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Steinbach F, Atxitia U, Yao K, Borchert M, Engel D, Bencivenga F, Foglia L, Mincigrucci R, Pedersoli E, De Angelis D, Pancaldi M, Fainozzi D, Pelli Cresi JS, Paltanin E, Capotondi F, Masciovecchio C, Eisebitt S, von Korff Schmising C. Exploring the Fundamental Spatial Limits of Magnetic All-Optical Switching. NANO LETTERS 2024; 24:6865-6871. [PMID: 38809171 DOI: 10.1021/acs.nanolett.4c00129] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2024]
Abstract
All-optical switching (AOS) results in ultrafast and deterministic magnetization reversal upon single laser pulse excitation, potentially supporting faster and more energy-efficient data storage. To explore the fundamental limits of achievable bit densities in AOS, we have used soft X-ray transient grating spectroscopy to study the ultrafast magnetic response of a GdFe alloy after a spatially structured excitation with a periodicity of 17 nm. The ultrafast spatial evolution of the magnetization in combination with atomistic spin dynamics and microscopic temperature model calculations allows us to derive a detailed phase diagram of AOS as a function of both the absorbed energy density and the nanoscale excitation period. Our results suggest that the minimum size for AOS in GdFe alloys, induced by a nanoscale periodic excitation, is around 25 nm and that this limit is governed by ultrafast lateral electron diffusion and by the threshold for optical damage.
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Affiliation(s)
- Felix Steinbach
- Max-Born-Institute for Nonlinear Optics and Short Pulse Spectroscopy, Max-Born Strasse 2A, 12489 Berlin, Germany
| | - Unai Atxitia
- Instituto de Ciencia de Materiales de Madrid, CSIC, Cantoblanco, 28049 Madrid, Spain
| | - Kelvin Yao
- Max-Born-Institute for Nonlinear Optics and Short Pulse Spectroscopy, Max-Born Strasse 2A, 12489 Berlin, Germany
| | - Martin Borchert
- Max-Born-Institute for Nonlinear Optics and Short Pulse Spectroscopy, Max-Born Strasse 2A, 12489 Berlin, Germany
| | - Dieter Engel
- Max-Born-Institute for Nonlinear Optics and Short Pulse Spectroscopy, Max-Born Strasse 2A, 12489 Berlin, Germany
| | | | - Laura Foglia
- Elettra Sincrotrone Trieste S.C.p.A., 34149 Basovizza, Trieste, Italy
| | | | | | - Dario De Angelis
- Elettra Sincrotrone Trieste S.C.p.A., 34149 Basovizza, Trieste, Italy
| | - Matteo Pancaldi
- Elettra Sincrotrone Trieste S.C.p.A., 34149 Basovizza, Trieste, Italy
| | - Danny Fainozzi
- Elettra Sincrotrone Trieste S.C.p.A., 34149 Basovizza, Trieste, Italy
| | | | - Ettore Paltanin
- Elettra Sincrotrone Trieste S.C.p.A., 34149 Basovizza, Trieste, Italy
| | - Flavio Capotondi
- Elettra Sincrotrone Trieste S.C.p.A., 34149 Basovizza, Trieste, Italy
| | | | - Stefan Eisebitt
- Max-Born-Institute for Nonlinear Optics and Short Pulse Spectroscopy, Max-Born Strasse 2A, 12489 Berlin, Germany
- Institut für Optik und Atomare Physik, Technische Universität Berlin, Straße des 17. Juni 135, 10623 Berlin, Germany
| | - Clemens von Korff Schmising
- Max-Born-Institute for Nonlinear Optics and Short Pulse Spectroscopy, Max-Born Strasse 2A, 12489 Berlin, Germany
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3
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Yao K, Steinbach F, Borchert M, Schick D, Engel D, Bencivenga F, Mincigrucci R, Foglia L, Pedersoli E, De Angelis D, Pancaldi M, Wehinger B, Capotondi F, Masciovecchio C, Eisebitt S, von Korff Schmising C. All-Optical Switching on the Nanometer Scale Excited and Probed with Femtosecond Extreme Ultraviolet Pulses. NANO LETTERS 2022; 22:4452-4458. [PMID: 35605204 DOI: 10.1021/acs.nanolett.2c01060] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Ultrafast control of magnetization on the nanometer length scale, in particular all-optical switching, is key to putting ultrafast magnetism on the path toward future technological application in data storage technology. However, magnetization manipulation with light on this length scale is challenging due to the wavelength limitations of optical radiation. Here, we excite transient magnetic gratings in a GdFe alloy with a periodicity of 87 nm by the interference of two coherent femtosecond light pulses in the extreme ultraviolet spectral range. The subsequent ultrafast evolution of the magnetization pattern is probed by diffraction of a third, time-delayed pulse tuned to the Gd N-edge at a wavelength of 8.3 nm. By examining the simultaneously recorded first and second order diffractions and by performing reference real-space measurements with a wide-field magneto-optical microscope with femtosecond time resolution, we can conclusively demonstrate the ultrafast emergence of all-optical switching on the nanometer length scale.
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Affiliation(s)
- Kelvin Yao
- Max-Born-Institut für Nichtlineare Optik und Kurzzeitspektroskopie, Max-Born-Straße 2A, 12489 Berlin, Germany
| | - Felix Steinbach
- Max-Born-Institut für Nichtlineare Optik und Kurzzeitspektroskopie, Max-Born-Straße 2A, 12489 Berlin, Germany
| | - Martin Borchert
- Max-Born-Institut für Nichtlineare Optik und Kurzzeitspektroskopie, Max-Born-Straße 2A, 12489 Berlin, Germany
| | - Daniel Schick
- Max-Born-Institut für Nichtlineare Optik und Kurzzeitspektroskopie, Max-Born-Straße 2A, 12489 Berlin, Germany
| | - Dieter Engel
- Max-Born-Institut für Nichtlineare Optik und Kurzzeitspektroskopie, Max-Born-Straße 2A, 12489 Berlin, Germany
| | - Filippo Bencivenga
- Elettra Sincrotrone Trieste S.C.p.A., Strada Statale 14 km 163.5, 34149 Basovizza, Trieste, Italy
| | - Riccardo Mincigrucci
- Elettra Sincrotrone Trieste S.C.p.A., Strada Statale 14 km 163.5, 34149 Basovizza, Trieste, Italy
| | - Laura Foglia
- Elettra Sincrotrone Trieste S.C.p.A., Strada Statale 14 km 163.5, 34149 Basovizza, Trieste, Italy
| | - Emanuele Pedersoli
- Elettra Sincrotrone Trieste S.C.p.A., Strada Statale 14 km 163.5, 34149 Basovizza, Trieste, Italy
| | - Dario De Angelis
- Elettra Sincrotrone Trieste S.C.p.A., Strada Statale 14 km 163.5, 34149 Basovizza, Trieste, Italy
| | - Matteo Pancaldi
- Elettra Sincrotrone Trieste S.C.p.A., Strada Statale 14 km 163.5, 34149 Basovizza, Trieste, Italy
| | - Björn Wehinger
- Elettra Sincrotrone Trieste S.C.p.A., Strada Statale 14 km 163.5, 34149 Basovizza, Trieste, Italy
- Department of Molecular Sciences and Nanosystems, Ca' Foscari University of Venice, via Torino 155, 30172 Venezia Mestre, Italy
| | - Flavio Capotondi
- Elettra Sincrotrone Trieste S.C.p.A., Strada Statale 14 km 163.5, 34149 Basovizza, Trieste, Italy
| | - Claudio Masciovecchio
- Elettra Sincrotrone Trieste S.C.p.A., Strada Statale 14 km 163.5, 34149 Basovizza, Trieste, Italy
| | - Stefan Eisebitt
- Max-Born-Institut für Nichtlineare Optik und Kurzzeitspektroskopie, Max-Born-Straße 2A, 12489 Berlin, Germany
- Institut fuer Optik und Atomare Physik, Technische Universitaet Berlin, Strasse des 17. Juni 135, 10623 Berlin, Germany
| | - Clemens von Korff Schmising
- Max-Born-Institut für Nichtlineare Optik und Kurzzeitspektroskopie, Max-Born-Straße 2A, 12489 Berlin, Germany
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Turenne D, Yaroslavtsev A, Wang X, Unikandanuni V, Vaskivskyi I, Schneider M, Jal E, Carley R, Mercurio G, Gort R, Agarwal N, Van Kuiken B, Mercadier L, Schlappa J, Le Guyader L, Gerasimova N, Teichmann M, Lomidze D, Castoldi A, Potorochin D, Mukkattukavil D, Brock J, Zhou Hagström N, Reid AH, Shen X, Wang XJ, Maldonado P, Kvashnin Y, Carva K, Wang J, Takahashi YK, Fullerton EE, Eisebitt S, Oppeneer PM, Molodtsov S, Scherz A, Bonetti S, Iacocca E, Dürr HA. Nonequilibrium sub-10 nm spin-wave soliton formation in FePt nanoparticles. SCIENCE ADVANCES 2022; 8:eabn0523. [PMID: 35363518 PMCID: PMC10938569 DOI: 10.1126/sciadv.abn0523] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Accepted: 02/10/2022] [Indexed: 06/14/2023]
Abstract
Magnetic nanoparticles such as FePt in the L10 phase are the bedrock of our current data storage technology. As the grains become smaller to keep up with technological demands, the superparamagnetic limit calls for materials with higher magnetocrystalline anisotropy. This, in turn, reduces the magnetic exchange length to just a few nanometers, enabling magnetic structures to be induced within the nanoparticles. Here, we describe the existence of spin-wave solitons, dynamic localized bound states of spin-wave excitations, in FePt nanoparticles. We show with time-resolved x-ray diffraction and micromagnetic modeling that spin-wave solitons of sub-10 nm sizes form out of the demagnetized state following femtosecond laser excitation. The measured soliton spin precession frequency of 0.1 THz positions this system as a platform to develop novel miniature devices.
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Affiliation(s)
- Diego Turenne
- Department of Physics and Astronomy, Uppsala University, 751 20 Uppsala, Sweden
| | - Alexander Yaroslavtsev
- Department of Physics and Astronomy, Uppsala University, 751 20 Uppsala, Sweden
- European XFEL GmbH, Holzkoppel 4, 22869 Schenefeld, Germany
| | - Xiaocui Wang
- Department of Physics and Astronomy, Uppsala University, 751 20 Uppsala, Sweden
| | | | - Igor Vaskivskyi
- Complex Matter Department, Jožef Stefan Institute, Ljubljana, Slovenia
| | | | - Emmanuelle Jal
- Sorbonne Université, CNRS, Laboratoire de Chimie Physique-Matière et Rayonnement, 75005 Paris, France
| | - Robert Carley
- European XFEL GmbH, Holzkoppel 4, 22869 Schenefeld, Germany
| | | | - Rafael Gort
- European XFEL GmbH, Holzkoppel 4, 22869 Schenefeld, Germany
| | - Naman Agarwal
- European XFEL GmbH, Holzkoppel 4, 22869 Schenefeld, Germany
| | | | | | | | | | | | | | - David Lomidze
- European XFEL GmbH, Holzkoppel 4, 22869 Schenefeld, Germany
| | - Andrea Castoldi
- Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Milano, Italy
- Istituto Nazionale di Fisica Nucleare, Sezione di Milano, Milano, Italy
| | - Dimitri Potorochin
- European XFEL GmbH, Holzkoppel 4, 22869 Schenefeld, Germany
- Deutsches Elektronen-Synchrotron, 22607 Hamburg, Germany
- Institute of Experimental Physics, Technische Universität Bergakademie Freiberg, 09599 Freiberg, Germany
| | | | - Jeffrey Brock
- Center for Memory and Recording Research, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0401, USA
| | | | - Alexander H. Reid
- SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025, USA
| | - Xiaozhe Shen
- SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025, USA
| | - Xijie J. Wang
- SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025, USA
| | - Pablo Maldonado
- Department of Physics and Astronomy, Uppsala University, 751 20 Uppsala, Sweden
| | - Yaroslav Kvashnin
- Department of Physics and Astronomy, Uppsala University, 751 20 Uppsala, Sweden
| | - Karel Carva
- Faculty of Mathematics and Physics, Department of Condensed Matter Physics, Charles University, Ke Karlovu 5, 121 16 Prague, Czech Republic
| | - Jian Wang
- Magnet Materials Unit, National Institute for Materials Science, Tsukuba 305-0047, Japan
| | - Yukiko K. Takahashi
- Magnet Materials Unit, National Institute for Materials Science, Tsukuba 305-0047, Japan
| | - Eric E. Fullerton
- Center for Memory and Recording Research, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0401, USA
| | - Stefan Eisebitt
- Max-Born-Institut, Berlin, Germany
- Institut für Optik und Atomare Physik, Technische Universität Berlin, Berlin, Germany
| | - Peter M. Oppeneer
- Department of Physics and Astronomy, Uppsala University, 751 20 Uppsala, Sweden
| | - Serguei Molodtsov
- European XFEL GmbH, Holzkoppel 4, 22869 Schenefeld, Germany
- Institute of Experimental Physics, Technische Universität Bergakademie Freiberg, 09599 Freiberg, Germany
| | - Andreas Scherz
- European XFEL GmbH, Holzkoppel 4, 22869 Schenefeld, Germany
| | - Stefano Bonetti
- Department of Physics, Stockholm University, 106 91 Stockholm, Sweden
- Department of Molecular Sciences and Nanosystems, Ca’ Foscari University of Venice, 30172 Venice, Italy
| | - Ezio Iacocca
- Department of Mathematics, Physics and Electrical Engineering, Northumbria University, Newcastle upon Tyne NE1 8ST, UK
- Center for Magnetism and Magnetic Materials, University of Colorado Colorado Springs, Colorado Springs, CO 80918, USA
| | - Hermann A. Dürr
- Department of Physics and Astronomy, Uppsala University, 751 20 Uppsala, Sweden
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5
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Rösner B, Vodungbo B, Chardonnet V, Döring F, Guzenko VA, Hennes M, Kleibert A, Lebugle M, Lüning J, Mahne N, Merhe A, Naumenko D, Nikolov IP, Lopez-Quintas I, Pedersoli E, Ribič PR, Savchenko T, Watts B, Zangrando M, Capotondi F, David C, Jal E. Simultaneous two-color snapshot view on ultrafast charge and spin dynamics in a Fe-Cu-Ni tri-layer. STRUCTURAL DYNAMICS (MELVILLE, N.Y.) 2020; 7:054302. [PMID: 32984434 PMCID: PMC7511239 DOI: 10.1063/4.0000033] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Accepted: 08/28/2020] [Indexed: 06/11/2023]
Abstract
Ultrafast phenomena on a femtosecond timescale are commonly examined by pump-probe experiments. This implies multiple measurements, where the sample under investigation is pumped with a short light pulse and then probed with a second pulse at various time delays to follow its dynamics. Recently, the principle of streaking extreme ultraviolet (XUV) pulses in the temporal domain has enabled recording the dynamics of a system within a single pulse. However, separate pump-probe experiments at different absorption edges still lack a unified timing, when comparing the dynamics in complex systems. Here, we report on an experiment using a dedicated optical element and the two-color emission of the FERMI XUV free-electron laser to follow the charge and spin dynamics in composite materials at two distinct absorption edges, simultaneously. The sample, consisting of ferromagnetic Fe and Ni layers, separated by a Cu layer, is pumped by an infrared laser and probed by a two-color XUV pulse with photon energies tuned to the M-shell resonances of these two transition metals. The experimental geometry intrinsically avoids any timing uncertainty between the two elements and unambiguously reveals an approximately 100 fs delay of the magnetic response with respect to the electronic excitation for both Fe and Ni. This delay shows that the electronic and spin degrees of freedom are decoupled during the demagnetization process. We furthermore observe that the electronic dynamics of Ni and Fe show pronounced differences when probed at their resonance, while the demagnetization dynamics are similar. These observations underline the importance of simultaneous investigation of the temporal response of both charge and spin in multi-component materials. In a more general scenario, the experimental approach can be extended to continuous energy ranges, promising the development of jitter-free transient absorption spectroscopy in the XUV and soft X-ray regimes.
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Affiliation(s)
| | - Boris Vodungbo
- Sorbonne Université, CNRS, Laboratoire de Chimie Physique – Matière et Rayonnement, LCPMR, Paris 75005, France
| | - Valentin Chardonnet
- Sorbonne Université, CNRS, Laboratoire de Chimie Physique – Matière et Rayonnement, LCPMR, Paris 75005, France
| | | | | | - Marcel Hennes
- Sorbonne Université, CNRS, Laboratoire de Chimie Physique – Matière et Rayonnement, LCPMR, Paris 75005, France
| | | | | | - Jan Lüning
- Sorbonne Université, CNRS, Laboratoire de Chimie Physique – Matière et Rayonnement, LCPMR, Paris 75005, France
| | - Nicola Mahne
- IOM-CNR, Strada Statale 14-km 163,5, Basovizza, Trieste 34149, Italy
| | - Aladine Merhe
- Sorbonne Université, CNRS, Laboratoire de Chimie Physique – Matière et Rayonnement, LCPMR, Paris 75005, France
| | - Denys Naumenko
- Elettra-Sincrotrone Trieste, Strada Statale 14-km 163,5, Basovizza, Trieste 34149, Italy
| | - Ivaylo P. Nikolov
- Elettra-Sincrotrone Trieste, Strada Statale 14-km 163,5, Basovizza, Trieste 34149, Italy
| | - Ignacio Lopez-Quintas
- Elettra-Sincrotrone Trieste, Strada Statale 14-km 163,5, Basovizza, Trieste 34149, Italy
| | - Emanuele Pedersoli
- Elettra-Sincrotrone Trieste, Strada Statale 14-km 163,5, Basovizza, Trieste 34149, Italy
| | | | | | | | | | - Flavio Capotondi
- Elettra-Sincrotrone Trieste, Strada Statale 14-km 163,5, Basovizza, Trieste 34149, Italy
| | | | - Emmanuelle Jal
- Sorbonne Université, CNRS, Laboratoire de Chimie Physique – Matière et Rayonnement, LCPMR, Paris 75005, France
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6
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Weder D, von Korff Schmising C, Günther CM, Schneider M, Engel D, Hessing P, Strüber C, Weigand M, Vodungbo B, Jal E, Liu X, Merhe A, Pedersoli E, Capotondi F, Lüning J, Pfau B, Eisebitt S. Transient magnetic gratings on the nanometer scale. STRUCTURAL DYNAMICS (MELVILLE, N.Y.) 2020; 7:054501. [PMID: 32923511 PMCID: PMC7481012 DOI: 10.1063/4.0000017] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Accepted: 08/04/2020] [Indexed: 06/11/2023]
Abstract
Laser-driven non-local electron dynamics in ultrathin magnetic samples on a sub-10 nm length scale is a key process in ultrafast magnetism. However, the experimental access has been challenging due to the nanoscopic and femtosecond nature of such transport processes. Here, we present a scattering-based experiment relying on a laser-induced electro- and magneto-optical grating in a Co/Pd ferromagnetic multilayer as a new technique to investigate non-local magnetization dynamics on nanometer length and femtosecond timescales. We induce a spatially modulated excitation pattern using tailored Al near-field masks with varying periodicities on a nanometer length scale and measure the first four diffraction orders in an x-ray scattering experiment with magnetic circular dichroism contrast at the free-electron laser facility FERMI, Trieste. The design of the periodic excitation mask leads to a strongly enhanced and characteristic transient scattering response allowing for sub-wavelength in-plane sensitivity for magnetic structures. In conjunction with scattering simulations, the experiment allows us to infer that a potential ultrafast lateral expansion of the initially excited regions of the magnetic film mediated by hot-electron transport and spin transport remains confined to below three nanometers.
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Affiliation(s)
- D. Weder
- Max-Born-Institute for Nonlinear Optics and Short Pulse Spectroscopy, 12489 Berlin, Germany
| | - C. von Korff Schmising
- Max-Born-Institute for Nonlinear Optics and Short Pulse Spectroscopy, 12489 Berlin, Germany
| | - C. M. Günther
- Zentraleinrichtung Elektronenmikroskopie (ZELMI), Technische Universität Berlin, 10623 Berlin, Germany
| | - M. Schneider
- Max-Born-Institute for Nonlinear Optics and Short Pulse Spectroscopy, 12489 Berlin, Germany
| | - D. Engel
- Max-Born-Institute for Nonlinear Optics and Short Pulse Spectroscopy, 12489 Berlin, Germany
| | - P. Hessing
- Max-Born-Institute for Nonlinear Optics and Short Pulse Spectroscopy, 12489 Berlin, Germany
| | - C. Strüber
- Max-Born-Institute for Nonlinear Optics and Short Pulse Spectroscopy, 12489 Berlin, Germany
| | - M. Weigand
- Helmholtz-Zentrum Berlin für Materialien und Energie, 12489 Berlin, Germany
| | - B. Vodungbo
- Sorbonne Université, CNRS, Laboratoire de Chimie Physique–Matière et Rayonnement, LCPMR, 75005 Paris, France
| | - E. Jal
- Sorbonne Université, CNRS, Laboratoire de Chimie Physique–Matière et Rayonnement, LCPMR, 75005 Paris, France
| | - X. Liu
- Sorbonne Université, CNRS, Laboratoire de Chimie Physique–Matière et Rayonnement, LCPMR, 75005 Paris, France
| | - A. Merhe
- Sorbonne Université, CNRS, Laboratoire de Chimie Physique–Matière et Rayonnement, LCPMR, 75005 Paris, France
| | - E. Pedersoli
- Elettra-Sincrotrone Trieste, Basovizza, 34149 Trieste, Italy
| | - F. Capotondi
- Elettra-Sincrotrone Trieste, Basovizza, 34149 Trieste, Italy
| | - J. Lüning
- Helmholtz-Zentrum Berlin für Materialien und Energie, 12489 Berlin, Germany
| | - B. Pfau
- Max-Born-Institute for Nonlinear Optics and Short Pulse Spectroscopy, 12489 Berlin, Germany
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von Reppert A, Willig L, Pudell JE, Zeuschner SP, Sellge G, Ganss F, Hellwig O, Arregi JA, Uhlíř V, Crut A, Bargheer M. Spin stress contribution to the lattice dynamics of FePt. SCIENCE ADVANCES 2020; 6:eaba1142. [PMID: 32685678 PMCID: PMC7343378 DOI: 10.1126/sciadv.aba1142] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Accepted: 05/22/2020] [Indexed: 06/07/2023]
Abstract
Invar-behavior occurring in many magnetic materials has long been of interest to materials science. Here, we show not only invar behavior of a continuous film of FePt but also even negative thermal expansion of FePt nanograins upon equilibrium heating. Yet, both samples exhibit pronounced transient expansion upon laser heating in femtosecond x-ray diffraction experiments. We show that the granular microstructure is essential to support the contractive out-of-plane stresses originating from in-plane expansion via the Poisson effect that add to the uniaxial contractive stress driven by spin disorder. We prove the spin contribution by saturating the magnetic excitations with a first laser pulse and then detecting the purely expansive response to a second pulse. The contractive spin stress is reestablished on the same 100-ps time scale that we observe for the recovery of the ferromagnetic order. Finite-element modeling of the mechanical response of FePt nanosystems confirms the morphology dependence of the dynamics.
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Affiliation(s)
- A. von Reppert
- Institute of Physics and Astronomy, University of Potsdam, Karl-Liebknecht-Str. 24-25, 14476 Potsdam, Germany
| | - L. Willig
- Institute of Physics and Astronomy, University of Potsdam, Karl-Liebknecht-Str. 24-25, 14476 Potsdam, Germany
- Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Wilhelm-Conrad-12 Röntgen Campus, BESSY II, Albert-Einstein-Str. 15, 12489 Berlin, Germany
| | - J.-E. Pudell
- Institute of Physics and Astronomy, University of Potsdam, Karl-Liebknecht-Str. 24-25, 14476 Potsdam, Germany
- Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Wilhelm-Conrad-12 Röntgen Campus, BESSY II, Albert-Einstein-Str. 15, 12489 Berlin, Germany
| | - S. P. Zeuschner
- Institute of Physics and Astronomy, University of Potsdam, Karl-Liebknecht-Str. 24-25, 14476 Potsdam, Germany
- Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Wilhelm-Conrad-12 Röntgen Campus, BESSY II, Albert-Einstein-Str. 15, 12489 Berlin, Germany
| | - G. Sellge
- Institut für Physik, Technische Universität Chemnitz, Reichenhainer Str. 70, 09126 Chemnitz, Germany
- Institut für Ionenstrahlphysik und Materialforschung, Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstrasse 400, 01328 Dresden, Germany
| | - F. Ganss
- Institut für Physik, Technische Universität Chemnitz, Reichenhainer Str. 70, 09126 Chemnitz, Germany
| | - O. Hellwig
- Institut für Physik, Technische Universität Chemnitz, Reichenhainer Str. 70, 09126 Chemnitz, Germany
- Institut für Ionenstrahlphysik und Materialforschung, Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstrasse 400, 01328 Dresden, Germany
| | - J. A. Arregi
- CEITEC BUT, Brno University of Technology, Purkyňova 123, 612 00 Brno, Czechia
| | - V. Uhlíř
- CEITEC BUT, Brno University of Technology, Purkyňova 123, 612 00 Brno, Czechia
- Institute of Physical Engineering, Brno University of Technology, Technická 2, 616 69 Brno, Czechia
| | - A. Crut
- FemtoNanoOptics Group, Institut Lumière Matière, Université de Lyon, CNRS-Université Lyon 1, 69622 Villeurbanne, France
| | - M. Bargheer
- Institute of Physics and Astronomy, University of Potsdam, Karl-Liebknecht-Str. 24-25, 14476 Potsdam, Germany
- Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Wilhelm-Conrad-12 Röntgen Campus, BESSY II, Albert-Einstein-Str. 15, 12489 Berlin, Germany
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8
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Atif M, Karim RA, Khaliq Z, Bongiovanni R. Facile Oxidation Approach to Amend Surface Chemistry of Carbon Particles for Augmented Dispersion in Epoxy Matrix. RUSS J APPL CHEM+ 2020. [DOI: 10.1134/s1070427220020214] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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9
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Iacocca E, Liu TM, Reid AH, Fu Z, Ruta S, Granitzka PW, Jal E, Bonetti S, Gray AX, Graves CE, Kukreja R, Chen Z, Higley DJ, Chase T, Le Guyader L, Hirsch K, Ohldag H, Schlotter WF, Dakovski GL, Coslovich G, Hoffmann MC, Carron S, Tsukamoto A, Kirilyuk A, Kimel AV, Rasing T, Stöhr J, Evans RFL, Ostler T, Chantrell RW, Hoefer MA, Silva TJ, Dürr HA. Spin-current-mediated rapid magnon localisation and coalescence after ultrafast optical pumping of ferrimagnetic alloys. Nat Commun 2019; 10:1756. [PMID: 30988403 PMCID: PMC6465265 DOI: 10.1038/s41467-019-09577-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2018] [Accepted: 03/13/2019] [Indexed: 11/09/2022] Open
Abstract
Sub-picosecond magnetisation manipulation via femtosecond optical pumping has attracted wide attention ever since its original discovery in 1996. However, the spatial evolution of the magnetisation is not yet well understood, in part due to the difficulty in experimentally probing such rapid dynamics. Here, we find evidence of a universal rapid magnetic order recovery in ferrimagnets with perpendicular magnetic anisotropy via nonlinear magnon processes. We identify magnon localisation and coalescence processes, whereby localised magnetic textures nucleate and subsequently interact and grow in accordance with a power law formalism. A hydrodynamic representation of the numerical simulations indicates that the appearance of noncollinear magnetisation via optical pumping establishes exchange-mediated spin currents with an equivalent 100% spin polarised charge current density of 107 A cm-2. Such large spin currents precipitate rapid recovery of magnetic order after optical pumping. The magnon processes discussed here provide new insights for the stabilization of desired meta-stable states.
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Affiliation(s)
- E Iacocca
- Department of Applied Mathematics, University of Colorado, Boulder, CO, 80309, USA
- National Institute of Standards and Technology, Boulder, CO, 80305, USA
- Department of Physics, Division for Theoretical Physics, Chalmers University of Technology, Gothenburg, 412 96, Sweden
| | - T-M Liu
- SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA, 94025, USA
| | - A H Reid
- SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA, 94025, USA
| | - Z Fu
- School of Physics, Science, and Engineering, Tongji University, Shanghai, 200092, China
| | - S Ruta
- Department of Physics, University of York, York, YO10 5DD, UK
| | - P W Granitzka
- SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA, 94025, USA
| | - E Jal
- SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA, 94025, USA
| | - S Bonetti
- SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA, 94025, USA
- Department of Physics, Stockholm University, Stockholm, 106 91, Sweden
- Department of Molecular Science and Nanosystems, Ca' Foscari University of Venice, Venezia-Mestre, 30172, Italy
| | - A X Gray
- SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA, 94025, USA
- Department of Physics, Temple University, 1925 N. 12th St., Philadelphia, PA, 19122, USA
| | - C E Graves
- SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA, 94025, USA
| | - R Kukreja
- SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA, 94025, USA
| | - Z Chen
- SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA, 94025, USA
| | - D J Higley
- SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA, 94025, USA
| | - T Chase
- SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA, 94025, USA
| | - L Le Guyader
- SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA, 94025, USA
- Spectroscopy & Coherent Scattering, European X-Ray Free-Electron Laser Facility GmbH, Holzkoppel 4, 22869, Schenefeld, Germany
| | - K Hirsch
- SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA, 94025, USA
| | - H Ohldag
- SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA, 94025, USA
| | - W F Schlotter
- SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA, 94025, USA
| | - G L Dakovski
- SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA, 94025, USA
| | - G Coslovich
- SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA, 94025, USA
| | - M C Hoffmann
- SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA, 94025, USA
| | - S Carron
- SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA, 94025, USA
| | - A Tsukamoto
- Department of Electronics and Computer Science, Nihon University, 7-24-1 Narashino-dai Funabashi, Chiba, 274-8501, Japan
| | - A Kirilyuk
- Institute for Molecules and Materials, Radboud University, Heyendaalseweg 135, 6525 AJ, Nijmegen, The Netherlands
| | - A V Kimel
- Institute for Molecules and Materials, Radboud University, Heyendaalseweg 135, 6525 AJ, Nijmegen, The Netherlands
| | - Th Rasing
- Institute for Molecules and Materials, Radboud University, Heyendaalseweg 135, 6525 AJ, Nijmegen, The Netherlands
| | - J Stöhr
- SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA, 94025, USA
| | - R F L Evans
- Department of Physics, University of York, York, YO10 5DD, UK
| | - T Ostler
- Physique des Matériaux et Nanostructures, Université de Liège, Liège, B-4000, Sart Tilman, Belgium
- Faculty of Arts, Computing, Engineering and Sciences, Sheffield Hallam University, Howard Street, Sheffield, S1 1WB, UK
| | - R W Chantrell
- Department of Physics, University of York, York, YO10 5DD, UK
- Institute for Molecules and Materials, Radboud University, Heyendaalseweg 135, 6525 AJ, Nijmegen, The Netherlands
| | - M A Hoefer
- Department of Applied Mathematics, University of Colorado, Boulder, CO, 80309, USA
| | - T J Silva
- National Institute of Standards and Technology, Boulder, CO, 80305, USA
| | - H A Dürr
- SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA, 94025, USA.
- Department of Physics and Astronomy, Uppsala University, Box 516, 751 20, Uppsala, Sweden.
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Abstract
The Einstein-de Haas effect was originally observed in a landmark experiment1 demonstrating that the angular momentum associated with aligned electron spins in a ferromagnet can be converted to mechanical angular momentum by reversing the direction of magnetization using an external magnetic field. A related problem concerns the timescale of this angular momentum transfer. Experiments have established that intense photoexcitation in several metallic ferromagnets leads to a drop in magnetization on a timescale shorter than 100 femtoseconds-a phenomenon called ultrafast demagnetization2-4. Although the microscopic mechanism for this process has been hotly debated, the key question of where the angular momentum goes on these femtosecond timescales remains unanswered. Here we use femtosecond time-resolved X-ray diffraction to show that most of the angular momentum lost from the spin system upon laser-induced demagnetization of ferromagnetic iron is transferred to the lattice on sub-picosecond timescales, launching a transverse strain wave that propagates from the surface into the bulk. By fitting a simple model of the X-ray data to simulations and optical data, we estimate that the angular momentum transfer occurs on a timescale of 200 femtoseconds and corresponds to 80 per cent of the angular momentum that is lost from the spin system. Our results show that interaction with the lattice has an essential role in the process of ultrafast demagnetization in this system.
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11
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Malvestuto M, Ciprian R, Caretta A, Casarin B, Parmigiani F. Ultrafast magnetodynamics with free-electron lasers. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2018; 30:053002. [PMID: 29315080 DOI: 10.1088/1361-648x/aaa211] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The study of ultrafast magnetodynamics has entered a new era thanks to the groundbreaking technological advances in free-electron laser (FEL) light sources. The advent of these light sources has made possible unprecedented experimental schemes for time-resolved x-ray magneto-optic spectroscopies, which are now paving the road for exploring the ultimate limits of out-of-equilibrium magnetic phenomena. In particular, these studies will provide insights into elementary mechanisms governing spin and orbital dynamics, therefore contributing to the development of ultrafast devices for relevant magnetic technologies. This topical review focuses on recent advancement in the study of non-equilibrium magnetic phenomena from the perspective of time-resolved extreme ultra violet (EUV) and soft x-ray spectroscopies at FELs with highlights of some important experimental results.
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Affiliation(s)
- Marco Malvestuto
- Elettra-Sincrotrone Trieste S.C.p.A. Strada Statale 14-km 163.5 in AREA Science Park 34149 Basovizza, Trieste, Italy
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12
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Reid AH, Shen X, Maldonado P, Chase T, Jal E, Granitzka PW, Carva K, Li RK, Li J, Wu L, Vecchione T, Liu T, Chen Z, Higley DJ, Hartmann N, Coffee R, Wu J, Dakovski GL, Schlotter WF, Ohldag H, Takahashi YK, Mehta V, Hellwig O, Fry A, Zhu Y, Cao J, Fullerton EE, Stöhr J, Oppeneer PM, Wang XJ, Dürr HA. Beyond a phenomenological description of magnetostriction. Nat Commun 2018; 9:388. [PMID: 29374151 PMCID: PMC5786062 DOI: 10.1038/s41467-017-02730-7] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2016] [Accepted: 12/19/2017] [Indexed: 11/10/2022] Open
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.
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Affiliation(s)
- A H Reid
- Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA, 94025, USA. .,Linac Coherent Light Source, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA, 94025, USA.
| | - X Shen
- Accelerator Division, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA, 94025, USA
| | - P Maldonado
- Department of Physics and Astronomy, Uppsala University, P. O. Box 516, S-75120, Uppsala, Sweden
| | - T Chase
- Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA, 94025, USA.,Department of Applied Physics, Stanford University, Stanford, CA, 94305, USA
| | - E Jal
- Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA, 94025, USA.,CNRS, Laboratoire de Chimie Physique - Matière et Rayonnement, Sorbonne Universités, UPMC Univ. Paris 06, 75005, Paris, France
| | - P W Granitzka
- Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA, 94025, USA.,Van der Waals-Zeeman Institute, University of Amsterdam, 1018XE, Amsterdam, The Netherlands
| | - K Carva
- Faculty of Mathematics and Physics, Department of Condensed Matter Physics, Charles University, Ke Karlovu 5, CZ-12116, Prague 2, Czech Republic
| | - R K Li
- Accelerator Division, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA, 94025, USA
| | - J Li
- Brookhaven National Laboratory, Upton, NY, 1193, USA
| | - L Wu
- Brookhaven National Laboratory, Upton, NY, 1193, USA
| | - T Vecchione
- Accelerator Division, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA, 94025, USA
| | - T Liu
- Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA, 94025, USA.,Department of Physics, Stanford University, Stanford, CA, 94305, USA
| | - Z Chen
- Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA, 94025, USA.,Department of Physics, Stanford University, Stanford, CA, 94305, USA
| | - D J Higley
- Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA, 94025, USA.,Department of Applied Physics, Stanford University, Stanford, CA, 94305, USA
| | - N Hartmann
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA, 94025, USA
| | - R Coffee
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA, 94025, USA
| | - J Wu
- Accelerator Division, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA, 94025, USA
| | - G L Dakovski
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA, 94025, USA
| | - W F Schlotter
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA, 94025, USA
| | - H Ohldag
- Stanford Synchrotron Radiation Laboratory, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA, 94025, USA
| | - Y K Takahashi
- Magnetic Materials Unit, National Institute for Materials Science, Tsukuba, 305-0047, Japan
| | - V Mehta
- San Jose Research Center, HGST a Western Digital Company, 3403 Yerba Buena Road, San Jose, CA, 95135, USA.,Thomas J. Watson Research Center, 1101 Kitchawan Road, Yorktown Heights, NY, 10598, USA
| | - O Hellwig
- San Jose Research Center, HGST a Western Digital Company, 3403 Yerba Buena Road, San Jose, CA, 95135, USA.,Institute of Physics, Technische Universität Chemnitz, Reichenhainer Straße 70, D-09107, Chemnitz, Germany.,Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, 01328, Dresden, Germany
| | - A Fry
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA, 94025, USA
| | - Y Zhu
- Brookhaven National Laboratory, Upton, NY, 1193, USA
| | - J Cao
- Department of Physics and National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL, 32310, USA
| | - E E Fullerton
- Center for Memory and Recording Research, UC San Diego, 9500 Gilman Drive, La Jolla, CA, 92093-0401, USA
| | - J Stöhr
- Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA, 94025, USA
| | - P M Oppeneer
- Department of Physics and Astronomy, Uppsala University, P. O. Box 516, S-75120, Uppsala, Sweden
| | - X J Wang
- Accelerator Division, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA, 94025, USA
| | - H A Dürr
- Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA, 94025, USA. .,Department of Physics and Astronomy, Uppsala University, P. O. Box 516, S-75120, Uppsala, Sweden.
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13
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Carva K, Baláž P, Radu I. Laser-Induced Ultrafast Magnetic Phenomena. HANDBOOK OF MAGNETIC MATERIALS 2017. [DOI: 10.1016/bs.hmm.2017.09.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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