1
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Siemens A, Silveira FAO, Schmelcher P. Compression-induced crossovers for the ground state of classical dipole lattices on a Möbius strip. Phys Rev E 2024; 109:064125. [PMID: 39021025 DOI: 10.1103/physreve.109.064125] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2024] [Accepted: 05/24/2024] [Indexed: 07/20/2024]
Abstract
We explore the ground-state properties of a lattice of classical dipoles spanned on the surface of a Möbius strip. The dipole equilibrium configurations depend significantly on the geometrical parameters of the Möbius strip, as well as on the lattice dimensions. As a result of the variable dipole spacing on the curved surface of the Möbius strip, the ground state can consist of multiple domains with different dipole orientations which are separated by domain-wall-like boundaries. We analyze in particular the dependence of the ground-state dipole configuration on the width of the Möbius strip and highlight two crossovers in the ground state that can be correspondingly tuned. A first crossover changes the dipole lattice from a phase which resists compression to a phase that favors it. The second crossover leads to an exchange of the topological properties of the two involved domains. We conclude with a brief summary and an outlook on more complex topologically intricate surfaces.
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2
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McKeever C, Aziz M. Effect of Multilayered Structure on the Static and Dynamic Properties of Magnetic Nanospheres. ACS APPLIED MATERIALS & INTERFACES 2022; 14:35177-35183. [PMID: 35879264 PMCID: PMC9354015 DOI: 10.1021/acsami.2c05715] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
The development of flexible and lightweight electromagnetic interference (EMI)-shielding materials and microwave absorbers requires precise control and optimization of core-shell constituents within composite materials. Here, a theoretical model is proposed to predict the static and dynamic properties of multilayered core-shell particles comprised of exchange-coupled layers, as in the case of a spherical iron core coupled to an oxide shell across a spacer layer. The theory of exchange resonance in homogeneous spheres is shown to be a limiting special case of this more general theory. Nucleation of magnetization reversal occurs through either quasi-uniform or curling magnetization processes in core-shell particles, where a purely homogeneous magnetization configuration is forbidden by the multilayered morphology. The energy is minimized through mixing of modes for specific interface conditions, leading to many inhomogeneous solutions, which grow as 2n with increasing layers, where n represents the number of magnetic layers. The analytical predictions are confirmed using numerical simulations.
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Affiliation(s)
- Conor McKeever
- Department
of Physics and Astronomy, University of
Exeter, Exeter EX4 4QL, United Kingdom
- MaxLLG,
Exeter Science Park, Exeter EX5 2FN, United Kingdom
| | - Mustafa Aziz
- Department
of Engineering, University of Exeter, Exeter EX4 4QF, United Kingdom
- MaxLLG,
Exeter Science Park, Exeter EX5 2FN, United Kingdom
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3
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Skoric L, Donnelly C, Hierro-Rodriguez A, Cascales Sandoval MA, Ruiz-Gómez S, Foerster M, Niño MA, Belkhou R, Abert C, Suess D, Fernández-Pacheco A. Domain Wall Automotion in Three-Dimensional Magnetic Helical Interconnectors. ACS NANO 2022; 16:8860-8868. [PMID: 35580039 PMCID: PMC9245342 DOI: 10.1021/acsnano.1c10345] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
The fundamental limits currently faced by traditional computing devices necessitate the exploration of ways to store, compute, and transmit information going beyond the current CMOS-based technologies. Here, we propose a three-dimensional (3D) magnetic interconnector that exploits geometry-driven automotion of domain walls (DWs), for the transfer of magnetic information between functional magnetic planes. By combining state-of-the-art 3D nanoprinting and standard physical vapor deposition, we prototype 3D helical DW conduits. We observe the automotion of DWs by imaging their magnetic state under different field sequences using X-ray microscopy, observing a robust unidirectional motion of DWs from the bottom to the top of the spirals. From experiments and micromagnetic simulations, we determine that the large thickness gradients present in the structure are the main mechanism for 3D DW automotion. We obtain direct evidence of how this tailorable magnetic energy gradient is imprinted in the devices, and how it competes with pinning effects that are due to local changes in the energy landscape. Our work also predicts how this effect could lead to high DW velocities, reaching the Walker limit during automotion. This work demonstrates a possible mechanism for efficient transfer of magnetic information in three dimensions.
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Affiliation(s)
- Luka Skoric
- Department
of Physics, Cavendish Laboratory, University
of Cambridge, JJ Thomson Ave, Cambridge CB3 0HE, United Kingdom
- E-mail: (L. Skoric)
| | - Claire Donnelly
- Department
of Physics, Cavendish Laboratory, University
of Cambridge, JJ Thomson Ave, Cambridge CB3 0HE, United Kingdom
- Max
Planck Institute for Chemical Physics of Solids, 01187 Dresden, Germany
| | - Aurelio Hierro-Rodriguez
- SUPA,
School of Physics and Astronomy, University
of Glasgow, Glasgow G12 8QQ, United Kingdom
- Depto.
Física, Universidad de Oviedo, 33007 Oviedo, Spain
| | | | - Sandra Ruiz-Gómez
- Max
Planck Institute for Chemical Physics of Solids, 01187 Dresden, Germany
- ALBA
Synchrotron Light Facility, 08290 Cerdanyola del Vallès, Spain
| | - Michael Foerster
- ALBA
Synchrotron Light Facility, 08290 Cerdanyola del Vallès, Spain
| | - Miguel A. Niño
- ALBA
Synchrotron Light Facility, 08290 Cerdanyola del Vallès, Spain
| | - Rachid Belkhou
- SOLEIL
Synchrotron, L’ormes
des Merisiers, Saint Aubin
BP-48, 91192 Gif-Sur-Yvette Cedex, France
| | - Claas Abert
- Faculty of
Physics, University of Vienna, 1010 Vienna, Austria
- Research
Platform MMM Mathematics-Magnetism-Materials, University of Vienna, 1010 Vienna, Austria
| | - Dieter Suess
- Faculty of
Physics, University of Vienna, 1010 Vienna, Austria
- Research
Platform MMM Mathematics-Magnetism-Materials, University of Vienna, 1010 Vienna, Austria
| | - Amalio Fernández-Pacheco
- Insituto
de Nanociencia y Materiales de Aragón (INMA). CSIC-Universidad de Zaragoza, 50009 Zaragoza, Spain
- E-mail: (A. Fernández-Pacheco)
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4
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Asymmetric Motion of Magnetic Skyrmions in Ferromagnetic Nanotubes Induced by a Magnetic Field. Symmetry (Basel) 2022. [DOI: 10.3390/sym14061195] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Magnetic skyrmions, featuring topological stability and low driving current density, are believed to be a promising candidate of information carriers. One of the obstacles to application is the skyrmion Hall effect, which can lead to the annihilation of moving skyrmions at the lateral boundary of thin-film tracks. In order to resolve this issue, it was recently proposed to exploit ferromagnetic nanotubes as alternative skyrmion guides. In this work, we investigate the field-effect of current-driven skyrmion motion in nanotubes using micromagnetic simulations. It is found that, in the presence of an axial field, the skyrmion motion becomes asymmetric in tubes. This is fundamentally different from the flat strip, in which a field has little influence on the skyrmion dynamics. Based on the dissipation tensor determined by the spin texture of the skyrmions, the solution of the Thiele equation is obtained, yielding a perfect match with simulations. We argue that the asymmetry of the skyrmion dynamics originates from the curvature of the nanotube.
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5
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Edström A, Amoroso D, Picozzi S, Barone P, Stengel M. Curved Magnetism in CrI_{3}. PHYSICAL REVIEW LETTERS 2022; 128:177202. [PMID: 35570427 DOI: 10.1103/physrevlett.128.177202] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/28/2021] [Revised: 03/08/2022] [Accepted: 04/07/2022] [Indexed: 06/15/2023]
Abstract
Curved magnets attract considerable interest for their unusually rich phase diagram, often encompassing exotic (e.g., topological or chiral) spin states. Micromagnetic simulations are playing a central role in the theoretical understanding of such phenomena; their predictive power, however, rests on the availability of reliable model parameters to describe a given material or nanostructure. Here we demonstrate how noncollinear-spin polarized density-functional theory can be used to determine the flexomagnetic coupling coefficients in real systems. By focusing on monolayer CrI_{3}, we find a crossover as a function of curvature between a magnetization normal to the surface to a cycloidal state, which we rationalize in terms of effective anisotropy and Dzyaloshinskii-Moriya contributions to the magnetic energy. Our results reveal an unexpectedly large impact of spin-orbit interactions on the curvature-induced anisotropy, which we discuss in the context of existing phenomenological models.
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Affiliation(s)
- Alexander Edström
- Institut de Ciència de Materials de Barcelona (ICMAB-CSIC), Campus UAB, 08193 Bellaterra, Spain
- Department of Applied Physics, School of Engineering Sciences, KTH Royal Institute of Technology, AlbaNova University Center, 10691 Stockholm, Sweden
| | - Danila Amoroso
- Consiglio Nazionale delle Ricerche CNR-SPIN, c/o Università degli Studi 'G. D'Annunzio', 66100 Chieti, Italy
- NanoMat/Q-mat/CESAM, Université de Liège, B-4000 Liege, Belgium
| | - Silvia Picozzi
- Consiglio Nazionale delle Ricerche CNR-SPIN, c/o Università degli Studi 'G. D'Annunzio', 66100 Chieti, Italy
| | - Paolo Barone
- Consiglio Nazionale delle Ricerche CNR-SPIN, Area della Ricerca di Tor Vergata,Via del Fosso del Cavaliere 100, I-00133 Rome, Italy
| | - Massimiliano Stengel
- Institut de Ciència de Materials de Barcelona (ICMAB-CSIC), Campus UAB, 08193 Bellaterra, Spain
- ICREA-Instituciò Catalana de Recerca i Estudis Avançats, 08010 Barcelona, Spain
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6
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Sheka DD, Pylypovskyi OV, Volkov OM, Yershov KV, Kravchuk VP, Makarov D. Fundamentals of Curvilinear Ferromagnetism: Statics and Dynamics of Geometrically Curved Wires and Narrow Ribbons. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2022; 18:e2105219. [PMID: 35044074 DOI: 10.1002/smll.202105219] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2021] [Revised: 11/06/2021] [Indexed: 06/14/2023]
Abstract
Low-dimensional magnetic architectures including wires and thin films are key enablers of prospective ultrafast and energy efficient memory, logic, and sensor devices relying on spin-orbitronic and magnonic concepts. Curvilinear magnetism emerged as a novel approach in material science, which allows tailoring of the fundamental anisotropic and chiral responses relying on the geometrical curvature of magnetic architectures. Much attention is dedicated to magnetic wires of Möbius, helical, or DNA-like double helical shapes, which act as prototypical objects for the exploration of the fundamentals of curvilinear magnetism. Although there is a bulk number of original publications covering fabrication, characterization, and theory of magnetic wires, there is no comprehensive review of the theoretical framework of how to describe these architectures. Here, theoretical activities on the topic of curvilinear magnetic wires and narrow nanoribbons are summarized, providing a systematic review of the emergent interactions and novel physical effects caused by the curvature. Prospective research directions of curvilinear spintronics and spin-orbitronics are discussed, the fundamental framework for curvilinear magnonics are outlined, and mechanically flexible curvilinear architectures for soft robotics are introduced.
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Affiliation(s)
- Denis D Sheka
- Faculty of Radiophysics, Electronics and Computer Systems, Taras Shevchenko National University of Kyiv, Kyiv, 01601, Ukraine
| | - 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
| | - Oleksii M Volkov
- Helmholtz-Zentrum Dresden - Rossendorf e.V., Institute of Ion Beam Physics and Materials Research, 01328, Dresden, Germany
| | - Kostiantyn V Yershov
- Leibniz-Institut für Festkörper- und Werkstoffforschung, IFW Dresden, 01171, Dresden, Germany
- Bogolyubov Institute for Theoretical Physics of National Academy of Sciences of Ukraine, Kyiv, 03142, Ukraine
| | - Volodymyr P Kravchuk
- Institut für Theoretische Festkörperphysik, Karlsruher Institut für Technologie, 76131, Karlsruhe, Germany
- Bogolyubov Institute for Theoretical Physics of National Academy of Sciences of Ukraine, Kyiv, 03142, Ukraine
| | - Denys Makarov
- Helmholtz-Zentrum Dresden - Rossendorf e.V., Institute of Ion Beam Physics and Materials Research, 01328, Dresden, Germany
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7
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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. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2022; 34:e2101758. [PMID: 34705309 PMCID: PMC11469131 DOI: 10.1002/adma.202101758] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [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 Research01328DresdenGermany
| | - Oleksii M. Volkov
- Helmholtz‐Zentrum Dresden ‐ Rossendorf e.V.Institute of Ion Beam Physics and Materials Research01328DresdenGermany
| | - Attila Kákay
- Helmholtz‐Zentrum Dresden ‐ Rossendorf e.V.Institute of Ion Beam Physics and Materials Research01328DresdenGermany
| | - Oleksandr V. Pylypovskyi
- Helmholtz‐Zentrum Dresden ‐ Rossendorf e.V.Institute of Ion Beam Physics and Materials Research01328DresdenGermany
- Kyiv Academic UniversityKyiv03142Ukraine
| | - Barbora Budinská
- Superconductivity and Spintronics LaboratoryNanomagnetism and MagnonicsFaculty of PhysicsUniversity of ViennaVienna1090Austria
| | - Oleksandr V. Dobrovolskiy
- Superconductivity and Spintronics LaboratoryNanomagnetism and MagnonicsFaculty of PhysicsUniversity of ViennaVienna1090Austria
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8
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Intrinsic DMI-free skyrmion formation and robust dynamic behaviors in magnetic hemispherical shells. Sci Rep 2021; 11:3886. [PMID: 33594108 PMCID: PMC7887229 DOI: 10.1038/s41598-021-81624-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Accepted: 01/05/2021] [Indexed: 11/17/2022] Open
Abstract
We performed finite-element micromagnetic simulations to examine the formation of skyrmions without intrinsic Dzyaloshinskii–Moriya interaction (DMI) in magnetic hemispherical shells. We found that curvature-induced DM-like interaction allows for further stabilization of skyrmions without the DMI in curved-geometry hemispherical shells for a specific range of uniaxial perpendicular magnetic anisotropy (PMA) constant Ku. The larger the curvature of the shell, the higher the Ku value required for the formation of the skyrmions. With well-stabilized skyrmions, we also found in-plane gyration modes and azimuthal spin-wave modes as well as an out-of-plane breathing mode, similarly to previously found modes for planar geometries. Furthermore, additional higher-frequency hybrid modes were observed due to coupling between the gyration and azimuthal modes. This work provides further physical insight into the static and dynamic properties of intrinsic DMI-free skyrmions formed in curved-geometry systems.
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9
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Burks EC, Gilbert DA, Murray PD, Flores C, Felter TE, Charnvanichborikarn S, Kucheyev SO, Colvin JD, Yin G, Liu K. 3D Nanomagnetism in Low Density Interconnected Nanowire Networks. NANO LETTERS 2021; 21:716-722. [PMID: 33301687 DOI: 10.1021/acs.nanolett.0c04366] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Free-standing, interconnected metallic nanowire networks with densities as low as 40 mg/cm3 have been achieved over centimeter-scale areas, using electrodeposition into polycarbonate membranes that have been ion-tracked at multiple angles. Networks of interconnected magnetic nanowires further provide an exciting platform to explore 3-dimensional nanomagnetism, where their structure, topology, and frustration may be used as additional degrees of freedom to tailor the materials properties. New magnetization reversal mechanisms in cobalt networks are captured by the first-order reversal curve method, which demonstrate the evolution from strong demagnetizing dipolar interactions to intersection-mediated domain wall pinning and propagation, and eventually to shape-anisotropy dominated magnetization reversal. These findings open up new possibilities for 3-dimensional integrated magnetic devices for memory, complex computation, and neuromorphics.
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Affiliation(s)
- Edward C Burks
- Physics Department, University of California, Davis, California 95618, United States
| | - Dustin A Gilbert
- Physics Department, University of California, Davis, California 95618, United States
- Department of Materials Science and Engineering, University of Tennessee, Knoxville, Tennessee 37996, United States
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37996, United States
| | - Peyton D Murray
- Physics Department, University of California, Davis, California 95618, United States
| | - Chad Flores
- Physics Department, University of California, Davis, California 95618, United States
| | - Thomas E Felter
- Sandia National Laboratories, Livermore, California 94551, United States
| | | | - Sergei O Kucheyev
- Lawrence Livermore National Laboratory, Livermore, California 94551, United States
| | - Jeffrey D Colvin
- Lawrence Livermore National Laboratory, Livermore, California 94551, United States
| | - Gen Yin
- Physics Department, Georgetown University, Washington, D.C. 20057, United States
| | - Kai Liu
- Physics Department, University of California, Davis, California 95618, United States
- Physics Department, Georgetown University, Washington, D.C. 20057, United States
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10
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Liu Y, Cai N, Yu X, Xuan S. Nucleation and stability of skyrmions in three-dimensional chiral nanostructures. Sci Rep 2020; 10:21717. [PMID: 33303955 PMCID: PMC7730437 DOI: 10.1038/s41598-020-78838-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Accepted: 11/25/2020] [Indexed: 11/21/2022] Open
Abstract
We studied the magnetization evolution in three-dimensional chiral nanostructures, including nanotubes and circularly curved thin films, by micromagnetic simulations. We found that in a nanotube skyrmions can be formed by broken of the helical stripes on the left and right sides of the nanotube, and the formation of skyrmions doesn't correspond to any abrupt change of topological number. Skyrmions can exist in a large range of magnetic field, and the thinner nanotube has a larger field range for skyrmion existence. The configuration of a skyrmion in nanotubes is different from the one in thin film. From the outer to the inner circular layer, the size of the skyrmion becomes larger, and the deformation becomes more obvious. In circularly curved magnetic films with fixed arc length, there are three kinds of hysteresis processes are found. For the curved films with a large radius, the magnetization evolution behavior is similar to the case in two-dimensional thin films. For the curved films with a small radius, the skyrmions are created by broken of the helical stripes on the left and right sides of the curved film. For the curved film with a medium radius, no skyrmion is formed in the hysteresis process.
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Affiliation(s)
- Yan Liu
- College of Sciences, Northeastern University, Shenyang, 110819, People's Republic of China.
| | - Na Cai
- College of Sciences, Northeastern University, Shenyang, 110819, People's Republic of China
| | - Xingxing Yu
- College of Sciences, Northeastern University, Shenyang, 110819, People's Republic of China
| | - Shengjie Xuan
- College of Sciences, Northeastern University, Shenyang, 110819, People's Republic of China
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11
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Tejo F, Toneto D, Oyarzún S, Hermosilla J, Danna CS, Palma JL, da Silva RB, Dorneles LS, Denardin JC. Stabilization of Magnetic Skyrmions on Arrays of Self-Assembled Hexagonal Nanodomes for Magnetic Recording Applications. ACS APPLIED MATERIALS & INTERFACES 2020; 12:53454-53461. [PMID: 33169962 DOI: 10.1021/acsami.0c14350] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Magnetic skyrmions are nontrivial spin textures that resist external perturbations, being promising candidates for the next-generation recording devices. Nevertheless, a major challenge in realizing skyrmion-based devices is the stabilization of ordered arrays of these spin textures under ambient conditions and zero applied field. Here, we demonstrate for the first time the formation and stabilization of magnetic skyrmions on the arrays of self-assembled hexagonal nanodomes taking advantage of the intrinsic properties of its curved geometry. Magnetic force microscopy images from the arrays of 100 nm nanodomes showed stable skyrmions at the zero field that are arranged following the topography of the nanostructure. Micromagnetic simulations are compared to the experiments to determine the correlation of the domain textures with the topography of the samples. We propose a simple method to nucleate and annihilate skyrmions, opening the possibility for an ultradense data storage based on the high stability and low energy consumption of the skyrmionic textures.
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Affiliation(s)
- Felipe Tejo
- Departamento de Física, Universidad de Santiago de Chile, Santiago 9170124, Chile
- CEDENNA, Universidad de Santiago de Chile, Santiago, Chile
- Instituto de Ciencia de Materiales de Madrid, CSIC, Cantoblanco, 28049 Madrid, Spain
| | - Denilson Toneto
- Departamento de Física, Universidade Federal de Santa Maria, UFSM, Santa Maria, RS 97105-900, Brazil
| | - Simón Oyarzún
- Departamento de Física, Universidad de Santiago de Chile, Santiago 9170124, Chile
- CEDENNA, Universidad de Santiago de Chile, Santiago, Chile
| | - José Hermosilla
- Departamento de Física, Universidad de Santiago de Chile, Santiago 9170124, Chile
| | - Caroline S Danna
- Departamento de Física, Universidad de Santiago de Chile, Santiago 9170124, Chile
| | - Juan L Palma
- Escuela de Ingeniería, Universidad Central de Chile, Santiago 8330601, Chile
- CEDENNA, Universidad de Santiago de Chile, Santiago, Chile
| | - Ricardo B da Silva
- Departamento de Física, Universidade Federal de Santa Maria, UFSM, Santa Maria, RS 97105-900, Brazil
| | - Lucio S Dorneles
- Departamento de Física, Universidade Federal de Santa Maria, UFSM, Santa Maria, RS 97105-900, Brazil
| | - Juliano C Denardin
- Departamento de Física, Universidad de Santiago de Chile, Santiago 9170124, Chile
- CEDENNA, Universidad de Santiago de Chile, Santiago, Chile
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12
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Berganza E, Jaafar M, Fernandez-Roldan JA, Goiriena-Goikoetxea M, Pablo-Navarro J, García-Arribas A, Guslienko K, Magén C, De Teresa JM, Chubykalo-Fesenko O, Asenjo A. Half-hedgehog spin textures in sub-100 nm soft magnetic nanodots. NANOSCALE 2020; 12:18646-18653. [PMID: 32584341 DOI: 10.1039/d0nr02173c] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Topologically non-trivial structures such as magnetic skyrmions are nanometric spin textures of outstanding potential for spintronic applications due to their unique features. It is well known that Néel skyrmions of definite chirality are stabilized by the Dzyaloshinskii-Moriya exchange interaction (DMI) in bulk non-centrosymmetric materials or ultrathin films with strong spin-orbit coupling at the interface. In this work, we show that soft magnetic (permalloy) hemispherical nanodots are able to host three-dimensional chiral structures (half-hedgehog spin textures) with non-zero tropological charge. They are observed at room temperature, in absence of DMI interaction and they can be further stabilized by the magnetic field arising from the Magnetic Force Microscopy probe. Micromagnetic simulations corroborate the experimental data. Our work implies the existence of a new degree of freedom to create and manipulate complex 3D spin-textures in soft magnetic nanodots and opens up future possibilities to explore their magnetization dynamics.
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Affiliation(s)
- Eider Berganza
- Instituto de Ciencia de Materiales de Madrid, CSIC, 28049 Madrid, Spain
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13
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Fernández-Pacheco A, Skoric L, De Teresa JM, Pablo-Navarro J, Huth M, Dobrovolskiy OV. Writing 3D Nanomagnets Using Focused Electron Beams. MATERIALS (BASEL, SWITZERLAND) 2020; 13:E3774. [PMID: 32859076 PMCID: PMC7503546 DOI: 10.3390/ma13173774] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 08/10/2020] [Accepted: 08/20/2020] [Indexed: 12/18/2022]
Abstract
Focused electron beam induced deposition (FEBID) is a direct-write nanofabrication technique able to pattern three-dimensional magnetic nanostructures at resolutions comparable to the characteristic magnetic length scales. FEBID is thus a powerful tool for 3D nanomagnetism which enables unique fundamental studies involving complex 3D geometries, as well as nano-prototyping and specialized applications compatible with low throughputs. In this focused review, we discuss recent developments of this technique for applications in 3D nanomagnetism, namely the substantial progress on FEBID computational methods, and new routes followed to tune the magnetic properties of ferromagnetic FEBID materials. We also review a selection of recent works involving FEBID 3D nanostructures in areas such as scanning probe microscopy sensing, magnetic frustration phenomena, curvilinear magnetism, magnonics and fluxonics, offering a wide perspective of the important role FEBID is likely to have in the coming years in the study of new phenomena involving 3D magnetic nanostructures.
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Affiliation(s)
- Amalio Fernández-Pacheco
- SUPA, School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, UK
- Cavendish Laboratory, University of Cambridge, JJ Thomson Avenue, Cambridge CB3 0HE, UK;
| | - Luka Skoric
- Cavendish Laboratory, University of Cambridge, JJ Thomson Avenue, Cambridge CB3 0HE, UK;
| | - José María De Teresa
- Instituto de Nanociencia y Materiales de Aragón (INMA), Universidad de Zaragoza-CSIC, 50009 Zaragoza, Spain
- Laboratorio de Microscopías Avanzadas (LMA) and Departamento de Física de la Materia Condensada, Universidad de Zaragoza, 50009 Zaragoza, Spain;
| | - Javier Pablo-Navarro
- Laboratorio de Microscopías Avanzadas (LMA) and Departamento de Física de la Materia Condensada, Universidad de Zaragoza, 50009 Zaragoza, Spain;
- Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, 01328 Dresden, Germany
| | - Michael Huth
- Institute of Physics, Goethe University Frankfurt, 60438 Frankfurt am Main, Germany;
| | - Oleksandr V. Dobrovolskiy
- Institute of Physics, Goethe University Frankfurt, 60438 Frankfurt am Main, Germany;
- Faculty of Physics, University of Vienna, 1090 Vienna, Austria
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14
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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 LETTERS 2020; 20:3642-3650. [PMID: 32250635 DOI: 10.1021/acs.nanolett.0c00578] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [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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15
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Donnelly C, Scagnoli V. Imaging three-dimensional magnetic systems with x-rays. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2020; 32:213001. [PMID: 31796657 DOI: 10.1088/1361-648x/ab5e3c] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Recent progress in nanofabrication and additive manufacturing have facilitated the building of nanometer-scale three-dimensional (3D) structures, that promise to lead to an emergence of new functionalities within a number of fields, compared to state-of-the-art two dimensional systems. In magnetism, the move to 3D systems offers the possibility for novel magnetic properties not available in planar systems, as well as enhanced performance, both of which are key for the development of new technological applications. In this review paper we will focus our attention on 3D magnetic systems and how their magnetic configuration can be retrieved using x-ray magnetic nanotomography. We will start with an introduction to magnetic materials, and their relevance to our everyday life, along with the growing impact that they will have in the coming years in, for example, reducing energy consumption. We will then briefly introduce common methods used to study magnetic materials, such as electron holography, neutron and x-ray imaging. In particular, we will focus on x-ray magnetic circular dichroism (XMCD) and how it can be used to image magnetic moment configurations. As a next step we will introduce tomography for 3D imaging, and how it can be adapted to study magnetic materials. Particular attention will be given to explaining the reconstruction algorithms that can be used to retrieve the magnetic moment configuration from the experimental data, as these represent one of the main challenges so far, as well as the different experimental geometries that are available. Recent experimental results will be used as specific examples to guide the reader through each step in order to make sure that the paper will be accessible for those interested in the topic that do not have a specialized background on magnetic imaging. Finally, we will describe the future prospects of such studies, identifying the current challenges facing the field, and how these can be tackled. In particular we will highlight the exciting possibilities offered by the next generation of synchrotron sources which will deliver diffraction limited beams, as well as with the extension of well-established methodologies currently implemented for the study of two-dimensional magnetic materials to achieve higher dimensional investigations.
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Affiliation(s)
- C Donnelly
- Cavendish Laboratory, University of Cambridge, JJ Thomson Ave, Cambridge CB3 0HE, United Kingdom
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16
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Schöbitz M, De Riz A, Martin S, Bochmann S, Thirion C, Vogel J, Foerster M, Aballe L, Menteş TO, Locatelli A, Genuzio F, Le-Denmat S, Cagnon L, Toussaint JC, Gusakova D, Bachmann J, Fruchart O. Fast Domain Wall Motion Governed by Topology and Œrsted Fields in Cylindrical Magnetic Nanowires. PHYSICAL REVIEW LETTERS 2019; 123:217201. [PMID: 31809154 DOI: 10.1103/physrevlett.123.217201] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2019] [Indexed: 05/26/2023]
Abstract
While the usual approach to tailor the behavior of condensed matter and nanosized systems is the choice of material or finite-size or interfacial effects, topology alone may be the key. In the context of the motion of magnetic domain walls (DWs), known to suffer from dynamic instabilities with low mobilities, we report unprecedented velocities >600 m/s for DWs driven by spin-transfer torques in cylindrical nanowires made of a standard ferromagnetic material. The reason is the robust stabilization of a DW type with a specific topology by the Œrsted field associated with the current. This opens the route to the realization of predicted new physics, such as the strong coupling of DWs with spin waves above >600 m/s.
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Affiliation(s)
- M Schöbitz
- Univ. Grenoble Alpes, CNRS, CEA, Spintec, 38054 Grenoble, France
- Friedrich-Alexander-Universität Erlangen-Nürnberg, Inorganic Chemistry, 91058 Erlangen, Germany
- Univ. Grenoble Alpes, CNRS, Institut Néel, 38042 Grenoble, France
| | - A De Riz
- Univ. Grenoble Alpes, CNRS, CEA, Spintec, 38054 Grenoble, France
| | - S Martin
- Univ. Grenoble Alpes, CNRS, CEA, Spintec, 38054 Grenoble, France
- Univ. Grenoble Alpes, CNRS, Institut Néel, 38042 Grenoble, France
| | - S Bochmann
- Friedrich-Alexander-Universität Erlangen-Nürnberg, Inorganic Chemistry, 91058 Erlangen, Germany
| | - C Thirion
- Univ. Grenoble Alpes, CNRS, Institut Néel, 38042 Grenoble, France
| | - J Vogel
- Univ. Grenoble Alpes, CNRS, Institut Néel, 38042 Grenoble, France
| | - M Foerster
- Alba Synchrotron Light Facility, CELLS, 08290 Barcelona, Spain
| | - L Aballe
- Alba Synchrotron Light Facility, CELLS, 08290 Barcelona, Spain
| | - T O Menteş
- Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, 34149 Trieste, Italy
| | - A Locatelli
- Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, 34149 Trieste, Italy
| | - F Genuzio
- Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, 34149 Trieste, Italy
| | - S Le-Denmat
- Univ. Grenoble Alpes, CNRS, Institut Néel, 38042 Grenoble, France
| | - L Cagnon
- Univ. Grenoble Alpes, CNRS, Institut Néel, 38042 Grenoble, France
| | - J C Toussaint
- Univ. Grenoble Alpes, CNRS, Institut Néel, 38042 Grenoble, France
| | - D Gusakova
- Univ. Grenoble Alpes, CNRS, CEA, Spintec, 38054 Grenoble, France
| | - J Bachmann
- Friedrich-Alexander-Universität Erlangen-Nürnberg, Inorganic Chemistry, 91058 Erlangen, Germany
- Institute of Chemistry, Saint Petersburg State University, St. Petersburg 198504, Russia
| | - O Fruchart
- Univ. Grenoble Alpes, CNRS, CEA, Spintec, 38054 Grenoble, France
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17
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Winding number selection on merons by Gaussian curvature's sign. Sci Rep 2019; 9:14309. [PMID: 31586087 PMCID: PMC6778112 DOI: 10.1038/s41598-019-50395-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2019] [Accepted: 08/19/2019] [Indexed: 11/15/2022] Open
Abstract
We study the relationship between the winding number of magnetic merons and the Gaussian curvature of two-dimensional magnetic surfaces. We show that positive (negative) Gaussian curvatures privilege merons with positive (negative) winding number. As in the case of unidimensional domain walls, we found that chirality is connected to the polarity of the core. Both effects allow to predict the topological properties of metastable states knowing the geometry of the surface. These features are related with the recently predicted Dzyaloshinskii-Moriya emergent term of curved surfaces. The presented results are at our knowledge the first ones drawing attention about a direct relation between geometric properties of the surfaces and the topology of the hosted solitons.
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18
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Zhou XF, Wu C, Guo GC, Wang R, Pu H, Zhou ZW. Synthetic Landau Levels and Spinor Vortex Matter on a Haldane Spherical Surface with a Magnetic Monopole. PHYSICAL REVIEW LETTERS 2018; 120:130402. [PMID: 29694171 DOI: 10.1103/physrevlett.120.130402] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Indexed: 06/08/2023]
Abstract
We present a flexible scheme to realize exact flat Landau levels on curved spherical geometry in a system of spinful cold atoms. This is achieved by applying the Floquet engineering of a magnetic quadrupole field to create a synthetic monopole field in real space. The system can be exactly mapped to the electron-monopole system on a sphere, thus realizing Haldane's spherical geometry for fractional quantum Hall physics. This method works for either bosons or fermions. We investigate the ground-state vortex pattern for an s-wave interacting atomic condensate by mapping this system to the classical Thompson's problem. The distortion and stability of the vortex pattern are further studied in the presence of dipolar interaction. Our scheme is compatible with the current experimental setup, and may serve as a promising route of investigating quantum Hall physics and exotic spinor vortex matter on curved space.
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Affiliation(s)
- Xiang-Fa Zhou
- Key Laboratory of Quantum Information, Chinese Academy of Sciences, University of Science and Technology of China, Hefei 230026, China
- Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, China
| | - Congjun Wu
- Department of Physics, University of California, San Diego, San Diego, California 92093, USA
| | - Guang-Can Guo
- Key Laboratory of Quantum Information, Chinese Academy of Sciences, University of Science and Technology of China, Hefei 230026, China
- Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, China
| | - Ruquan Wang
- Institute of Physics, Chinese Academy of Sciences, Beijing 100080, People's Republic of China
- Collaborative Innovation Center of Quantum Matter, Beijing, China
| | - Han Pu
- Department of Physics and Astronomy, and Rice Center for Quantum Materials, Rice University, Houston, Texas 77251, USA
- Center for Cold Atom Physics, Chinese Academy of Sciences, Wuhan 430071, People's Republic of China
| | - Zheng-Wei Zhou
- Key Laboratory of Quantum Information, Chinese Academy of Sciences, University of Science and Technology of China, Hefei 230026, China
- Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, China
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19
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Mesoscale Dzyaloshinskii-Moriya interaction: geometrical tailoring of the magnetochirality. Sci Rep 2018; 8:866. [PMID: 29339741 PMCID: PMC5770476 DOI: 10.1038/s41598-017-18835-4] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2017] [Accepted: 12/18/2017] [Indexed: 11/08/2022] Open
Abstract
Crystals with broken inversion symmetry can host fundamentally appealing and technologically relevant periodical or localized chiral magnetic textures. The type of the texture as well as its magnetochiral properties are determined by the intrinsic Dzyaloshinskii-Moriya interaction (DMI), which is a material property and can hardly be changed. Here we put forth a method to create new artificial chiral nanoscale objects with tunable magnetochiral properties from standard magnetic materials by using geometrical manipulations. We introduce a mesoscale Dzyaloshinskii-Moriya interaction that combines the intrinsic spin-orbit and extrinsic curvature-driven DMI terms and depends both on the material and geometrical parameters. The vector of the mesoscale DMI determines magnetochiral properties of any curved magnetic system with broken inversion symmetry. The strength and orientation of this vector can be changed by properly choosing the geometry. For a specific example of nanosized magnetic helix, the same material system with different geometrical parameters can acquire one of three zero-temperature magnetic phases, namely, phase with a quasitangential magnetization state, phase with a periodical state and one intermediate phase with a periodical domain wall state. Our approach paves the way towards the realization of a new class of nanoscale spintronic and spinorbitronic devices with the geometrically tunable magnetochirality.
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20
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21
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Fernández-Pacheco A, Streubel R, Fruchart O, Hertel R, Fischer P, Cowburn RP. Three-dimensional nanomagnetism. Nat Commun 2017; 8:15756. [PMID: 28598416 PMCID: PMC5494189 DOI: 10.1038/ncomms15756] [Citation(s) in RCA: 155] [Impact Index Per Article: 22.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2016] [Accepted: 04/20/2017] [Indexed: 01/18/2023] Open
Abstract
Magnetic nanostructures are being developed for use in many aspects of our daily life, spanning areas such as data storage, sensing and biomedicine. Whereas patterned nanomagnets are traditionally two-dimensional planar structures, recent work is expanding nanomagnetism into three dimensions; a move triggered by the advance of unconventional synthesis methods and the discovery of new magnetic effects. In three-dimensional nanomagnets more complex magnetic configurations become possible, many with unprecedented properties. Here we review the creation of these structures and their implications for the emergence of new physics, the development of instrumentation and computational methods, and exploitation in numerous applications. Nanoscale magnetic devices play a key role in modern technologies but current applications involve only 2D structures like magnetic discs. Here the authors review recent progress in the fabrication and understanding of 3D magnetic nanostructures, enabling more diverse functionalities.
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Affiliation(s)
| | - Robert Streubel
- Division of Materials Sciences, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - Olivier Fruchart
- Univ. Grenoble Alpes, CNRS, CEA, Grenoble INP, INAC, SPINTEC, F-38000 Grenoble, France
| | - Riccardo Hertel
- Université de Strasbourg, CNRS, Institut de Physique et Chimie des Matériaux de Strasbourg, UMR 7504, Department of Magnetic Objects on the Nanoscale, F-67000 Strasbourg, France
| | - Peter Fischer
- Division of Materials Sciences, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.,Department of Physics, UC Santa Cruz, Santa Cruz, California 95064, USA
| | - Russell P Cowburn
- Cavendish Laboratory, University of Cambridge, JJ Thomson Avenue, Cambridge CB3 0HE, UK
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22
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Ochoa H, Zarzuela R, Tserkovnyak Y. Emergent Gauge Fields from Curvature in Single Layers of Transition-Metal Dichalcogenides. PHYSICAL REVIEW LETTERS 2017; 118:026801. [PMID: 28128602 DOI: 10.1103/physrevlett.118.026801] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2016] [Indexed: 05/06/2023]
Abstract
We analyze the electron dynamics in corrugated layers of transition-metal dichalcogenides. Due to the strong spin-orbit coupling, the intrinsic (Gaussian) curvature leads to an emergent gauge field associated with the Berry connection of the spinor wave function. We discuss the gauge field created by topological defects of the lattice, namely, tetragonal and octogonal disclinations and edge dislocations. Ripples and topological disorder induce the same dephasing effects as a random magnetic field, suppressing the weak localization effects. This geometric magnetic field can be detected in an Aharonov-Bohm interferometry experiment by measuring the local density of states in the vicinity of corrugations.
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Affiliation(s)
- Héctor Ochoa
- Department of Physics and Astronomy, University of California, Los Angeles, California 90095, USA
| | - Ricardo Zarzuela
- Department of Physics and Astronomy, University of California, Los Angeles, California 90095, USA
| | - Yaroslav Tserkovnyak
- Department of Physics and Astronomy, University of California, Los Angeles, California 90095, USA
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23
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Pylypovskyi OV, Sheka DD, Kravchuk VP, Yershov KV, Makarov D, Gaididei Y. Rashba Torque Driven Domain Wall Motion in Magnetic Helices. Sci Rep 2016; 6:23316. [PMID: 27008975 PMCID: PMC4806324 DOI: 10.1038/srep23316] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2015] [Accepted: 03/03/2016] [Indexed: 11/20/2022] Open
Abstract
Manipulation of the domain wall propagation in magnetic wires is a key practical task for a number of devices including racetrack memory and magnetic logic. Recently, curvilinear effects emerged as an efficient mean to impact substantially the statics and dynamics of magnetic textures. Here, we demonstrate that the curvilinear form of the exchange interaction of a magnetic helix results in an effective anisotropy term and Dzyaloshinskii-Moriya interaction with a complete set of Lifshitz invariants for a one-dimensional system. In contrast to their planar counterparts, the geometrically induced modifications of the static magnetic texture of the domain walls in magnetic helices offer unconventional means to control the wall dynamics relying on spin-orbit Rashba torque. The chiral symmetry breaking due to the Dzyaloshinskii-Moriya interaction leads to the opposite directions of the domain wall motion in left- or right-handed helices. Furthermore, for the magnetic helices, the emergent effective anisotropy term and Dzyaloshinskii-Moriya interaction can be attributed to the clear geometrical parameters like curvature and torsion offering intuitive understanding of the complex curvilinear effects in magnetism.
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Affiliation(s)
| | - Denis D. Sheka
- Taras Shevchenko National University of Kyiv, 01601 Kyiv, Ukraine
| | - Volodymyr P. Kravchuk
- Bogolyubov Institute for Theoretical Physics of the National Academy of Sciences of Ukraine, 03680 Kyiv, Ukraine
| | - Kostiantyn V. Yershov
- Bogolyubov Institute for Theoretical Physics of the National Academy of Sciences of Ukraine, 03680 Kyiv, Ukraine
- National University of “Kyiv-Mohyla Academy”, 04655 Kyiv, Ukraine
| | - Denys Makarov
- Helmholtz-Zentrum Dresden-Rossendorf e. V., Institute of Ion Beam Physics and Materials Research, 01328 Dresden, Germany
- Institute for Integrative Nanosciences, IFW Dresden, 01069 Dresden, Germany
| | - Yuri Gaididei
- Bogolyubov Institute for Theoretical Physics of the National Academy of Sciences of Ukraine, 03680 Kyiv, Ukraine
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24
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Wegrowe JE, Olive E. The magnetic monopole and the separation between fast and slow magnetic degrees of freedom. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2016; 28:106001. [PMID: 26871542 DOI: 10.1088/0953-8984/28/10/106001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The Landau-Lifshitz-Gilbert (LLG) equation that describes the dynamics of a macroscopic magnetic moment finds its limit of validity at very short times. The reason for this limit is well understood in terms of separation of the characteristic time scales between slow degrees of freedom (the magnetization) and fast degrees of freedom. The fast degrees of freedom are introduced as the variation of the angular momentum responsible for the inertia. In order to study the effect of the fast degrees of freedom on the precession, we calculate the geometric phase of the magnetization (i.e. the Hannay angle) and the corresponding magnetic monopole. In the case of the pure precession (the slow manifold), a simple expression of the magnetic monopole is given as a function of the slowness parameter, i.e. as a function of the ratio of the slow over the fast characteristic times.
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Affiliation(s)
- J-E Wegrowe
- LSI, Ecole Polytechnique, CEA, CNRS, Université Paris-Saclay, 91128 Palaiseau Cedex, France
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25
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Streubel R, Kronast F, Fischer P, Parkinson D, Schmidt OG, Makarov D. Retrieving spin textures on curved magnetic thin films with full-field soft X-ray microscopies. Nat Commun 2015; 6:7612. [PMID: 26139445 PMCID: PMC4506513 DOI: 10.1038/ncomms8612] [Citation(s) in RCA: 94] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2014] [Accepted: 05/22/2015] [Indexed: 11/09/2022] Open
Abstract
X-ray tomography is a well-established technique to characterize 3D structures in material sciences and biology; its magnetic analogue--magnetic X-ray tomography--is yet to be developed. Here we demonstrate the visualization and reconstruction of magnetic domain structures in a 3D curved magnetic thin films with tubular shape by means of full-field soft X-ray microscopies. The 3D arrangement of the magnetization is retrieved from a set of 2D projections by analysing the evolution of the magnetic contrast with varying projection angle. Using reconstruction algorithms to analyse the angular evolution of 2D projections provides quantitative information about domain patterns and magnetic coupling phenomena between windings of azimuthally and radially magnetized tubular objects. The present approach represents a first milestone towards visualizing magnetization textures of 3D curved thin films with virtually arbitrary shape.
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Affiliation(s)
- Robert Streubel
- Institute for Integrative Nanosciences, IFW Dresden, 01069 Dresden, Germany
| | - Florian Kronast
- Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Berlin 12489, Germany
| | - Peter Fischer
- Center for X-ray Optics, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
- Department of Physics, UC Santa Cruz, Santa Cruz, California 95064, USA
| | - Dula Parkinson
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - Oliver G. Schmidt
- Institute for Integrative Nanosciences, IFW Dresden, 01069 Dresden, Germany
- Material Systems for Nanoelectronics, TU Chemnitz, Chemnitz 09107, Germany
| | - Denys Makarov
- Institute for Integrative Nanosciences, IFW Dresden, 01069 Dresden, Germany
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