المؤلفون: Hennes, M., Merhe, A., Liu, X., Weder, D., Schmising, C. von Korff, Schneider, M., Günther, C. M., Mahieu, B., Malinowski, G., Hehn, M., Lacour, D., Capotondi, F., Pedersoli, E., Nikolov, I. P., Chardonnet, V., Jal, E., Lüning, J., Vodungbo, B.

مصطلحات موضوعية: Condensed Matter - Mesoscale and Nanoscale Physics

الوصف: We use time-resolved x-ray resonant magnetic scattering (tr-XRMS) at the Co M$_{2,3}$- and Tb O$_1$-edges to study ultrafast demagnetization in an amorphous Co$_{88}$Tb$_{12}$ alloy with stripe domains. Combining the femtosecond temporal with nanometer spatial resolution of our experiment, we demonstrate that the equilibrium spin texture of the thin film remains unaltered by the optical pump-pulse on ultrashort timescales ($<$1 ps). However, after $\simeq$ 4 ps, we observe the onset of a significant domain wall broadening, which we attribute to a reduction of the uniaxial magnetic anisotropy of the system, due to energy transfer to the lattice. Static temperature dependent magnetometry measurements combined with analytical modeling of the magnetic structure of the thin film corroborate this interpretation.

الوصول الحر: http://arxiv.org/abs/2006.11246Test

المؤلفون: Engel, RY, Alexander, O, Atak, K, Bovensiepen, U, Buck, J, Carley, R, Cascella, M, Chardonnet, V, Chiuzbaian, GS, David, C, Döring, F, Eschenlohr, A, Gerasimova, N, de Groot, F, Guyader, LL, Humphries, OS, Izquierdo, M, Jal, E, Kubec, A, Laarmann, T, Lambert, C-H, Lüning, J, Marangos, JP, Mercadier, L, Mercurio, G, Miedema, PS, Ollefs, K, Pfau, B, Rösner, B, Rossnagel, K, Rothenbach, N, Scherz, A, Schlappa, J, Scholz, M, Schunck, JO, Setoodehnia, K, Stamm, C, Techert, S, Vinko, SM, Wende, H, Yaroslavtsev, AA, Yin, Z, Beye, M

الوصف: Free-electron lasers provide bright, ultrashort, and monochromatic x-ray pulses, enabling novel spectroscopic measurements not only with femtosecond temporal resolution: The high fluence of their x-ray pulses can also easily enter the regime of the non-linear x-ray–matter interaction. Entering this regime necessitates a rigorous analysis and reliable prediction of the relevant non-linear processes for future experiment designs. Here, we show non-linear changes in the L3-edge absorption of metallic nickel thin films, measured with fluences up to 60 J/cm2. We present a simple but predictive rate model that quantitatively describes spectral changes based on the evolution of electronic populations within the pulse duration. Despite its simplicity, the model reaches good agreement with experimental results over more than three orders of magnitude in fluence, while providing a straightforward understanding of the interplay of physical processes driving the non-linear changes. Our findings provide important insights for the design and evaluation of future high-fluence free-electron laser experiments and contribute to the understanding of non-linear electron dynamics in x-ray absorption processes in solids at the femtosecond timescale.

العلاقة: https://ora.ox.ac.uk/objects/uuid:38508e4a-f20f-4d5a-9ff4-23b45edf8172Test; https://doi.org/10.1063/4.0000206Test

الإتاحة: https://doi.org/10.1063/4.0000206Test
https://ora.ox.ac.uk/objects/uuid:38508e4a-f20f-4d5a-9ff4-23b45edf8172Test

المؤلفون: Engel RY, Alexander O, Atak K, Bovensiepen U, Buck J, Carley R, Cascella M, Chardonnet V, Chiuzbaian GS, David C, Döring F, Eschenlohr A, Gerasimova N, Groot Fd, Guyader LL, Humphries OS, Izquierdo M, Jal E, Kubec A, Laarmann T, Lambert C, Lüning J, Marangos JP, Mercadier L, Mercurio G, Miedema PS, Ollefs K, Pfau B, Rösner B, Rossnagel K, Rothenbach N, Scherz A, Schlappa J, Scholz M, Schunck JO, Setoodehnia K, Stamm C, Techert S, Vinko SM, Wende H, Yaroslavtsev AA, Yin Z, Beye M

العلاقة: urn:ISSN:2329-7778; Struct Dynam; http://purl.org/net/epubs/series/48700450Test; Science and Technology Facilities Council (2007- ); Central Laser Facility (1977- ); http://purl.org/net/epubs/work/55327301Test

الإتاحة: http://purl.org/net/epubs/work/55327301Test

المؤلفون: Kjellsson, L., Ekholm, V., Agåker, M., Såthe, C., Pietzsch, A., Karlsson, H. O., Jaouen, N., Nicolaou, A., Guarise, M., Hague, C., Lüning, J., Chiuzbǎian, S. G., Rubensson, J. E.

المصدر: Physical Review A. 103(2)

مصطلحات موضوعية: Naturvetenskap, Fysik, Atom- och molekylfysik och optik, Natural Sciences, Physical Sciences, Atom and Molecular Physics and Optics

الوصف: Resonant inelastic x-ray scattering spectra excited at the π∗-resonance of the nitrogen molecule are presented. Well-resolved vibrational excitations in the electronic ground state, and in the 3σg-11πg1a1Πg state are observed. The spectra are analyzed within the Kramers-Heisenberg formalism, and the importance of lifetime-vibrational interference effects is highlighted. In addition, strongly dissociative multiply excited final states populated in radiative electron rearrangement are found in the valence ionization continua. The vibrational wave functions of the core-excited state are imaged on the strongly dissociative final state potentials.

الوصول الحر: https://lup.lub.lu.se/record/a45e12c2-6e90-441e-8034-7c07228f07edTest
http://dx.doi.org/10.1103/PhysRevA.103.022812Test

المؤلفون: Fan, G., Légaré, K., Cardin, V., Xie, X., Safaei, R., Kaksis, E., Andriukaitis, G., Pugžlys, A., Schmidt, B., Wolf, J., Hehn, Michel, Malinowski, Grégory, Vodungbo, B., Jal, E., Lüning, J., Jaouen, N., Giovannetti, G., Calegari, F., Tao, Z., Baltuška, A., Légaré, F., Balčiūnas, T.

المساهمون: Vienna University of Technology (TU Wien), Institut National de la Recherche Scientifique Québec (INRS), Hamburg Centre for Ultrafast Imaging Universität Hamburg, Universität Hamburg (UHH), Istituto Nazionale di Geofisica e di Oceanografia Sperimentale (OGS), SwissFEL, Paul Scherrer Institut, Few-Cycle inc, Max Planck Institute for Extraterrestrial Physics (MPE), Max-Planck-Gesellschaft, Group of Applied Physics - Biophotonics Geneva (GAP-Biophotonics), Group of Applied Physics Geneva (GAP), Université de Genève = University of Geneva (UNIGE)-Université de Genève = University of Geneva (UNIGE), Institut Jean Lamour (IJL), Institut de Chimie - CNRS Chimie (INC-CNRS)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Chimie Physique - Matière et Rayonnement (LCPMR), Institut de Chimie - CNRS Chimie (INC-CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Synchrotron SOLEIL (SSOLEIL), Centre National de la Recherche Scientifique (CNRS), Deutsches Elektronen-Synchrotron Hamburg (DESY), Fudan University Shanghai, National Key Research and Development Program of China, Shanghai Municipal Science and Technology Basic Research, Natural Sciences and Engineering Research Council of Canada (NSERC)CGIAR, Fonds de recherche du Quebec - Nature et technologies, German Research Foundation (DFG), ANR-15-CE24-0009,UMAMI,Comprendre les mécanismes de renversement de l'aimantation induit par excitation laser(2015)

المصدر: ISSN: 2334-2536.

مصطلحات موضوعية: [PHYS]Physics [physics], [PHYS.COND]Physics [physics]/Condensed Matter [cond-mat], [PHYS.PHYS]Physics [physics]/Physics [physics]

الوصف: International audience ; Development of ultrafast table-top x-ray sources that can map various spin, orbital, and electronic configurations and reordering processes on their natural time and length scales is an essential topic for modern condensed matter physics as well as ultrafast science. In this work, we demonstrate spatiotemporally resolved resonant magnetic scattering (XRMS) to probe the inner-shell 4d electrons of a rare-earth (RE) composite ferrimagnetic system using a bright > 200 e V soft x-ray high harmonic generation (HHG) source, which is relevant for future energy-efficient, high-speed spintronic applications. The XRMS is enabled by direct driving of the HHG process with power-scalable, high-energy Yb laser technology. The optimally phase-matched broadband plateau of the HHG offers a record photon flux ( > 2 × 1 0 9 p h o t o n s / s / 1 % bandwidth) with excellent spatial coherence and covers the entire resonant energy range of RE’s N 4 , 5 edges. We verify the underlying physics of our x-ray generation strategy through the analysis of microscopic and macroscopic processes. Using a CoTb alloy as a prototypical ferrimagnetic system, we retrieve the spin dynamics, and resolve a fast demagnetization time of 500 ± 126 f s , concomitant with an expansion of the domain periodicity, corresponding to a domain wall velocity of ∼ 750 m / s . The results confirm that, far from cross-contamination of low-energy absorption edges in multi-element systems, the highly localized states of 4 d electrons associated with the N 4 , 5 edges can provide high-quality core-level magnetic information on par with what can be obtained at the M edges, which is currently accessible only at large-scale x-ray facilities. The analysis also indicates the rich material-, composition-, and probing-energy-dependent driving mechanism of RE-associated multicomponent systems. Considering the rapid emergence of high-power Yb lasers combined with novel nonlinear compression technology, this work indicates potential for ...

العلاقة: hal-03764416; https://hal.univ-lorraine.fr/hal-03764416Test; https://hal.univ-lorraine.fr/hal-03764416/documentTest; https://hal.univ-lorraine.fr/hal-03764416/file/2022-Fan-Ultrafast%20magnetic%20scattering%20on%20ferrimagnets%20enabled%20by%20a%20bright%20Yb-based%20soft%20x-ray%20source.pdfTest

الإتاحة: https://doi.org/10.1364/OPTICA.443440Test
https://hal.univ-lorraine.fr/hal-03764416Test
https://hal.univ-lorraine.fr/hal-03764416/documentTest
https://hal.univ-lorraine.fr/hal-03764416/file/2022-Fan-Ultrafast%20magnetic%20scattering%20on%20ferrimagnets%20enabled%20by%20a%20bright%20Yb-based%20soft%20x-ray%20source.pdfTest

المؤلفون: Penco, G., Perosa, G., Allaria, E., Badano, L., Bencivenga, F., Brynes, A., Callegari, C., Capotondi, F., Caretta, A., Cinquegrana, P., Dal Zilio, S., Danailov, M., de Angelis, D., Demidovich, A., Di Mitri, S., Foglia, L., Gaio, G., Gessini, A., Giannessi, L., Kurdi, G., Manfredda, M., Malvestuto, M., Masciovecchio, C., Mincigrucci, R., Nikolov, I., Pedersoli, E., Pelli Cresi, S., Principi, E., Rebernik, P., Simoncig, A., Spampinati, S., Spezzani, C., Sottocorona, F., Trovó, M., Zangrando, M., Chardonnet, V., Hennes, M., Lüning, J., Vodungbo, B., Bougiatioti, P., David, C., Roesner, B., Sacchi, Maurizio, Roussel, Eléonore, Jal, E., de Ninno, G.

المساهمون: Elettra Sincrotrone Trieste, Università degli studi di Trieste = University of Trieste, Deutsches Elektronen-Synchrotron Hamburg (DESY), CNR Istituto Officina dei Materiali (IOM), National Research Council of Italy, Laboratori Nazionali di Frascati = National Laboratory of Frascati (LNF), Istituto Nazionale di Fisica Nucleare (INFN), Laboratoire de Chimie Physique - Matière et Rayonnement (LCPMR), Institut de Chimie - CNRS Chimie (INC-CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Paul Scherrer Institute (PSI), Croissance et propriétés de systèmes hybrides en couches minces (INSP-E8), Institut des Nanosciences de Paris (INSP), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Synchrotron SOLEIL (SSOLEIL), Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique des Lasers, Atomes et Molécules - UMR 8523 (PhLAM), Université de Lille-Centre National de la Recherche Scientifique (CNRS), DYnamique des Systèmes COmplexes (DYSCO), Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), University of Nova Gorica

المصدر: ISSN: 2469-9926.

مصطلحات موضوعية: [SPI.OPTI]Engineering Sciences [physics]/Optics / Photonic, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], [PHYS.COND.CM-SCM]Physics [physics]/Condensed Matter [cond-mat]/Soft Condensed Matter [cond-mat.soft], [PHYS.PHYS.PHYS-OPTICS]Physics [physics]/Physics [physics]/Optics [physics.optics]

الوصف: International audience

العلاقة: hal-03741782; https://cnrs.hal.science/hal-03741782Test; https://cnrs.hal.science/hal-03741782/documentTest; https://cnrs.hal.science/hal-03741782/file/Penco-2022-Nonlinear_harmonics_of_a_seeded-%28published_version%29.pdfTest

الإتاحة: https://doi.org/10.1103/PhysRevA.105.053524Test
https://cnrs.hal.science/hal-03741782Test
https://cnrs.hal.science/hal-03741782/documentTest
https://cnrs.hal.science/hal-03741782/file/Penco-2022-Nonlinear_harmonics_of_a_seeded-%28published_version%29.pdfTest

المؤلفون: Liu, X., Jal, E., Delaunay, R., Jarrier, R., Chiuzbaian, G. S., Malinowski, G., Golz, T., Zapolnova, E., Pan, R., Stojanovic, N., Luening, J., Vodungbo, B.

مصطلحات موضوعية: X ray free electrons laser, ultrafast demagnetization, terahertz radiations

الوصف: Coherent terahertz control of magnetization dynamics is an area of current interest due to its great potential for the realization of magnetization control on ultrafast timescales in commercial devices. Here we report on an experiment realized at the THz beamline of the free electron laser FLASH at DESY which offers a tunable terahertz radiation source and spontaneously synchronized free electron laser X ray pulses to resonantly probe the magnetization state of a ferromagnetic film. In this proof of principle experiment, we have excited a thin Permalloy film at different THz wavelengths and recorded the induced magnetization dynamics with photons resonantly tuned to the Ni M2,3 absorption edge. For THz pump pulses including higher orders of the undulator source we observed demagnetization dynamics, which precise shape depended on the employed fundamental wavelength of the undulator source. Analyzing the shape in detail, we can reconstruct the temporal profile of the electric field of the THz pump pulse. This offers a new method for the realization of an in situ terahertz beamline diagnostic which will help researchers to adjust the pulse characteristics as needed, for example, for future studies of THz induced coherent control of magnetization dynamics

وصف الملف: application/pdf

العلاقة: http://www.helmholtz-berlin.de/pubbin/oai_publication?VT=1&ID=109145Test

الإتاحة: https://doi.org/10.3390/app12031323Test
http://www.helmholtz-berlin.de/pubbin/oai_publication?VT=1&ID=109145Test

المؤلفون: Fan, Guangyu, Légaré, K., Hehn, M., Malinowski, G., Vodungbo, B., Jal, Emmanuelle, Lüning, J., Jaouen, N., Giovannetti, G., Calegari, F., Tao, Z., Baltuška, A., Cardin, V., Légaré, F., Balciunas, Tadas, Xie, Xinhua, Safaei, R., Kaksis, E., Andriukaitis, G., Pugžlys, A., Schmidt, B. E., Wolf, J. P.

المصدر: Optica 9(4), 399 - 407 (2022). doi:10.1364/OPTICA.443440

مصطلحات موضوعية: info:eu-repo/classification/ddc/620

جغرافية الموضوع: DE

الوصف: Development of ultrafast table-top x-ray sources that can map various spin, orbital, and electronic configurations and reordering processes on their natural time and length scales is an essential topic for modern condensed matter physics as well as ultrafast science. In this work, we demonstrate spatiotemporally resolved resonant magnetic scattering (XRMS) to probe the inner-shell 4d electrons of a rare-earth (RE) composite ferrimagnetic system using a bright >200eV soft x-ray high harmonic generation (HHG) source, which is relevant for future energy-efficient, high-speed spintronic applications. The XRMS is enabled by direct driving of the HHG process with power-scalable, high-energy Yb laser technology. The optimally phase-matched broadband plateau of the HHG offers a record photon flux (>2×109photons/s/1% bandwidth) with excellent spatial coherence and covers the entire resonant energy range of RE’s N4,5 edges. We verify the underlying physics of our x-ray generation strategy through the analysis of microscopic and macroscopic processes. Using a CoTb alloy as a prototypical ferrimagnetic system, we retrieve the spin dynamics, and resolve a fast demagnetization time of 500±126fs, concomitant with an expansion of the domain periodicity, corresponding to a domain wall velocity of ∼750m/s. The results confirm that, far from cross-contamination of low-energy absorption edges in multi-element systems, the highly localized states of 4d electrons associated with the N4,5 edges can provide high-quality core-level magnetic information on par with what can be obtained at the M edges, which is currently accessible only at large-scale x-ray facilities. The analysis also indicates the rich material-, composition-, and probing-energy-dependent driving mechanism of RE-associated multicomponent systems. Considering the rapid emergence of high-power Yb lasers combined with novel nonlinear compression technology, this work indicates potential for next-generation high-performance soft x-ray HHG-based sources in future ...

العلاقة: info:eu-repo/semantics/altIdentifier/wos/WOS:000786174500010; info:eu-repo/semantics/altIdentifier/issn/2334-2536; https://bib-pubdb1.desy.de/record/476742Test; https://bib-pubdb1.desy.de/search?p=id:%22PUBDB-2022-01870%22Test

الإتاحة: https://doi.org/10.1364/OPTICA.443440Test
https://doi.org/10.3204/PUBDB-2022-01870Test
https://bib-pubdb1.desy.de/record/476742Test
https://bib-pubdb1.desy.de/search?p=id:%22PUBDB-2022-01870%22Test

المؤلفون: Goslawski, P., Abo Bakr, M., Andreas, F., Arlandoo, M., Bengtsson, J., Dürr, V., Holldack, K., Hwang, J. G., Jankowiak, A., Kuske, B.C., Li, J., Lüning, J., Matveenko, A.N., Mertens, T., Meseck, A., Rial, E.C.M., Ries, M., Sauerborn, M.K., Scheer, M., Schnizer, P., Schälicke, A., Shi, L., Viefhaus, J.

مصطلحات موضوعية: Accelerator research and development

الوصف: HZB operates and develops two synchrotron radiation sources at Berlin Adlershof. The larger one, BESSY II with an energy of 1.7 GeV and 240 m circumference is optimized for soft X rays and in operation since 1999. The smaller one is the MLS Metrology Light Source , owned by the Physikalische Technische Bundesanstalt PTB Germany s National Metrology Institute. It is designed to fulfill the special metrology needs of the PTB with an energy of 0.6 GeV and 48 m circumference, covering the spectral range from THz and IR to EUV VUV. In 2020 a discussion process has been started to define the requirements for successors of BESSY II and MLS and to study the possibilities integrate them into a new photon science facility in Berlin Adlershof. Here, we give a status report and present a first envisaged parameter space to both machines

العلاقة: http://www.helmholtz-berlin.de/pubbin/oai_publication?VT=1&ID=104995Test

الإتاحة: http://www.helmholtz-berlin.de/pubbin/oai_publication?VT=1&ID=104995Test

المؤلفون: Ekholm, V., Chiuzbian, G. S., S the, C., Nicolaou, A., Guarise, M., Simon, M., Jaouen, N., Lüning, J., Hague, C. F., Gel'mukhanov, F., Odelius, M., Björneholm, O., Rubensson, J. E.

المصدر: Journal of Physics B: Atomic, Molecular and Optical Physics. 53(18)

مصطلحات موضوعية: resonant inelastic x-ray scattering, SF, symmetry selection rules, ultrafast dynamics, vibronic couplings, Naturvetenskap, Fysik, Atom- och molekylfysik och optik, Natural Sciences, Physical Sciences, Atom and Molecular Physics and Optics

الوصف: Resonant inelastic x-ray scattering spectra excited at the fluorine K resonances of SF6 have been recorded. While a small but significant propensity for electronically parity-allowed transitions is found, the observation of parity-forbidden electronic transitions is attributed to vibronic coupling that breaks the global inversion symmetry of the electronic wavefunction and localizes the core hole. The dependence of the scattering cross section on the polarization of the incident radiation and the scattering angle is interpreted in terms of local π/σ symmetry around the S-F bond. This symmetry selectivity prevails during the dissociation that occurs during the scattering process.

الوصول الحر: https://lup.lub.lu.se/record/f578a603-5e92-47db-a45d-d400ccde9f73Test
http://dx.doi.org/10.1088/1361-6455/aba204Test