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Avdizhiyan A, Janus W, Szpytma M, Ślezak T, Przybylski M, Chrobak M, Roddatis V, Stupakiewicz A, Razdolski I. Ultrafast Laser-Induced Dynamics of Non-Equilibrium Electron Spill-Out in Nanoplasmonic Bilayers. NANO LETTERS 2024; 24:466-471. [PMID: 38150569 DOI: 10.1021/acs.nanolett.3c04318] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2023]
Abstract
Contemporary quantum plasmonics capture subtle corrections to the properties of plasmonic nano-objects in equilibrium. Here, we demonstrate non-equilibrium spill-out redistribution of the electronic density at the ultrafast time scale. As revealed by time-resolved 2D spectroscopy of nanoplasmonic Fe/Au bilayers, an injection of the laser-excited non-thermal electrons induces transient electron spill-out thus changing the plasma frequency. The response of the local electronic density switches the electronic density behavior from spill-in to strong (an order of magnitude larger) spill-out at the femtosecond time scale. The superdiffusive transport of hot electrons and the lack of a direct laser heating indicate significantly non-thermal origin of the underlying physics. Our results demonstrate an ultrafast and non-thermal way to control surface plasmon dispersion through transient variations of the spatial electron distribution at the nanoscale. These findings expand quantum plasmonics into previously unexplored directions by introducing ultrashort time scales in the non-equilibrium electronic systems.
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Affiliation(s)
- Artur Avdizhiyan
- Faculty of Physics, University of Bialystok, 15-245 Bialystok, Poland
| | - Weronika Janus
- Faculty of Physics and Applied Computer Science, AGH University of Krakow, 30-059 Kraków, Poland
| | - Marcin Szpytma
- Faculty of Physics and Applied Computer Science, AGH University of Krakow, 30-059 Kraków, Poland
| | - Tomasz Ślezak
- Faculty of Physics and Applied Computer Science, AGH University of Krakow, 30-059 Kraków, Poland
| | - Marek Przybylski
- Academic Centre for Materials and Nanotechnology, AGH University of Krakow, 30-059 Kraków, Poland
| | - Maciej Chrobak
- Academic Centre for Materials and Nanotechnology, AGH University of Krakow, 30-059 Kraków, Poland
- Faculty of Physics and Applied Computer Science, AGH University of Krakow, 30-059 Kraków, Poland
| | | | | | - Ilya Razdolski
- Faculty of Physics, University of Bialystok, 15-245 Bialystok, Poland
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Igarashi J, Zhang W, Remy Q, Díaz E, Lin JX, Hohlfeld J, Hehn M, Mangin S, Gorchon J, Malinowski G. Optically induced ultrafast magnetization switching in ferromagnetic spin valves. NATURE MATERIALS 2023:10.1038/s41563-023-01499-z. [PMID: 36894773 DOI: 10.1038/s41563-023-01499-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Accepted: 02/06/2023] [Indexed: 05/07/2023]
Abstract
The discovery of spin-transfer torque (STT) enabled the control of the magnetization direction in magnetic devices in nanoseconds using an electrical current. Ultrashort optical pulses have also been used to manipulate the magnetization of ferrimagnets at picosecond timescales by bringing the system out of equilibrium. So far, these methods of magnetization manipulation have mostly been developed independently within the fields of spintronics and ultrafast magnetism. Here we show optically induced ultrafast magnetization reversal taking place within less than a picosecond in rare-earth-free archetypal spin valves of [Pt/Co]/Cu/[Co/Pt] commonly used for current-induced STT switching. We find that the magnetization of the free layer can be switched from a parallel to an antiparallel alignment, as in STT, indicating the presence of an unexpected, intense and ultrafast source of opposite angular momentum in our structures. Our findings provide a route to ultrafast magnetization control by bridging concepts from spintronics and ultrafast magnetism.
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Affiliation(s)
| | - Wei Zhang
- Université de Lorraine, CNRS, IJL, Nancy, France
- Anhui High Reliability Chips Engineering Laboratory, Hefei Innovation Research Institute, Beihang University, Hefei, China
- MIIT Key Laboratory of Spintronics, School of Integrated Circuit Science and Engineering, Beihang University, Beijing, China
| | - Quentin Remy
- Université de Lorraine, CNRS, IJL, Nancy, France
- Cavendish Laboratory, University of Cambridge, Cambridge, UK
| | - Eva Díaz
- Université de Lorraine, CNRS, IJL, Nancy, France
| | - Jun-Xiao Lin
- Université de Lorraine, CNRS, IJL, Nancy, France
| | | | - Michel Hehn
- Université de Lorraine, CNRS, IJL, Nancy, France
- Center for Science and Innovation in Spintronics, Tohoku University, Sendai, Japan
| | - Stéphane Mangin
- Université de Lorraine, CNRS, IJL, Nancy, France
- Cavendish Laboratory, University of Cambridge, Cambridge, UK
- Center for Science and Innovation in Spintronics, Tohoku University, Sendai, Japan
| | - Jon Gorchon
- Université de Lorraine, CNRS, IJL, Nancy, France.
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Petrov AV, Nikitin SI, Tagirov LR, Gumarov AI, Yanilkin IV, Yusupov RV. Ultrafast signatures of magnetic inhomogeneity in Pd 1- x Fe x ( x ≤ 0.08) epitaxial thin films. BEILSTEIN JOURNAL OF NANOTECHNOLOGY 2022; 13:836-844. [PMID: 36105688 PMCID: PMC9443348 DOI: 10.3762/bjnano.13.74] [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: 03/31/2022] [Accepted: 07/28/2022] [Indexed: 06/15/2023]
Abstract
A series of Pd1- x Fe x alloy epitaxial films (x = 0, 0.038, 0.062, and 0.080), a material promising for superconducting spintronics, was prepared and studied with ultrafast optical and magneto-optical laser spectroscopy in a wide temperature range of 4-300 K. It was found that the transition to the ferromagnetic state causes a qualitative change of both the reflectivity and the magneto-optical Kerr effect transients. A nanoscale magnetic inhomogeneity of the ferromagnet/paramagnet type inherent in the palladium-rich Pd1- x Fe x alloys reveals itself through the occurrence of a relatively slow, 10-25 ps, photoinduced demagnetization component following a subpicosecond one; the former vanishes at low temperatures only in the x = 0.080 sample. We argue that the 10 ps timescale demagnetization originates most probably from the diffusive transport of d electrons under the condition of nanoscale magnetic inhomogeneities. The low-temperature fraction of the residual paramagnetic phase can be deduced from the magnitude of the slow reflectivity relaxation component. It is estimated as ≈30% for x = 0.038 and ≈15% for x = 0.062 films. The minimal iron content ensuring the magnetic homogeneity of the ferromagnetic state in the Pd1- x Fe x alloy at low temperatures is about 7-8 atom %.
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Affiliation(s)
| | | | - Lenar R Tagirov
- Zavoisky Physical-Technical Institute, FRC Kazan Scientific Centre of RAS, Sibirsky trakt 10/7, Kazan, Russia
| | - Amir I Gumarov
- Kazan Federal University, Kremlyovskaya 18, Kazan, Russia
- Zavoisky Physical-Technical Institute, FRC Kazan Scientific Centre of RAS, Sibirsky trakt 10/7, Kazan, Russia
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Detection of femtosecond spin injection into a thin gold layer by time and spin resolved photoemission. Sci Rep 2020; 10:12632. [PMID: 32724122 PMCID: PMC7387461 DOI: 10.1038/s41598-020-69477-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Accepted: 07/13/2020] [Indexed: 11/14/2022] Open
Abstract
The ultrafast demagnetization effect allows for the generation of femtosecond spin current pulses, which is expected to extend the fields of spin transport and spintronics to the femtosecond time domain. Thus far, directly observing the spin polarization induced by spin injection on the femtosecond time scale has not been possible. Herein, we present time- and spin-resolved photoemission results of spin injection from a laser-excited ferromagnet into a thin gold layer. The injected spin polarization is aligned along the magnetization direction of the underlying ferromagnet. Its decay time depends on the thickness of the gold layer, indicating that transport as well as storage of spins are relevant. This capacitive aspect of spin transport may limit the speed of future spintronic devices.
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Bühlmann K, Gort R, Fognini A, Däster S, Holenstein S, Hartmann N, Zemp Y, Salvatella G, Michlmayr TU, Bähler T, Kutnyakhov D, Medjanik K, Schönhense G, Vaterlaus A, Acremann Y. Compact setup for spin-, time-, and angle-resolved photoemission spectroscopy. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2020; 91:063001. [PMID: 32611013 DOI: 10.1063/5.0004861] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Accepted: 05/16/2020] [Indexed: 06/11/2023]
Abstract
We present a compact setup for spin-, time-, and angle-resolved photoemission spectroscopy. A 10 kHz titanium sapphire laser system delivers pulses of 20 fs duration, which drive a high harmonic generation-based source for ultraviolet photons at 21 eV for photoemission. The same laser also excites the sample for pump-probe experiments. Emitted electrons pass through a hemispherical energy analyzer and a spin-filtering element. The latter is based on spin-polarized low-energy electron diffraction on an Au-passivated iridium crystal. The performance of the measurement system is discussed in terms of the resolution and efficiency of the spin filter, which are higher than those for Mott-based techniques.
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Affiliation(s)
- K Bühlmann
- Laboratory for Solid State Physics, ETH Zurich, 8093 Zurich, Switzerland
| | - R Gort
- Laboratory for Solid State Physics, ETH Zurich, 8093 Zurich, Switzerland
| | - A Fognini
- Laboratory for Solid State Physics, ETH Zurich, 8093 Zurich, Switzerland
| | - S Däster
- Laboratory for Solid State Physics, ETH Zurich, 8093 Zurich, Switzerland
| | - S Holenstein
- Laboratory for Solid State Physics, ETH Zurich, 8093 Zurich, Switzerland
| | - N Hartmann
- Laboratory for Solid State Physics, ETH Zurich, 8093 Zurich, Switzerland
| | - Y Zemp
- Laboratory for Solid State Physics, ETH Zurich, 8093 Zurich, Switzerland
| | - G Salvatella
- Laboratory for Solid State Physics, ETH Zurich, 8093 Zurich, Switzerland
| | - T U Michlmayr
- Laboratory for Solid State Physics, ETH Zurich, 8093 Zurich, Switzerland
| | - T Bähler
- Laboratory for Solid State Physics, ETH Zurich, 8093 Zurich, Switzerland
| | - D Kutnyakhov
- Institute of Physics, Johannes Gutenberg University of Mainz, 55128 Mainz, Germany
| | - K Medjanik
- Institute of Physics, Johannes Gutenberg University of Mainz, 55128 Mainz, Germany
| | - G Schönhense
- Institute of Physics, Johannes Gutenberg University of Mainz, 55128 Mainz, Germany
| | - A Vaterlaus
- Laboratory for Solid State Physics, ETH Zurich, 8093 Zurich, Switzerland
| | - Y Acremann
- Laboratory for Solid State Physics, ETH Zurich, 8093 Zurich, Switzerland
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Gottfried JM, Höfer U. Preface: fresh perspectives on internal interfaces. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2019; 31:500301. [PMID: 31535621 DOI: 10.1088/1361-648x/ab3ff0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Affiliation(s)
- J Michael Gottfried
- Department of Chemistry, University of Marburg, Marburg, Germany. Department of Physics, University of Marburg, Marburg, Germany
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