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Moalic M, Zelent M, Szulc K, Krawczyk M. The role of non-uniform magnetization texture for magnon-magnon coupling in an antidot lattice. Sci Rep 2024; 14:11501. [PMID: 38769393 PMCID: PMC11106278 DOI: 10.1038/s41598-024-61246-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2024] [Accepted: 05/03/2024] [Indexed: 05/22/2024] Open
Abstract
We numerically study the spin-wave dynamics in an antidot lattice based on a Co/Pd multilayer structure with reduced perpendicular magnetic anisotropy at the edges of the antidots. This structure forms a magnonic crystal with a periodic antidot pattern and a periodic magnetization configuration consisting of out-of-plane magnetized bulk and in-plane magnetized rims. Our results show a different behavior of spin waves in the bulk and in the rims under varying out-of-plane external magnetic field strength, revealing complex spin-wave spectra and hybridizations between the modes of these two subsystems. A particularly strong magnon-magnon coupling, due to exchange interactions, is found between the fundamental bulk spin-wave mode and the second-order radial rim modes. However, the dynamical coupling between the spin-wave modes at low frequencies, involving the first-order radial rim modes, is masked by the changes in the static magnetization at the bulk-rim interface with magnetic field changes. The study expands the horizons of magnonic-crystal research by combining periodic structural patterning and non-collinear magnetization texture to achieve strong magnon-magnon coupling, highlighting the significant role of exchange interactions in the hybridization.
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Affiliation(s)
- Mathieu Moalic
- Institute of Spintronics and Quantum Information, Faculty of Physics, Adam Mickiewicz University, Poznan, Poland.
| | - Mateusz Zelent
- Institute of Spintronics and Quantum Information, Faculty of Physics, Adam Mickiewicz University, Poznan, Poland
| | - Krzysztof Szulc
- Institute of Spintronics and Quantum Information, Faculty of Physics, Adam Mickiewicz University, Poznan, Poland
| | - Maciej Krawczyk
- Institute of Spintronics and Quantum Information, Faculty of Physics, Adam Mickiewicz University, Poznan, Poland
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2
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Tian C, Adeyeye AO. Tunable 2-D magnonic crystals: effect of packing density. NANOSCALE 2024; 16:4858-4865. [PMID: 38314839 DOI: 10.1039/d3nr05582e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2024]
Abstract
Magnonic crystals, periodic arrays of magnetic structures, have emerged as a promising platform for manipulating and controlling spin waves in magnetic materials. Magnetic antidot nanostructures, representing 2-D magnonic crystals, are versatile platforms for controlling and manipulating magnons. In this work, we systematically investigate the effects of inter-hole spacing and lattice (rhombic and honeycomb) arrangements on the dynamic properties of Ni80Fe20 antidot structures. The dynamic responses of antidot lattices of fixed hole diameter (d = 280 nm) and inter-hole spacing (s) between 90 and 345 nm are investigated using broadband ferromagnetic spectroscopy. Multiple resonance modes sensitive to s are observed due to the inhomogeneous internal field distribution induced by the presence of holes. There is a marked variation in mode frequency, mode intensity and the number of modes for rhombic antidot lattice as the inter-hole spacing and applied field direction are varied. Our experimental results are in good agreement with micromagnetic simulations. Our findings may find application in the design of magnonic-based devices.
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Affiliation(s)
- C Tian
- Department of Electrical and Computer Engineering, National University of Singapore, 117576, Singapore.
| | - A O Adeyeye
- Department of Electrical and Computer Engineering, National University of Singapore, 117576, Singapore.
- Department of Physics, Durham University, South Rd, Durham, DH1 3LE, UK
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3
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Stenning KD, Gartside JC, Dion T, Vanstone A, Arroo DM, Branford WR. Magnonic Bending, Phase Shifting and Interferometry in a 2D Reconfigurable Nanodisk Crystal. ACS NANO 2021; 15:674-685. [PMID: 33320533 DOI: 10.1021/acsnano.0c06894] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Strongly interacting nanomagnetic systems are pivotal across next-generation technologies including reconfigurable magnonics and neuromorphic computation. Controlling magnetization states and local coupling between neighboring nanoelements allows vast reconfigurability and a host of associated functionalities. However, existing designs typically suffer from an inability to tailor interelement coupling post-fabrication and nanoelements restricted to a pair of Ising-like magnetization states. Here, we propose a class of reconfigurable magnonic crystals incorporating nanodisks as the functional element. Ferromagnetic nanodisks are crucially bistable in macrospin and vortex states, allowing interelement coupling to be selectively activated (macrospin) or deactivated (vortex). Through microstate engineering, we leverage the distinct coupling behaviors and magnonic band structures of bistable nanodisks to achieve reprogrammable magnonic waveguiding, bending, gating, and phase-shifting across a 2D network. The potential of nanodisk-based magnonics for wave-based computation is demonstrated via an all-magnon interferometer exhibiting XNOR logic functionality. Local microstate control is achieved here via topological magnetic writing using a magnetic force microscope tip.
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Affiliation(s)
- Kilian D Stenning
- Blackett Laboratory, Imperial College London, London SW7 2AZ, United Kingdom
| | - Jack C Gartside
- Blackett Laboratory, Imperial College London, London SW7 2AZ, United Kingdom
| | - Troy Dion
- Blackett Laboratory, Imperial College London, London SW7 2AZ, United Kingdom
- London Centre for Nanotechnology, University College London, London WC1H 0AH, United Kingdom
| | - Alexander Vanstone
- Blackett Laboratory, Imperial College London, London SW7 2AZ, United Kingdom
| | - Daan M Arroo
- London Centre for Nanotechnology, University College London, London WC1H 0AH, United Kingdom
| | - Will R Branford
- Blackett Laboratory, Imperial College London, London SW7 2AZ, United Kingdom
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Zakeri K. Magnonic crystals: towards terahertz frequencies. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2020; 32:363001. [PMID: 32289765 DOI: 10.1088/1361-648x/ab88f2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2019] [Accepted: 04/14/2020] [Indexed: 06/11/2023]
Abstract
This topical review presents an overview of the recent experimental and theoretical attempts on designing magnonic crystals for operation at different frequencies. The focus is put on the microscopic physical mechanisms involved in the formation of the magnonic band structure, allowed as well as forbidden magnon states in various systems, including ultrathin films, multilayers and artificial magnetic structures. The essential criteria for the formation of magnonic bandgaps in different frequency regimes are explained in connection with the magnon dynamics in such structures. The possibility of designing small-size magnonic crystals for operation at ultrahigh frequencies (terahertz and sub-terahertz regime) is discussed. Recently discovered magnonic crystals based on topological defects and using periodic Dzyaloshinskii-Moriya interaction, are outlined. Different types of magnonic crystals, capable of operation at different frequency regimes, are put within a rather unified picture.
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Affiliation(s)
- Khalil Zakeri
- Heisenberg Spin-dynamics Group, Physikalisches Institut, Karlsruhe Institute of Technology, Wolfgang-Gaede-Str. 1, D-76131 Karlsruhe, Germany
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Qin HJ, Tsurkan S, Ernst A, Zakeri K. Experimental Realization of Atomic-Scale Magnonic Crystals. PHYSICAL REVIEW LETTERS 2019; 123:257202. [PMID: 31922781 DOI: 10.1103/physrevlett.123.257202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2019] [Indexed: 06/10/2023]
Abstract
We introduce a new approach of materials design for terahertz magnonics making use of quantum confinement of terahertz magnons in layered ferromagnets. We show that in atomically designed multilayers composed of alternating atomic layers of ferromagnetic metals one can efficiently excite different magnon modes associated with the quantum confinement in the third dimension, i.e., the direction perpendicular to the layers. We demonstrate experimentally that the magnonic band structure of these systems can be tuned by changing the material combination and the number of atomic layers. We realize the idea of opening band gaps, with a size of up to several tens of millielectronvolts, between different terahertz magnon bands and thereby report on the first step toward the realization of atomic-scale magnonic crystals.
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Affiliation(s)
- H J Qin
- Heisenberg Spin-dynamics Group, Physikalisches Institut, Karlsruhe Institute of Technology, Wolfgang-Gaede-Straße 1, D-76131 Karlsruhe, Germany
- NanoSpin, Department of Applied Physics, Aalto University School of Science, FI-00076 Aalto, Finland
| | - S Tsurkan
- Heisenberg Spin-dynamics Group, Physikalisches Institut, Karlsruhe Institute of Technology, Wolfgang-Gaede-Straße 1, D-76131 Karlsruhe, Germany
| | - A Ernst
- Institute for Theoretical Physics, Johannes Kepler University, Altenberger Straße 69, 4040 Linz, Austria
- Max-Planck-Institut für Mikrostrukturphysik, Weinberg 2, D-06120 Halle, Germany
| | - Kh Zakeri
- Heisenberg Spin-dynamics Group, Physikalisches Institut, Karlsruhe Institute of Technology, Wolfgang-Gaede-Straße 1, D-76131 Karlsruhe, Germany
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Richardson D, Kalinikos BA, Carr LD, Wu M. Spontaneous Exact Spin-Wave Fractals in Magnonic Crystals. PHYSICAL REVIEW LETTERS 2018; 121:107204. [PMID: 30240252 DOI: 10.1103/physrevlett.121.107204] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Indexed: 06/08/2023]
Abstract
Exact fractals of nonlinear waves that rely on strong dispersion and nonlinearity and arise spontaneously out of magnetic media were observed for the first time. The experiments make use of a microwave to excite a spin wave in a quasi-one-dimensional magnonic crystal. When the power of the input microwave (P_{in}) is low, the output signal has a power-frequency spectrum that consists of a single peak. When P_{in} is increased to a certain level, new side modes are generated through modulational instability, resulting in a comblike frequency spectrum. With a further increase in P_{in}, each peak in the frequency comb can evolve into its own finer comb through the modulational instability. As P_{in} is increased further, one can observe yet another set of finer frequency combs. Such a frequency-domain fractal manifests itself as multiple layers of amplitude modulation in the time-domain signal.
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Affiliation(s)
- Daniel Richardson
- Department of Physics, Colorado State University, Fort Collins, Colorado 80523, USA
| | - Boris A Kalinikos
- Department of Physics, Colorado State University, Fort Collins, Colorado 80523, USA
- St. Petersburg Electrotechnical University, 197376 St. Petersburg, Russia
| | - Lincoln D Carr
- Department of Physics, Colorado School of Mines, Golden, Colorado 80401, USA
| | - Mingzhong Wu
- Department of Physics, Colorado State University, Fort Collins, Colorado 80523, USA
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Tacchi S, Gubbiotti G, Madami M, Carlotti G. Brillouin light scattering studies of 2D magnonic crystals. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2017; 29:073001. [PMID: 28008880 DOI: 10.1088/1361-648x/29/7/073001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Magnonic crystals, materials with periodic modulation of their magnetic properties, represent the magnetic counterpart of photonic, phononic and plasmonic crystals, and have been largely investigated in recent years because of the possibility of using spin waves as a new means for carrying and processing information over a very large frequency bandwidth. Here, we review recent Brillouin light scattering studies of 2D magnonic crystals consisting of single- and bi-component arrays of interacting magnetic dots or antidot lattices. In particular, we discuss the principal properties of the magnonic band diagram of such systems, with emphasis given to its dependence on both magnetic and the geometrical parameters. Thanks to the possibility of tailoring their band structure by means of several degrees of freedom, planar magnonic crystals offer a good opportunity to design an innovative class of nanoscale microwave devices.
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Affiliation(s)
- S Tacchi
- Istituto Officina dei Materiali del CNR (CNR-IOM), Sede Secondaria di Perugia, c/o Dipartimento di Fisica e Geologia, Università di Perugia, I-06123 Perugia, Italy
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Tacchi S, Gruszecki P, Madami M, Carlotti G, Kłos JW, Krawczyk M, Adeyeye A, Gubbiotti G. Universal dependence of the spin wave band structure on the geometrical characteristics of two-dimensional magnonic crystals. Sci Rep 2015; 5:10367. [PMID: 26012863 PMCID: PMC4445068 DOI: 10.1038/srep10367] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2015] [Accepted: 04/08/2015] [Indexed: 11/09/2022] Open
Abstract
In the emerging field of magnon-spintronics, spin waves are exploited to encode, carry and process information in materials with periodic modulation of their magnetic properties, named magnonic crystals. These enable the redesign of the spin wave dispersion, thanks to its dependence on the geometric and magnetic parameters, resulting in the appearance of allowed and forbidden band gaps for specific propagation directions. In this work, we analyze the spin waves band structure of two-dimensional magnonic crystals consisting of permalloy square antidot lattices with different geometrical parameters. We show that the frequency of the most intense spin-wave modes, measured by Brillouin light scattering, exhibits a universal dependence on the aspect ratio (thickness over width) of the effective nanowire enclosed between adjacent rows of holes. A similar dependence also applies to both the frequency position and the width of the main band gap of the fundamental (dispersive) mode at the edge of the first Brillouin zone. These experimental findings are successfully explained by calculations based on the plane-wave method. Therefore, a unified vision of the spin-waves characteristics in two-dimensional antidot lattices is provided, paving the way to the design of tailored nanoscale devices, such as tunable magnonic filters and phase-shifters, with predicted functionalities.
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Affiliation(s)
- S. Tacchi
- Istituto Officina dei Materiali del CNR (CNR-IOM), Unità di Perugia, c/o Dipartimento di Fisica e Geologia, Perugia, Italy
| | - P. Gruszecki
- Faculty of Physics, Adam Mickiewicz University in Poznan, Umultowska 85, Poznan 61-614, Poland
| | - M. Madami
- Dipartimento di Fisica e Geologia, Università di Perugia, Italy
| | - G. Carlotti
- Dipartimento di Fisica e Geologia, Università di Perugia, Italy
| | - J. W. Kłos
- Faculty of Physics, Adam Mickiewicz University in Poznan, Umultowska 85, Poznan 61-614, Poland
| | - M. Krawczyk
- Faculty of Physics, Adam Mickiewicz University in Poznan, Umultowska 85, Poznan 61-614, Poland
| | - A. Adeyeye
- Information Storage Materials Laboratory, Department of Electrical and Computer Engineering, National University of Singapore, 117576 Singapore
| | - G. Gubbiotti
- Istituto Officina dei Materiali del CNR (CNR-IOM), Unità di Perugia, c/o Dipartimento di Fisica e Geologia, Perugia, Italy
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Krawczyk M, Grundler D. Review and prospects of magnonic crystals and devices with reprogrammable band structure. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2014; 26:123202. [PMID: 24599025 DOI: 10.1088/0953-8984/26/12/123202] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Research efforts addressing spin waves (magnons) in microand nanostructured ferromagnetic materials have increased tremendously in recent years. Corresponding experimental and theoretical work in magnonics faces significant challenges in that spinwave dispersion relations are highly anisotropic and different magnetic states might be realized via, for example, the magnetic field history. At the same time, these features offer novel opportunities for wave control in solids going beyond photonics and plasmonics. In this topical review we address materials with a periodic modulation of magnetic parameters that give rise to artificially tailored band structures and allow unprecedented control of spin waves. In particular, we discuss recent achievements and perspectives of reconfigurable magnonic devices for which band structures can be reprogrammed during operation. Such characteristics might be useful for multifunctional microwave and logic devices operating over a broad frequency regime on either the macroor nanoscale.
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Wave modes of collective vortex gyration in dipolar-coupled-dot-array magnonic crystals. Sci Rep 2013; 3:2262. [PMID: 23877284 PMCID: PMC3719073 DOI: 10.1038/srep02262] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2013] [Accepted: 07/05/2013] [Indexed: 11/15/2022] Open
Abstract
Lattice vibration modes are collective excitations in periodic arrays of atoms or molecules. These modes determine novel transport properties in solid crystals. Analogously, in periodical arrangements of magnetic vortex-state disks, collective vortex motions have been predicted. Here, we experimentally observe wave modes of collective vortex gyration in one-dimensional (1D) periodic arrays of magnetic disks using time-resolved scanning transmission x-ray microscopy. The observed modes are interpreted based on micromagnetic simulation and numerical calculation of coupled Thiele equations. Dispersion of the modes is found to be strongly affected by both vortex polarization and chirality ordering, as revealed by the explicit analytical form of 1D infinite arrays. A thorough understanding thereof is fundamental both for lattice vibrations and vortex dynamics, which we demonstrate for 1D magnonic crystals. Such magnetic disk arrays with vortex-state ordering, referred to as magnetic metastructure, offer potential implementation into information processing devices.
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Sanina VA, Golovenchits EI, Zalesskii VG. Spin-wave excitations in superlattices self-assembled in multiferroic single crystals. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2012; 24:346002. [PMID: 22872124 DOI: 10.1088/0953-8984/24/34/346002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Spin-wave excitations revealed in the dynamically equilibrated one-dimensional superlattices formed due to phase separation and charge carrier self-organization in doped single crystals of Eu(0.8)Ce(0.2)Mn(2)O(5) and Tb(0.95)Bi(0.05)MnO(3) multiferroics are discussed. Similar excitations, but having lower intensities, were also observed in undoped RMn(2)O(5) (R=Eu, Er, Tb, Bi). This suggests that a charge transfer between manganese ions with different valences, which give rise to the superlattice formation, occurs in undoped multiferroics as well. The spin excitations observed in the native superlattices represent a set of homogeneous spin-wave resonances excited in individual superlattice layers. The positions of these resonances depend on the relation between the numbers of Mn(3+) and Mn(4+) ions, charge carrier concentrations, and barrier depths in the superlattice layers. It has been found that the spin-wave excitations observed in the frequency interval studied (30-50 GHz) form two spin-wave minibands with a gap between them.
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Affiliation(s)
- V A Sanina
- A F Ioffe Physical Technical Institute, 26 Politekhnicheskaya, St Petersburg 194021, Russia.
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