für Nichtlineare Optik und Kurzzeitspektroskopie, 12489 Berlin, Germany
| | - Jannick Weisshaupt
- Max-Born-Institut für Nichtlineare Optik und Kurzzeitspektroskopie, 12489 Berlin, Germany
| | | | - Michael Woerner
- Max-Born-Institut für Nichtlineare Optik und Kurzzeitspektroskopie, 12489 Berlin, Germany
| | - Thomas Elsaesser
- Max-Born-Institut für Nichtlineare Optik und Kurzzeitspektroskopie, 12489 Berlin, Germany
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32
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Callahan PG, Echlin MP, Pollock TM, De Graef M. Reconstruction of Laser-Induced Surface Topography from Electron Backscatter Diffraction Patterns. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2017; 23:730-740. [PMID: 28784197 DOI: 10.1017/s1431927617012326] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
We demonstrate that the surface topography of a sample can be reconstructed from electron backscatter diffraction (EBSD) patterns collected with a commercial EBSD system. This technique combines the location of the maximum background intensity with a correction from Monte Carlo simulations to determine the local surface normals at each point in an EBSD scan. A surface height map is then reconstructed from the local surface normals. In this study, a Ni sample was machined with a femtosecond laser, which causes the formation of a laser-induced periodic surface structure (LIPSS). The topography of the LIPSS was analyzed using atomic force microscopy (AFM) and reconstructions from EBSD patterns collected at 5 and 20 kV. The LIPSS consisted of a combination of low frequency waviness due to curtaining and high frequency ridges. The morphology of the reconstructed low frequency waviness and high frequency ridges matched the AFM data. The reconstruction technique does not require any modification to existing EBSD systems and so can be particularly useful for measuring topography and its evolution during in situ experiments.
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Affiliation(s)
- Patrick G Callahan
- 1Materials Department,University of California Santa Barbara,Santa Barbara,CA93106-5050USA
| | - McLean P Echlin
- 1Materials Department,University of California Santa Barbara,Santa Barbara,CA93106-5050USA
| | - Tresa M Pollock
- 1Materials Department,University of California Santa Barbara,Santa Barbara,CA93106-5050USA
| | - Marc De Graef
- 2Department of Materials Science and Engineering,Carnegie Mellon University,5000 Forbes Avenue,Pittsburgh,PA15213-3890,USA
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33
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Silly MG, Ferté T, Tordeux MA, Pierucci D, Beaulieu N, Chauvet C, Pressacco F, Sirotti F, Popescu H, Lopez-Flores V, Tortarolo M, Sacchi M, Jaouen N, Hollander P, Ricaud JP, Bergeard N, Boeglin C, Tudu B, Delaunay R, Luning J, Malinowski G, Hehn M, Baumier C, Fortuna F, Krizmancic D, Stebel L, Sergo R, Cautero G. Pump-probe experiments at the TEMPO beamline using the low-α operation mode of Synchrotron SOLEIL. JOURNAL OF SYNCHROTRON RADIATION 2017; 24:886-897. [PMID: 28664896 DOI: 10.1107/s1600577517007913] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2017] [Accepted: 05/28/2017] [Indexed: 06/07/2023]
Abstract
The SOLEIL synchrotron radiation source is regularly operated in special filling modes dedicated to pump-probe experiments. Among others, the low-α mode operation is characterized by shorter pulse duration and represents the natural bridge between 50 ps synchrotron pulses and femtosecond experiments. Here, the capabilities in low-α mode of the experimental set-ups developed at the TEMPO beamline to perform pump-probe experiments with soft X-rays based on photoelectron or photon detection are presented. A 282 kHz repetition-rate femtosecond laser is synchronized with the synchrotron radiation time structure to induce fast electronic and/or magnetic excitations. Detection is performed using a two-dimensional space resolution plus time resolution detector based on microchannel plates equipped with a delay line. Results of time-resolved photoelectron spectroscopy, circular dichroism and magnetic scattering experiments are reported, and their respective advantages and limitations in the framework of high-time-resolution pump-probe experiments compared and discussed.
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Affiliation(s)
- Mathieu G Silly
- Synchrotron SOLEIL, L'Orme des Merisiers, Saint Aubin, Gif sur Yvette 91192, France
| | - Tom Ferté
- Université de Strasbourg, CNRS, Institut de Physique et Chimie des Matériaux de Strasbourg, UMR 7504, F-67000 Strasbourg, France
| | - Marie Agnes Tordeux
- Synchrotron SOLEIL, L'Orme des Merisiers, Saint Aubin, Gif sur Yvette 91192, France
| | - Debora Pierucci
- Synchrotron SOLEIL, L'Orme des Merisiers, Saint Aubin, Gif sur Yvette 91192, France
| | - Nathan Beaulieu
- Synchrotron SOLEIL, L'Orme des Merisiers, Saint Aubin, Gif sur Yvette 91192, France
| | - Christian Chauvet
- Synchrotron SOLEIL, L'Orme des Merisiers, Saint Aubin, Gif sur Yvette 91192, France
| | - Federico Pressacco
- Synchrotron SOLEIL, L'Orme des Merisiers, Saint Aubin, Gif sur Yvette 91192, France
| | - Fausto Sirotti
- Synchrotron SOLEIL, L'Orme des Merisiers, Saint Aubin, Gif sur Yvette 91192, France
| | - Horia Popescu
- Synchrotron SOLEIL, L'Orme des Merisiers, Saint Aubin, Gif sur Yvette 91192, France
| | - Victor Lopez-Flores
- Synchrotron SOLEIL, L'Orme des Merisiers, Saint Aubin, Gif sur Yvette 91192, France
| | - Marina Tortarolo
- Synchrotron SOLEIL, L'Orme des Merisiers, Saint Aubin, Gif sur Yvette 91192, France
| | - Maurizio Sacchi
- Synchrotron SOLEIL, L'Orme des Merisiers, Saint Aubin, Gif sur Yvette 91192, France
| | - Nicolas Jaouen
- Synchrotron SOLEIL, L'Orme des Merisiers, Saint Aubin, Gif sur Yvette 91192, France
| | - Philippe Hollander
- Synchrotron SOLEIL, L'Orme des Merisiers, Saint Aubin, Gif sur Yvette 91192, France
| | - Jean Paul Ricaud
- Synchrotron SOLEIL, L'Orme des Merisiers, Saint Aubin, Gif sur Yvette 91192, France
| | - Nicolas Bergeard
- Université de Strasbourg, CNRS, Institut de Physique et Chimie des Matériaux de Strasbourg, UMR 7504, F-67000 Strasbourg, France
| | - Christine Boeglin
- Université de Strasbourg, CNRS, Institut de Physique et Chimie des Matériaux de Strasbourg, UMR 7504, F-67000 Strasbourg, France
| | - Bharati Tudu
- Sorbonne Universités, UPMC Université Paris VI, CNRS, Laboratoire de Chimie Physique - Matière et Rayonnement, Paris 75005, France
| | - Renaud Delaunay
- Sorbonne Universités, UPMC Université Paris VI, CNRS, Laboratoire de Chimie Physique - Matière et Rayonnement, Paris 75005, France
| | - Jan Luning
- Synchrotron SOLEIL, L'Orme des Merisiers, Saint Aubin, Gif sur Yvette 91192, France
| | - Gregory Malinowski
- P2M - Institut Jean Lamour UMR7198, CNRS - Université de Lorraine, Vandoeuvre-les-Nancy 54506, France
| | - Michel Hehn
- P2M - Institut Jean Lamour UMR7198, CNRS - Université de Lorraine, Vandoeuvre-les-Nancy 54506, France
| | - Cédric Baumier
- CSNSM, Université Paris Sud and CNRS/IN2P3, Batiment 104 et 108, Orsay 91405, France
| | - Franck Fortuna
- CSNSM, Université Paris Sud and CNRS/IN2P3, Batiment 104 et 108, Orsay 91405, France
| | - Damjan Krizmancic
- Laboratorio TASC, IOM-CNR, SS 14 Km 163.5, Basovizza, I-34149 Trieste, Italy
| | - Luigi Stebel
- ELETTRA Sincrotrone Trieste SCpA, Area Science Park, Strada Statale 14 Km 163.5, I-34012 Basovizza, Italy
| | - Rudi Sergo
- ELETTRA Sincrotrone Trieste SCpA, Area Science Park, Strada Statale 14 Km 163.5, I-34012 Basovizza, Italy
| | - Giuseppe Cautero
- ELETTRA Sincrotrone Trieste SCpA, Area Science Park, Strada Statale 14 Km 163.5, I-34012 Basovizza, Italy
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34
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Weisshaupt J, Rouzée A, Woerner M, Vrakking MJJ, Elsaesser T, Shirley EL, Borgschulte A. Ultrafast modulation of electronic structure by coherent phonon excitations. PHYSICAL REVIEW. B 2017; 95:10.1103/PhysRevB.95.081101. [PMID: 38618525 PMCID: PMC11015475 DOI: 10.1103/physrevb.95.081101] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/16/2024]
Abstract
Femtosecond x-ray absorption spectroscopy with a laser-driven high-harmonic source is used to map ultrafast changes of x-ray absorption by femtometer-scale coherent phonon displacements. In LiBH4, displacements along an A g phonon mode at 10 THz are induced by impulsive Raman excitation and give rise to oscillatory changes of x-ray absorption at the Li K-edge. Electron density maps from femtosecond x-ray diffraction data show that the electric field of the pump pulse induces a charge transfer from the BH 4 - to neighboring Li+ ions, resulting in a differential Coulomb force that drives lattice vibrations in this virtual transition state.
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Affiliation(s)
- J. Weisshaupt
- Max-Born-Institut für Nichtlineare Optik und Kurzzeitspektroskopie, D-12489 Berlin, Germany
| | - A. Rouzée
- Max-Born-Institut für Nichtlineare Optik und Kurzzeitspektroskopie, D-12489 Berlin, Germany
| | - M. Woerner
- Max-Born-Institut für Nichtlineare Optik und Kurzzeitspektroskopie, D-12489 Berlin, Germany
| | - M. J. J. Vrakking
- Max-Born-Institut für Nichtlineare Optik und Kurzzeitspektroskopie, D-12489 Berlin, Germany
| | - T. Elsaesser
- Max-Born-Institut für Nichtlineare Optik und Kurzzeitspektroskopie, D-12489 Berlin, Germany
| | - E. L. Shirley
- National Institute of Standards and Technology, Gaithersburg, MD 20899-8441, USA
| | - A. Borgschulte
- Swiss Federal Laboratories for Materials Science and Technology, Laboratory for Hydrogen and Energy, EMPA, CH-8600 Dübendorf Switzerland
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35
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Pertot Y, Schmidt C, Matthews M, Chauvet A, Huppert M, Svoboda V, von Conta A, Tehlar A, Baykusheva D, Wolf JP, Wörner HJ. Time-resolved x-ray absorption spectroscopy with a water window high-harmonic source. Science 2017; 355:264-267. [DOI: 10.1126/science.aah6114] [Citation(s) in RCA: 231] [Impact Index Per Article: 33.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2016] [Accepted: 12/15/2016] [Indexed: 11/02/2022]
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36
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Schick D, Eckert S, Pontius N, Mitzner R, Föhlisch A, Holldack K, Sorgenfrei F. Versatile soft X-ray-optical cross-correlator for ultrafast applications. STRUCTURAL DYNAMICS (MELVILLE, N.Y.) 2016; 3:054304. [PMID: 27795974 PMCID: PMC5065566 DOI: 10.1063/1.4964296] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/11/2016] [Accepted: 09/21/2016] [Indexed: 06/06/2023]
Abstract
We present an X-ray-optical cross-correlator for the soft ([Formula: see text]) up to the hard X-ray regime based on a molybdenum-silicon superlattice. The cross-correlation is done by probing intensity and position changes of superlattice Bragg peaks caused by photoexcitation of coherent phonons. This approach is applicable for a wide range of X-ray photon energies as well as for a broad range of excitation wavelengths and requires no external fields or changes of temperature. Moreover, the cross-correlator can be employed on a 10 ps or 100 fs time scale featuring up to 50% total X-ray reflectivity and transient signal changes of more than 20%.
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Affiliation(s)
- Daniel Schick
- Institut für Methoden und Instrumentierung der Forschung mit Synchrotronstrahlung, Helmholtz-Zentrum Berlin für Materialien und Energie GmbH , Albert-Einstein-Straße 15, 12489 Berlin, Germany
| | - Sebastian Eckert
- Institut für Physik und Astronomie, Universität Potsdam , Karl-Liebknecht-Straße 24-25, 14476 Potsdam, Germany
| | - Niko Pontius
- Institut für Methoden und Instrumentierung der Forschung mit Synchrotronstrahlung, Helmholtz-Zentrum Berlin für Materialien und Energie GmbH , Albert-Einstein-Straße 15, 12489 Berlin, Germany
| | - Rolf Mitzner
- Institut für Methoden und Instrumentierung der Forschung mit Synchrotronstrahlung, Helmholtz-Zentrum Berlin für Materialien und Energie GmbH , Albert-Einstein-Straße 15, 12489 Berlin, Germany
| | | | - Karsten Holldack
- Institut für Methoden und Instrumentierung der Forschung mit Synchrotronstrahlung, Helmholtz-Zentrum Berlin für Materialien und Energie GmbH , Albert-Einstein-Straße 15, 12489 Berlin, Germany
| | - Florian Sorgenfrei
- Institut für Physik und Astronomie, Universität Potsdam , Karl-Liebknecht-Straße 24-25, 14476 Potsdam, Germany
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37
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Cremons DR, Plemmons DA, Flannigan DJ. Femtosecond electron imaging of defect-modulated phonon dynamics. Nat Commun 2016; 7:11230. [PMID: 27079790 PMCID: PMC4835536 DOI: 10.1038/ncomms11230] [Citation(s) in RCA: 75] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2015] [Accepted: 02/25/2016] [Indexed: 11/09/2022] Open
Abstract
Precise manipulation and control of coherent lattice oscillations via nanostructuring and phonon-wave interference has the potential to significantly impact a broad array of technologies and research areas. Resolving the dynamics of individual phonons in defect-laden materials presents an enormous challenge, however, owing to the interdependent nanoscale and ultrafast spatiotemporal scales. Here we report direct, real-space imaging of the emergence and evolution of acoustic phonons at individual defects in crystalline WSe2 and Ge. Via bright-field imaging with an ultrafast electron microscope, we are able to image the sub-picosecond nucleation and the launch of wavefronts at step edges and resolve dispersion behaviours during propagation and scattering. We discover that the appearance of speed-of-sound (for example, 6 nm ps(-1)) wavefronts are influenced by spatially varying nanoscale strain fields, taking on the appearance of static bend contours during propagation. These observations provide unprecedented insight into the roles played by individual atomic and nanoscale features on acoustic-phonon dynamics.
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Affiliation(s)
- Daniel R Cremons
- Department of Chemical Engineering and Materials Science, University of Minnesota, 421 Washington Avenue SE, Minneapolis, Minnesota 55455, USA
| | - Dayne A Plemmons
- Department of Chemical Engineering and Materials Science, University of Minnesota, 421 Washington Avenue SE, Minneapolis, Minnesota 55455, USA
| | - David J Flannigan
- Department of Chemical Engineering and Materials Science, University of Minnesota, 421 Washington Avenue SE, Minneapolis, Minnesota 55455, USA
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38
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Shinokita K, Reimann K, Woerner M, Elsaesser T, Hey R, Flytzanis C. Strong Amplification of Coherent Acoustic Phonons by Intraminiband Currents in a Semiconductor Superlattice. PHYSICAL REVIEW LETTERS 2016; 116:075504. [PMID: 26943546 DOI: 10.1103/physrevlett.116.075504] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2015] [Indexed: 05/06/2023]
Abstract
Sound amplification in an electrically biased superlattice (SL) is studied in optical experiments with 100 fs time resolution. Coherent SL phonons with frequencies of 40, 375, and 410 GHz give rise to oscillatory reflectivity changes. With currents from 0.5 to 1.3 A, the Fourier amplitude of the 410 GHz phonon increases by more than a factor of 2 over a 200 ps period. This amplification is due to stimulated Čerenkov phonon emission by electrons undergoing intraminiband transport. The gain coefficient of 8×10^{3} cm^{-1} is reproduced by theoretical calculations and holds potential for novel sub-THz phonon emitters.
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Affiliation(s)
- Keisuke Shinokita
- Max-Born-Institut für Nichtlineare Optik und Kurzzeitspektroskopie, 12489 Berlin, Germany
| | - Klaus Reimann
- Max-Born-Institut für Nichtlineare Optik und Kurzzeitspektroskopie, 12489 Berlin, Germany
| | - Michael Woerner
- Max-Born-Institut für Nichtlineare Optik und Kurzzeitspektroskopie, 12489 Berlin, Germany
| | - Thomas Elsaesser
- Max-Born-Institut für Nichtlineare Optik und Kurzzeitspektroskopie, 12489 Berlin, Germany
| | - Rudolf Hey
- Paul-Drude-Institut für Festkörperelektronik, 10117 Berlin, Germany
| | - Christos Flytzanis
- Laboratoire Pierre Aigrain, École Normale Supérieure, 75231 Paris, France
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39
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Wenz J, Schleede S, Khrennikov K, Bech M, Thibault P, Heigoldt M, Pfeiffer F, Karsch S. Quantitative X-ray phase-contrast microtomography from a compact laser-driven betatron source. Nat Commun 2015; 6:7568. [PMID: 26189811 PMCID: PMC4518247 DOI: 10.1038/ncomms8568] [Citation(s) in RCA: 94] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2014] [Accepted: 05/19/2015] [Indexed: 11/09/2022] Open
Abstract
X-ray phase-contrast imaging has recently led to a revolution in resolving power and tissue contrast in biomedical imaging, microscopy and materials science. The necessary high spatial coherence is currently provided by either large-scale synchrotron facilities with limited beamtime access or by microfocus X-ray tubes with rather limited flux. X-rays radiated by relativistic electrons driven by well-controlled high-power lasers offer a promising route to a proliferation of this powerful imaging technology. A laser-driven plasma wave accelerates and wiggles electrons, giving rise to a brilliant keV X-ray emission. This so-called betatron radiation is emitted in a collimated beam with excellent spatial coherence and remarkable spectral stability. Here we present a phase-contrast microtomogram of a biological sample using betatron X-rays. Comprehensive source characterization enables the reconstruction of absolute electron densities. Our results suggest that laser-based X-ray technology offers the potential for filling the large performance gap between synchrotron- and current X-ray tube-based sources. With excellent resolving power and tissue contrast, X-ray phase-contrast imaging holds great promise but the source requirements have limited its use. Here, Wenz et al. show a phase-contrast microtomogram of a biological sample using X-ray radiation driven by a high-power laser.
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Affiliation(s)
- J Wenz
- 1] Ludwig-Maximilians-Universität München, Fakultät für Physik, Am Coulombwall 1, Garching 85748, Germany [2] MPI für Quantenoptik, Abteilung für Attosekundenphysik, Hans-Kopfermann-Str. 1, Garching 85748, Germany
| | - S Schleede
- Lehrstuhl für Biomedizinische Physik, Physik-Department &Institut für Medizintechnik, Technische Universität München, Garching 85748, Germany
| | - K Khrennikov
- 1] Ludwig-Maximilians-Universität München, Fakultät für Physik, Am Coulombwall 1, Garching 85748, Germany [2] MPI für Quantenoptik, Abteilung für Attosekundenphysik, Hans-Kopfermann-Str. 1, Garching 85748, Germany
| | - M Bech
- 1] Lehrstuhl für Biomedizinische Physik, Physik-Department &Institut für Medizintechnik, Technische Universität München, Garching 85748, Germany [2] Department of Medical Radiation Physics, Clinical Sciences, Lund University, Barngatan 2:B, Lund 22185, Sweden
| | - P Thibault
- 1] Lehrstuhl für Biomedizinische Physik, Physik-Department &Institut für Medizintechnik, Technische Universität München, Garching 85748, Germany [2] Department of Physics and Astronomy, University College London, Gower street, London WC1E 6BT, UK
| | - M Heigoldt
- 1] Ludwig-Maximilians-Universität München, Fakultät für Physik, Am Coulombwall 1, Garching 85748, Germany [2] MPI für Quantenoptik, Abteilung für Attosekundenphysik, Hans-Kopfermann-Str. 1, Garching 85748, Germany
| | - F Pfeiffer
- Lehrstuhl für Biomedizinische Physik, Physik-Department &Institut für Medizintechnik, Technische Universität München, Garching 85748, Germany
| | - S Karsch
- 1] Ludwig-Maximilians-Universität München, Fakultät für Physik, Am Coulombwall 1, Garching 85748, Germany [2] MPI für Quantenoptik, Abteilung für Attosekundenphysik, Hans-Kopfermann-Str. 1, Garching 85748, Germany
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40
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Frigge T, Hafke B, Tinnemann V, Witte T, Horn-von Hoegen M. Spot profile analysis and lifetime mapping in ultrafast electron diffraction: Lattice excitation of self-organized Ge nanostructures on Si(001). STRUCTURAL DYNAMICS (MELVILLE, N.Y.) 2015; 2:035101. [PMID: 26798797 PMCID: PMC4711617 DOI: 10.1063/1.4922023] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/24/2015] [Accepted: 05/22/2015] [Indexed: 06/05/2023]
Abstract
Ultrafast high energy electron diffraction in reflection geometry is employed to study the structural dynamics of self-organized Germanium hut-, dome-, and relaxed clusters on Si(001) upon femtosecond laser excitation. Utilizing the difference in size and strain state the response of hut- and dome clusters can be distinguished by a transient spot profile analysis. Surface diffraction from {105}-type facets provide exclusive information on hut clusters. A pixel-by-pixel analysis of the dynamics of the entire diffraction pattern gives time constants of 40, 160, and 390 ps, which are assigned to the cooling time constants for hut-, dome-, and relaxed clusters.
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Affiliation(s)
- T Frigge
- Department of Physics and Center for Nanointegration (CENIDE), University of Duisburg-Essen , Lotharstr. 1, 47057 Duisburg, Germany
| | - B Hafke
- Department of Physics and Center for Nanointegration (CENIDE), University of Duisburg-Essen , Lotharstr. 1, 47057 Duisburg, Germany
| | - V Tinnemann
- Department of Physics and Center for Nanointegration (CENIDE), University of Duisburg-Essen , Lotharstr. 1, 47057 Duisburg, Germany
| | - T Witte
- Department of Physics and Center for Nanointegration (CENIDE), University of Duisburg-Essen , Lotharstr. 1, 47057 Duisburg, Germany
| | - M Horn-von Hoegen
- Department of Physics and Center for Nanointegration (CENIDE), University of Duisburg-Essen , Lotharstr. 1, 47057 Duisburg, Germany
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41
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Bennett K, Biggs JD, Zhang Y, Dorfman KE, Mukamel S. Time-, frequency-, and wavevector-resolved x-ray diffraction from single molecules. J Chem Phys 2015; 140:204311. [PMID: 24880284 DOI: 10.1063/1.4878377] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Using a quantum electrodynamic framework, we calculate the off-resonant scattering of a broadband X-ray pulse from a sample initially prepared in an arbitrary superposition of electronic states. The signal consists of single-particle (incoherent) and two-particle (coherent) contributions that carry different particle form factors that involve different material transitions. Single-molecule experiments involving incoherent scattering are more influenced by inelastic processes compared to bulk measurements. The conditions under which the technique directly measures charge densities (and can be considered as diffraction) as opposed to correlation functions of the charge-density are specified. The results are illustrated with time- and wavevector-resolved signals from a single amino acid molecule (cysteine) following an impulsive excitation by a stimulated X-ray Raman process resonant with the sulfur K-edge. Our theory and simulations can guide future experimental studies on the structures of nano-particles and proteins.
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Affiliation(s)
- Kochise Bennett
- University of California, Irvine, California 92697-2025, USA
| | - Jason D Biggs
- University of California, Irvine, California 92697-2025, USA
| | - Yu Zhang
- University of California, Irvine, California 92697-2025, USA
| | | | - Shaul Mukamel
- University of California, Irvine, California 92697-2025, USA
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42
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van Capel PJS, Péronne E, Dijkhuis JI. Nonlinear ultrafast acoustics at the nano scale. ULTRASONICS 2015; 56:36-51. [PMID: 25455188 DOI: 10.1016/j.ultras.2014.09.021] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2014] [Revised: 09/29/2014] [Accepted: 09/29/2014] [Indexed: 06/04/2023]
Abstract
Pulsed femtosecond lasers can generate acoustic pulses propagating in solids while displaying either diffraction, attenuation, nonlinearity and/or dispersion. When acoustic attenuation and diffraction are negligible, shock waves or solitons can form during propagation. Both wave types are phonon wavepackets with characteristic length scales as short as a few nanometer. Hence, they are well suited for acoustic characterization and manipulation of materials on both ultrafast and ultrashort scales. This work presents an overview of nonlinear ultrasonics since its first experimental demonstration at the beginning of this century to the more recent developments. We start by reviewing the main properties of nonlinear ultrafast acoustic propagation based on the underlying equations. Then we show various results obtained by different groups around the world with an emphasis on recent work. Current issues and directions of future research are discussed.
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Affiliation(s)
- P J S van Capel
- Debye Institute for Nanomaterials Science, Center for Extreme Matter and Emergent Phenomena, Utrecht University, P.O. Box 80000, 3508 TA Utrecht, The Netherlands.
| | - E Péronne
- CNRS, UMR 7588, Institut des NanoSciences de Paris, F-75005 Paris, France; Sorbonne Universités, UPMC Univ. Paris 06, UMR 7588, INSP, F-75005 Paris, France.
| | - J I Dijkhuis
- Debye Institute for Nanomaterials Science, Center for Extreme Matter and Emergent Phenomena, Utrecht University, P.O. Box 80000, 3508 TA Utrecht, The Netherlands.
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43
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Vanacore GM, Hu J, Liang W, Bietti S, Sanguinetti S, Zewail AH. Diffraction of quantum dots reveals nanoscale ultrafast energy localization. NANO LETTERS 2014; 14:6148-54. [PMID: 25099123 DOI: 10.1021/nl502293a] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Unlike in bulk materials, energy transport in low-dimensional and nanoscale systems may be governed by a coherent "ballistic" behavior of lattice vibrations, the phonons. If dominant, such behavior would determine the mechanism for transport and relaxation in various energy-conversion applications. In order to study this coherent limit, both the spatial and temporal resolutions must be sufficient for the length-time scales involved. Here, we report observation of the lattice dynamics in nanoscale quantum dots of gallium arsenide using ultrafast electron diffraction. By varying the dot size from h = 11 to 46 nm, the length scale effect was examined, together with the temporal change. When the dot size is smaller than the inelastic phonon mean-free path, the energy remains localized in high-energy acoustic modes that travel coherently within the dot. As the dot size increases, an energy dissipation toward low-energy phonons takes place, and the transport becomes diffusive. Because ultrafast diffraction provides the atomic-scale resolution and a sufficiently high time resolution, other nanostructured materials can be studied similarly to elucidate the nature of dynamical energy localization.
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Affiliation(s)
- Giovanni M Vanacore
- Physical Biology Center for Ultrafast Science and Technology, Arthur Amos Noyes Laboratory of Chemical Physics, California Institute of Technology , Pasadena, California 91125, United States
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44
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Schick D, Herzog M, Bojahr A, Leitenberger W, Hertwig A, Shayduk R, Bargheer M. Ultrafast lattice response of photoexcited thin films studied by X-ray diffraction. STRUCTURAL DYNAMICS (MELVILLE, N.Y.) 2014; 1:064501. [PMID: 26798784 PMCID: PMC4714650 DOI: 10.1063/1.4901228] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2014] [Accepted: 10/28/2014] [Indexed: 05/06/2023]
Abstract
Using ultrafast X-ray diffraction, we study the coherent picosecond lattice dynamics of photoexcited thin films in the two limiting cases, where the photoinduced stress profile decays on a length scale larger and smaller than the film thickness. We solve a unifying analytical model of the strain propagation for acoustic impedance-matched opaque films on a semi-infinite transparent substrate, showing that the lattice dynamics essentially depend on two parameters: One for the spatial profile and one for the amplitude of the strain. We illustrate the results by comparison with high-quality ultrafast X-ray diffraction data of SrRuO3 films on SrTiO3 substrates.
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Affiliation(s)
| | | | - André Bojahr
- Institut für Physik und Astronomie, Universität Potsdam , Karl-Liebknecht-Straße 24-25, 14476 Potsdam, Germany
| | - Wolfram Leitenberger
- Institut für Physik und Astronomie, Universität Potsdam , Karl-Liebknecht-Straße 24-25, 14476 Potsdam, Germany
| | - Andreas Hertwig
- Bundesanstalt für Materialforschung und -prüfung , Unter den Eichen 87, 12205 Berlin, Germany
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45
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Elsaesser T, Woerner M. Perspective: structural dynamics in condensed matter mapped by femtosecond x-ray diffraction. J Chem Phys 2014; 140:020901. [PMID: 24437858 DOI: 10.1063/1.4855115] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Ultrashort soft and hard x-ray pulses are sensitive probes of structural dynamics on the picometer length and femtosecond time scales of electronic and atomic motions. Recent progress in generating such pulses has initiated new directions of condensed matter research, exploiting a variety of x-ray absorption, scattering, and diffraction methods to probe photoinduced structural dynamics. Atomic motion, changes of local structure and long-range order, as well as correlated electron motion and charge transfer have been resolved in space and time, providing a most direct access to the physical mechanisms and interactions driving reversible and irreversible changes of structure. This perspective combines an overview of recent advances in femtosecond x-ray diffraction with a discussion on ongoing and future developments.
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Affiliation(s)
- T Elsaesser
- Max-Born-Institut für Nichtlineare Optik und Kurzzeitspektroskopie, 12489 Berlin, Germany
| | - M Woerner
- Max-Born-Institut für Nichtlineare Optik und Kurzzeitspektroskopie, 12489 Berlin, Germany
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46
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Zhang BB, Sun SS, Sun DR, Tao Y. Note: A novel normalization scheme for laser-based plasma x-ray sources. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2014; 85:096110. [PMID: 25273796 DOI: 10.1063/1.4896252] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
A kHz repetition rate laser pump-X-ray probe system for ultrafast X-ray diffraction is set up based on a laser-driven plasma X-ray source. A simple and reliable normalization approach has been developed to minimize the impact of large X-ray pulse intensity fluctuation on data quality. It utilizes one single X-ray area detector to record both sample and reference signals simultaneously. Performance of this novel normalization method is demonstrated in reflectivity oscillation measurement of a superlattice sample at sub-ps resolution.
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Affiliation(s)
- B B Zhang
- Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China
| | - S S Sun
- Institute of Physics, Chinese Academy of Sciences, Beijing 100090, China
| | - D R Sun
- Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China
| | - Y Tao
- Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China
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47
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Affiliation(s)
- Majed Chergui
- Ecole Polytechnique Fédérale de Lausanne, Laboratoire de Spectroscopie Ultrarapide, ISIC, FSB, Station 6, CH-1015 Lausanne, Switzerland.
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48
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Loether A, Gao Y, Chen Z, DeCamp MF, Dufresne EM, Walko DA, Wen H. Transient crystalline superlattice generated by a photoacoustic transducer. STRUCTURAL DYNAMICS (MELVILLE, N.Y.) 2014; 1:024301. [PMID: 26798773 PMCID: PMC4711598 DOI: 10.1063/1.4867494] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2013] [Accepted: 02/18/2014] [Indexed: 05/22/2023]
Abstract
Designing an efficient and simple method for modulating the intensity of x-ray radiation on a picosecond time-scale has the potential to produce ultrafast pulses of hard x-rays. In this work, we generate a tunable transient superlattice, in an otherwise perfect crystal, by photoexciting a metal film on a crystalline substrate. The resulting transient strain has amplitudes approaching 1%, wavevectors greater than [Formula: see text], and lifetimes approaching 1 ns. This method has the potential to generate isolated picosecond x-ray bursts with scattering efficiencies in excess of 10%.
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Affiliation(s)
- A Loether
- Department of Physics and Astronomy, University of Delaware , Newark, Delaware 19716, USA
| | | | - Z Chen
- Department of Physics and Astronomy, University of Delaware , Newark, Delaware 19716, USA
| | - M F DeCamp
- Department of Physics and Astronomy, University of Delaware , Newark, Delaware 19716, USA
| | - E M Dufresne
- Argonne National Laboratory , Argonne, Illinois 60439, USA
| | - D A Walko
- Argonne National Laboratory , Argonne, Illinois 60439, USA
| | - H Wen
- Argonne National Laboratory , Argonne, Illinois 60439, USA
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49
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Jurgilaitis A, Enquist H, Andreasson BP, Persson AIH, Borg BM, Caroff P, Dick KA, Harb M, Linke H, Nüske R, Wernersson LE, Larsson J. Time-resolved X-ray diffraction investigation of the modified phonon dispersion in InSb nanowires. NANO LETTERS 2014; 14:541-546. [PMID: 24387246 DOI: 10.1021/nl403596b] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The modified phonon dispersion is of importance for understanding the origin of the reduced heat conductivity in nanowires. We have measured the phonon dispersion for 50 nm diameter InSb (111) nanowires using time-resolved X-ray diffraction. By comparing the sound speed of the bulk (3880 m/s) and that of a classical thin rod (3600 m/s) to our measurement (2880 m/s), we conclude that the origin of the reduced sound speed and thereby to the reduced heat conductivity is that the C44 elastic constant is reduced by 35% compared to the bulk material.
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Affiliation(s)
- A Jurgilaitis
- Department of Physics and ‡MAX IV Laboratory, Lund University , P.O. Box 118, SE-221 00 Lund, Sweden
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50
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Jurgilaitis A, Enquist H, Harb M, Dick KA, Borg BM, Nüske R, Wernersson LE, Larsson J. Measurements of light absorption efficiency in InSb nanowires. STRUCTURAL DYNAMICS (MELVILLE, N.Y.) 2014; 1:014502. [PMID: 26913673 PMCID: PMC4711595 DOI: 10.1063/1.4833559] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2013] [Accepted: 10/31/2013] [Indexed: 06/02/2023]
Abstract
We report on measurements of the light absorption efficiency of InSb nanowires. The absorbed 70 fs light pulse generates carriers, which equilibrate with the lattice via electron-phonon coupling. The increase in lattice temperature is manifested as a strain that can be measured with X-ray diffraction. The diffracted X-ray signal from the excited sample was measured using a streak camera. The amount of absorbed light was deduced by comparing X-ray diffraction measurements with simulations. It was found that 3.0(6)% of the radiation incident on the sample was absorbed by the nanowires, which cover 2.5% of the sample.
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Affiliation(s)
- A Jurgilaitis
- Department of Physics, Lund University , P.O. Box 118, SE-221 00 Lund, Sweden
| | - H Enquist
- MAX IV laboratory, Lund University , P.O. Box 118, Lund, Sweden
| | - M Harb
- Department of Physics, Lund University , P.O. Box 118, SE-221 00 Lund, Sweden
| | | | - B M Borg
- Department of Physics, Lund University , P.O. Box 118, SE-221 00 Lund, Sweden
| | - R Nüske
- Department of Physics, Lund University , P.O. Box 118, SE-221 00 Lund, Sweden
| | - L-E Wernersson
- Department of Electrical and Information Technology, Lund University , P.O. Box 118, SE-221 00 Lund, Sweden
| | - J Larsson
- Department of Physics, Lund University , P.O. Box 118, SE-221 00 Lund, Sweden
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