1
|
Makiuchi T, Hioki T, Shimizu H, Hoshi K, Elyasi M, Yamamoto K, Yokoi N, Serga AA, Hillebrands B, Bauer GEW, Saitoh E. Persistent magnetic coherence in magnets. Nat Mater 2024:10.1038/s41563-024-01798-z. [PMID: 38321239 DOI: 10.1038/s41563-024-01798-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2023] [Accepted: 01/05/2024] [Indexed: 02/08/2024]
Abstract
When excited, the magnetization in a magnet precesses around the field in an anticlockwise manner on a timescale governed by viscous magnetization damping, after which any information carried by the initial actuation seems to be lost. This damping appears to be a fundamental bottleneck for the use of magnets in information processing. However, here we demonstrate the recall of the magnetization-precession phase after times that exceed the damping timescale by two orders of magnitude using dedicated two-colour microwave pump-probe experiments for a Y3Fe5O12 microstructured film. Time-resolved magnetization state tomography confirms the persistent magnetic coherence by revealing a double-exponential decay of magnetization correlation. We attribute persistent magnetic coherence to a feedback effect, that is, coherent coupling of the uniform precession with long-lived excitations at the minima of the spin-wave dispersion relation. Our finding liberates magnetic systems from the strong damping in nanostructures that has limited their use in coherent information storage and processing.
Collapse
Affiliation(s)
- T Makiuchi
- Department of Applied Physics, University of Tokyo, Tokyo, Japan
- Quantum-Phase Electronics Center, University of Tokyo, Tokyo, Japan
| | - T Hioki
- Department of Applied Physics, University of Tokyo, Tokyo, Japan
- WPI Advanced Institute for Materials Research, Tohoku University, Sendai, Japan
| | - H Shimizu
- Department of Applied Physics, University of Tokyo, Tokyo, Japan
| | - K Hoshi
- Department of Applied Physics, University of Tokyo, Tokyo, Japan
- Institute for AI and Beyond, University of Tokyo, Tokyo, Japan
| | - M Elyasi
- WPI Advanced Institute for Materials Research, Tohoku University, Sendai, Japan
| | - K Yamamoto
- Advanced Science Research Center, Japan Atomic Energy Agency, Tokai, Japan
| | - N Yokoi
- Department of Applied Physics, University of Tokyo, Tokyo, Japan
- Institute for AI and Beyond, University of Tokyo, Tokyo, Japan
| | - A A Serga
- Department of Physics and Research Center OPTIMAS, RPTU Kaiserslautern-Landau, Kaiserslautern, Germany
| | - B Hillebrands
- Department of Physics and Research Center OPTIMAS, RPTU Kaiserslautern-Landau, Kaiserslautern, Germany
| | - G E W Bauer
- WPI Advanced Institute for Materials Research, Tohoku University, Sendai, Japan
- Kavli Institute for Theoretical Sciences, University of the Chinese Academy of Sciences, Beijing, China
| | - E Saitoh
- Department of Applied Physics, University of Tokyo, Tokyo, Japan.
- Quantum-Phase Electronics Center, University of Tokyo, Tokyo, Japan.
- WPI Advanced Institute for Materials Research, Tohoku University, Sendai, Japan.
- Institute for AI and Beyond, University of Tokyo, Tokyo, Japan.
- Advanced Science Research Center, Japan Atomic Energy Agency, Tokai, Japan.
- RIKEN Center for Emergent Matter Science, Wako, Japan.
| |
Collapse
|
2
|
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.
Collapse
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
| |
Collapse
|
3
|
Barman A, Gubbiotti G, Ladak S, Adeyeye AO, Krawczyk M, Gräfe J, Adelmann C, Cotofana S, Naeemi A, Vasyuchka VI, Hillebrands B, Nikitov SA, Yu H, Grundler D, Sadovnikov AV, Grachev AA, Sheshukova SE, Duquesne JY, Marangolo M, Csaba G, Porod W, Demidov VE, Urazhdin S, Demokritov SO, Albisetti E, Petti D, Bertacco R, Schultheiss H, Kruglyak VV, Poimanov VD, Sahoo S, Sinha J, Yang H, Münzenberg M, Moriyama T, Mizukami S, Landeros P, Gallardo RA, Carlotti G, Kim JV, Stamps RL, Camley RE, Rana B, Otani Y, Yu W, Yu T, Bauer GEW, Back C, Uhrig GS, Dobrovolskiy OV, Budinska B, Qin H, van Dijken S, Chumak AV, Khitun A, Nikonov DE, Young IA, Zingsem BW, Winklhofer M. The 2021 Magnonics Roadmap. J Phys Condens Matter 2021; 33:413001. [PMID: 33662946 DOI: 10.1088/1361-648x/abec1a] [Citation(s) in RCA: 50] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Accepted: 03/04/2021] [Indexed: 05/26/2023]
Abstract
Magnonics is a budding research field in nanomagnetism and nanoscience that addresses the use of spin waves (magnons) to transmit, store, and process information. The rapid advancements of this field during last one decade in terms of upsurge in research papers, review articles, citations, proposals of devices as well as introduction of new sub-topics prompted us to present the first roadmap on magnonics. This is a collection of 22 sections written by leading experts in this field who review and discuss the current status besides presenting their vision of future perspectives. Today, the principal challenges in applied magnonics are the excitation of sub-100 nm wavelength magnons, their manipulation on the nanoscale and the creation of sub-micrometre devices using low-Gilbert damping magnetic materials and its interconnections to standard electronics. To this end, magnonics offers lower energy consumption, easier integrability and compatibility with CMOS structure, reprogrammability, shorter wavelength, smaller device features, anisotropic properties, negative group velocity, non-reciprocity and efficient tunability by various external stimuli to name a few. Hence, despite being a young research field, magnonics has come a long way since its early inception. This roadmap asserts a milestone for future emerging research directions in magnonics, and hopefully, it will inspire a series of exciting new articles on the same topic in the coming years.
Collapse
Affiliation(s)
- Anjan Barman
- Department of Condensed Matter Physics and Material Sciences, S N Bose National Centre for Basic Sciences, Salt Lake, Kolkata 700106, India
| | - Gianluca Gubbiotti
- Istituto Officina dei Materiali del Consiglio nazionale delle Ricerche (IOM-CNR), Perugia, Italy
| | - S Ladak
- School of Physics and Astronomy, Cardiff University, United Kingdom
| | - A O Adeyeye
- Department of Physics, University of Durham, United Kingdom
| | - M Krawczyk
- Adam Mickiewicz University, Poznan, Poland
| | - J Gräfe
- Max Planck Institute for Intelligent Systems, Stuttgart, Germany
| | | | - S Cotofana
- Delft University of Technology, The Netherlands
| | - A Naeemi
- Georgia Institute of Technology, United States of America
| | - V I Vasyuchka
- Department of Physics and State Research Center OPTIMAS, Technische Universität Kaiserslautern (TUK), Kaiserslautern, Germany
| | - B Hillebrands
- Department of Physics and State Research Center OPTIMAS, Technische Universität Kaiserslautern (TUK), Kaiserslautern, Germany
| | - S A Nikitov
- Kotelnikov Institute of Radioengineering and Electronics, Moscow, Russia
| | - H Yu
- Fert Beijing Institute, BDBC, School of Microelectronics, Beijing Advanced Innovation Center for Big Data and Brian Computing, Beihang University, People's Republic of China
| | - D Grundler
- Laboratory of Nanoscale Magnetic Materials and Magnonics, Institute of Materials (IMX), Institute of Electrical and Micro Engineering, School of Engineering, École Polytechnique Fédérale de Lausanne (EPFL), Switzerland
| | - A V Sadovnikov
- Kotelnikov Institute of Radioengineering and Electronics, Moscow, Russia
- Laboratory 'Magnetic Metamaterials', Saratov State University, Saratov, Russia
| | - A A Grachev
- Kotelnikov Institute of Radioengineering and Electronics, Moscow, Russia
- Laboratory 'Magnetic Metamaterials', Saratov State University, Saratov, Russia
| | - S E Sheshukova
- Kotelnikov Institute of Radioengineering and Electronics, Moscow, Russia
- Laboratory 'Magnetic Metamaterials', Saratov State University, Saratov, Russia
| | - J-Y Duquesne
- Institut des NanoSciences de Paris, Sorbonne University, CNRS, Paris, France
| | - M Marangolo
- Institut des NanoSciences de Paris, Sorbonne University, CNRS, Paris, France
| | - G Csaba
- Pázmány University, Budapest, Hungary
| | - W Porod
- University of Notre Dame, IN, United States of America
| | - V E Demidov
- Institute for Applied Physics, University of Muenster, Muenster, Germany
| | - S Urazhdin
- Department of Physics, Emory University, Atlanta, United States of America
| | - S O Demokritov
- Institute for Applied Physics, University of Muenster, Muenster, Germany
| | | | - D Petti
- Polytechnic University of Milan, Italy
| | | | - H Schultheiss
- Helmholtz-Center Dresden-Rossendorf, Institute of Ion Beam Physics and Materials Research, Germany
- Technische Universität Dresden, Germany
| | | | | | - S Sahoo
- Department of Condensed Matter Physics and Material Sciences, S N Bose National Centre for Basic Sciences, Salt Lake, Kolkata 700106, India
| | - J Sinha
- Department of Physics and Nanotechnology, SRM Institute of Science and Technology, Kattankulathur, India
| | - H Yang
- Department of Electrical and Computer Engineering, National University of Singapore, Singapore
| | - M Münzenberg
- Institute of Physics, University of Greifswald, Greifswald, Germany
| | - T Moriyama
- Institute for Chemical Research, Kyoto University, Gokasho, Uji, Kyoto, Japan
- Centre for Spintronics Research Network, Japan
| | - S Mizukami
- Centre for Spintronics Research Network, Japan
- Advanced Institute for Materials Research (WPI-AIMR), Tohoku University, Sendai, Japan
| | - P Landeros
- Departamento de Física, Universidad Técnica Federico Santa María, Valparaíso, Chile
- Center for the Development of Nanoscience and Nanotechnology (CEDENNA), Santiago, Chile
| | - R A Gallardo
- Departamento de Física, Universidad Técnica Federico Santa María, Valparaíso, Chile
- Center for the Development of Nanoscience and Nanotechnology (CEDENNA), Santiago, Chile
| | - G Carlotti
- Dipartimento di Fisica e Geologia, University of Perugia, Perugia, Italy
- CNR Instituto Nanoscienze, Modena, Italy
| | - J-V Kim
- Centre for Nanosciences and Nanotechnology, CNRS, Université Paris-Saclay, Palaiseau, France
| | - R L Stamps
- Department of Physics and Astronomy, University of Manitoba, Canada
| | - R E Camley
- Center for Magnetism and Magnetic Nanostructures, University of Colorado, Colorado Springs, United States of America
| | | | - Y Otani
- RIKEN, Japan
- Institute for Solid State Physics (ISSP), University of Tokyo, Japan
| | - W Yu
- Institute for Materials Research, Tohoku University, Sendai, 980-8577, Japan
| | - T Yu
- Max Planck Institute for the Structure and Dynamics of Matter, Hamburg, Germany
| | - G E W Bauer
- Advanced Institute for Materials Research (WPI-AIMR), Tohoku University, Sendai, Japan
- Zernike Institute for Advanced Materials, Groningen University, The Netherlands
| | - C Back
- Technical University Munich, Germany
| | - G S Uhrig
- Technical University Dortmund, Germany
| | | | - B Budinska
- Faculty of Physics, University of Vienna, Vienna, Austria
| | - H Qin
- Department of Applied Physics, School of Science, Aalto University, Finland
| | - S van Dijken
- Department of Applied Physics, School of Science, Aalto University, Finland
| | - A V Chumak
- Faculty of Physics, University of Vienna, Vienna, Austria
| | - A Khitun
- University of California Riverside, United States of America
| | - D E Nikonov
- Components Research, Intel, Hillsboro, Oregon, United States of America
| | - I A Young
- Components Research, Intel, Hillsboro, Oregon, United States of America
| | - B W Zingsem
- The University of Duisburg-Essen, CENIDE, Germany
| | - M Winklhofer
- The Carl von Ossietzky University of Oldenburg, Germany
| |
Collapse
|
4
|
Ramos R, Hioki T, Hashimoto Y, Kikkawa T, Frey P, Kreil AJE, Vasyuchka VI, Serga AA, Hillebrands B, Saitoh E. Room temperature and low-field resonant enhancement of spin Seebeck effect in partially compensated magnets. Nat Commun 2019; 10:5162. [PMID: 31727884 PMCID: PMC6856150 DOI: 10.1038/s41467-019-13121-5] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [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: 03/21/2019] [Accepted: 10/08/2019] [Indexed: 11/09/2022] Open
Abstract
Resonant enhancement of spin Seebeck effect (SSE) due to phonons was recently discovered in Y[Formula: see text]Fe[Formula: see text]O[Formula: see text] (YIG). This effect is explained by hybridization between the magnon and phonon dispersions. However, this effect was observed at low temperatures and high magnetic fields, limiting the scope for applications. Here we report observation of phonon-resonant enhancement of SSE at room temperature and low magnetic field. We observe in Lu[Formula: see text]BiFe[Formula: see text]GaO[Formula: see text] an enhancement 700% greater than that in a YIG film and at very low magnetic fields around 10[Formula: see text] T, almost one order of magnitude lower than that of YIG. The result can be explained by the change in the magnon dispersion induced by magnetic compensation due to the presence of non-magnetic ion substitutions. Our study provides a way to tune the magnon response in a crystal by chemical doping, with potential applications for spintronic devices.
Collapse
Affiliation(s)
- R Ramos
- WPI Advanced Institute for Materials Research, Tohoku University, Sendai, 980-8577, Japan.
| | - T Hioki
- Institute for Materials Research, Tohoku University, Sendai, 980-8577, Japan
| | - Y Hashimoto
- WPI Advanced Institute for Materials Research, Tohoku University, Sendai, 980-8577, Japan
| | - T Kikkawa
- WPI Advanced Institute for Materials Research, Tohoku University, Sendai, 980-8577, Japan.,Institute for Materials Research, Tohoku University, Sendai, 980-8577, Japan
| | - P Frey
- Fachbereich Physik and Landesforschungszentrum OPTIMAS, Technische Universität Kaiserslautern, 67663, Kaiserslautern, Germany
| | - A J E Kreil
- Fachbereich Physik and Landesforschungszentrum OPTIMAS, Technische Universität Kaiserslautern, 67663, Kaiserslautern, Germany
| | - V I Vasyuchka
- Fachbereich Physik and Landesforschungszentrum OPTIMAS, Technische Universität Kaiserslautern, 67663, Kaiserslautern, Germany
| | - A A Serga
- Fachbereich Physik and Landesforschungszentrum OPTIMAS, Technische Universität Kaiserslautern, 67663, Kaiserslautern, Germany
| | - B Hillebrands
- Fachbereich Physik and Landesforschungszentrum OPTIMAS, Technische Universität Kaiserslautern, 67663, Kaiserslautern, Germany
| | - E Saitoh
- WPI Advanced Institute for Materials Research, Tohoku University, Sendai, 980-8577, Japan.,Institute for Materials Research, Tohoku University, Sendai, 980-8577, Japan.,Department of Applied Physics, The University of Tokyo, Tokyo, 113-8656, Japan.,Center for Spintronics Research Network, Tohoku University, Sendai, 980-8577, Japan.,Advanced Science Research Center, Japan Atomic Energy Agency, Tokai, 319-1195, Japan
| |
Collapse
|
5
|
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.
Collapse
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
| |
Collapse
|
6
|
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.
Collapse
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
| |
Collapse
|
7
|
Bunyaev SA, Golub VO, Salyuk OY, Tartakovskaya EV, Santos NM, Timopheev AA, Sobolev NA, Serga AA, Chumak AV, Hillebrands B, Kakazei GN. Splitting of standing spin-wave modes in circular submicron ferromagnetic dot under axial symmetry violation. Sci Rep 2015; 5:18480. [PMID: 26690826 PMCID: PMC4686882 DOI: 10.1038/srep18480] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [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: 08/21/2015] [Accepted: 11/17/2015] [Indexed: 11/30/2022] Open
Abstract
The spin wave dynamics in patterned magnetic nanostructures is under intensive study during the last two decades. On the one hand, this interest is generated by new physics that can be explored in such structures. On the other hand, with the development of nanolithography, patterned nanoelements and their arrays can be used in many practical applications (magnetic recording systems both as media and read-write heads, magnetic random access memory, and spin-torque oscillators just to name a few). In the present work the evolution of spin wave spectra of an array of non-interacting Permalloy submicron circular dots for the case of magnetic field deviation from the normal to the array plane have been studied by ferromagnetic resonance technique. It is shown that such symmetry violation leads to a splitting of spin-wave modes, and that the number of the split peaks depends on the mode number. A quantitative description of the observed spectra is given using a perturbation theory for small angles of field inclination from the symmetry direction. The obtained results give possibility to predict transformation of spin wave spectra depending on direction of the external magnetic field that can be important for spintronic and nanomagnetic applications.
Collapse
Affiliation(s)
- S A Bunyaev
- IFIMUP and IN-Institute of Nanoscience and Nanotechnology, Departamento de Física, Universidade do Porto, 4169-007 Porto, Portugal
| | - V O Golub
- Institute of Magnetism, National Academy of Sciences of Ukraine, 36b Vernadskogo Blvd, 03142 Kiev, Ukraine
| | - O Yu Salyuk
- Institute of Magnetism, National Academy of Sciences of Ukraine, 36b Vernadskogo Blvd, 03142 Kiev, Ukraine
| | - E V Tartakovskaya
- Institute of Magnetism, National Academy of Sciences of Ukraine, 36b Vernadskogo Blvd, 03142 Kiev, Ukraine
| | - N M Santos
- Departamento de Física and I3N, Universidade de Aveiro, 3810-193 Aveiro, Portugal
| | - A A Timopheev
- Departamento de Física and I3N, Universidade de Aveiro, 3810-193 Aveiro, Portugal
| | - N A Sobolev
- Departamento de Física and I3N, Universidade de Aveiro, 3810-193 Aveiro, Portugal.,National University of Science and Technology "MISiS", 119049 Moscow, Russia
| | - A A Serga
- Fachbereich Physik and Forschungszentrum OPTIMAS, Technische Universität Kaiserslautern, 67663 Kaiserslautern, Germany
| | - A V Chumak
- Fachbereich Physik and Forschungszentrum OPTIMAS, Technische Universität Kaiserslautern, 67663 Kaiserslautern, Germany
| | - B Hillebrands
- Fachbereich Physik and Forschungszentrum OPTIMAS, Technische Universität Kaiserslautern, 67663 Kaiserslautern, Germany
| | - G N Kakazei
- IFIMUP and IN-Institute of Nanoscience and Nanotechnology, Departamento de Física, Universidade do Porto, 4169-007 Porto, Portugal
| |
Collapse
|
8
|
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.
Collapse
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
| |
Collapse
|
9
|
Vogt K, Fradin F, Pearson J, Sebastian T, Bader S, Hillebrands B, Hoffmann A, Schultheiss H. Realization of a spin-wave multiplexer. Nat Commun 2014; 5:3727. [DOI: 10.1038/ncomms4727] [Citation(s) in RCA: 273] [Impact Index Per Article: 27.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2014] [Accepted: 03/26/2014] [Indexed: 11/09/2022] Open
|
10
|
Vasyuchka VI, Serga AA, Sandweg CW, Slobodianiuk DV, Melkov GA, Hillebrands B. Explosive electromagnetic radiation by the relaxation of a multimode magnon system. Phys Rev Lett 2013; 111:187206. [PMID: 24237559 DOI: 10.1103/physrevlett.111.187206] [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: 06/27/2013] [Indexed: 06/02/2023]
Abstract
Microwave emission from a parametrically pumped ferrimagnetic film of yttrium iron garnet was studied versus the magnon density evolution, which was detected by Brillouin light scattering spectroscopy. It has been found that the shutdown of external microwave pumping leads to an unexpected effect: The conventional monotonic decrease of the population of parametrically injected magnons is accompanied by an explosive behavior of electromagnetic radiation at the magnon frequency. The developed theory shows that this explosion is caused by a nonlinear energy transfer from parametrically driven short-wavelength dipolar-exchange magnons to a long-wavelength dipolar magnon mode effectively coupled to an electromagnetic wave.
Collapse
Affiliation(s)
- V I Vasyuchka
- Fachbereich Physik and Landesforschungszentrum OPTIMAS, Technische Universität Kaiserslautern, 67663 Kaiserslautern, Germany
| | | | | | | | | | | |
Collapse
|
11
|
Agrawal M, Vasyuchka VI, Serga AA, Karenowska AD, Melkov GA, Hillebrands B. Direct measurement of magnon temperature: new insight into magnon-phonon coupling in magnetic insulators. Phys Rev Lett 2013; 111:107204. [PMID: 25166706 DOI: 10.1103/physrevlett.111.107204] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2013] [Indexed: 06/03/2023]
Abstract
We present spatially resolved measurements of the magnon temperature in a magnetic insulator subject to a thermal gradient. Our data reveal an unexpectedly close correspondence between the spatial dependencies of the exchange magnon and phonon temperatures. These results indicate that if--as is currently thought--the transverse spin Seebeck effect is caused by a temperature difference between the magnon and phonon baths, it must be the case that the magnon temperature is spectrally nonuniform and that the effect is driven by the sparsely populated dipolar region of the magnon spectrum.
Collapse
Affiliation(s)
- M Agrawal
- Fachbereich Physik and Landesforschungszentrum OPTIMAS, Technische Universität Kaiserslautern, 67663 Kaiserslautern, Germany and Graduate School Materials Science in Mainz, Gottlieb-Daimer-Strasse 47, 67663 Kaiserslautern, Germany
| | - V I Vasyuchka
- Fachbereich Physik and Landesforschungszentrum OPTIMAS, Technische Universität Kaiserslautern, 67663 Kaiserslautern, Germany
| | - A A Serga
- Fachbereich Physik and Landesforschungszentrum OPTIMAS, Technische Universität Kaiserslautern, 67663 Kaiserslautern, Germany
| | - A D Karenowska
- Department of Physics, Clarendon Laboratory, University of Oxford, Oxford OX1 3PU, United Kingdom
| | - G A Melkov
- Faculty of Radiophysics, Taras Shevchenko National University of Kyiv, 01601 Kyiv, Ukraine
| | - B Hillebrands
- Fachbereich Physik and Landesforschungszentrum OPTIMAS, Technische Universität Kaiserslautern, 67663 Kaiserslautern, Germany
| |
Collapse
|
12
|
An T, Vasyuchka VI, Uchida K, Chumak AV, Yamaguchi K, Harii K, Ohe J, Jungfleisch MB, Kajiwara Y, Adachi H, Hillebrands B, Maekawa S, Saitoh E. Unidirectional spin-wave heat conveyer. Nat Mater 2013; 12:549-553. [PMID: 23603850 DOI: 10.1038/nmat3628] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2012] [Accepted: 03/12/2013] [Indexed: 06/02/2023]
Abstract
When energy is introduced into a region of matter, it heats up and the local temperature increases. This energy spontaneously diffuses away from the heated region. In general, heat should flow from warmer to cooler regions and it is not possible to externally change the direction of heat conduction. Here we show a magnetically controllable heat flow caused by a spin-wave current. The direction of the flow can be switched by applying a magnetic field. When microwave energy is applied to a region of ferrimagnetic Y3Fe5O12, an end of the magnet far from this region is found to be heated in a controlled manner and a negative temperature gradient towards it is formed. This is due to unidirectional energy transfer by the excitation of spin-wave modes without time-reversal symmetry and to the conversion of spin waves into heat. When a Y3Fe5O12 film with low damping coefficients is used, spin waves are observed to emit heat at the sample end up to 10 mm away from the excitation source. The magnetically controlled remote heating we observe is directly applicable to the fabrication of a heat-flow controller.
Collapse
Affiliation(s)
- T An
- Institute for Materials Research, Tohoku University, Sendai 980-8577, Japan.
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
13
|
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.
Collapse
Affiliation(s)
- T Sebastian
- Fachbereich Physik and Forschungszentrum OPTIMAS, Technische Universität Kaiserslautern, 67663 Kaiserslautern, Germany.
| | | | | | | | | | | | | | | | | |
Collapse
|
14
|
Harzer J, Hillebrands B, Pogosova I, Herrmann M, Güntherodt G, Weller D. Structural and Magnetic Properties of e-Beam Prepared CoxPt1-x Alloy Films. ACTA ACUST UNITED AC 2012. [DOI: 10.1557/proc-313-387] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
ABSTRACTWe have investigated structural and magnetic properties of CoPt alloy films with strong perpendicular magnetic anisotropy in the thickness range between 100Å and 400A. From a detailed x-ray analysis we find highly (111) -textured CoPt Microcrystal-lites in all samples. STM studies reveal a granular topography with grain diameters of up to 250Å. Measurements of hysteresis loops yield a saturation field which increases with thickness, and which is consistent with a freely mobile domain Model. Brillouin light scattering measurements of the frequencies of the surface and standing spin wave modes yield a bulk exchange constant, which is strongly dependent on the Pt content.
Collapse
|
15
|
Chumak AV, Vasyuchka VI, Serga AA, Kostylev MP, Tiberkevich VS, Hillebrands B. Storage-recovery phenomenon in magnonic crystal. Phys Rev Lett 2012; 108:257207. [PMID: 23004653 DOI: 10.1103/physrevlett.108.257207] [Citation(s) in RCA: 6] [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: 07/05/2011] [Revised: 03/19/2012] [Indexed: 06/01/2023]
Abstract
The phenomenon of coherent wave trapping and restoration is demonstrated experimentally in a magnonic crystal. Unlike the conventional scheme used in photonics, the trapping occurs not due to the deceleration of the incident wave when it enters the periodic structure but due to excitation of the quasinormal modes of the artificial crystal. This excitation occurs at the group velocity minima of the decelerated wave in narrow frequency regions near the edges of the band gaps of the crystal. The restoration of the traveling wave is implemented by means of phase-sensitive parametric amplification of the stored mode.
Collapse
Affiliation(s)
- A V Chumak
- Fachbereich Physik and Forschungszentrum OPTIMAS, Technische Universität Kaiserslautern, 67663 Kaiserslautern, Germany.
| | | | | | | | | | | |
Collapse
|
16
|
Karenowska AD, Gregg JF, Tiberkevich VS, Slavin AN, Chumak AV, Serga AA, Hillebrands B. Oscillatory energy exchange between waves coupled by a dynamic artificial crystal. Phys Rev Lett 2012; 108:015505. [PMID: 22304269 DOI: 10.1103/physrevlett.108.015505] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/26/2010] [Indexed: 05/31/2023]
Abstract
We describe a general mechanism of controllable energy exchange between waves propagating in a dynamic artificial crystal. We show that if a spatial periodicity is temporarily imposed on the transmission properties of a wave-carrying medium while a wave is inside, this wave is coupled to a secondary counterpropagating wave and energy oscillates between the two. The oscillation frequency is determined by the width of the spectral band gap created by the periodicity and the frequency difference between the coupled waves. The effect is demonstrated with spin waves in a dynamic magnonic crystal.
Collapse
Affiliation(s)
- A D Karenowska
- Department of Physics, Clarendon Laboratory, University of Oxford, OX1 3PU Oxford, United Kingdom.
| | | | | | | | | | | | | |
Collapse
|
17
|
Uchida K, Adachi H, An T, Ota T, Toda M, Hillebrands B, Maekawa S, Saitoh E. Long-range spin Seebeck effect and acoustic spin pumping. Nat Mater 2011; 10:737-741. [PMID: 21857673 DOI: 10.1038/nmat3099] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2011] [Accepted: 07/13/2011] [Indexed: 05/31/2023]
Abstract
Imagine that a metallic wire is attached to a part of a large insulator, which itself exhibits no magnetization. It seems impossible for electrons in the wire to register where the wire is positioned on the insulator. Here we found that, using a Ni₈₁Fe₁₉/Pt bilayer wire on an insulating sapphire plate, electrons in the wire recognize their position on the sapphire. Under a temperature gradient in the sapphire, surprisingly, the voltage generated in the Pt layer is shown to reflect the wire position, although the wire is isolated both electrically and magnetically. This non-local voltage is due to the coupling of spins and phonons: the only possible carrier of information in this system. We demonstrate this coupling by directly injecting sound waves, which realizes the acoustic spin pumping. Our finding provides a persuasive answer to the long-range nature of the spin Seebeck effect, and it opens the door to 'acoustic spintronics' in which sound waves are exploited for constructing spin-based devices.
Collapse
|
18
|
Fohr F, Kaltenborn S, Hamrle J, Schultheiss H, Serga AA, Schneider HC, Hillebrands B, Fukuma Y, Wang L, Otani Y. Optical detection of spin transport in nonmagnetic metals. Phys Rev Lett 2011; 106:226601. [PMID: 21702621 DOI: 10.1103/physrevlett.106.226601] [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: 11/21/2010] [Indexed: 05/31/2023]
Abstract
We determine the dynamic magnetization induced in nonmagnetic metal wedges composed of silver, copper, and platinum by means of Brillouin light scattering microscopy. The magnetization is transferred from a ferromagnetic Ni80Fe20 layer to the metal wedge via the spin pumping effect. The spin pumping efficiency can be controlled by adding an insulating interlayer between the magnetic and nonmagnetic layer. By comparing the experimental results to a dynamical macroscopic spin-transport model we determine the transverse relaxation time of the pumped spin current which is much smaller than the longitudinal relaxation time.
Collapse
Affiliation(s)
- F Fohr
- Fachbereich Physik and Forschungszentrum OPTIMAS, Technische Universität Kaiserslautern, Kaiserslautern, Germany
| | | | | | | | | | | | | | | | | | | |
Collapse
|
19
|
Sandweg CW, Kajiwara Y, Chumak AV, Serga AA, Vasyuchka VI, Jungfleisch MB, Saitoh E, Hillebrands B. Spin pumping by parametrically excited exchange magnons. Phys Rev Lett 2011; 106:216601. [PMID: 21699324 DOI: 10.1103/physrevlett.106.216601] [Citation(s) in RCA: 15] [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: 03/11/2011] [Indexed: 05/31/2023]
Abstract
We experimentally show that exchange magnons can be detected by using a combination of spin pumping and the inverse spin-Hall effect proving its wavelength integrating capability down to the submicrometer scale. The magnons were injected in a ferrite yttrium iron garnet film by parametric pumping and the inverse spin-Hall effect voltage was detected in an attached Pt layer. The role of the density, wavelength, and spatial localization of the magnons for the spin pumping efficiency is revealed.
Collapse
Affiliation(s)
- C W Sandweg
- Fachbereich Physik and Forschungszentrum OPTIMAS, Technische Universität Kaiserslautern, 67663 Kaiserslautern, Germany.
| | | | | | | | | | | | | | | |
Collapse
|
20
|
Abstract
We show both theoretically and experimentally that a collapsing (2+1)-dimensional wave packet in a medium with cubic nonlinearity and a two-dimensional dispersion of an order higher than parabolic irradiates untrapped dispersive waves. The studies are performed for a spin-wave bullet propagating in an in-plane magnetized ferrimagnetic film. An induced uniaxial anisotropy in such a medium leads to the formation of narrow spin-wave caustic beams whose angles to the bullet's propagation direction are modified by the motion of the source.
Collapse
Affiliation(s)
- M P Kostylev
- School of Physics, M013, University of Western Australia, Crawley, WA 6009, Australia
| | | | | |
Collapse
|
21
|
Lee S, Dutcher JR, Hillebrands B, Stegeman GI, Knoll W, Duda G, Wegner G, Nizzoli F. Structural Dependence of the Elastic Constants of Polymeric Langmuir-Blodgett Films Studied Using Brillouin Scattering. ACTA ACUST UNITED AC 2011. [DOI: 10.1557/proc-188-355] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
ABSTRACTWe have used Brillouin scattering to study the dependence of the elastic constants of uniaxial polymeric Langmuir-Blodgett thin films on the thickness of the polymeric molecule monolayers. With increasing monolayer thickness, an overall decrease in the elastic constants and an increase in the refractive index n33 was observed.
Collapse
|
22
|
Sandweg CW, Jungfleisch MB, Vasyuchka VI, Serga AA, Clausen P, Schultheiss H, Hillebrands B, Kreisel A, Kopietz P. Wide-range wavevector selectivity of magnon gases in Brillouin light scattering spectroscopy. Rev Sci Instrum 2010; 81:073902. [PMID: 20687737 DOI: 10.1063/1.3454918] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Brillouin light scattering spectroscopy is a powerful technique for the study of fast magnetization dynamics with both frequency and wavevector resolutions. Here, we report on a distinct improvement of this spectroscopic technique toward two-dimensional wide-range wavevector selectivity in a backward scattering geometry. Spin-wave wavevectors oriented perpendicularly to the bias magnetic field are investigated by tilting the sample within the magnet gap. Wavevectors which are oriented parallel to the applied magnetic field are analyzed by turning the entire setup, including the magnet system. The setup features a wide selectivity of wavevectors up to 2.04x10(5) rad/cm for both orientations, and allows selecting and measuring wavevectors of dipole- and exchange-dominated spin waves of any orientation to the magnetization simultaneously.
Collapse
Affiliation(s)
- C W Sandweg
- Fachbereich Physik and Forschungszentrum OPTIMAS, Technische Universität Kaiserslautern, 67663 Kaiserslautern, Germany.
| | | | | | | | | | | | | | | | | |
Collapse
|
23
|
Schneider T, Serga AA, Chumak AV, Sandweg CW, Trudel S, Wolff S, Kostylev MP, Tiberkevich VS, Slavin AN, Hillebrands B. Nondiffractive subwavelength wave beams in a medium with externally controlled anisotropy. Phys Rev Lett 2010; 104:197203. [PMID: 20866995 DOI: 10.1103/physrevlett.104.197203] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2009] [Indexed: 05/29/2023]
Abstract
We predict and experimentally demonstrate that in a medium with externally induced anisotropy, a wave source of a sufficiently small size can excite practically nondiffractive wave beams with stable subwavelength transverse aperture. The direction of beam propagation is controlled by rotating the induced anisotropy axis. Nondiffractive wave beam propagation, reflection, and scattering, as well as beam steering have been directly observed by optically probing dipolar spin waves in yttrium iron garnet films, where the uniaxial anisotropy was created by an in-plane bias magnetic field.
Collapse
Affiliation(s)
- T Schneider
- Fachbereich Physik and Forschungszentrum OPTIMAS, Technische Universität Kaiserslautern, 67663 Kaiserslautern, Germany
| | | | | | | | | | | | | | | | | | | |
Collapse
|
24
|
Schultheiss H, Janssens X, van Kampen M, Ciubotaru F, Hermsdoerfer SJ, Obry B, Laraoui A, Serga AA, Lagae L, Slavin AN, Leven B, Hillebrands B. Direct current control of three magnon scattering processes in spin-valve nanocontacts. Phys Rev Lett 2009; 103:157202. [PMID: 19905663 DOI: 10.1103/physrevlett.103.157202] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2009] [Revised: 07/28/2009] [Indexed: 05/28/2023]
Abstract
We have investigated the generation of spin waves in the free layer of an extended spin-valve structure with a nanoscaled point contact driven by both microwave and direct electric current using Brillouin light scattering microscopy. Simultaneously with the directly excited spin waves, strong nonlinear effects are observed, namely, the generation of eigenmodes with integer multiple frequencies (2f, 3f, 4f) and modes with noninteger factors (0.5f, 1.5f) with respect to the excitation frequency f. The origin of these nonlinear modes is traced back to three-magnon-scattering processes. The direct current influence on the generation of the fundamental mode at frequency f is related to the spin-transfer torque, while the efficiency of three-magnon-scattering processes is controlled by the Oersted field as an additional effect of the direct current.
Collapse
Affiliation(s)
- H Schultheiss
- Fachbereich Physik and Forschungszentrum OPTIMAS, Technische Universität Kaiserslautern, 67663 Kaiserslautern, Germany
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
25
|
Neumann T, Schneider T, Serga AA, Hillebrands B. An electro-optic modulator-assisted wavevector-resolving Brillouin light scattering setup. Rev Sci Instrum 2009; 80:053905. [PMID: 19485518 DOI: 10.1063/1.3131663] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Brillouin light scattering spectroscopy is a powerful technique which incorporates several extensions such as space-, time-, phase-, and wavevector-resolution. Here, we report on the improvement of the wavevector-resolving setup by including an electro-optic modulator. This provides a reference to calibrate the position of the diaphragm hole which is used for wavevector selection. The accuracy of this calibration is only limited by the accuracy of the wavevector measurement itself. To demonstrate the validity of the approach the wavevectors of dipole-dominated spin waves excited by a microstrip antenna were measured.
Collapse
Affiliation(s)
- T Neumann
- Fachbereich Physik and Forschungszentrum OPTIMAS, Technische Universität Kaiserslautern, 67663 Kaiserslautern, Germany.
| | | | | | | |
Collapse
|
26
|
Fohr F, Serga AA, Schneider T, Hamrle J, Hillebrands B. Phase sensitive Brillouin scattering measurements with a novel magneto-optic modulator. Rev Sci Instrum 2009; 80:043903. [PMID: 19405671 DOI: 10.1063/1.3115210] [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] [Indexed: 05/27/2023]
Abstract
A recently reported phase sensitive Brillouin light scattering technique is improved by use of a magnetic modulator. This modulator is based on Brillouin light scattering in a thin ferrite film. Using this magnetic modulator in time and space Brillouin light scattering measurements, we have increased phase contrast and excluded influence of optical inhomogeneities in the sample. We also demonstrate that the quality of the resulting interference patterns can be improved by data postprocessing using the simultaneously recorded information about the reference light.
Collapse
Affiliation(s)
- F Fohr
- Fachbereich Physik and Forschungszentrum OPTIMAS, Technische Universität Kaiserslautern, Erwin-Schrödinger-Strasse 56, D-67663 Kaiserslautern, Germany
| | | | | | | | | |
Collapse
|
27
|
Serga AA, Kostylev MP, Hillebrands B. Formation of guided spin-wave bullets in ferrimagnetic film stripes. Phys Rev Lett 2008; 101:137204. [PMID: 18851489 DOI: 10.1103/physrevlett.101.137204] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2008] [Indexed: 05/26/2023]
Abstract
The formation of quasi-2D nonlinear spin-wave eigenmodes in longitudinally magnetized stripes of a ferrimagnetic film, the so-called guided spin-wave bullets, was experimentally observed by using time- and space-resolved Brillouin light scattering spectroscopy and confirmed by numerical simulation. They represent stable spin-wave packets propagating along a waveguide structure, for which both transversal instability and interaction with the side edges of the waveguide are important. The experiments and the numerical simulation of the evolution of the spin-wave excitations show that the shape of the formed packets and their behavior are strongly influenced by the confinement conditions. The discovery of these modes demonstrates the existence of quasistable nonlinear solutions in the transition regime between one-dimensional and two-dimensional wave packet propagation.
Collapse
Affiliation(s)
- A A Serga
- Fachbereich Physik, Technische Universität Kaiserslautern, 67663 Kaiserslautern, Germany
| | | | | |
Collapse
|
28
|
Schultheiss H, Schäfer S, Candeloro P, Leven B, Hillebrands B, Slavin AN. Observation of coherence and partial decoherence of quantized spin waves in nanoscaled magnetic ring structures. Phys Rev Lett 2008; 100:047204. [PMID: 18352326 DOI: 10.1103/physrevlett.100.047204] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/10/2007] [Indexed: 05/26/2023]
Abstract
Experiments and simulations are reported, which demonstrate the influence of partial decoherence of spin-wave modes on the dynamics in small magnetic structures. Microfocus Brillouin light scattering spectroscopy was performed on 15 nm thick Ni81Fe19 rings with diameters from 1 to 3 microm. For the so-called "onion" magnetization state several effects were identified. First, in the pole regions of the rings spin-wave wells are created due to the inhomogeneous internal field leading to spin-wave confinement. Second, in the regions in between, modes are observed which show a well pronounced quantization in radial direction but a transition from partial to full coherency in azimuthal direction as a function of decreasing ring size. In particular for larger rings a continuous frequency variation with position is observed which is well reproduced by spin-wave calculations and micromagnetic simulations.
Collapse
Affiliation(s)
- H Schultheiss
- Fachbereich Physik and Forschungsschwerpunkt MINAS, Technische Universität Kaiserslautern, D-67663 Kaiserslautern, Germany
| | | | | | | | | | | |
Collapse
|
29
|
Serga AA, Chumak AV, André A, Melkov GA, Slavin AN, Demokritov SO, Hillebrands B. Parametrically stimulated recovery of a microwave signal stored in standing spin-wave modes of a magnetic film. Phys Rev Lett 2007; 99:227202. [PMID: 18233319 DOI: 10.1103/physrevlett.99.227202] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2007] [Indexed: 05/25/2023]
Abstract
We demonstrate that a microwave signal carried by a packet of dipolar spin waves propagating in a tangentially magnetized magnetic film can be stored in the form of standing dipole-exchange spin-wave modes of the film and can be recovered by means of a double-frequency parametric pumping mechanism. This mechanism is based on the parametric amplification of the standing (thickness) modes of the film by external pumping. The time of recovery, duration, and power of the recovered pulse signal are controlled by the power of the pumping signal.
Collapse
Affiliation(s)
- A A Serga
- Fachbereich Physik and Forschungsschwerpunkt MINAS, Technische Universität Kaiserslautern, 67663 Kaiserslautern, Germany
| | | | | | | | | | | | | |
Collapse
|
30
|
Demokritov SO, Demidov VE, Dzyapko O, Melkov GA, Serga AA, Hillebrands B, Slavin AN. Bose–Einstein condensation of quasi-equilibrium magnons at room temperature under pumping. Nature 2006; 443:430-3. [PMID: 17006509 DOI: 10.1038/nature05117] [Citation(s) in RCA: 173] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2006] [Accepted: 07/21/2006] [Indexed: 11/09/2022]
Abstract
Bose-Einstein condensation is one of the most fascinating phenomena predicted by quantum mechanics. It involves the formation of a collective quantum state composed of identical particles with integer angular momentum (bosons), if the particle density exceeds a critical value. To achieve Bose-Einstein condensation, one can either decrease the temperature or increase the density of bosons. It has been predicted that a quasi-equilibrium system of bosons could undergo Bose-Einstein condensation even at relatively high temperatures, if the flow rate of energy pumped into the system exceeds a critical value. Here we report the observation of Bose-Einstein condensation in a gas of magnons at room temperature. Magnons are the quanta of magnetic excitations in a magnetically ordered ensemble of magnetic moments. In thermal equilibrium, they can be described by Bose-Einstein statistics with zero chemical potential and a temperature-dependent density. In the experiments presented here, we show that by using a technique of microwave pumping it is possible to excite additional magnons and to create a gas of quasi-equilibrium magnons with a non-zero chemical potential. With increasing pumping intensity, the chemical potential reaches the energy of the lowest magnon state, and a Bose condensate of magnons is formed.
Collapse
Affiliation(s)
- S O Demokritov
- Institute for Applied Physics, University of Münster, 48149 Münster, Germany.
| | | | | | | | | | | | | |
Collapse
|
31
|
Serga AA, Hillebrands B, Demokritov SO, Slavin AN, Wierzbicki P, Vasyuchka V, Dzyapko O, Chumak A. Parametric generation of forward and phase-conjugated spin-wave bullets in magnetic films. Phys Rev Lett 2005; 94:167202. [PMID: 15904263 DOI: 10.1103/physrevlett.94.167202] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2004] [Indexed: 05/02/2023]
Abstract
We show experimentally as well as by numerical simulation that interaction of a linear two-dimensional spin-wave packet with quasiuniform pulsed pumping leads to the formation of strongly self-focused nonlinear spin-wave bullets propagating in both forward and reversed directions. The focusing of the reversed, phase-conjugated wave bullet is stronger than that of the forward one, because not only the nonlinear four-wave self-focusing effect but also linear focusing due to two-dimensional phase conjugation contributes to the focusing of the reversed bullet.
Collapse
Affiliation(s)
- A A Serga
- Fachbereich Physik, Technische Universität Kaiserslautern, Kaiserslautern, Germany
| | | | | | | | | | | | | | | |
Collapse
|
32
|
Demokritov SO, Serga AA, André A, Demidov VE, Kostylev MP, Hillebrands B, Slavin AN. Tunneling of dipolar spin waves through a region of inhomogeneous magnetic field. Phys Rev Lett 2004; 93:047201. [PMID: 15323787 DOI: 10.1103/physrevlett.93.047201] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2003] [Indexed: 05/24/2023]
Abstract
We show experimentally and by numerical simulations that spin waves propagating in a magnetic film can pass through a region of a magnetic field inhomogeneity or they can be reflected by the region depending on the sign of the inhomogeneity. If the reflecting region is narrow enough, spin-wave tunneling takes place. We investigate the tunneling mechanism and demonstrate that it has a magnetic dipole origin.
Collapse
Affiliation(s)
- S O Demokritov
- Fachbereich Physik and Focschungsschwerpunkt MINAS, Technische Universität Kaiserslautern, 67663 Kaiserslautern, Germany.
| | | | | | | | | | | | | |
Collapse
|
33
|
Wittkowski T, Jung K, Hillebrands B, Stöckel S, Weise K, Marx G. Surface acoustic waves for the characterization of BN-coated fibres observed by Brillouin light scattering. Anal Bioanal Chem 2004; 379:594-8. [PMID: 14963626 DOI: 10.1007/s00216-004-2513-5] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2003] [Revised: 01/08/2004] [Accepted: 01/14/2004] [Indexed: 11/25/2022]
Abstract
The observation of acoustic phonons located at the surface of uncoated fibres or guided in thin films deposited on fibres by Brillouin light scattering spectroscopy (BLS) is reported. The BLS technique is non-destructive and non-intrusive and is well applicable to non-planar sample geometries. Investigations were carried out on bundles of commercially available carbon fibres, in which a single fibre was 5 microm in diameter. With regard to the detected surface acoustic excitations, each fibre can be considered as an infinite halfspace owing to the large ratio of fibre diameter to wavelength. The shear modulus, which is highly relevant for the intended technical application, was determined by measurement of the Rayleigh mode phase velocity of the uncoated fibres. These fibre bundles were coated with boron nitride (BN) in a continuously driven thermal chemical vapour deposition (CVD) process using trimethyl borate and ammonia as precursors. In comparison to carbon, BN is expected to improve the mechanical properties of fibre-reinforced composites such as fracture toughness at high temperatures. The measured velocity dispersion of the Rayleigh mode of this film-on-substrate system permitted the comparison of the shear stiffness of the carbon fibre and of the BN film material. The results evidence the desired effect of a distinct stiffness reduction of the coated fibre relative to the uncoated fibre in the near-surface region. Additional information can be obtained on the homogeneity of the deposition across the whole fibre bundle.
Collapse
Affiliation(s)
- T Wittkowski
- Fachbereich Physik and Forschungsschwerpunkt MINAS, Technische Universität Kaiserslautern, Erwin-Schrödinger-Str. 56, 67663 Kaiserslautern, Germany.
| | | | | | | | | | | |
Collapse
|
34
|
Serga AA, Demokritov SO, Hillebrands B, Slavin AN. Self-generation of two-dimensional spin-wave bullets. Phys Rev Lett 2004; 92:117203. [PMID: 15089163 DOI: 10.1103/physrevlett.92.117203] [Citation(s) in RCA: 4] [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: 09/21/2003] [Indexed: 05/24/2023]
Abstract
The experimental observation of self-generation of two-dimensional, self-focusing nonlinear spin wave packets-spin wave bullets-in an active ring is reported. The ring is composed of a ferrite film with two antennae for excitation and detection of the wave packets, and a microwave amplifier connecting the antennae and closing the ring. Experimental observation has been made by using the time and space resolved Brillouin light scattering technique. The parameters of spin wave bullets self-generated from noise in an active ring are similar to those of bullets coherently excited by external microwave pulses. The observed self-generation process provides unambiguous evidence that wave bullets are intrinsic excitations of a two-dimensional nonlinear medium with dissipation that is focusing in both directions.
Collapse
Affiliation(s)
- A A Serga
- Fachbereich Physik and Forschungsschwerpunkt MINAS, Technische Universität Kaiserslautern, Erwin-Schrödinger-Strasse 56, 67663 Kaiserslautern, Germany
| | | | | | | |
Collapse
|
35
|
Slavin AN, Büttner O, Bauer M, Demokritov SO, Hillebrands B, Kostylev MP, Kalinikos BA, Grimalsky VV, Rapoport Y. Collision properties of quasi-one-dimensional spin wave solitons and two-dimensional spin wave bullets. Chaos 2003; 13:693-701. [PMID: 12777134 DOI: 10.1063/1.1557961] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Collision properties of quasi-one-dimensional spin wave envelope solitons propagating in narrow ferrite film waveguides and of two-dimensional self-focused spin wave packets (spin wave bullets) propagating in wide ferrite film samples are studied both experimentally and numerically. The experiments, performed by means of a space- and time-resolved Brillouin light scattering technique, have shown that quasi-one-dimensional spin wave envelope solitons retain their shapes after collisions, while two-dimensional spin wave bullets are destroyed in collisions. The experiments have also shown that the introduction of a fixed phase shift between the colliding envelope solitons leads to a qualitative change in their interaction at the collision point. Numerical modeling of head-on collisions of nonlinear spin wave packets based on two different approaches provides a good qualitative description of the observed collision phenomena.
Collapse
Affiliation(s)
- A N Slavin
- Department of Physics, Oakland University, Rochester, Michigan 48309, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
36
|
Demokritov SO, Bayer C, Poppe S, Rickart M, Fassbender J, Hillebrands B, Kholin DI, Kreines NM, Liedke OM. Control of interlayer exchange coupling in Fe/Cr/Fe trilayers by ion beam irradiation. Phys Rev Lett 2003; 90:097201. [PMID: 12689250 DOI: 10.1103/physrevlett.90.097201] [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: 08/05/2002] [Indexed: 05/24/2023]
Abstract
The manipulation of the antiferromagnetic interlayer coupling in epitaxial Fe/Cr/Fe(001) trilayers by 5 keV He ion beam irradiation has been investigated. It is shown that even for irradiation with low fluences a drastic change in strength of the coupling appears. For thin Cr spacers (below 0.6-0.7 nm) it decreases with fluence, becoming ferromagnetic for fluences above 2x10(14) ions/cm(2). The effect is connected with the creation of magnetic bridges in the layered system due to atomic exchange events caused by the bombardment. For thicker Cr spacers an enhancement of the antiferromagnetic coupling strength is found. A possible explanation of the enhancement effect is given.
Collapse
Affiliation(s)
- S O Demokritov
- Fachbereich Physik, Technische Universität Kaiserslautern, D-67663 Kaiserslautern, Germany
| | | | | | | | | | | | | | | | | |
Collapse
|
37
|
Schumacher HW, Chappert C, Crozat P, Sousa RC, Freitas PP, Miltat J, Fassbender J, Hillebrands B. Phase coherent precessional magnetization reversal in microscopic spin valve elements. Phys Rev Lett 2003; 90:017201. [PMID: 12570642 DOI: 10.1103/physrevlett.90.017201] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2002] [Indexed: 05/24/2023]
Abstract
We evidence multiple coherent precessional magnetization reversal in microscopic spin valves. Stable, reversible, and highly efficient magnetization switching is triggered by transverse field pulses as short as 140 ps with energies down to 15 pJ. At high fields a phase coherent reversal is found revealing periodic transitions from switching to nonswitching under variation of pulse parameters. At the low field limit the existence of a relaxation dominated regime is established allowing switching by pulse amplitudes below the quasistatic switching threshold.
Collapse
Affiliation(s)
- H W Schumacher
- Institut d'Electronique Fondamentale, UMR 8622, CNRS, Université Paris Sud, Bâtiment 220, 91405 Orsay, France.
| | | | | | | | | | | | | | | |
Collapse
|
38
|
Fassbender J, Poppe S, Mewes T, Mougin A, Hillebrands B, Engel D, Jung M, Ehresmann A, Schmoranzer H, Faini G, Kirk K, Chapman J. Magnetization Reversal of Exchange Bias Double Layers Magnetically Patterned by Ion Irradiation. ACTA ACUST UNITED AC 2002. [DOI: 10.1002/1521-396x(200202)189:2<439::aid-pssa439>3.0.co;2-4] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
|
39
|
Jorzick J, Demokritov SO, Hillebrands B, Bailleul M, Fermon C, Guslienko KY, Slavin AN, Berkov DV, Gorn NL. Spin wave wells in nonellipsoidal micrometer size magnetic elements. Phys Rev Lett 2002; 88:047204. [PMID: 11801164 DOI: 10.1103/physrevlett.88.047204] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2001] [Indexed: 05/23/2023]
Abstract
We show experimentally and by model calculations that in finite, nonellipsoidal, micrometer size magnetic thin film elements the dynamic magnetic eigenexcitations (spin waves) may exhibit strong spatial localization. This localization is due to the formation of a potential well for spin waves in the highly inhomogeneous internal magnetic field within the element.
Collapse
Affiliation(s)
- J Jorzick
- Fachbereich Physik, Universität Kaiserslautern, 67663 Kaiserslautern, Germany
| | | | | | | | | | | | | | | | | |
Collapse
|
40
|
Visnovsky S, Lopusnik R, Bauer M, Bok J, Fassbender J, Hillebrands B. Magnetooptic ellipsometry in multilayers at arbitrary magnetization. Opt Express 2001; 9:121-135. [PMID: 19421281 DOI: 10.1364/oe.9.000121] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
The Yeh's 4 x 4 matrix formalism is applied to determine the electromagnetic wave response in multilayers with arbitrary magnetization. With restriction to magneto-optic (MO) effects linear in the off-diagonal permittivity tensor elements, a simplified characteristic matrix for a magnetic layer is obtained. For a magnetic film-substrate system analytical representations of the MO response expressed in terms of the Jones reflection matrix are provided. These are numerically evaluated for cases when the magnetization develops in three mutually perpendicular planes.
Collapse
|
41
|
Mock R, Hillebrands B, Sandercock R. Construction and performance of a Brillouin scattering set-up using a triple-pass tandem Fabry-Perot interferometer. ACTA ACUST UNITED AC 2000. [DOI: 10.1088/0022-3735/20/6/017] [Citation(s) in RCA: 142] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
42
|
Buttner O, Bauer M, Rueff A, Demokritov SO, Hillebrands B, Slavin AN, Kostylev MP, Kalinikos BA. Space- and time-resolved Brillouin light scattering from nonlinear spin-wave packets. Ultrasonics 2000; 38:443-449. [PMID: 10829703 DOI: 10.1016/s0041-624x(99)00208-5] [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] [Indexed: 05/23/2023]
Abstract
We have constructed a new Brillouin light scattering apparatus, based on the Sandercock multipass tandem interferometer design, for space- and time-resolved investigations of nonlinear wave packets in thin films. We have applied the method to studies of nonlinear spin-wave pulse propagation in yttrium iron garnet (YIG) films. Spatial resolution is achieved by scanning the laser spot across the YIG film surface, and temporal resolution is obtained by measuring the elapsed time between the launch of spin-wave pulses by an applied microwave pulse and the arrival of the respective inelastically scattered photons at the detector. We report the observation of nonlinear self-focusing of wave beams and pulses in one and two dimensions, the formation of one-dimensional envelope solitons, and of strongly localized, two-dimensional wave packets, 'spin-wave bullets', analogous to 'light bullets' predicted in nonlinear optics. By generating two counter-propagating wave pulses, pulse collision experiments were performed. We show that quasi-one-dimensional envelope solitons formed in narrow film stripes ('waveguides') retain their shapes after collision, while two-dimensional spin-wave packets formed in wide YIG films are destroyed in collision.
Collapse
Affiliation(s)
- O Buttner
- Fachbereich Physik and Zentrum fur Lasermesstechnik und Diagnostik, Universitat Kaiserslautern, Germany
| | | | | | | | | | | | | | | |
Collapse
|
43
|
Hillebrands B, Demokritov SO, Mathieu C, Riedling S, Büttner O, Frank A, Roos B, Jorzick J, Slavin AN, Bartenlian B, Chappert C, Rousseaux F, Decanini D, Cambril E, Müller A, Hartmann U. Arrays of Interacting Magnetic Dots and Wires: Static and Dynamic Properties. ACTA ACUST UNITED AC 1999. [DOI: 10.3379/jmsjmag.23.670] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
|
44
|
Weber W, Bischof A, Allenspach R, Back CH, Fassbender J, May U, Schirmer B, Jungblut RM, Güntherodt G, Hillebrands B. Structural relaxation and magnetic anisotropy in Co/Cu(001) films. Phys Rev B Condens Matter 1996; 54:4075-4079. [PMID: 9986308 DOI: 10.1103/physrevb.54.4075] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
|
45
|
Theis-Bröhl K, Scheidt R, Zeidler T, Schreiber F, Zabel H, Mathieu T, Mathieu C, Hillebrands B. Magnetic exchange-coupling effects in asymmetric trilayer structures of MBE-grown Co/Cr/Fe. Phys Rev B Condens Matter 1996; 53:11613-11620. [PMID: 9982784 DOI: 10.1103/physrevb.53.11613] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
|
46
|
Hillebrands B, Fassbender J, Jungblut R, Güntherodt G, Roberts DJ, Gehring GA. Suppression of the magnetocrystalline bulk anisotropy in thin epitaxial Co(110) films on Cu(110). Phys Rev B Condens Matter 1996; 53:R10548-R10551. [PMID: 9982728 DOI: 10.1103/physrevb.53.r10548] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
|
47
|
Fassbender J, May U, Schirmer B, Jungblut RM, Hillebrands B, Güntherodt G. Oscillatory surface in-plane lattice spacing during growth of Co and of Cu on a Cu(001) single crystal. Phys Rev Lett 1995; 75:4476-4479. [PMID: 10059918 DOI: 10.1103/physrevlett.75.4476] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
|
48
|
Jiang X, Fassbender J, Hillebrands B. Elastic constants of WC-a-C:H composite films studied by Brillouin spectroscopy. Phys Rev B Condens Matter 1994; 49:13815-13819. [PMID: 10010328 DOI: 10.1103/physrevb.49.13815] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
|
49
|
Krams P, Hillebrands B, Güntherodt G, Oepen HP. Magnetic anisotropies of ultrathin Co films on Cu(1 1 13) substrates. Phys Rev B Condens Matter 1994; 49:3633-3636. [PMID: 10011243 DOI: 10.1103/physrevb.49.3633] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
|
50
|
Stamps RL, Camley RE, Hillebrands B, Güntherodt G. Spin-wave propagation on imperfect ultrathin ferromagnetic films. Phys Rev B Condens Matter 1993; 47:5072-5076. [PMID: 10006671 DOI: 10.1103/physrevb.47.5072] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
|