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Volkov OM, Pylypovskyi OV, Porrati F, Kronast F, Fernandez-Roldan JA, Kákay A, Kuprava A, Barth S, Rybakov FN, Eriksson O, Lamb-Camarena S, Makushko P, Mawass MA, Shakeel S, Dobrovolskiy OV, Huth M, Makarov D. Three-dimensional magnetic nanotextures with high-order vorticity in soft magnetic wireframes. Nat Commun 2024; 15:2193. [PMID: 38467623 PMCID: PMC10928081 DOI: 10.1038/s41467-024-46403-8] [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] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2023] [Accepted: 02/22/2024] [Indexed: 03/13/2024] Open
Abstract
Additive nanotechnology enable curvilinear and three-dimensional (3D) magnetic architectures with tunable topology and functionalities surpassing their planar counterparts. Here, we experimentally reveal that 3D soft magnetic wireframe structures resemble compact manifolds and accommodate magnetic textures of high order vorticity determined by the Euler characteristic, χ. We demonstrate that self-standing magnetic tetrapods (homeomorphic to a sphere; χ = + 2) support six surface topological solitons, namely four vortices and two antivortices, with a total vorticity of + 2 equal to its Euler characteristic. Alternatively, wireframe structures with one loop (homeomorphic to a torus; χ = 0) possess equal number of vortices and antivortices, which is relevant for spin-wave splitters and 3D magnonics. Subsequent introduction of n holes into the wireframe geometry (homeomorphic to an n-torus; χ < 0) enables the accommodation of a virtually unlimited number of antivortices, which suggests their usefulness for non-conventional (e.g., reservoir) computation. Furthermore, complex stray-field topologies around these objects are of interest for superconducting electronics, particle trapping and biomedical applications.
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Affiliation(s)
- Oleksii M Volkov
- Helmholtz-Zentrum Dresden-Rossendorf e.V., Institute of Ion Beam Physics and Materials Research, Bautzner Landstr. 400, 01328, Dresden, Germany.
| | - Oleksandr V Pylypovskyi
- Helmholtz-Zentrum Dresden-Rossendorf e.V., Institute of Ion Beam Physics and Materials Research, Bautzner Landstr. 400, 01328, Dresden, Germany.
- Kyiv Academic University, 03142, Kyiv, Ukraine.
| | - Fabrizio Porrati
- Physikalisches Institut, Johann Wolfgang Goethe-Universität Frankfurt am Main, Max-von-Laue-Str. 1, 60438, Frankfurt am Main, Germany.
| | - Florian Kronast
- Helmholtz-Zentrum Berlin für Materialien und Energie, Albert-Einstein-Str. 15, 12489, Berlin, Germany
| | - Jose A Fernandez-Roldan
- Helmholtz-Zentrum Dresden-Rossendorf e.V., Institute of Ion Beam Physics and Materials Research, Bautzner Landstr. 400, 01328, Dresden, Germany
| | - Attila Kákay
- Helmholtz-Zentrum Dresden-Rossendorf e.V., Institute of Ion Beam Physics and Materials Research, Bautzner Landstr. 400, 01328, Dresden, Germany
| | - Alexander Kuprava
- Physikalisches Institut, Johann Wolfgang Goethe-Universität Frankfurt am Main, Max-von-Laue-Str. 1, 60438, Frankfurt am Main, Germany
| | - Sven Barth
- Physikalisches Institut, Johann Wolfgang Goethe-Universität Frankfurt am Main, Max-von-Laue-Str. 1, 60438, Frankfurt am Main, Germany
| | - Filipp N Rybakov
- Department of Physics and Astronomy, Uppsala University, Box-516, Uppsala, SE-751 20, Sweden
| | - Olle Eriksson
- Department of Physics and Astronomy, Uppsala University, Box-516, Uppsala, SE-751 20, Sweden
- Wallenberg Initiative Materials Science for Sustainability, Uppsala University, 75121, Uppsala, Sweden
| | - Sebastian Lamb-Camarena
- University of Vienna, Faculty of Physics, Nanomagnetism and Magnonics, Superconductivity and Spintronics Laboratory, Währinger Str. 17, 1090, Vienna, Austria
- University of Vienna, Vienna Doctoral School in Physics, Boltzmanngasse 5, A-1090, Vienna, Austria
| | - Pavlo Makushko
- Helmholtz-Zentrum Dresden-Rossendorf e.V., Institute of Ion Beam Physics and Materials Research, Bautzner Landstr. 400, 01328, Dresden, Germany
| | - Mohamad-Assaad Mawass
- Helmholtz-Zentrum Berlin für Materialien und Energie, Albert-Einstein-Str. 15, 12489, Berlin, Germany
- Department of Interface Science, Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4 - 6, 14195, Berlin, Germany
| | - Shahrukh Shakeel
- Helmholtz-Zentrum Dresden-Rossendorf e.V., Institute of Ion Beam Physics and Materials Research, Bautzner Landstr. 400, 01328, Dresden, Germany
| | - Oleksandr V Dobrovolskiy
- University of Vienna, Faculty of Physics, Nanomagnetism and Magnonics, Superconductivity and Spintronics Laboratory, Währinger Str. 17, 1090, Vienna, Austria
| | - Michael Huth
- Physikalisches Institut, Johann Wolfgang Goethe-Universität Frankfurt am Main, Max-von-Laue-Str. 1, 60438, Frankfurt am Main, Germany
| | - Denys Makarov
- Helmholtz-Zentrum Dresden-Rossendorf e.V., Institute of Ion Beam Physics and Materials Research, Bautzner Landstr. 400, 01328, Dresden, Germany.
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2
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Volkov OM, Wolf D, Pylypovskyi OV, Kákay A, Sheka DD, Büchner B, Fassbender J, Lubk A, Makarov D. Chirality coupling in topological magnetic textures with multiple magnetochiral parameters. Nat Commun 2023; 14:1491. [PMID: 36932066 PMCID: PMC10023801 DOI: 10.1038/s41467-023-37081-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] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2022] [Accepted: 03/01/2023] [Indexed: 03/19/2023] Open
Abstract
Chiral effects originate from the lack of inversion symmetry within the lattice unit cell or sample's shape. Being mapped onto magnetic ordering, chirality enables topologically non-trivial textures with a given handedness. Here, we demonstrate the existence of a static 3D texture characterized by two magnetochiral parameters being magnetic helicity of the vortex and geometrical chirality of the core string itself in geometrically curved asymmetric permalloy cap with a size of 80 nm and a vortex ground state. We experimentally validate the nonlocal chiral symmetry breaking effect in this object, which leads to the geometric deformation of the vortex string into a helix with curvature 3 μm-1 and torsion 11 μm-1. The geometric chirality of the vortex string is determined by the magnetic helicity of the vortex texture, constituting coupling of two chiral parameters within the same texture. Beyond the vortex state, we anticipate that complex curvilinear objects hosting 3D magnetic textures like curved skyrmion tubes and hopfions can be characterized by multiple coupled magnetochiral parameters, that influence their statics and field- or current-driven dynamics for spin-orbitronics and magnonics.
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Affiliation(s)
- Oleksii M Volkov
- Helmholtz-Zentrum Dresden-Rossendorf e.V., Institute of Ion Beam Physics and Materials Research, Bautzner Landstr. 400, 01328, Dresden, Germany.
| | - Daniel Wolf
- Institute for Solid State Research, IFW Dresden, 01069, Dresden, Germany.
| | - Oleksandr V Pylypovskyi
- Helmholtz-Zentrum Dresden-Rossendorf e.V., Institute of Ion Beam Physics and Materials Research, Bautzner Landstr. 400, 01328, Dresden, Germany.,Kyiv Academic University, 03142, Kyiv, Ukraine
| | - Attila Kákay
- Helmholtz-Zentrum Dresden-Rossendorf e.V., Institute of Ion Beam Physics and Materials Research, Bautzner Landstr. 400, 01328, Dresden, Germany
| | - Denis D Sheka
- Taras Shevchenko National University of Kyiv, 01601, Kyiv, Ukraine
| | - Bernd Büchner
- Institute for Solid State Research, IFW Dresden, 01069, Dresden, Germany.,Institute of Solid State and Materials Physics, TU Dresden, 01069, Dresden, Germany.,Würzburg-Dresden Cluster of Excellence ct.qmat, Dresden, Germany
| | - Jürgen Fassbender
- Helmholtz-Zentrum Dresden-Rossendorf e.V., Institute of Ion Beam Physics and Materials Research, Bautzner Landstr. 400, 01328, Dresden, Germany
| | - Axel Lubk
- Institute for Solid State Research, IFW Dresden, 01069, Dresden, Germany.,Institute of Solid State and Materials Physics, TU Dresden, 01069, Dresden, Germany.,Würzburg-Dresden Cluster of Excellence ct.qmat, Dresden, Germany
| | - Denys Makarov
- Helmholtz-Zentrum Dresden-Rossendorf e.V., Institute of Ion Beam Physics and Materials Research, Bautzner Landstr. 400, 01328, Dresden, Germany.
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Makarov D, Volkov OM, Kákay A, Pylypovskyi OV, Budinská B, Dobrovolskiy OV. New Dimension in Magnetism and Superconductivity: 3D and Curvilinear Nanoarchitectures. Adv Mater 2022; 34:e2101758. [PMID: 34705309 DOI: 10.1002/adma.202101758] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Revised: 05/16/2021] [Indexed: 06/13/2023]
Abstract
Traditionally, the primary field, where curvature has been at the heart of research, is the theory of general relativity. In recent studies, however, the impact of curvilinear geometry enters various disciplines, ranging from solid-state physics over soft-matter physics, chemistry, and biology to mathematics, giving rise to a plethora of emerging domains such as curvilinear nematics, curvilinear studies of cell biology, curvilinear semiconductors, superfluidity, optics, 2D van der Waals materials, plasmonics, magnetism, and superconductivity. Here, the state of the art is summarized and prospects for future research in curvilinear solid-state systems exhibiting such fundamental cooperative phenomena as ferromagnetism, antiferromagnetism, and superconductivity are outlined. Highlighting the recent developments and current challenges in theory, fabrication, and characterization of curvilinear micro- and nanostructures, special attention is paid to perspective research directions entailing new physics and to their strong application potential. Overall, the perspective is aimed at crossing the boundaries between the magnetism and superconductivity communities and drawing attention to the conceptual aspects of how extension of structures into the third dimension and curvilinear geometry can modify existing and aid launching novel functionalities. In addition, the perspective should stimulate the development and dissemination of research and development oriented techniques to facilitate rapid transitions from laboratory demonstrations to industry-ready prototypes and eventual products.
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Affiliation(s)
- Denys Makarov
- Helmholtz-Zentrum Dresden - Rossendorf e.V., Institute of Ion Beam Physics and Materials Research, 01328, Dresden, Germany
| | - Oleksii M Volkov
- Helmholtz-Zentrum Dresden - Rossendorf e.V., Institute of Ion Beam Physics and Materials Research, 01328, Dresden, Germany
| | - Attila Kákay
- Helmholtz-Zentrum Dresden - Rossendorf e.V., Institute of Ion Beam Physics and Materials Research, 01328, Dresden, Germany
| | - Oleksandr V Pylypovskyi
- Helmholtz-Zentrum Dresden - Rossendorf e.V., Institute of Ion Beam Physics and Materials Research, 01328, Dresden, Germany
- Kyiv Academic University, Kyiv, 03142, Ukraine
| | - Barbora Budinská
- Superconductivity and Spintronics Laboratory, Nanomagnetism and Magnonics, Faculty of Physics, University of Vienna, Vienna, 1090, Austria
| | - Oleksandr V Dobrovolskiy
- Superconductivity and Spintronics Laboratory, Nanomagnetism and Magnonics, Faculty of Physics, University of Vienna, Vienna, 1090, Austria
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Saha S, Zhou J, Hofhuis K, Kákay A, Scagnoli V, Heyderman LJ, Gliga S. Spin-Wave Dynamics and Symmetry Breaking in an Artificial Spin Ice. Nano Lett 2021; 21:2382-2389. [PMID: 33689358 DOI: 10.1021/acs.nanolett.0c04294] [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: 06/12/2023]
Abstract
Artificial spin ices are periodic arrangements of interacting nanomagnets which allow investigating emergent phenomena in the presence of geometric frustration. Recently, it has been shown that artificial spin ices can be used as building blocks for creating functional materials, such as magnonic crystals. We investigate the magnetization dynamics in a system exhibiting anisotropic magnetostatic interactions owing to locally broken structural inversion symmetry. We find a rich spin-wave spectrum and investigate its evolution in an external magnetic field. We determine the evolution of individual modes, from building blocks up to larger arrays, highlighting the role of symmetry breaking in defining the mode profiles. Moreover, we demonstrate that the mode spectra exhibit signatures of long-range interactions in the system. These results contribute to the understanding of magnetization dynamics in spin ices beyond the kagome and square ice geometries and are relevant for the realization of reconfigurable magnonic crystals based on spin ices.
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Affiliation(s)
- Susmita Saha
- Laboratory for Mesoscopic Systems, Department of Materials, ETH Zurich, 8093 Zurich, Switzerland
- Paul Scherrer Institute, 5232 Villigen PSI, Switzerland
- Department of Physics and Astronomy, Uppsala University, Box 516, SE-75120 Uppsala, Sweden
| | - Jingyuan Zhou
- Laboratory for Mesoscopic Systems, Department of Materials, ETH Zurich, 8093 Zurich, Switzerland
- Paul Scherrer Institute, 5232 Villigen PSI, Switzerland
| | - Kevin Hofhuis
- Laboratory for Mesoscopic Systems, Department of Materials, ETH Zurich, 8093 Zurich, Switzerland
- Paul Scherrer Institute, 5232 Villigen PSI, Switzerland
| | - Attila Kákay
- Helmholtz-Zentrum Dresden-Rossendorf, Dresden 01328, Germany
| | - Valerio Scagnoli
- Laboratory for Mesoscopic Systems, Department of Materials, ETH Zurich, 8093 Zurich, Switzerland
- Paul Scherrer Institute, 5232 Villigen PSI, Switzerland
| | - Laura J Heyderman
- Laboratory for Mesoscopic Systems, Department of Materials, ETH Zurich, 8093 Zurich, Switzerland
- Paul Scherrer Institute, 5232 Villigen PSI, Switzerland
| | - Sebastian Gliga
- Laboratory for Mesoscopic Systems, Department of Materials, ETH Zurich, 8093 Zurich, Switzerland
- Paul Scherrer Institute, 5232 Villigen PSI, Switzerland
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5
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Körber L, Schultheiss K, Hula T, Verba R, Fassbender J, Kákay A, Schultheiss H. Nonlocal Stimulation of Three-Magnon Splitting in a Magnetic Vortex. Phys Rev Lett 2020; 125:207203. [PMID: 33258661 DOI: 10.1103/physrevlett.125.207203] [Citation(s) in RCA: 1] [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] [Received: 05/27/2020] [Accepted: 10/05/2020] [Indexed: 06/12/2023]
Abstract
We present a combined numerical, theoretical, and experimental study on stimulated three-magnon splitting in a magnetic disk in the vortex state. Our micromagnetic simulations and Brillouin-light-scattering results confirm that three-magnon splitting can be triggered even below threshold by exciting one of the secondary modes by magnons propagating in a waveguide next to the disk. The experiments show that stimulation is possible over an extended range of excitation powers and a wide range of frequencies around the eigenfrequencies of the secondary modes. Rate-equation calculations predict an instantaneous response to stimulation and the possibility to prematurely trigger three-magnon splitting even above threshold in a sustainable manner. These predictions are confirmed experimentally using time-resolved Brillouin-light-scattering measurements and are in a good qualitative agreement with the theoretical results. We believe that the controllable mechanism of stimulated three-magnon splitting could provide a possibility to utilize magnon-based nonlinear networks as hardware for neuromorphic computing.
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Affiliation(s)
- L Körber
- Helmholtz-Zentrum Dresden - Rossendorf, Institut für Ionenstrahlphysik und Materialforschung, D-01328 Dresden, Germany
- Fakultät Physik, Technische Universität Dresden, D-01062 Dresden, Germany
| | - K Schultheiss
- Helmholtz-Zentrum Dresden - Rossendorf, Institut für Ionenstrahlphysik und Materialforschung, D-01328 Dresden, Germany
| | - T Hula
- Helmholtz-Zentrum Dresden - Rossendorf, Institut für Ionenstrahlphysik und Materialforschung, D-01328 Dresden, Germany
- Institut für Physik, Technische Universität Chemnitz, D-09126 Chemnitz, Germany
| | - R Verba
- Institute of Magnetism, Kyiv 03142, Ukraine
| | - J Fassbender
- Helmholtz-Zentrum Dresden - Rossendorf, Institut für Ionenstrahlphysik und Materialforschung, D-01328 Dresden, Germany
- Fakultät Physik, Technische Universität Dresden, D-01062 Dresden, Germany
| | - A Kákay
- Helmholtz-Zentrum Dresden - Rossendorf, Institut für Ionenstrahlphysik und Materialforschung, D-01328 Dresden, Germany
| | - H Schultheiss
- Helmholtz-Zentrum Dresden - Rossendorf, Institut für Ionenstrahlphysik und Materialforschung, D-01328 Dresden, Germany
- Fakultät Physik, Technische Universität Dresden, D-01062 Dresden, Germany
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6
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Ramasubramanian L, Kákay A, Fowley C, Yildirim O, Matthes P, Sorokin S, Titova A, Hilliard D, Böttger R, Hübner R, Gemming S, Schulz SE, Kronast F, Makarov D, Fassbender J, Deac A. Tunable Magnetic Vortex Dynamics in Ion-Implanted Permalloy Disks. ACS Appl Mater Interfaces 2020; 12:27812-27818. [PMID: 32442364 DOI: 10.1021/acsami.0c08024] [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: 06/11/2023]
Abstract
Nanoscale, low-phase-noise, tunable transmitter-receiver links are key for enabling the progress of wireless communication. We demonstrate that vortex-based spin-torque nano-oscillators, which are intrinsically low-noise devices because of their topologically protected magnetic structure, can achieve frequency tunability when submitted to local ion implantation. In the experiments presented here, the gyrotropic mode is excited with spin-polarized alternating currents and anisotropic magnetoresistance measurements yield discrete frequencies from a single device. Indeed, chromium-implanted regions of permalloy disks exhibit different saturation magnetization than neighboring, non-irradiated areas, and thus different resonance frequency, corresponding to the specific area where the core is gyrating. Our study proves that such devices can be fabricated without the need for further lithographical steps, suggesting ion irradiation can be a viable and cost-effective fabrication method for densely packed networks of oscillators.
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Affiliation(s)
- Lakshmi Ramasubramanian
- Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, Dresden 01328, Germany
- Technische Universität Chemnitz, Chemnitz 09126, Germany
| | - Attila Kákay
- Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, Dresden 01328, Germany
| | - Ciarán Fowley
- Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, Dresden 01328, Germany
| | - Oguz Yildirim
- Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, Dresden 01328, Germany
- EMPA-Swiss Federal Laboratories for Materials Science and Technology, Dübendorf 8600, Switzerland
| | - Patrick Matthes
- Fraunhofer Institute for Electronic Nano Systems, Chemnitz 09126, Germany
| | - Serhii Sorokin
- Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, Dresden 01328, Germany
- Institute of Solid State Physics, TU Dresden, Dresden 01069, Germany
| | - Aleksandra Titova
- Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, Dresden 01328, Germany
- Institute of Solid State Physics, TU Dresden, Dresden 01069, Germany
| | - Donovan Hilliard
- Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, Dresden 01328, Germany
- Technische Universität Chemnitz, Chemnitz 09126, Germany
| | - Roman Böttger
- Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, Dresden 01328, Germany
| | - René Hübner
- Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, Dresden 01328, Germany
| | - Sibylle Gemming
- Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, Dresden 01328, Germany
- Technische Universität Chemnitz, Chemnitz 09126, Germany
| | - Stefan E Schulz
- Technische Universität Chemnitz, Chemnitz 09126, Germany
- Fraunhofer Institute for Electronic Nano Systems, Chemnitz 09126, Germany
| | - Florian Kronast
- Helmholtz-Zentrum Berlin für Materialen und Energie, Berlin 12489, Germany
| | - Denys Makarov
- Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, Dresden 01328, Germany
| | - Jürgen Fassbender
- Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, Dresden 01328, Germany
- Institute of Solid State Physics, TU Dresden, Dresden 01069, Germany
| | - Alina Deac
- Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, Dresden 01328, Germany
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Llandro J, Love DM, Kovács A, Caron J, Vyas KN, Kákay A, Salikhov R, Lenz K, Fassbender J, Scherer MRJ, Cimorra C, Steiner U, Barnes CHW, Dunin-Borkowski RE, Fukami S, Ohno H. Visualizing Magnetic Structure in 3D Nanoscale Ni-Fe Gyroid Networks. Nano Lett 2020; 20:3642-3650. [PMID: 32250635 DOI: 10.1021/acs.nanolett.0c00578] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Arrays of interacting 2D nanomagnets display unprecedented electromagnetic properties via collective effects, demonstrated in artificial spin ices and magnonic crystals. Progress toward 3D magnetic metamaterials is hampered by two challenges: fabricating 3D structures near intrinsic magnetic length scales (sub-100 nm) and visualizing their magnetic configurations. Here, we fabricate and measure nanoscale magnetic gyroids, periodic chiral networks comprising nanowire-like struts forming three-connected vertices. Via block copolymer templating, we produce Ni75Fe25 single-gyroid and double-gyroid (an inversion pair of single-gyroids) nanostructures with a 42 nm unit cell and 11 nm diameter struts, comparable to the exchange length in Ni-Fe. We visualize their magnetization distributions via off-axis electron holography with nanometer spatial resolution and interpret the patterns using finite-element micromagnetic simulations. Our results suggest an intricate, frustrated remanent state which is ferromagnetic but without a unique equilibrium configuration, opening new possibilities for collective phenomena in magnetism, including 3D magnonic crystals and unconventional computing.
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Affiliation(s)
- Justin Llandro
- Laboratory for Nanoelectronics and Spintronics, Research Institute of Electrical Communication, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan
- Center for Spintronics Research Network, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan
- Center for Science and Innovation in Spintronics, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan
| | - David M Love
- Cavendish Laboratory, University of Cambridge, J.J. Thomson Avenue, Cambridge CB3 0HE, United Kingdom
| | - András Kovács
- Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons and Peter Grünberg Institute, Forschungszentrum Jülich, 52425 Jülich, Germany
| | - Jan Caron
- Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons and Peter Grünberg Institute, Forschungszentrum Jülich, 52425 Jülich, Germany
| | - Kunal N Vyas
- Cavendish Laboratory, University of Cambridge, J.J. Thomson Avenue, Cambridge CB3 0HE, United Kingdom
| | - Attila Kákay
- Helmholtz-Zentrum Dresden - Rossendorf (HZDR), Bautzner Landstrasse 400, 01328 Dresden, Germany
| | - Ruslan Salikhov
- Helmholtz-Zentrum Dresden - Rossendorf (HZDR), Bautzner Landstrasse 400, 01328 Dresden, Germany
| | - Kilian Lenz
- Helmholtz-Zentrum Dresden - Rossendorf (HZDR), Bautzner Landstrasse 400, 01328 Dresden, Germany
| | - Jürgen Fassbender
- Helmholtz-Zentrum Dresden - Rossendorf (HZDR), Bautzner Landstrasse 400, 01328 Dresden, Germany
- Technische Universität Dresden, Haeckelstrasse 3, 01069 Dresden, Germany
| | - Maik R J Scherer
- Cavendish Laboratory, University of Cambridge, J.J. Thomson Avenue, Cambridge CB3 0HE, United Kingdom
| | - Christian Cimorra
- Cavendish Laboratory, University of Cambridge, J.J. Thomson Avenue, Cambridge CB3 0HE, United Kingdom
| | - Ullrich Steiner
- Adolphe Merkle Institute, Chemin des Verdiers 4, 1700 Fribourg, Switzerland
| | - Crispin H W Barnes
- Cavendish Laboratory, University of Cambridge, J.J. Thomson Avenue, Cambridge CB3 0HE, United Kingdom
| | - Rafal E Dunin-Borkowski
- Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons and Peter Grünberg Institute, Forschungszentrum Jülich, 52425 Jülich, Germany
| | - Shunsuke Fukami
- Laboratory for Nanoelectronics and Spintronics, Research Institute of Electrical Communication, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan
- Center for Spintronics Research Network, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan
- Center for Science and Innovation in Spintronics, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan
- Center for Innovative Integrated Electronic Systems, Tohoku University, 468-1 Aramaki Aza Aoba, Aoba-ku, Sendai 980-0845 Japan
- WPI Advanced Institute for Materials Research, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan
| | - Hideo Ohno
- Laboratory for Nanoelectronics and Spintronics, Research Institute of Electrical Communication, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan
- Center for Spintronics Research Network, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan
- Center for Science and Innovation in Spintronics, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan
- Center for Innovative Integrated Electronic Systems, Tohoku University, 468-1 Aramaki Aza Aoba, Aoba-ku, Sendai 980-0845 Japan
- WPI Advanced Institute for Materials Research, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan
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8
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Lenz K, Narkowicz R, Wagner K, Reiche CF, Körner J, Schneider T, Kákay A, Schultheiss H, Weissker U, Wolf D, Suter D, Büchner B, Fassbender J, Mühl T, Lindner J. Magnetization Dynamics of an Individual Single-Crystalline Fe-Filled Carbon Nanotube. Small 2019; 15:e1904315. [PMID: 31709700 DOI: 10.1002/smll.201904315] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2019] [Revised: 09/20/2019] [Indexed: 06/10/2023]
Abstract
The magnetization dynamics of individual Fe-filled multiwall carbon-nanotubes (FeCNT), grown by chemical vapor deposition, are investigated by microresonator ferromagnetic resonance (FMR) and Brillouin light scattering (BLS) microscopy and corroborated by micromagnetic simulations. Currently, only static magnetometry measurements are available. They suggest that the FeCNTs consist of a single-crystalline Fe nanowire throughout the length. The number and structure of the FMR lines and the abrupt decay of the spin-wave transport seen in BLS indicate, however, that the Fe filling is not a single straight piece along the length. Therefore, a stepwise cutting procedure is applied in order to investigate the evolution of the ferromagnetic resonance lines as a function of the nanowire length. The results show that the FeCNT is indeed not homogeneous along the full length but is built from 300 to 400 nm long single-crystalline segments. These segments consist of magnetically high quality Fe nanowires with almost the bulk values of Fe and with a similar small damping in relation to thin films, promoting FeCNTs as appealing candidates for spin-wave transport in magnonic applications.
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Affiliation(s)
- Kilian Lenz
- Helmholtz-Zentrum Dresden - Rossendorf, Institute of Ion Beam Physics and Materials Research, Bautzner Landstr. 400, 01328, Dresden, Germany
| | - Ryszard Narkowicz
- Helmholtz-Zentrum Dresden - Rossendorf, Institute of Ion Beam Physics and Materials Research, Bautzner Landstr. 400, 01328, Dresden, Germany
| | - Kai Wagner
- Helmholtz-Zentrum Dresden - Rossendorf, Institute of Ion Beam Physics and Materials Research, Bautzner Landstr. 400, 01328, Dresden, Germany
| | - Christopher F Reiche
- Leibniz Institute for Solid State and Materials Research, IFW Dresden, Helmholtzstr. 20, 01069, Dresden, Germany
| | - Julia Körner
- Leibniz Institute for Solid State and Materials Research, IFW Dresden, Helmholtzstr. 20, 01069, Dresden, Germany
| | - Tobias Schneider
- Helmholtz-Zentrum Dresden - Rossendorf, Institute of Ion Beam Physics and Materials Research, Bautzner Landstr. 400, 01328, Dresden, Germany
- Technische Universität Chemnitz, Institute of Physics, Reichenhainer Str. 70, 09107, Chemnitz, Germany
| | - Attila Kákay
- Helmholtz-Zentrum Dresden - Rossendorf, Institute of Ion Beam Physics and Materials Research, Bautzner Landstr. 400, 01328, Dresden, Germany
| | - Helmut Schultheiss
- Helmholtz-Zentrum Dresden - Rossendorf, Institute of Ion Beam Physics and Materials Research, Bautzner Landstr. 400, 01328, Dresden, Germany
- Institute for Physics of Solids, Technische Universität Dresden, Zellescher Weg 16, 01069, Dresden, Germany
| | - Uhland Weissker
- Leibniz Institute for Solid State and Materials Research, IFW Dresden, Helmholtzstr. 20, 01069, Dresden, Germany
- Transfer Office, Technische Universität Dresden, Helmholtzstr. 9, 01069, Dresden, Germany
| | - Daniel Wolf
- Leibniz Institute for Solid State and Materials Research, IFW Dresden, Helmholtzstr. 20, 01069, Dresden, Germany
| | - Dieter Suter
- Department of Physics, Technical University of Dortmund, Otto-Hahn-Straße 4a, 44227, Dortmund, Germany
| | - Bernd Büchner
- Leibniz Institute for Solid State and Materials Research, IFW Dresden, Helmholtzstr. 20, 01069, Dresden, Germany
- Institute for Physics of Solids, Technische Universität Dresden, Zellescher Weg 16, 01069, Dresden, Germany
- Center for Transport and Devices of Emergent Materials, Technische Universität Dresden, 01062, Dresden, Germany
| | - Jürgen Fassbender
- Helmholtz-Zentrum Dresden - Rossendorf, Institute of Ion Beam Physics and Materials Research, Bautzner Landstr. 400, 01328, Dresden, Germany
- Institute for Physics of Solids, Technische Universität Dresden, Zellescher Weg 16, 01069, Dresden, Germany
| | - Thomas Mühl
- Leibniz Institute for Solid State and Materials Research, IFW Dresden, Helmholtzstr. 20, 01069, Dresden, Germany
- Center for Transport and Devices of Emergent Materials, Technische Universität Dresden, 01062, Dresden, Germany
| | - Jürgen Lindner
- Helmholtz-Zentrum Dresden - Rossendorf, Institute of Ion Beam Physics and Materials Research, Bautzner Landstr. 400, 01328, Dresden, Germany
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9
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Nord M, Semisalova A, Kákay A, Hlawacek G, MacLaren I, Liersch V, Volkov OM, Makarov D, Paterson GW, Potzger K, Lindner J, Fassbender J, McGrouther D, Bali R. Strain Anisotropy and Magnetic Domains in Embedded Nanomagnets. Small 2019; 15:e1904738. [PMID: 31709733 DOI: 10.1002/smll.201904738] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2019] [Revised: 09/27/2019] [Indexed: 06/10/2023]
Abstract
Nanoscale modifications of strain and magnetic anisotropy can open pathways to engineering magnetic domains for device applications. A periodic magnetic domain structure can be stabilized in sub-200 nm wide linear as well as curved magnets, embedded within a flat non-ferromagnetic thin film. The nanomagnets are produced within a non-ferromagnetic B2-ordered Fe60 Al40 thin film, where local irradiation by a focused ion beam causes the formation of disordered and strongly ferromagnetic regions of A2 Fe60 Al40 . An anisotropic lattice relaxation is observed, such that the in-plane lattice parameter is larger when measured parallel to the magnet short-axis as compared to its length. This in-plane structural anisotropy manifests a magnetic anisotropy contribution, generating an easy-axis parallel to the short axis. The competing effect of the strain and shape anisotropies stabilizes a periodic domain pattern in linear as well as spiral nanomagnets, providing a versatile and geometrically controllable path to engineering the strain and thereby the magnetic anisotropy at the nanoscale.
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Affiliation(s)
- Magnus Nord
- SUPA, School of Physics and Astronomy, University of Glasgow, Glasgow, G12 8QQ, UK
- Electron Microscopy for Materials Science, University of Antwerp, Antwerp, 2000, Belgium
| | - Anna Semisalova
- Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, 01328, Dresden, Germany
| | - Attila Kákay
- Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, 01328, Dresden, Germany
| | - Gregor Hlawacek
- Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, 01328, Dresden, Germany
| | - Ian MacLaren
- SUPA, School of Physics and Astronomy, University of Glasgow, Glasgow, G12 8QQ, UK
| | - Vico Liersch
- Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, 01328, Dresden, Germany
| | - Oleksii M Volkov
- Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, 01328, Dresden, Germany
| | - Denys Makarov
- Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, 01328, Dresden, Germany
| | - Gary W Paterson
- SUPA, School of Physics and Astronomy, University of Glasgow, Glasgow, G12 8QQ, UK
| | - Kay Potzger
- Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, 01328, Dresden, Germany
| | - Jürgen Lindner
- Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, 01328, Dresden, Germany
| | - Jürgen Fassbender
- Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, 01328, Dresden, Germany
| | - Damien McGrouther
- SUPA, School of Physics and Astronomy, University of Glasgow, Glasgow, G12 8QQ, UK
| | - Rantej Bali
- Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, 01328, Dresden, Germany
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10
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Volkov OM, Kákay A, Kronast F, Mönch I, Mawass MA, Fassbender J, Makarov D. Experimental Observation of Exchange-Driven Chiral Effects in Curvilinear Magnetism. Phys Rev Lett 2019; 123:077201. [PMID: 31491129 DOI: 10.1103/physrevlett.123.077201] [Citation(s) in RCA: 5] [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: 04/30/2019] [Indexed: 05/12/2023]
Abstract
The main origin of the chiral symmetry breaking and, thus, for the magnetochiral effects in magnetic materials is associated with an antisymmetric exchange interaction, the intrinsic Dzyaloshinskii-Moriya interaction (DMI). Recently, numerous inspiring theoretical works predict that the bending of a thin film to a curved surface is often sufficient to induce similar chiral effects. However, these originate from the exchange or magnetostatic interactions and can stabilize noncollinear magnetic structures or influence spin-wave propagation. Here, we demonstrate that curvature-induced chiral effects are experimentally observable rather than theoretical abstraction and are present even in conventional soft ferromagnetic materials. We show that, by measuring the depinning field of domain walls in the simplest possible curve, a flat parabolic stripe, the effective exchange-driven DMI interaction constant can be quantified. Remarkably, its value can be as high as the interfacial DMI constant for thin films and can be tuned by the parabola's curvature.
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Affiliation(s)
- Oleksii M Volkov
- Helmholtz-Zentrum Dresden-Rossendorf e.V., Institute of Ion Beam Physics and Materials Research, 01328 Dresden, Germany
| | - Attila Kákay
- Helmholtz-Zentrum Dresden-Rossendorf e.V., Institute of Ion Beam Physics and Materials Research, 01328 Dresden, Germany
| | - Florian Kronast
- Helmholtz-Zentrum Berlin für Materialen und Energie, 12489 Berlin, Germany
| | - Ingolf Mönch
- Helmholtz-Zentrum Dresden-Rossendorf e.V., Institute of Ion Beam Physics and Materials Research, 01328 Dresden, Germany
| | | | - Jürgen Fassbender
- Helmholtz-Zentrum Dresden-Rossendorf e.V., Institute of Ion Beam Physics and Materials Research, 01328 Dresden, Germany
| | - Denys Makarov
- Helmholtz-Zentrum Dresden-Rossendorf e.V., Institute of Ion Beam Physics and Materials Research, 01328 Dresden, Germany
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11
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Sluka V, Schneider T, Gallardo RA, Kákay A, Weigand M, Warnatz T, Mattheis R, Roldán-Molina A, Landeros P, Tiberkevich V, Slavin A, Schütz G, Erbe A, Deac A, Lindner J, Raabe J, Fassbender J, Wintz S. Emission and propagation of 1D and 2D spin waves with nanoscale wavelengths in anisotropic spin textures. Nat Nanotechnol 2019; 14:328-333. [PMID: 30804478 DOI: 10.1038/s41565-019-0383-4] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2018] [Accepted: 01/21/2019] [Indexed: 05/26/2023]
Abstract
Spin waves offer intriguing perspectives for computing and signal processing, because their damping can be lower than the ohmic losses in conventional complementary metal-oxide-semiconductor (CMOS) circuits. Magnetic domain walls show considerable potential as magnonic waveguides for on-chip control of the spatial extent and propagation of spin waves. However, low-loss guidance of spin waves with nanoscale wavelengths and around angled tracks remains to be shown. Here, we demonstrate spin wave control using natural anisotropic features of magnetic order in an interlayer exchange-coupled ferromagnetic bilayer. We employ scanning transmission X-ray microscopy to image the generation of spin waves and their propagation across distances exceeding multiples of the wavelength. Spin waves propagate in extended planar geometries as well as along straight or curved one-dimensional domain walls. We observe wavelengths between 1 μm and 150 nm, with excitation frequencies ranging from 250 MHz to 3 GHz. Our results show routes towards the practical implementation of magnonic waveguides in the form of domain walls in future spin wave logic and computational circuits.
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Affiliation(s)
- Volker Sluka
- Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany.
| | | | - Rodolfo A Gallardo
- Universidad Técnica Federico Santa María, Valparaíso, Chile
- Center for the Development of Nanoscience and Nanotechnology (CEDENNA), Santiago, Chile
| | - Attila Kákay
- Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany
| | - Markus Weigand
- Max-Planck-Institut für Intelligente Systeme, Stuttgart, Germany
| | - Tobias Warnatz
- Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany
- Uppsala Universitet, Uppsala, Sweden
| | - Roland Mattheis
- Leibniz Institut für Photonische Technologien, Jena, Germany
| | | | - Pedro Landeros
- Universidad Técnica Federico Santa María, Valparaíso, Chile
- Center for the Development of Nanoscience and Nanotechnology (CEDENNA), Santiago, Chile
| | | | | | - Gisela Schütz
- Max-Planck-Institut für Intelligente Systeme, Stuttgart, Germany
| | - Artur Erbe
- Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany
| | - Alina Deac
- Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany
| | | | - Jörg Raabe
- Paul Scherrer Institut, Villigen, PSI, Switzerland
| | - Jürgen Fassbender
- Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany
- Technische Universität Dresden, Dresden, Germany
| | - Sebastian Wintz
- Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany.
- Paul Scherrer Institut, Villigen, PSI, Switzerland.
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12
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Schultheiss K, Verba R, Wehrmann F, Wagner K, Körber L, Hula T, Hache T, Kákay A, Awad AA, Tiberkevich V, Slavin AN, Fassbender J, Schultheiss H. Excitation of Whispering Gallery Magnons in a Magnetic Vortex. Phys Rev Lett 2019; 122:097202. [PMID: 30932517 DOI: 10.1103/physrevlett.122.097202] [Citation(s) in RCA: 1] [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: 09/02/2018] [Indexed: 06/09/2023]
Abstract
We present the generation of whispering gallery magnons with unprecedented high wave vectors via nonlinear 3-magnon scattering in a μm-sized magnetic Ni_{81}Fe_{19} disc which is in the vortex state. These modes exhibit a strong localization at the perimeter of the disc and practically zero amplitude in an extended area around the vortex core. They originate from the splitting of the fundamental radial magnon modes, which can be resonantly excited in a vortex texture by an out-of-plane microwave field. We shed light on the basics of this nonlinear scattering mechanism from an experimental and theoretical point of view. Using Brillouin light scattering microscopy, we investigated the frequency and power dependence of the 3-magnon splitting. The spatially resolved mode profiles give evidence for the localization at the boundaries of the disc and allow for a direct determination of the modes wave number.
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Affiliation(s)
- K Schultheiss
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Ion Beam Physics and Materials Research, Bautzner Landstraße 400, 01328 Dresden, Germany
| | - R Verba
- Institute of Magnetism, National Academy of Sciences of Ukraine, Kyiv 03680, Ukraine
| | - F Wehrmann
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Ion Beam Physics and Materials Research, Bautzner Landstraße 400, 01328 Dresden, Germany
| | - K Wagner
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Ion Beam Physics and Materials Research, Bautzner Landstraße 400, 01328 Dresden, Germany
- Technische Universität Dresden, 01062 Dresden, Germany
| | - L Körber
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Ion Beam Physics and Materials Research, Bautzner Landstraße 400, 01328 Dresden, Germany
- Technische Universität Dresden, 01062 Dresden, Germany
| | - T Hula
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Ion Beam Physics and Materials Research, Bautzner Landstraße 400, 01328 Dresden, Germany
- Westsächsische Hochschule Zwickau, 08056 Zwickau, Germany
| | - T Hache
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Ion Beam Physics and Materials Research, Bautzner Landstraße 400, 01328 Dresden, Germany
- Institut für Physik, Technische Universität Chemnitz, 09107 Chemnitz, Germany
| | - A Kákay
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Ion Beam Physics and Materials Research, Bautzner Landstraße 400, 01328 Dresden, Germany
| | - A A Awad
- Department of Physics, University of Gothenburg, 412 96 Gothenburg, Sweden
| | - V Tiberkevich
- Department of Physics, Oakland University, Rochester, Michigan 48309, USA
| | - A N Slavin
- Department of Physics, Oakland University, Rochester, Michigan 48309, USA
| | - J Fassbender
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Ion Beam Physics and Materials Research, Bautzner Landstraße 400, 01328 Dresden, Germany
- Technische Universität Dresden, 01062 Dresden, Germany
| | - H Schultheiss
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Ion Beam Physics and Materials Research, Bautzner Landstraße 400, 01328 Dresden, Germany
- Technische Universität Dresden, 01062 Dresden, Germany
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13
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Zimmermann M, Meier TNG, Dirnberger F, Kákay A, Decker M, Wintz S, Finizio S, Josten E, Raabe J, Kronseder M, Bougeard D, Lindner J, Back CH. Origin and Manipulation of Stable Vortex Ground States in Permalloy Nanotubes. Nano Lett 2018; 18:2828-2834. [PMID: 29620910 DOI: 10.1021/acs.nanolett.7b05222] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
We present a detailed study on the static magnetic properties of individual permalloy nanotubes (NTs) with hexagonal cross-sections. Anisotropic magnetoresistance (AMR) measurements and scanning transmission X-ray microscopy (STXM) are used to investigate their magnetic ground states and its stability. We find that the magnetization in zero applied magnetic field is in a very stable vortex state. Its origin is attributed to a strong growth-induced anisotropy with easy axis perpendicular to the long axis of the tubes. AMR measurements of individual NTs in combination with micromagnetic simulations allow the determination of the magnitude of the growth-induced anisotropy for different types of NT coatings. We show that the strength of the anisotropy can be controlled by introducing a buffer layer underneath the magnetic layer. The magnetic ground states depend on the external magnetic field history and are directly imaged using STXM. Stable vortex domains can be introduced by external magnetic fields and can be erased by radio-frequency magnetic fields applied at the center of the tubes via a strip line antenna.
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Affiliation(s)
- Michael Zimmermann
- Physics Department , Universität Regensburg , Universitätsstraße 31 , D-93053 Regensburg , Germany
| | | | - Florian Dirnberger
- Physics Department , Universität Regensburg , Universitätsstraße 31 , D-93053 Regensburg , Germany
| | - Attila Kákay
- Helmholtz-Zentrum, Dresden Rossendorf , Institute of Ion Beam Physics and Material Research , Bautzner Landstraße 400 , 01328 Dresden , Germany
| | - Martin Decker
- Physics Department , Universität Regensburg , Universitätsstraße 31 , D-93053 Regensburg , Germany
| | - Sebastian Wintz
- Helmholtz-Zentrum, Dresden Rossendorf , Institute of Ion Beam Physics and Material Research , Bautzner Landstraße 400 , 01328 Dresden , Germany
- Paul Scherrer Institut , 5232 Villigen , Switzerland
| | | | - Elisabeth Josten
- Helmholtz-Zentrum, Dresden Rossendorf , Institute of Ion Beam Physics and Material Research , Bautzner Landstraße 400 , 01328 Dresden , Germany
| | - Jörg Raabe
- Paul Scherrer Institut , 5232 Villigen , Switzerland
| | - Matthias Kronseder
- Physics Department , Universität Regensburg , Universitätsstraße 31 , D-93053 Regensburg , Germany
| | - Dominique Bougeard
- Physics Department , Universität Regensburg , Universitätsstraße 31 , D-93053 Regensburg , Germany
| | - Jürgen Lindner
- Helmholtz-Zentrum, Dresden Rossendorf , Institute of Ion Beam Physics and Material Research , Bautzner Landstraße 400 , 01328 Dresden , Germany
| | - Christian Horst Back
- Physics Department , Universität Regensburg , Universitätsstraße 31 , D-93053 Regensburg , Germany
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14
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Kravchuk VP, Sheka DD, Kákay A, Volkov OM, Rößler UK, van den Brink J, Makarov D, Gaididei Y. Multiplet of Skyrmion States on a Curvilinear Defect: Reconfigurable Skyrmion Lattices. Phys Rev Lett 2018; 120:067201. [PMID: 29481278 DOI: 10.1103/physrevlett.120.067201] [Citation(s) in RCA: 6] [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: 06/19/2017] [Revised: 08/11/2017] [Indexed: 06/08/2023]
Abstract
Typically, the chiral magnetic Skyrmion is a single-state excitation. Here we propose a system, where multiplet of Skyrmion states appears and one of these states can be the ground one. We show that the presence of a localized curvilinear defect drastically changes the magnetic properties of a thin perpendicularly magnetized ferromagnetic film. For a large enough defect amplitude a discrete set of equilibrium magnetization states appears forming a ladder of energy levels. Each equilibrium state has either a zero or a unit topological charge; i.e., topologically trivial and Skyrmion multiplets generally appear. Transitions between the levels with the same topological charge are allowed and can be utilized to encode and switch a bit of information. There is a wide range of geometrical and material parameters, where the Skyrmion level has the lowest energy. Thus, periodically arranged curvilinear defects can result in a Skyrmion lattice as the ground state.
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Affiliation(s)
- Volodymyr P Kravchuk
- Bogolyubov Institute for Theoretical Physics of National Academy of Sciences of Ukraine, 03680 Kyiv, Ukraine
- Leibniz-Institut für Festkörper- und Werkstoffforschung, IFW Dresden, D-01171 Dresden, Germany
| | - Denis D Sheka
- Taras Shevchenko National University of Kyiv, 01601 Kyiv, Ukraine
| | - Attila Kákay
- Helmholtz-Zentrum Dresden-Rossendorf e.V., Institute of Ion Beam Physics and Materials Research, 01328 Dresden, Germany
| | - Oleksii M Volkov
- Helmholtz-Zentrum Dresden-Rossendorf e.V., Institute of Ion Beam Physics and Materials Research, 01328 Dresden, Germany
| | - Ulrich K Rößler
- Leibniz-Institut für Festkörper- und Werkstoffforschung, IFW Dresden, D-01171 Dresden, Germany
| | - Jeroen van den Brink
- Leibniz-Institut für Festkörper- und Werkstoffforschung, IFW Dresden, D-01171 Dresden, Germany
- Institute for Theoretical Physics, TU Dresden, 01069 Dresden, Germany
| | - Denys Makarov
- Helmholtz-Zentrum Dresden-Rossendorf e.V., Institute of Ion Beam Physics and Materials Research, 01328 Dresden, Germany
| | - Yuri Gaididei
- Bogolyubov Institute for Theoretical Physics of National Academy of Sciences of Ukraine, 03680 Kyiv, Ukraine
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15
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Otálora JA, Yan M, Schultheiss H, Hertel R, Kákay A. Curvature-Induced Asymmetric Spin-Wave Dispersion. Phys Rev Lett 2016; 117:227203. [PMID: 27925729 DOI: 10.1103/physrevlett.117.227203] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2016] [Indexed: 06/06/2023]
Abstract
In magnonics, spin waves are conceived of as electron-charge-free information carriers. Their wave behavior has established them as the key elements to achieve low power consumption, fast operative rates, and good packaging in magnon-based computational technologies. Hence, knowing alternative ways that reveal certain properties of their undulatory motion is an important task. Here, we show using micromagnetic simulations and analytical calculations that spin-wave propagation in ferromagnetic nanotubes is fundamentally different than in thin films. The dispersion relation is asymmetric regarding the sign of the wave vector. It is a purely curvature-induced effect and its fundamental origin is identified to be the classical dipole-dipole interaction. The analytical expression of the dispersion relation has the same mathematical form as in thin films with the Dzyalonshiinsky-Moriya interaction. Therefore, this curvature-induced effect can be seen as a "dipole-induced Dzyalonshiinsky-Moriya-like" effect.
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Affiliation(s)
- Jorge A Otálora
- Departamento de Física, Universidad Técnica Federico Santa María, Avenida España 1680, Casilla 110-V, Valparaíso, Chile and Departamento de Física, CEDENNA, Universidad Santiago de Chile, USACH, 9170124 Santiago, Chile
| | - Ming Yan
- Department of Physics, Shanghai University, 99 Shangda Road, BaoShan District, Shanghai 200444, China
| | - Helmut Schultheiss
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Ion Beam Physics and Materials Research, Bautzner Landstraße 400, 01328 Dresden, Germany and Technische Universität Dresden, D-01062 Dresden, Germany
| | - Riccardo Hertel
- Karlsuhe Institute of Technology, Physikalisches Institut, Wolfgang-Gaede-Str. 1, D-76131 Karlsruhe, Germany and Institut de Physique et Chimie des Matériaux de Strasbourg, UMR 7504, CNRS, and Université de Strasbourg, 23 rue du Loess, F-67300 Strasbourg, France
| | - Attila Kákay
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Ion Beam Physics and Materials Research, Bautzner Landstraße 400, 01328 Dresden, Germany
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16
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Wagner K, Kákay A, Schultheiss K, Henschke A, Sebastian T, Schultheiss H. Magnetic domain walls as reconfigurable spin-wave nanochannels. Nat Nanotechnol 2016; 11:432-6. [PMID: 26828849 DOI: 10.1038/nnano.2015.339] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2015] [Accepted: 12/16/2015] [Indexed: 05/26/2023]
Abstract
In the research field of magnonics, it is envisaged that spin waves will be used as information carriers, promoting operation based on their wave properties. However, the field still faces major challenges. To become fully competitive, novel schemes for energy-efficient control of spin-wave propagation in two dimensions have to be realized on much smaller length scales than used before. In this Letter, we address these challenges with the experimental realization of a novel approach to guide spin waves in reconfigurable, nano-sized magnonic waveguides. For this purpose, we make use of two inherent characteristics of magnetism: the non-volatility of magnetic remanence states and the nanometre dimensions of domain walls formed within these magnetic configurations. We present the experimental observation and micromagnetic simulations of spin-wave propagation inside nano-sized domain walls and realize a first step towards a reconfigurable domain-wall-based magnonic nanocircuitry.
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Affiliation(s)
- K Wagner
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Ion Beam Physics and Materials Research, Bautzner Landstraße 400, 01328 Dresden, Germany
- Technische Universität Dresden, D-01062 Dresden, Germany
| | - A Kákay
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Ion Beam Physics and Materials Research, Bautzner Landstraße 400, 01328 Dresden, Germany
| | - K Schultheiss
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Ion Beam Physics and Materials Research, Bautzner Landstraße 400, 01328 Dresden, Germany
| | - A Henschke
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Ion Beam Physics and Materials Research, Bautzner Landstraße 400, 01328 Dresden, Germany
| | - T Sebastian
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Ion Beam Physics and Materials Research, Bautzner Landstraße 400, 01328 Dresden, Germany
| | - H Schultheiss
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Ion Beam Physics and Materials Research, Bautzner Landstraße 400, 01328 Dresden, Germany
- Technische Universität Dresden, D-01062 Dresden, Germany
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Sluka V, Kákay A, Deac AM, Bürgler DE, Schneider CM, Hertel R. Spin-torque-induced dynamics at fine-split frequencies in nano-oscillators with two stacked vortices. Nat Commun 2015; 6:6409. [DOI: 10.1038/ncomms7409] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2014] [Accepted: 01/27/2015] [Indexed: 11/09/2022] Open
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Gliga S, Kákay A, Hertel R, Heinonen OG. Spectral analysis of topological defects in an artificial spin-ice lattice. Phys Rev Lett 2013; 110:117205. [PMID: 25166572 DOI: 10.1103/physrevlett.110.117205] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2012] [Indexed: 06/03/2023]
Abstract
Arrays of suitably patterned and arranged magnetic elements may display artificial spin-ice structures with topological defects in the magnetization, such as Dirac monopoles and Dirac strings. It is known that these defects strongly influence the quasistatic and equilibrium behavior of the spin-ice lattice. Here, we study the eigenmode dynamics of such defects in a square lattice consisting of stadiumlike thin film elements using micromagnetic simulations. We find that the topological defects display distinct signatures in the mode spectrum, providing a means to qualitatively and quantitatively analyze monopoles and strings that can be measured experimentally.
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Affiliation(s)
- Sebastian Gliga
- Center for Nanoscale Materials, Argonne National Laboratory, Lemont, Illinois 60439, USA and Max-Planck-Institut für Mikrostrukturphysik, Weinberg 2, D-06120 Halle, Germany
| | - Attila Kákay
- Peter Grünberg Institut (PGI-6), Forschungszentrum Jülich GmbH, D-52428 Jülich, Germany
| | - Riccardo Hertel
- Institut de Physique et Chimie des Matériaux de Strasbourg, Université de Strasbourg, CNRS UMR 7504, 67034 Strasbourg, France
| | - Olle G Heinonen
- Materials Science Division, Argonne National Laboratory, Lemont, Illinois 60439, USA and Department of Physics and Astronomy, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, USA
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Seemann KM, Garcia-Sanchez F, Kronast F, Miguel J, Kákay A, Schneider CM, Hertel R, Freimuth F, Mokrousov Y, Blügel S. Disentangling the physical contributions to the electrical resistance in magnetic domain walls: a multiscale study. Phys Rev Lett 2012; 108:077201. [PMID: 22401245 DOI: 10.1103/physrevlett.108.077201] [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: 06/30/2011] [Indexed: 05/31/2023]
Abstract
We analyze the origin of the electrical resistance arising in domain walls of perpendicularly magnetized materials by considering a superposition of anisotropic magnetoresistance and the resistance implied by the magnetization chirality. The domain wall profiles of L1(0)-FePd and L1(0)-FePt are determined by micromagnetic simulations based on which we perform first-principles calculations to quantify electron transport through the core and closure region of the walls. The wall resistance, being twice as high in L1(0)-FePd than in L1(0)-FePt, is found to be clearly dominated in both cases by a high gradient of magnetization rotation, which agrees well with experimental observations.
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Affiliation(s)
- K M Seemann
- Peter Grünberg Institute, Forschungszentrum Jülich and Jülich-Aachen Research Alliance, Jülich, Germany.
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Yan M, Kákay A, Gliga S, Hertel R. Beating the walker limit with massless domain walls in cylindrical nanowires. Phys Rev Lett 2010; 104:057201. [PMID: 20366793 DOI: 10.1103/physrevlett.104.057201] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2009] [Indexed: 05/29/2023]
Abstract
We present a micromagnetic study on the current-induced domain-wall motion in cylindrical Permalloy nanowires with diameters below 50 nm. The transverse domain walls forming in such thin, round wires are found to differ significantly from those known from flat nanostrips. In particular, we show that these domain walls are zero-mass micromagnetic objects. As a consequence, they display outstanding dynamic properties, most importantly the absence of a breakdown velocity generally known as the Walker limit. Our simulation data are confirmed by an analytic model which provides a detailed physical understanding. We further predict that a particular effect of the current-induced dynamics of these domain walls could be exploited to measure the nonadiabatic spin-transfer torque coefficient.
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Affiliation(s)
- Ming Yan
- Institut für Festkörperforschung (IFF-9), Forschungszentrum Jülich GmbH, D-52428 Jülich, Germany
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