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1. Beyond a phenomenological description of magnetostriction

Author

William F. Schlotter, Xijie Wang, T. Vecchione, Pablo Maldonado, P. W. Granitzka, J. Cao, Yingchun Zhu, Karel Carva, Emmanuelle Jal, Nick Hartmann, Olav Hellwig, Xiaozhe Shen, Tianmin Liu, Alexander H. Reid, Ryan Coffee, Renkai Li, Eric E. Fullerton, Hendrik Ohldag, Liusuo Wu, Alan Fry, T. Chase, Jinpeng Wu, Georgi L. Dakovski, Zhao Chen, Virat Mehta, Hermann A. Dürr, Yukiko Takahashi, Daniel J. Higley, Jing Li, Peter M. Oppeneer, Joachim Stöhr, Department of Physics and Astronomy [Uppsala], Uppsala University, Chonnam National University [Gwangju], SLAC National Accelerator Laboratory (SLAC), Stanford University, HGST San Jose Research Center, Imagerie et modélisation Vasculaires, Thoraciques et Cérébrales (MOTIVATE), Centre de Recherche en Acquisition et Traitement de l'Image pour la Santé (CREATIS), Université Jean Monnet [Saint-Étienne] (UJM)-Hospices Civils de Lyon (HCL)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Jean Monnet [Saint-Étienne] (UJM)-Hospices Civils de Lyon (HCL)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM), Center for Magnetic Recording Research, University of California [San Diego] (UC San Diego), University of California-University of California, College of Materials Science and Optoelectronic Technology, and University of Chinese Academy Sciences

Subjects
Diffraction, Materials science, Phonon, Science, FOS: Physical sciences, General Physics and Astronomy, Physics::Optics, 02 engineering and technology, Electron, 01 natural sciences, General Biochemistry, Genetics and Molecular Biology, Article, Magnetization, Condensed Matter::Materials Science, 0103 physical sciences, [PHYS.COND]Physics [physics]/Condensed Matter [cond-mat], lcsh:Science, 010306 general physics, ComputingMilieux_MISCELLANEOUS, [PHYS]Physics [physics], Condensed Matter - Materials Science, Multidisciplinary, Condensed matter physics, Ultrafast electron diffraction, Demagnetizing field, Materials Science (cond-mat.mtrl-sci), Magnetostriction, General Chemistry, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Publisher Correction, cond-mat.mtrl-sci, Electron diffraction, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], lcsh:Q, Condensed Matter::Strongly Correlated Electrons, 0210 nano-technology, Den kondenserade materiens fysik
Abstract

Magnetostriction, the strain induced by a change in magnetization, is a universal effect in magnetic materials. Owing to the difficulty in unraveling its microscopic origin, it has been largely treated phenomenologically. Here, we show how the source of magnetostriction—the underlying magnetoelastic stress—can be separated in the time domain, opening the door for an atomistic understanding. X-ray and electron diffraction are used to separate the sub-picosecond spin and lattice responses of FePt nanoparticles. Following excitation with a 50-fs laser pulse, time-resolved X-ray diffraction demonstrates that magnetic order is lost within the nanoparticles with a time constant of 146 fs. Ultrafast electron diffraction reveals that this demagnetization is followed by an anisotropic, three-dimensional lattice motion. Analysis of the size, speed, and symmetry of the lattice motion, together with ab initio calculations accounting for the stresses due to electrons and phonons, allow us to reveal the magnetoelastic stress generated by demagnetization., Although magnetostriction is universal in magnetic materials, understanding its microscopic origin remains challenging. Here the authors use X-ray and ultrafast electron diffraction to separate the material’s sub-picosecond spin and lattice responses and reveal the magnetoelastic stress generated by demagnetization.

Published
2018

2. Covariance mapping of two-photon double core hole states in C2H2 and C2H6 produced by an x-ray free electron laser

Author

S. Mondal, Robert Richter, James M. Glownia, M. Siano, Melanie Mucke, Maria Novella Piancastelli, P. Linusson, Li Fang, P. v d Meulen, Osamu Takahashi, K. C. Prince, Brendan Murphy, Vitali Zhaunerchyk, Christoph Bostedt, Leszek J. Frasinski, Shin-ichi Wada, Nora Berrah, J. Ullrich, Lutz Foucar, John D. Bozek, James P. Cryan, Koji Motomura, Timur Osipov, Richard J. Squibb, S. Schorb, Mats Larsson, K. Ueda, John H. D. Eland, R. D. Thomas, Raimund Feifel, Ryan Coffee, Marc Messerschmidt, P. Salen, Department of Physics and Astronomy [Uppsala], Uppsala University, AlbaNova University Center (ALBANOVA), Stockholm University, Department of Physics, Imperial College London, Department of Biochemistry [Oxford], University of Oxford [Oxford], Max-Planck-Institut für Medizinische Forschung, Max-Planck-Gesellschaft, Advanced Study Group of the Max Planck Society, Max-Planck-Institut für Kernphysik (MPIK), Physikalisch-Technische Bundesanstalt [Braunschweig] (PTB), Tohoku University [Sendai], Western Michigan University [Kalamazoo], Center for High Energy Density Science, University of Connecticut (UCONN), SLAC National Accelerator Laboratory (SLAC), Stanford University, Synchrotron SOLEIL (SSOLEIL), Centre National de la Recherche Scientifique (CNRS), NSF BioXFEL Science and Technology Center, Institute for Environmental Science and Sustainable Development, Department of Physical Science, Laboratoire de Chimie Physique - Matière et Rayonnement (LCPMR), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Elettra Sincrotrone Trieste, and University of Oxford

Subjects
Physics, [PHYS]Physics [physics], Electron pair, 010304 chemical physics, Covariance mapping, Free-electron laser, General Physics and Astronomy, Synchrotron radiation, free electron laser, 01 natural sciences, Electron spectroscopy, Linear particle accelerator, covariance mapping, Auger, Ionization, few-photon process, 0103 physical sciences, Physical Sciences, Fysik, Physics::Accelerator Physics, double core hole, Atomic physics, 010306 general physics
Abstract

International audience; Few-photon ionization and relaxation processes in acetylene (C2H2) and ethane (C2H6) were investigated at the linac coherent light source x-ray free electron laser (FEL) at SLAC, Stanford using a highly efficient multi-particle correlation spectroscopy technique based on a magnetic bottle. The analysis method of covariance mapping has been applied and enhanced, allowing us to identify electron pairs associated with double core hole (DCH) production and competing multiple ionization processes including Auger decay sequences. The experimental technique and the analysis procedure are discussed in the light of earlier investigations of DCH studies carried out at the same FEL and at third generation synchrotron radiation sources. In particular, we demonstrate the capability of the covariance mapping technique to disentangle the formation of molecular DCH states which is barely feasible with conventional electron spectroscopy methods.

Published
2015

3. Sub-femtosecond precision measurement of relative X-ray arrival time for free-electron lasers

Author

Jean-Charles Castagna, Andreas Galler, John D. Bozek, Sebastian Carron, Nik Hartmann, Daniel J. Kane, Sebastian Schorb, William E. White, Mina R. Bionta, Thomas Feurer, M. Swiggers, Wolfram Helml, Serguei L. Molodtsov, Kevin Ferguson, Allan Fry, Jan Grünert, Ryan Coffee, Christoph P. Hauri, James M. Glownia, Christoph Bostedt, Institute of Applied Physics [Bern] (IAP), University of Bern, SLAC National Accelerator Laboratory (SLAC), Stanford University, European XFEL GmbH, Femto (LCAR), Laboratoire Collisions Agrégats Réactivité (LCAR), Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées, Paul Scherrer Institute (PSI), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), and Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)

Subjects
Physics, Free electron model, [PHYS]Physics [physics], business.industry, X-ray, 02 engineering and technology, 021001 nanoscience & nanotechnology, Laser, 01 natural sciences, Arrival time, Atomic and Molecular Physics, and Optics, Electronic, Optical and Magnetic Materials, law.invention, Optics, law, Temporal resolution, 0103 physical sciences, Femtosecond, 010306 general physics, 0210 nano-technology, business, ComputingMilieux_MISCELLANEOUS
Abstract

Today's brightest coherent X-ray sources, X-ray free-electron lasers, produce ultrafast X-ray pulses for which full-width at half-maximum durations as short as 3 fs have been measured(1). There has been a marked increase in the popularity of such short pulses now that optical timing techniques have begun to report an X-ray/optical delay below similar to 10 fs r.m.s. errors. As a result, sub-10 fs optical pulses have been implemented at the Linac Coherent Light Source (LCLS) X-ray beamlines, thus warranting a push to reduce the error in X-ray/optical delay measurements to the ifs level. Here, we report a unique two-dimensional spectrogram measurement of the relative X-ray/optical delay. This easily scalable relative delay measurement already surpasses previous techniques by an order of magnitude with its sub-1 fs temporal resolution and opens up the prospect of time-resolved X-ray measurements to the attosecond community.

Published
2014

4. Achieving few-femtosecond time-sorting at hard X-ray free-electron lasers

Author

Mina R. Bionta, Doug French, M. Chollet, Nikita Medvedev, Marion Harmand, Ryan Coffee, Henrik T. Lemke, Beata Ziaja, Diling Zhu, Marco Cammarata, Sven Toleikis, David Fritz, Deutsches Elektronen-Synchrotron [Zeuthen] (DESY), Helmholtz-Gemeinschaft = Helmholtz Association, SLAC National Accelerator Laboratory (SLAC), Stanford University, Femto (LCAR), Laboratoire Collisions Agrégats Réactivité (LCAR), Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées, Deutsches Elektronen-Synchrotron [Hamburg] (DESY), Institut de Physique de Rennes (IPR), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Centre National de la Recherche Scientifique (CNRS), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS), Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS), and Université de Rennes (UR)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Free electron model, 02 engineering and technology, 01 natural sciences, Synchronization, Linear particle accelerator, law.invention, Optics, Ultrafast photonics, law, 0103 physical sciences, X-rays, LEDs and light sources, 010306 general physics, Jitter, Physics, business.industry, Lasers, Sorting, 021001 nanoscience & nanotechnology, Laser, Atomic and Molecular Physics, and Optics, Electronic, Optical and Magnetic Materials, Femtosecond, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], Optoelectronics, 0210 nano-technology, business, Ultrashort pulse
Abstract

International audience; Recently, few-femtosecond pulses have become available at hard X-ray free-electron lasers. Coupled with the available sub-10 fs optical pulses, investigations into few-femtosecond dynamics are not far off. However, achieving sufficient synchronization between optical lasers and X-ray pulses continues to be challenging. We report a 'measure-and-sort' approach, which achieves sub-10 fs root-mean-squared (r.m.s.) error measurement at hard X-ray FELs, far beyond the 100-200 fs r.m.s. jitter limitations. This timing diagnostic, now routinely available at the Linac Coherent Light Source (LCLS), is based on ultrafast free-carrier generation in optically transparent materials. Correlation between two independent measurements enables unambiguous demonstration of ~6 fs r.m.s. error in reporting the optical/X-ray delay, with single shot error suggesting the possibility of reaching few-femtosecond resolution.

Published
2013

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