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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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Johnsen PC, Ryan SA, Gentry C, Grafov A, Kapteyn H, Murnane M. A beamline for ultrafast extreme ultraviolet magneto-optical spectroscopy in reflection near the shot noise limit. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2023; 94:033001. [PMID: 37012828 DOI: 10.1063/5.0127119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Accepted: 01/30/2023] [Indexed: 06/19/2023]
Abstract
High harmonic generation (HHG) makes it possible to measure spin and charge dynamics in materials on femtosecond to attosecond timescales. However, the extreme nonlinear nature of the high harmonic process means that intensity fluctuations can limit measurement sensitivity. Here we present a noise-canceled, tabletop high harmonic beamline for time-resolved reflection mode spectroscopy of magnetic materials. We use a reference spectrometer to independently normalize the intensity fluctuations of each harmonic order and eliminate long term drift, allowing us to make spectroscopic measurements near the shot noise limit. These improvements allow us to significantly reduce the integration time required for high signal-to-noise (SNR) measurements of element-specific spin dynamics. Looking forward, improvements in the HHG flux, optical coatings, and grating design can further reduce the acquisition time for high SNR measurements by 1-2 orders of magnitude, enabling dramatically improved sensitivity to spin, charge, and phonon dynamics in magnetic materials.
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Affiliation(s)
- Peter C Johnsen
- Department of Physics and JILA, University of Colorado and NIST, Boulder, Colorado 80309-0440, USA
| | - Sinéad A Ryan
- Department of Physics and JILA, University of Colorado and NIST, Boulder, Colorado 80309-0440, USA
| | - Christian Gentry
- Department of Physics and JILA, University of Colorado and NIST, Boulder, Colorado 80309-0440, USA
| | - Anya Grafov
- Department of Physics and JILA, University of Colorado and NIST, Boulder, Colorado 80309-0440, USA
| | - Henry Kapteyn
- Department of Physics and JILA, University of Colorado and NIST, Boulder, Colorado 80309-0440, USA
| | - Margaret Murnane
- Department of Physics and JILA, University of Colorado and NIST, Boulder, Colorado 80309-0440, USA
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FEL Pulse Duration Evolution along Undulators at FLASH. APPLIED SCIENCES-BASEL 2022. [DOI: 10.3390/app12147048] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/10/2022]
Abstract
Self-amplified spontaneous-emission (SASE) free-electron lasers (FELs) deliver ultrashort pulses with femtosecond durations. Due to the fluctuating nature of the radiation properties of SASE FELs, characterizing FEL pulses on a single-shot basis is necessary. Therefore, we use terahertz streaking to characterize the temporal properties of ultrashort extreme ultraviolet pulses from the free-electron laser in Hamburg (FLASH). In this study, pulse duration as well as pulse energy are measured in a wavelength range from 8 to 34 nm as functions of undulators contributing to the lasing process. The results are compared to one-dimensional and three-dimensional, time-dependent FEL simulations.
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Pancaldi M, Strüber C, Friedrich B, Pedersoli E, De Angelis D, Nikolov IP, Manfredda M, Foglia L, Yulin S, Spezzani C, Sacchi M, Eisebitt S, von Korff Schmising C, Capotondi F. The COMIX polarimeter: a compact device for XUV polarization analysis. JOURNAL OF SYNCHROTRON RADIATION 2022; 29:969-977. [PMID: 35787562 PMCID: PMC9255573 DOI: 10.1107/s1600577522004027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Accepted: 04/13/2022] [Indexed: 06/15/2023]
Abstract
We report on the characterization of a novel extreme-ultraviolet polarimeter based on conical mirrors to simultaneously detect all the components of the electric field vector for extreme-ultraviolet radiation in the 45-90 eV energy range. The device has been characterized using a variable polarization source at the Elettra synchrotron, showing good performance in the ability to determine the radiation polarization. Furthermore, as a possible application of the device, Faraday spectroscopy and time-resolved experiments have been performed at the Fe M2,3-edge on an FeGd ferrimagnetic thin film using the FERMI free-electron laser source. The instrument is shown to be able to detect the small angular variation induced by an optical external stimulus on the polarization state of the light after interaction with magnetic thin film, making the device an appealing tool for magnetization dynamics research.
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Affiliation(s)
| | - Christian Strüber
- Department of Physics, Freie Universität Berlin, 14195 Berlin, Germany
| | - Bertram Friedrich
- Max Born Institute for Nonlinear Optics and Short Pulse Spectroscopy, 12489 Berlin, Germany
| | | | | | | | | | - Laura Foglia
- Elettra-Sincrotrone Trieste SCpA, 34149 Basovizza, Italy
| | - Sergiy Yulin
- Fraunhofer Institute for Applied Optics and Precision Engineering IOF, Albert-Einstein-Straße 7, 07745 Jena, Germany
| | - Carlo Spezzani
- Elettra-Sincrotrone Trieste SCpA, 34149 Basovizza, Italy
| | - Maurizio Sacchi
- Sorbonne Université, CNRS, Institut des NanoSciences de Paris, INSP, 75005 Paris, France
- Synchrotron SOLEIL, L’Orme des Merisiers, Saint-Aubin, BP 48, 91192 Gif-sur-Yvette, France
| | - Stefan Eisebitt
- Max Born Institute for Nonlinear Optics and Short Pulse Spectroscopy, 12489 Berlin, Germany
- Institut für Optik und Atomare Physik, Technische Universität Berlin, Strasse des 17 Juni 135, 10623 Berlin, Germany
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Möller C, Probst H, Otto J, Stroh K, Mahn C, Steil S, Moshnyaga V, Jansen GSM, Steil D, Mathias S. Ultrafast element-resolved magneto-optics using a fiber-laser-driven extreme ultraviolet light source. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2021; 92:065107. [PMID: 34243510 DOI: 10.1063/5.0050883] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Accepted: 05/16/2021] [Indexed: 06/13/2023]
Abstract
We present a novel setup to measure the transverse magneto-optical Kerr effect in the extreme ultraviolet spectral range based on a fiber laser amplifier system with a repetition rate between 100 and 300 kHz, which we use to measure element-resolved demagnetization dynamics. The setup is equipped with a strong electromagnet and a cryostat, allowing measurements between 10 and 420 K using magnetic fields up to 0.86 T. The performance of our setup is demonstrated by a set of temperature- and time-dependent magnetization measurements with elemental resolution.
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Affiliation(s)
- Christina Möller
- I. Physikalisches Institut, Universität Göttingen, Friedrich-Hund-Platz 1, 37077 Göttingen, Germany
| | - Henrike Probst
- I. Physikalisches Institut, Universität Göttingen, Friedrich-Hund-Platz 1, 37077 Göttingen, Germany
| | - Johannes Otto
- I. Physikalisches Institut, Universität Göttingen, Friedrich-Hund-Platz 1, 37077 Göttingen, Germany
| | - Karen Stroh
- I. Physikalisches Institut, Universität Göttingen, Friedrich-Hund-Platz 1, 37077 Göttingen, Germany
| | - Carsten Mahn
- I. Physikalisches Institut, Universität Göttingen, Friedrich-Hund-Platz 1, 37077 Göttingen, Germany
| | - Sabine Steil
- I. Physikalisches Institut, Universität Göttingen, Friedrich-Hund-Platz 1, 37077 Göttingen, Germany
| | - Vasily Moshnyaga
- I. Physikalisches Institut, Universität Göttingen, Friedrich-Hund-Platz 1, 37077 Göttingen, Germany
| | - G S Matthijs Jansen
- I. Physikalisches Institut, Universität Göttingen, Friedrich-Hund-Platz 1, 37077 Göttingen, Germany
| | - Daniel Steil
- I. Physikalisches Institut, Universität Göttingen, Friedrich-Hund-Platz 1, 37077 Göttingen, Germany
| | - Stefan Mathias
- I. Physikalisches Institut, Universität Göttingen, Friedrich-Hund-Platz 1, 37077 Göttingen, Germany
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