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Breitbach D, Schneider M, Heinz B, Kohl F, Maskill J, Scheuer L, Serha RO, Brächer T, Lägel B, Dubs C, Tiberkevich VS, Slavin AN, Serga AA, Hillebrands B, Chumak AV, Pirro P. Stimulated Amplification of Propagating Spin Waves. Phys Rev Lett 2023; 131:156701. [PMID: 37897745 DOI: 10.1103/physrevlett.131.156701] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2022] [Revised: 08/28/2023] [Accepted: 08/31/2023] [Indexed: 10/30/2023]
Abstract
Spin-wave amplification techniques are key to the realization of magnon-based computing concepts. We introduce a novel mechanism to amplify spin waves in magnonic nanostructures. Using the technique of rapid cooling, we create a nonequilibrium state in excess of high-energy magnons and demonstrate the stimulated amplification of an externally seeded, propagating spin wave. Using an extended kinetic model, we qualitatively show that the amplification is mediated by an effective energy flux of high energy magnons into the low energy propagating mode, driven by a nonequilibrium magnon distribution.
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Affiliation(s)
- D Breitbach
- Fachbereich Physik and Landesforschungszentrum OPTIMAS, Rheinland-Pfälzische Technische Universität Kaiserslautern-Landau, D-67663 Kaiserslautern, Germany
| | - M Schneider
- Fachbereich Physik and Landesforschungszentrum OPTIMAS, Rheinland-Pfälzische Technische Universität Kaiserslautern-Landau, D-67663 Kaiserslautern, Germany
| | - B Heinz
- Fachbereich Physik and Landesforschungszentrum OPTIMAS, Rheinland-Pfälzische Technische Universität Kaiserslautern-Landau, D-67663 Kaiserslautern, Germany
| | - F Kohl
- Fachbereich Physik and Landesforschungszentrum OPTIMAS, Rheinland-Pfälzische Technische Universität Kaiserslautern-Landau, D-67663 Kaiserslautern, Germany
| | - J Maskill
- Fachbereich Physik and Landesforschungszentrum OPTIMAS, Rheinland-Pfälzische Technische Universität Kaiserslautern-Landau, D-67663 Kaiserslautern, Germany
| | - L Scheuer
- Fachbereich Physik and Landesforschungszentrum OPTIMAS, Rheinland-Pfälzische Technische Universität Kaiserslautern-Landau, D-67663 Kaiserslautern, Germany
| | - R O Serha
- Fachbereich Physik and Landesforschungszentrum OPTIMAS, Rheinland-Pfälzische Technische Universität Kaiserslautern-Landau, D-67663 Kaiserslautern, Germany
- Faculty of Physics, University of Vienna, A-1090 Vienna, Austria
| | - T Brächer
- Fachbereich Physik and Landesforschungszentrum OPTIMAS, Rheinland-Pfälzische Technische Universität Kaiserslautern-Landau, D-67663 Kaiserslautern, Germany
| | - B Lägel
- Fachbereich Physik and Landesforschungszentrum OPTIMAS, Rheinland-Pfälzische Technische Universität Kaiserslautern-Landau, D-67663 Kaiserslautern, Germany
| | - C Dubs
- INNOVENT e.V. Technologieentwicklung, D-07745 Jena, Germany
| | - V S Tiberkevich
- Department of Physics, Oakland University, Rochester, Michigan 48309, USA
| | - A N Slavin
- Department of Physics, Oakland University, Rochester, Michigan 48309, USA
| | - A A Serga
- Fachbereich Physik and Landesforschungszentrum OPTIMAS, Rheinland-Pfälzische Technische Universität Kaiserslautern-Landau, D-67663 Kaiserslautern, Germany
| | - B Hillebrands
- Fachbereich Physik and Landesforschungszentrum OPTIMAS, Rheinland-Pfälzische Technische Universität Kaiserslautern-Landau, D-67663 Kaiserslautern, Germany
| | - A V Chumak
- Faculty of Physics, University of Vienna, A-1090 Vienna, Austria
| | - P Pirro
- Fachbereich Physik and Landesforschungszentrum OPTIMAS, Rheinland-Pfälzische Technische Universität Kaiserslautern-Landau, D-67663 Kaiserslautern, Germany
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Wang Q, Heinz B, Verba R, Kewenig M, Pirro P, Schneider M, Meyer T, Lägel B, Dubs C, Brächer T, Chumak AV. Spin Pinning and Spin-Wave Dispersion in Nanoscopic Ferromagnetic Waveguides. Phys Rev Lett 2019; 122:247202. [PMID: 31322366 DOI: 10.1103/physrevlett.122.247202] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Revised: 03/05/2019] [Indexed: 05/26/2023]
Abstract
Spin waves are investigated in yttrium iron garnet waveguides with a thickness of 39 nm and widths ranging down to 50 nm, i.e., with an aspect ratio thickness over width approaching unity, using Brillouin light scattering spectroscopy. The experimental results are verified by a semianalytical theory and micromagnetic simulations. A critical width is found, below which the exchange interaction suppresses the dipolar pinning phenomenon. This changes the quantization criterion for the spin-wave eigenmodes and results in a pronounced modification of the spin-wave characteristics. The presented semianalytical theory allows for the calculation of spin-wave mode profiles and dispersion relations in nanostructures.
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Affiliation(s)
- Q Wang
- Fachbereich Physik and Landesforschungszentrum OPTIMAS, Technische Universität Kaiserslautern, D-67663 Kaiserslautern, Germany
| | - B Heinz
- Fachbereich Physik and Landesforschungszentrum OPTIMAS, Technische Universität Kaiserslautern, D-67663 Kaiserslautern, Germany
- Graduate School Materials Science in Mainz, Staudingerweg 9, 55128 Mainz, Germany
| | - R Verba
- Institute of Magnetism, Kyiv 03680, Ukraine
| | - M Kewenig
- Fachbereich Physik and Landesforschungszentrum OPTIMAS, Technische Universität Kaiserslautern, D-67663 Kaiserslautern, Germany
| | - P Pirro
- Fachbereich Physik and Landesforschungszentrum OPTIMAS, Technische Universität Kaiserslautern, D-67663 Kaiserslautern, Germany
| | - M Schneider
- Fachbereich Physik and Landesforschungszentrum OPTIMAS, Technische Universität Kaiserslautern, D-67663 Kaiserslautern, Germany
| | - T Meyer
- Fachbereich Physik and Landesforschungszentrum OPTIMAS, Technische Universität Kaiserslautern, D-67663 Kaiserslautern, Germany
- THATec Innovation GmbH, Augustaanlage 23, 68165 Mannheim, Germany
| | - B Lägel
- Nano Structuring Center, Technische Universität Kaiserslautern, D-67663 Kaiserslautern, Germany
| | - C Dubs
- INNOVENT e.V., Technologieentwicklung, Prüssingstraße 27B, 07745 Jena, Germany
| | - T Brächer
- Fachbereich Physik and Landesforschungszentrum OPTIMAS, Technische Universität Kaiserslautern, D-67663 Kaiserslautern, Germany
| | - A V Chumak
- Fachbereich Physik and Landesforschungszentrum OPTIMAS, Technische Universität Kaiserslautern, D-67663 Kaiserslautern, Germany
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Mohseni M, Verba R, Brächer T, Wang Q, Bozhko DA, Hillebrands B, Pirro P. Backscattering Immunity of Dipole-Exchange Magnetostatic Surface Spin Waves. Phys Rev Lett 2019; 122:197201. [PMID: 31144927 DOI: 10.1103/physrevlett.122.197201] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2018] [Indexed: 06/09/2023]
Abstract
The existence of backscattering-immune spin-wave modes is demonstrated in magnetic thin films of nanoscale thickness. Our results reveal that chiral magnetostatic surface waves (CMSSWs), which propagate perpendicular to the magnetization direction in an in-plane magnetized thin film, are robust against backscattering from surface defects. CMSSWs are protected against various types of surface inhomogeneities and defects as long as their frequency lies inside the gap of the volume modes. Our explanation is independent of the topology of the modes and predicts that this robustness is a consequence of symmetry breaking of the dynamic magnetic fields of CMSSWs due to the off-diagonal part of the dipolar interaction tensor, which is present both for long- (dipole-dominated) and short-wavelength (exchange-dominated) spin waves. Micromagnetic simulations confirm the robust character of the CMSSWs. Our results open a new direction in designing highly efficient magnonic logic elements and devices employing CMSSWs in nanoscale thin films.
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Affiliation(s)
- M Mohseni
- Fachbereich Physik and Landesforschungszentrum OPTIMAS, Technische Universität Kaiserslautern, 67663 Kaiserslautern, Germany
| | - R Verba
- Institute of Magnetism, Kyiv 03680, Ukraine
| | - T Brächer
- Fachbereich Physik and Landesforschungszentrum OPTIMAS, Technische Universität Kaiserslautern, 67663 Kaiserslautern, Germany
| | - Q Wang
- Fachbereich Physik and Landesforschungszentrum OPTIMAS, Technische Universität Kaiserslautern, 67663 Kaiserslautern, Germany
| | - D A Bozhko
- Fachbereich Physik and Landesforschungszentrum OPTIMAS, Technische Universität Kaiserslautern, 67663 Kaiserslautern, Germany
| | - B Hillebrands
- Fachbereich Physik and Landesforschungszentrum OPTIMAS, Technische Universität Kaiserslautern, 67663 Kaiserslautern, Germany
| | - P Pirro
- Fachbereich Physik and Landesforschungszentrum OPTIMAS, Technische Universität Kaiserslautern, 67663 Kaiserslautern, Germany
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Brächer T, Fabre M, Meyer T, Fischer T, Auffret S, Boulle O, Ebels U, Pirro P, Gaudin G. Detection of Short-Waved Spin Waves in Individual Microscopic Spin-Wave Waveguides Using the Inverse Spin Hall Effect. Nano Lett 2017; 17:7234-7241. [PMID: 29148808 DOI: 10.1021/acs.nanolett.7b02458] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The miniaturization of complementary metal-oxide-semiconductor (CMOS) devices becomes increasingly difficult due to fundamental limitations and the increase of leakage currents. Large research efforts are devoted to find alternative concepts that allow for a larger data-density and lower power consumption than conventional semiconductor approaches. Spin waves have been identified as a potential technology that can complement and outperform CMOS in complex logic applications, profiting from the fact that these waves enable wave computing on the nanoscale. The practical application of spin waves, however, requires the demonstration of scalable, CMOS compatible spin-wave detection schemes in material systems compatible with standard spintronics as well as semiconductor circuitry. Here, we report on the wave-vector independent detection of short-waved spin waves with wavelengths down to 150 nm by the inverse spin Hall effect in spin-wave waveguides made from ultrathin Ta/Co8Fe72B20/MgO. These findings open up the path for miniaturized scalable interconnects between spin waves and CMOS and the use of ultrathin films made from standard spintronic materials in magnonics.
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Affiliation(s)
- T Brächer
- University Grenoble Alpes, CEA, CNRS, Grenoble INP, INAC, SPINTEC , F-38000 Grenoble, France
| | - M Fabre
- University Grenoble Alpes, CEA, CNRS, Grenoble INP, INAC, SPINTEC , F-38000 Grenoble, France
| | - T Meyer
- Fachbereich Physik and Landesforschungszentrum OPTIMAS, Technische Universität Kaiserslautern , 67663 Kaiserslautern, Germany
| | - T Fischer
- Fachbereich Physik and Landesforschungszentrum OPTIMAS, Technische Universität Kaiserslautern , 67663 Kaiserslautern, Germany
- Graduate School Materials Science in Mainz , Gottlieb-Daimler-Strasse 47, D-67663 Kaiserslautern, Germany
| | - S Auffret
- University Grenoble Alpes, CEA, CNRS, Grenoble INP, INAC, SPINTEC , F-38000 Grenoble, France
| | - O Boulle
- University Grenoble Alpes, CEA, CNRS, Grenoble INP, INAC, SPINTEC , F-38000 Grenoble, France
| | - U Ebels
- University Grenoble Alpes, CEA, CNRS, Grenoble INP, INAC, SPINTEC , F-38000 Grenoble, France
| | - P Pirro
- Fachbereich Physik and Landesforschungszentrum OPTIMAS, Technische Universität Kaiserslautern , 67663 Kaiserslautern, Germany
| | - G Gaudin
- University Grenoble Alpes, CEA, CNRS, Grenoble INP, INAC, SPINTEC , F-38000 Grenoble, France
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Brächer T, Heussner F, Pirro P, Meyer T, Fischer T, Geilen M, Heinz B, Lägel B, Serga AA, Hillebrands B. Phase-to-intensity conversion of magnonic spin currents and application to the design of a majority gate. Sci Rep 2016; 6:38235. [PMID: 27905539 PMCID: PMC5131322 DOI: 10.1038/srep38235] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2016] [Accepted: 11/07/2016] [Indexed: 12/02/2022] Open
Abstract
Magnonic spin currents in the form of spin waves and their quanta, magnons, are a promising candidate for a new generation of wave-based logic devices beyond CMOS, where information is encoded in the phase of travelling spin-wave packets. The direct readout of this phase on a chip is of vital importance to couple magnonic circuits to conventional CMOS electronics. Here, we present the conversion of the spin-wave phase into a spin-wave intensity by local non-adiabatic parallel pumping in a microstructure. This conversion takes place within the spin-wave system itself and the resulting spin-wave intensity can be conveniently transformed into a DC voltage. We also demonstrate how the phase-to-intensity conversion can be used to extract the majority information from an all-magnonic majority gate. This conversion method promises a convenient readout of the magnon phase in future magnon-based devices.
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Affiliation(s)
- T Brächer
- Univ. Grenoble Alpes, CNRS, CEA, INAC-SPINTEC, 17, rue des Martyrs 38054, Grenoble, France.,Graduate School Materials Science in Mainz, Gottlieb-Daimler-Strasse 47, D-67663 Kaiserslautern, Germany.,Fachbereich Physik and Forschungszentrum OPTIMAS, Technische Universität Kaiserslautern, D-67663 Kaiserslautern, Germany
| | - F Heussner
- Fachbereich Physik and Forschungszentrum OPTIMAS, Technische Universität Kaiserslautern, D-67663 Kaiserslautern, Germany
| | - P Pirro
- Fachbereich Physik and Forschungszentrum OPTIMAS, Technische Universität Kaiserslautern, D-67663 Kaiserslautern, Germany
| | - T Meyer
- Fachbereich Physik and Forschungszentrum OPTIMAS, Technische Universität Kaiserslautern, D-67663 Kaiserslautern, Germany
| | - T Fischer
- Graduate School Materials Science in Mainz, Gottlieb-Daimler-Strasse 47, D-67663 Kaiserslautern, Germany.,Fachbereich Physik and Forschungszentrum OPTIMAS, Technische Universität Kaiserslautern, D-67663 Kaiserslautern, Germany
| | - M Geilen
- Fachbereich Physik and Forschungszentrum OPTIMAS, Technische Universität Kaiserslautern, D-67663 Kaiserslautern, Germany
| | - B Heinz
- Fachbereich Physik and Forschungszentrum OPTIMAS, Technische Universität Kaiserslautern, D-67663 Kaiserslautern, Germany
| | - B Lägel
- Fachbereich Physik and Forschungszentrum OPTIMAS, Technische Universität Kaiserslautern, D-67663 Kaiserslautern, Germany
| | - A A Serga
- Fachbereich Physik and Forschungszentrum OPTIMAS, Technische Universität Kaiserslautern, D-67663 Kaiserslautern, Germany
| | - B Hillebrands
- Fachbereich Physik and Forschungszentrum OPTIMAS, Technische Universität Kaiserslautern, D-67663 Kaiserslautern, Germany
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Pirro P, Sebastian T, Brächer T, Serga AA, Kubota T, Naganuma H, Oogane M, Ando Y, Hillebrands B. Non-Gilbert-damping Mechanism in a Ferromagnetic Heusler Compound Probed by Nonlinear Spin Dynamics. Phys Rev Lett 2014; 113:227601. [PMID: 25494091 DOI: 10.1103/physrevlett.113.227601] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2014] [Indexed: 06/04/2023]
Abstract
The nonlinear decay of propagating spin waves in the low-Gilbert-damping Heusler film Co_{2}Mn_{0.6}Fe_{0.4}Si is reported. Here, two initial magnons with frequency f_{0} scatter into two secondary magnons with frequencies f_{1} and f_{2}. The most remarkable observation is that f_{1} stays fixed if f_{0} is changed. This indicates, that the f_{1} magnon mode has the lowest instability threshold, which, however, cannot be understood if only Gilbert damping is present. We show that the observed behavior is caused by interaction of the magnon modes f_{1} and f_{2} with the thermal magnon bath. This evidences a significant contribution of the intrinsic magnon-magnon scattering mechanisms to the magnetic damping in high-quality Heusler compounds.
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Affiliation(s)
- P Pirro
- Fachbereich Physik and Landesforschungszentrum OPTIMAS, Technische Universität Kaiserslautern, 67663 Kaiserslautern, Germany
| | - T Sebastian
- Fachbereich Physik and Landesforschungszentrum OPTIMAS, Technische Universität Kaiserslautern, 67663 Kaiserslautern, Germany
| | - T Brächer
- Fachbereich Physik and Landesforschungszentrum OPTIMAS, Technische Universität Kaiserslautern, 67663 Kaiserslautern, Germany and Graduate School Materials Science in Mainz, Gottlieb-Daimler-Straße 47, Germany
| | - A A Serga
- Fachbereich Physik and Landesforschungszentrum OPTIMAS, Technische Universität Kaiserslautern, 67663 Kaiserslautern, Germany
| | - T Kubota
- Institute for Materials Research, Tohoku University, Katahira 2-1-1, Aoba-ku, Sendai 980-8577, Japan
| | - H Naganuma
- Department of Applied Physics, Graduate School of Engineering, Tohoku University, Aoba-yama 6-6-05, Sendai 980-8579, Japan
| | - M Oogane
- Department of Applied Physics, Graduate School of Engineering, Tohoku University, Aoba-yama 6-6-05, Sendai 980-8579, Japan
| | - Y Ando
- Department of Applied Physics, Graduate School of Engineering, Tohoku University, Aoba-yama 6-6-05, Sendai 980-8579, Japan
| | - B Hillebrands
- Fachbereich Physik and Landesforschungszentrum OPTIMAS, Technische Universität Kaiserslautern, 67663 Kaiserslautern, Germany
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Sebastian T, Brächer T, Pirro P, Serga AA, Hillebrands B, Kubota T, Naganuma H, Oogane M, Ando Y. Nonlinear emission of spin-wave caustics from an edge mode of a microstructured Co2Mn(0:6)Fe(0:4)Si waveguide. Phys Rev Lett 2013; 110:067201. [PMID: 23432296 DOI: 10.1103/physrevlett.110.067201] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2012] [Indexed: 06/01/2023]
Abstract
Magnetic Heusler materials with very low Gilbert damping are expected to show novel magnonic transport phenomena. We report nonlinear generation of higher harmonics leading to the emission of caustic spin-wave beams in a low-damping microstructured Co(2)Mn(0.6)Fe(0.4)Si Heusler waveguide. The source for the higher harmonic generation is a localized edge mode formed by the strongly inhomogeneous field distribution at the edges of the spin-wave waveguide. The radiation characteristics of the propagating caustic waves observed at twice and three times the excitation frequency are described by an analytical calculation based on the anisotropic dispersion of spin waves in a magnetic thin film.
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Affiliation(s)
- T Sebastian
- Fachbereich Physik and Forschungszentrum OPTIMAS, Technische Universität Kaiserslautern, 67663 Kaiserslautern, Germany.
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