1
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Thomsen JD, Han MG, Penn AN, Foucher AC, Geiwitz M, Burch KS, Dekanovsky L, Sofer Z, Liu Y, Petrovic C, Ross FM, Zhu Y, Narang P. Effect of Surface Oxidation and Crystal Thickness on the Magnetic Properties and Magnetic Domain Structures of Cr 2Ge 2Te 6. ACS NANO 2024; 18:13458-13467. [PMID: 38739873 DOI: 10.1021/acsnano.3c09858] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2024]
Abstract
van der Waals (vdW) magnetic materials, such as Cr2Ge2Te6 (CGT), show promise for memory and logic applications. This is due to their broadly tunable magnetic properties and the presence of topological magnetic features such as skyrmionic bubbles. A systematic study of thickness and oxidation effects on magnetic domain structures is important for designing devices and vdW heterostructures for practical applications. Here, we investigate thickness effects on magnetic properties, magnetic domains, and bubbles in oxidation-controlled CGT crystals. We find that CGT exposed to ambient conditions for 5 days forms an oxide layer approximately 5 nm thick. This oxidation leads to a significant increase in the oxidation state of the Cr ions, indicating a change in local magnetic properties. This is supported by real-space magnetic texture imaging through Lorentz transmission electron microscopy. By comparing the thickness-dependent saturation field of oxidized and pristine crystals, we find that oxidation leads to a nonmagnetic surface layer that is thicker than the oxide layer alone. We also find that the stripe domain width and skyrmionic bubble size are strongly affected by the crystal thickness in pristine crystals. These findings underscore the impact of thickness and surface oxidation on the properties of CGT, such as saturation field and domain/skyrmionic bubble size, and suggest a pathway for manipulating magnetic properties through a controlled oxidation process.
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Affiliation(s)
- Joachim Dahl Thomsen
- Division of Physical Sciences, College of Letters and Science, University of California, Los Angeles, Los Angeles, California 90095, United States
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Myung-Geun Han
- Condensed Matter Physics and Materials Science Division, Brookhaven National Laboratory, Upton, New York 11973, United States
| | - Aubrey N Penn
- MIT.nano, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Alexandre C Foucher
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Michael Geiwitz
- Department of Physics, Boston College, Chestnut Hill, Massachusetts 02467, United States
| | - Kenneth Stephen Burch
- Department of Physics, Boston College, Chestnut Hill, Massachusetts 02467, United States
| | - Lukas Dekanovsky
- Department of Inorganic Chemistry, University of Chemistry and Technology Prague, Technická 5, Prague 6 166 28, Czech Republic
| | - Zdeněk Sofer
- Department of Inorganic Chemistry, University of Chemistry and Technology Prague, Technická 5, Prague 6 166 28, Czech Republic
| | - Yu Liu
- Condensed Matter Physics and Materials Science Division, Brookhaven National Laboratory, Upton, New York 11973, United States
- Center for Correlated Matter and School of Physics, Zhejiang University, Hangzhou 310058, People's Republic of China
| | - Cedomir Petrovic
- Condensed Matter Physics and Materials Science Division, Brookhaven National Laboratory, Upton, New York 11973, United States
- Shanghai Key Laboratory of Material Frontiers Research in Extreme Environments (MFree), Shanghai Advanced Research in Physical Sciences (SHARPS), Pudong, Shanghai 201203, People's Republic of China
| | - Frances M Ross
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Yimei Zhu
- Condensed Matter Physics and Materials Science Division, Brookhaven National Laboratory, Upton, New York 11973, United States
| | - Prineha Narang
- Division of Physical Sciences, College of Letters and Science, University of California, Los Angeles, Los Angeles, California 90095, United States
- Electrical and Computer Engineering Department, University of California, Los Angeles, Los Angeles, California 90095, United States
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2
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Feng X, Yan S, Zhang X, Yin L, Wang H, Wen Y, Yao J, Wang H, Cheng R, Li Z, He J. Spontaneous Skyrmion Bubbles in an Iron-Silicon Alloy with Uniaxial Magnetic Anisotropy. ACS NANO 2024; 18:8475-8483. [PMID: 38456704 DOI: 10.1021/acsnano.4c00658] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/09/2024]
Abstract
The magnetic skyrmions exhibit intriguing topological behaviors, holding promise for future applications in the realm of spintronic devices. Despite recent advancements, achieving spontaneous magnetic skyrmions and topological transitions in magnets featuring uniaxial magnetic anisotropy, particularly at elevated temperatures (>100 K), remains a challenging endeavor. Here, single-crystal Fe5Si3 nanorods with the central symmetry and uniaxial magnetic anisotropy were successfully synthesized on a mica substrate through chemical vapor deposition, which exhibit a high Curie temperature (TC) of about 372 K. The real-time observation, facilitated by Lorentz transmission electron microscopy, revealed the spontaneous formation of magnetic skyrmions and evolution of domains in focused ion beam-prepared Fe5Si3 thin foils. Moreover, Fe5Si3 device transport measurements expose notable magnetoresistance (MR) effects, enabling the interchange between positive and negative MR across specific temperature settings. These results offer various potential avenues for exploring diverse topological spin textures and their formation mechanisms, indicating inventive applications for iron-silicon alloy in the realm of spintronics.
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Affiliation(s)
- Xiaoqiang Feng
- Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education, and School of Physics and Technology, Wuhan University, Wuhan 430072, China
| | - Shanshan Yan
- State Key Laboratory of Featured Metal Materials and Life-cycle Safety for Composite Structures, and School of Physical Science and Technology, Guangxi University, Nanning 530004, China
| | - Xiaolin Zhang
- Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education, and School of Physics and Technology, Wuhan University, Wuhan 430072, China
| | - Lei Yin
- Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education, and School of Physics and Technology, Wuhan University, Wuhan 430072, China
| | - Hao Wang
- Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education, and School of Physics and Technology, Wuhan University, Wuhan 430072, China
| | - Yao Wen
- Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education, and School of Physics and Technology, Wuhan University, Wuhan 430072, China
| | - Jiayi Yao
- Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education, and School of Physics and Technology, Wuhan University, Wuhan 430072, China
| | - Hao Wang
- Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education, and School of Physics and Technology, Wuhan University, Wuhan 430072, China
| | - Ruiqing Cheng
- Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education, and School of Physics and Technology, Wuhan University, Wuhan 430072, China
- Hubei Luojia Laboratory, Wuhan 430072, China
| | - Zian Li
- State Key Laboratory of Featured Metal Materials and Life-cycle Safety for Composite Structures, and School of Physical Science and Technology, Guangxi University, Nanning 530004, China
| | - Jun He
- Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education, and School of Physics and Technology, Wuhan University, Wuhan 430072, China
- Hubei Luojia Laboratory, Wuhan 430072, China
- Wuhan Institute of Quantum Technology, Wuhan 430206, China
- Institute of Semiconductors, Henan Academy of Sciences, Zhengzhou 450046, China
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3
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Bhukta M, Dohi T, Bharadwaj VK, Zarzuela R, Syskaki MA, Foerster M, Niño MA, Sinova J, Frömter R, Kläui M. Homochiral antiferromagnetic merons, antimerons and bimerons realized in synthetic antiferromagnets. Nat Commun 2024; 15:1641. [PMID: 38409221 PMCID: PMC10897388 DOI: 10.1038/s41467-024-45375-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Accepted: 01/23/2024] [Indexed: 02/28/2024] Open
Abstract
The ever-growing demand for device miniaturization and energy efficiency in data storage and computing technology has prompted a shift towards antiferromagnetic topological spin textures as information carriers. This shift is primarily owing to their negligible stray fields, leading to higher possible device density and potentially ultrafast dynamics. We realize in this work such chiral in-plane topological antiferromagnetic spin textures namely merons, antimerons, and bimerons in synthetic antiferromagnets by concurrently engineering the effective perpendicular magnetic anisotropy, the interlayer exchange coupling, and the magnetic compensation ratio. We demonstrate multimodal vector imaging of the three-dimensional Néel order parameter, revealing the topology of those spin textures and a globally well-defined chirality, which is a crucial requirement for controlled current-induced dynamics. Our analysis reveals that the interplay between interlayer exchange and interlayer magnetic dipolar interactions plays a key role to significantly reduce the critical strength of the Dzyaloshinskii-Moriya interaction required to stabilize topological spin textures, such as antiferromagnetic merons, in synthetic antiferromagnets, making them a promising platform for next-generation spintronics applications.
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Affiliation(s)
- Mona Bhukta
- Institute of Physics, Johannes Gutenberg-University Mainz, 55099, Mainz, Germany
| | - Takaaki Dohi
- Institute of Physics, Johannes Gutenberg-University Mainz, 55099, Mainz, Germany.
- Laboratory for Nanoelectronics and Spintronics, Research Institute of Electrical Communication, Tohoku University, 2-1-1 Katahira, Aoba, Sendai, 980-8577, Japan.
| | | | - Ricardo Zarzuela
- Institute of Physics, Johannes Gutenberg-University Mainz, 55099, Mainz, Germany
| | - Maria-Andromachi Syskaki
- Institute of Physics, Johannes Gutenberg-University Mainz, 55099, Mainz, Germany
- Singulus Technologies AG, Hanauer Landstrasse 107, 63796, Kahl am Main, Germany
| | - Michael Foerster
- ALBA Synchrotron Light Facility, 08290, Cerdanyola del Vallés, Barcelona, Spain
| | - Miguel Angel Niño
- ALBA Synchrotron Light Facility, 08290, Cerdanyola del Vallés, Barcelona, Spain
| | - Jairo Sinova
- Institute of Physics, Johannes Gutenberg-University Mainz, 55099, Mainz, Germany
| | - Robert Frömter
- Institute of Physics, Johannes Gutenberg-University Mainz, 55099, Mainz, Germany.
| | - Mathias Kläui
- Institute of Physics, Johannes Gutenberg-University Mainz, 55099, Mainz, Germany.
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4
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Man P, Huang L, Zhao J, Ly TH. Ferroic Phases in Two-Dimensional Materials. Chem Rev 2023; 123:10990-11046. [PMID: 37672768 DOI: 10.1021/acs.chemrev.3c00170] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/08/2023]
Abstract
Two-dimensional (2D) ferroics, namely ferroelectric, ferromagnetic, and ferroelastic materials, are attracting rising interest due to their fascinating physical properties and promising functional applications. A variety of 2D ferroic phases, as well as 2D multiferroics and the novel 2D ferrovalleytronics/ferrotoroidics, have been recently predicted by theory, even down to the single atomic layers. Meanwhile, some of them have already been experimentally verified. In addition to the intrinsic 2D ferroics, appropriate stacking, doping, and defects can also artificially regulate the ferroic phases of 2D materials. Correspondingly, ferroic ordering in 2D materials exhibits enormous potential for future high density memory devices, energy conversion devices, and sensing devices, among other applications. In this paper, the recent research progresses on 2D ferroic phases are comprehensively reviewed, with emphasis on chemistry and structural origin of the ferroic properties. In addition, the promising applications of the 2D ferroics for information storage, optoelectronics, and sensing are also briefly discussed. Finally, we envisioned a few possible pathways for the future 2D ferroics research and development. This comprehensive overview on the 2D ferroic phases can provide an atlas for this field and facilitate further exploration of the intriguing new materials and physical phenomena, which will generate tremendous impact on future functional materials and devices.
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Affiliation(s)
- Ping Man
- Department of Chemistry and Center of Super-Diamond & Advanced Films (COSDAF), City University of Hong Kong, Kowloon, Hong Kong 999077, P. R. China
- City University of Hong Kong Shenzhen Research Institute, Shenzhen 518057, P. R. China
| | - Lingli Huang
- Department of Chemistry and Center of Super-Diamond & Advanced Films (COSDAF), City University of Hong Kong, Kowloon, Hong Kong 999077, P. R. China
- City University of Hong Kong Shenzhen Research Institute, Shenzhen 518057, P. R. China
| | - Jiong Zhao
- Department of Applied Physics, The Hong Kong Polytechnic University, Kowloon, Hong Kong 999077, P. R. China
- The Hong Kong Polytechnic University Shenzhen Research Institute, Shenzhen 518057, P. R. China
| | - Thuc Hue Ly
- Department of Chemistry and Center of Super-Diamond & Advanced Films (COSDAF), City University of Hong Kong, Kowloon, Hong Kong 999077, P. R. China
- City University of Hong Kong Shenzhen Research Institute, Shenzhen 518057, P. R. China
- Department of Chemistry and State Key Laboratory of Marine Pollution, City University of Hong Kong, Kowloon, Hong Kong 999077, P. R. China
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5
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Song Y, Xu T, Zhao G, Xu Y, Zhong Z, Zheng X, Shi N, Zhou C, Hao Y, Huang Q, Xing X, Zhang Y, Chen J. High-density, spontaneous magnetic biskyrmions induced by negative thermal expansion in ferrimagnets. SCIENCE ADVANCES 2023; 9:eadi1984. [PMID: 37672584 PMCID: PMC10482331 DOI: 10.1126/sciadv.adi1984] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2023] [Accepted: 08/04/2023] [Indexed: 09/08/2023]
Abstract
Magnetic skyrmions are topologically protected quasiparticles that are promising for applications in spintronics. However, the low stability of most magnetic skyrmions leads to either a narrow temperature range in which they can exist, a low density of skyrmions, or the need for an external magnetic field, which greatly limits their wide application. In this study, high-density, spontaneous magnetic biskyrmions existing within a wide temperature range and without the need for a magnetic field were formed in ferrimagnets owing to the existence of a negative thermal expansion of the lattice. Moreover, a strong connection between the atomic-scale ferrimagnetic structure and nanoscale magnetic domains in Ho(Co,Fe)3 was revealed via in situ neutron powder diffraction and Lorentz transmission electron microscopy measurements. The critical role of the negative thermal expansion in generating biskyrmions in HoCo3 based on the magnetoelastic coupling effect is further demonstrated by comparing the behavior of HoCo2.8Fe0.2 with a positive thermal expansion.
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Affiliation(s)
- Yuzhu Song
- Beijing Advanced Innovation Center for Materials Genome Engineering, Department of Physical Chemistry, University of Science and Technology Beijing, Beijing 100083, China
| | - Tiankuo Xu
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Guoping Zhao
- College of Physics and Electronic Engineering and Institute of Solid State Physics, Sichuan Normal University, Chengdu 610066, China
| | - Yuanji Xu
- Institute for Applied Physics, University of Science and Technology Beijing, Beijing 100083, China
| | - Zhicheng Zhong
- Key Laboratory of Magnetic Materials Devices & Zhejiang Province Key Laboratory of Magnetic Materials and Application Technology, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201, China
| | - Xinqi Zheng
- School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China
| | - Naike Shi
- Beijing Advanced Innovation Center for Materials Genome Engineering, Department of Physical Chemistry, University of Science and Technology Beijing, Beijing 100083, China
| | - Chang Zhou
- State Key Laboratory for Advanced Metals and Materials, University of Science and Technology Beijing, Beijing 100083, China
| | - Yiqing Hao
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433, China
| | - Qingzhen Huang
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg MD, 20899-6102, USA
| | - Xianran Xing
- Institute of Solid State Chemistry, University of Science and Technology Beijing, Beijing 100083, China
| | - Ying Zhang
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Jun Chen
- Beijing Advanced Innovation Center for Materials Genome Engineering, Department of Physical Chemistry, University of Science and Technology Beijing, Beijing 100083, China
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6
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Ghosh S, Low A, Ghorai S, Mandal K, Thirupathaiah S. Tuning of electrical, magnetic, and topological properties of magnetic Weyl semimetal Mn3+xGe by Fe doping. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2023; 35:485701. [PMID: 37604158 DOI: 10.1088/1361-648x/acf262] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2023] [Accepted: 08/21/2023] [Indexed: 08/23/2023]
Abstract
We report on the tuning of electrical, magnetic, and topological properties of the magnetic Weyl semimetal (Mn3+xGe) by Fe doping at the Mn site, Mn(3+x)-δFeδGe (δ= 0, 0.30, and 0.62). Fe doping significantly changes the electrical and magnetic properties of Mn3+xGe. The resistivity of the parent compound displays metallic behavior, the system withδ= 0.30 of Fe doping exhibits semiconducting or bad-metallic behavior, and the system withδ= 0.62 of Fe doping demonstrates a metal-insulator transition at around 100 K. Further, we observe that the Fe doping increases in-plane ferromagnetism, magnetocrystalline anisotropy, and induces a spin-glass state at low temperatures. Surprisingly, topological Hall state has been noticed at a Fe doping ofδ= 0.30 that is not found in the parent compound or withδ= 0.62 of Fe doping. In addition, spontaneous anomalous Hall effect observed in the parent system is significantly reduced with increasing Fe doping concentration.
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Affiliation(s)
- Susanta Ghosh
- Department of Condensed Matter and Materials Physics, S. N. Bose National Centre for Basic Sciences, Kolkata, West Bengal 700106, India
| | - Achintya Low
- Department of Condensed Matter and Materials Physics, S. N. Bose National Centre for Basic Sciences, Kolkata, West Bengal 700106, India
| | - Soumya Ghorai
- Department of Condensed Matter and Materials Physics, S. N. Bose National Centre for Basic Sciences, Kolkata, West Bengal 700106, India
| | - Kalyan Mandal
- Department of Condensed Matter and Materials Physics, S. N. Bose National Centre for Basic Sciences, Kolkata, West Bengal 700106, India
| | - Setti Thirupathaiah
- Department of Condensed Matter and Materials Physics, S. N. Bose National Centre for Basic Sciences, Kolkata, West Bengal 700106, India
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7
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Zhang H, Wang Z, Dahlbom D, Barros K, Batista CD. CP 2 skyrmions and skyrmion crystals in realistic quantum magnets. Nat Commun 2023; 14:3626. [PMID: 37336881 DOI: 10.1038/s41467-023-39232-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Accepted: 06/05/2023] [Indexed: 06/21/2023] Open
Abstract
Magnetic skyrmions are nanoscale topological textures that have been recently observed in different families of quantum magnets. These objects are called CP1 skyrmions because they are built from dipoles-the target manifold is the 1D complex projective space, CP1 ≅ S2. Here we report the emergence of magnetic CP2 skyrmions in a realistic spin-1 model, which includes both dipole and quadrupole moments. Unlike CP1 skyrmions, CP2 skyrmions can also arise as metastable textures of quantum paramagnets, opening a new road to discover emergent topological solitons in non-magnetic materials. The quantum phase diagram of the spin-1 model also includes magnetic field-induced CP2 skyrmion crystals that can be detected with regular momentum- (diffraction) and real-space (Lorentz transmission electron microscopy) experimental techniques.
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Affiliation(s)
- Hao Zhang
- Department of Physics and Astronomy, The University of Tennessee, Knoxville, TN, 37996, USA.
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA.
- Theoretical Division and CNLS, Los Alamos National Laboratory, Los Alamos, NM, 87545, USA.
| | - Zhentao Wang
- Department of Physics and Astronomy, The University of Tennessee, Knoxville, TN, 37996, USA
- School of Physics and Astronomy, University of Minnesota, Minneapolis, MN, 55455, USA
- Center for Correlated Matter and School of Physics, Zhejiang University, Hangzhou, 310058, China
| | - David Dahlbom
- Department of Physics and Astronomy, The University of Tennessee, Knoxville, TN, 37996, USA
| | - Kipton Barros
- Theoretical Division and CNLS, Los Alamos National Laboratory, Los Alamos, NM, 87545, USA
| | - Cristian D Batista
- Department of Physics and Astronomy, The University of Tennessee, Knoxville, TN, 37996, USA.
- Quantum Condensed Matter Division and Shull-Wollan Center, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA.
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8
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Zambrano-Rabanal C, Valderrama B, Tejo F, Elías RG, Nunez AS, Carvalho-Santos VL, Vidal-Silva N. Magnetostatic interaction between Bloch point nanospheres. Sci Rep 2023; 13:7171. [PMID: 37137960 PMCID: PMC10156691 DOI: 10.1038/s41598-023-34167-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2023] [Accepted: 04/25/2023] [Indexed: 05/05/2023] Open
Abstract
Three-dimensional topological textures have become a topic of intense interest in recent years. This work uses analytical and numerical calculations to determine the magnetostatic field produced by a Bloch point (BP) singularity confined in a magnetic nanosphere. It is observed that BPs hosted in a nanosphere generate magnetic fields with quadrupolar nature. This finding is interesting because it shows the possibility of obtaining quadrupole magnetic fields with just one magnetic particle, unlike other propositions considering arrays of magnetic elements to generate this kind of field. The obtained magnetostatic field allows us to determine the interaction between two BPs as a function of the relative orientation of their polarities and the distance between them. It is shown that depending on the rotation of one BP related to the other, the magnetostatic interaction varies in strength and character, being attractive or repulsive. The obtained results reveal that the BP interaction has a complex behavior beyond topological charge-mediated interaction.
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Affiliation(s)
| | - Boris Valderrama
- Facultad de Física, Pontificia Universidad Católica de Chile, Casilla 306, Santiago, Chile
| | - Felipe Tejo
- Escuela de Ingeniería, Universidad Central de Chile, Avda. Santa Isabel 1186, 8330601, Santiago, Chile
| | - Ricardo Gabriel Elías
- Departamento de Física, Universidad de Santiago de Chile (USACH), Avda. Víctor Jara 3493, Santiago, Chile
| | - Alvaro S Nunez
- Departamento de Física, FCFM, Universidad de Chile, Santiago, Chile
- Centro de nanociencia y nanotecnología CEDENNA, Avda. Ecuador 3493, Santiago, Chile
| | | | - Nicolás Vidal-Silva
- Departamento de Ciencias Físicas, Universidad de La Frontera, Casilla 54-D, Temuco, Chile.
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9
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Li Z, Yin Q, Jiang Y, Zhu Z, Gao Y, Wang S, Shen J, Zhao T, Cai J, Lei H, Lin SZ, Zhang Y, Shen B. Discovery of Topological Magnetic Textures near Room Temperature in Quantum Magnet TbMn 6 Sn 6. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2211164. [PMID: 36856016 DOI: 10.1002/adma.202211164] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Revised: 02/19/2023] [Indexed: 05/19/2023]
Abstract
The study of topology in quantum materials has fundamentally advanced the understanding in condensed matter physics and potential applications in next-generation quantum information technology. Recently, the discovery of a topological Chern phase in the spin-orbit-coupled Kagome lattice TbMn6 Sn6 has attracted considerable interest. Whereas these phenomena highlight the contribution of momentum space Berry curvature and Chern gap on the electronic transport properties, less is known about the intrinsic real space magnetic texture, which is crucial for understanding the electronic properties and further exploring the unique quantum behavior. Here, the stabilization of topological magnetic skyrmions in TbMn6 Sn6 using Lorentz transmission electron microscopy near room temperature, where the spins experience full spin reorientation transition between the a- and c-axes, is directly observed. An effective spin Hamiltonian based on the Ginzburg-Landau theory is constructed and micromagnetic simulation is performed to clarify the critical role of Ruderman-Kittel-Kasuya-Yosida interaction on the stabilization of skyrmion lattice. These results not only uncover nontrivial spin topological texture in TbMn6 Sn6 , but also provide a solid basis to study its interplay with electronic topology.
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Affiliation(s)
- Zhuolin Li
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, 101408, China
| | - Qiangwei Yin
- Laboratory for Neutron Scattering, Beijing Key Laboratory of Opto-Electronic Functional Materials & Micro-Nano Devices, Department of Physics, Renmin University of China, Beijing, 100872, China
| | - Yi Jiang
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, 101408, China
| | - ZhaoZhao Zhu
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, 101408, China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong, 523808, China
| | - Yang Gao
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, 101408, China
- School of Materials Science and Engineering, Anhui University, Hefei, 230601, China
| | - Shouguo Wang
- School of Materials Science and Engineering, Anhui University, Hefei, 230601, China
| | - Jun Shen
- Department of Energy and Power Engineering, School of Mechanical Engineering, Beijing Institute of Technology, Beijing, 100081, China
| | - Tongyun Zhao
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, 101408, China
| | - Jianwang Cai
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, 101408, China
| | - Hechang Lei
- Laboratory for Neutron Scattering, Beijing Key Laboratory of Opto-Electronic Functional Materials & Micro-Nano Devices, Department of Physics, Renmin University of China, Beijing, 100872, China
| | - Shi-Zeng Lin
- Theoretical Division and Center for Integrated Nanotechnologies, Los Alamos National Laboratory, Los Alamos, NM, 87545, USA
| | - Ying Zhang
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, 101408, China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong, 523808, China
| | - Baogen Shen
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, 101408, China
- Ningbo Institute of Materials Technology & Engineering, Chinese Academy of Sciences, Ningbo, Zhejiang, 315201, China
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10
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Hou Z, Wang Q, Zhang Q, Zhang S, Zhang C, Zhou G, Gao X, Zhao G, Zhang X, Wang W, Liu J. Current-Induced Reversible Split of Elliptically Distorted Skyrmions in Geometrically Confined Fe 3 Sn 2 Nanotrack. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2023; 10:e2206106. [PMID: 36683184 PMCID: PMC10037979 DOI: 10.1002/advs.202206106] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/29/2022] [Revised: 12/16/2022] [Indexed: 06/17/2023]
Abstract
Skyrmions are swirling spin textures with topological characters promising for future spintronic applications. Skyrmionic devices typically rely on the electrical manipulation of skyrmions with a circular shape. However, manipulating elliptically distorted skyrmions can lead to numerous exotic magneto-electrical functions distinct from those of conventional circular skyrmions, significantly broadening the capability to design innovative spintronic devices. Despite the promising potential, its experimental realization so far remains elusive. In this study, the current-driven dynamics of the elliptically distorted skyrmions in geometrically confined magnet Fe3 Sn2 is experimentally explored. This study finds that the elliptical skyrmions can reversibly split into smaller-sized circular skyrmions at a current density of 3.8 × 1010 A m-2 with the current injected along their minor axis. Combined experiments with micromagnetic simulations reveal that this dynamic behavior originates from a delicate interplay of the spin-transfer torque, geometrical confinement, and pinning effect, and strongly depends on the ratio of the major axis to the minor axis of the elliptical skyrmions. The results indicate that the morphology is a new degree of freedom for manipulating the current-driven dynamics of skyrmions, providing a compelling route for the future development of spintronic devices.
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Affiliation(s)
- Zhipeng Hou
- Guangdong Provincial Key Laboratory of Optical Information Materials and Technology & Institute for Advanced MaterialsSouth China Academy of Advanced OptoelectronicsSouth China Normal UniversityGuangzhou510006P. R. China
| | - Qingping Wang
- College of Electronic information and automationAba Teachers UniversityPixian StreetChengdu623002China
- College of Physics and Electronic EngineeringSichuan Normal UniversityChengdu610068China
| | - Qiang Zhang
- Core Technology PlatformsNew York University Abu DhabiP.O. Box 129188Abu DhabiUnited Arab Emirates
| | - Senfu Zhang
- Physical Science and Engineering DivisionKing Abdullah University of Science and TechnologyThuwal23955‐6900Saudi Arabia
| | - Chenhui Zhang
- Physical Science and Engineering DivisionKing Abdullah University of Science and TechnologyThuwal23955‐6900Saudi Arabia
| | - Guofu Zhou
- Guangdong Provincial Key Laboratory of Optical Information Materials and Technology & Institute for Advanced MaterialsSouth China Academy of Advanced OptoelectronicsSouth China Normal UniversityGuangzhou510006P. R. China
| | - Xingsen Gao
- Guangdong Provincial Key Laboratory of Optical Information Materials and Technology & Institute for Advanced MaterialsSouth China Academy of Advanced OptoelectronicsSouth China Normal UniversityGuangzhou510006P. R. China
| | - Guoping Zhao
- College of Physics and Electronic EngineeringSichuan Normal UniversityChengdu610068China
| | - Xixiang Zhang
- Physical Science and Engineering DivisionKing Abdullah University of Science and TechnologyThuwal23955‐6900Saudi Arabia
| | - Wenhong Wang
- School of Electronic and Information EngineeringTiangong UniversityTianjin300387China
| | - Junming Liu
- Guangdong Provincial Key Laboratory of Optical Information Materials and Technology & Institute for Advanced MaterialsSouth China Academy of Advanced OptoelectronicsSouth China Normal UniversityGuangzhou510006P. R. China
- Laboratory of Solid State Microstructures and Innovation Center of Advanced MicrostructuresNanjing UniversityNanjing211102China
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11
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Corona RM, Saavedra E, Castillo-Sepulveda S, Escrig J, Altbir D, Carvalho-Santos VL. Curvature-induced stabilization and field-driven dynamics of magnetic hopfions in toroidal nanorings. NANOTECHNOLOGY 2023; 34:165702. [PMID: 36689765 DOI: 10.1088/1361-6528/acb557] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2022] [Accepted: 01/23/2023] [Indexed: 06/17/2023]
Abstract
Three dimensional magnetic textures are a cornerstone in magnetism research. In this work, we analyze the stabilization and dynamic response of a magnetic hopfion hosted in a toroidal nanoring with intrinsic Dzyaloshinskii-Moriya interaction simulating FeGe. Our results evidence that unlike their planar counterparts, where perpendicular magnetic anisotropies are necessary to stabilize hopfions, the shape anisotropy originated on the torus symmetry naturally yields the nucleation of these topological textures. We also analyze the magnetization dynamical response by applying a magnetic field pulse to differentiate among several magnetic patterns. Finally, to understand the nature of spin wave modes, we analyze the spatial distributions of the resonant mode amplitudes and phases and describe the differences among bulk and surface modes. Importantly, hopfions lying in toroidal nanorings present a non-circularly symmetric poloidal resonant mode, which is not observed in other systems hosting hopfions.
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Affiliation(s)
- R M Corona
- Universidad de Santiago de Chile, Departamento de Física, Avda. Víctor Jara 3493, 9170124 Santiago, Chile
- Center for the Development of Nanoscience and Nanotechnology, CEDENNA, Avda. Libertador Bernardo O'Higgins 3363, 9170124 Santiago, Chile
| | - E Saavedra
- Universidad de Santiago de Chile, Departamento de Física, Avda. Víctor Jara 3493, 9170124 Santiago, Chile
- Center for the Development of Nanoscience and Nanotechnology, CEDENNA, Avda. Libertador Bernardo O'Higgins 3363, 9170124 Santiago, Chile
| | - S Castillo-Sepulveda
- Departamento de Ingeniería, Universidad Autónoma de Chile, Avda. Pedro de Valdivia 425, Providencia, Chile
| | - J Escrig
- Universidad de Santiago de Chile, Departamento de Física, Avda. Víctor Jara 3493, 9170124 Santiago, Chile
- Center for the Development of Nanoscience and Nanotechnology, CEDENNA, Avda. Libertador Bernardo O'Higgins 3363, 9170124 Santiago, Chile
| | - D Altbir
- Universidad de Santiago de Chile, Departamento de Física, Avda. Víctor Jara 3493, 9170124 Santiago, Chile
- Center for the Development of Nanoscience and Nanotechnology, CEDENNA, Avda. Libertador Bernardo O'Higgins 3363, 9170124 Santiago, Chile
| | - V L Carvalho-Santos
- Universidade Federal de Viçosa, Departamento de Física, Avenida Peter Henry Rolfs s/n, 36570-000, Viçosa, MG, Brasil
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12
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Zuo S, Qiao K, Zhang Y, Zhao T, Jiang C, Shen B. Spontaneous Biskyrmion Lattice in a Centrosymmetric Rhombohedral Rare-Earth Magnet with Easy-Plane Anisotropy. NANO LETTERS 2023; 23:550-557. [PMID: 36633430 DOI: 10.1021/acs.nanolett.2c04001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Magnetic skyrmion and its derivatives have demonstrated fascinating topological behaviors with potential applications in future spintronic devices. Despite the recent progress, the spontaneous skyrmion lattice and successive topological transition in the magnets with easy-plane magnetic anisotropy are still elusive especially at room temperature. Here, in a centrosymmetric rhombohedral Nd2Co17 magnet with easy-plane magnetic anisotropy, spontaneous biskyrmions are observed over a wide temperature range across room temperature, and then evolve into enclosed in-plane domains with nanometric size due to the enhancement of the planar magnetic anisotropy. The spontaneous generation of the biskyrmion lattice and its evolution along different crystal orientations demonstrate the crucial role of intrinsic bi-anisotropy and demagnetization effects. This discovery provides a fundamental insight into the nature of topological magnetic textures in easy-plane anisotropy materials and suggests an arena to explore the topological states in rare-earth magnets as well as their applications in spintronics.
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Affiliation(s)
- Shulan Zuo
- School of Materials Science and Engineering, Beihang University, Beijing100191, P. R. China
| | - Kaiming Qiao
- School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing100083, P. R. China
| | - Ying Zhang
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing100190, P. R. China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong523808, P. R. China
| | - Tongyun Zhao
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing100190, P. R. China
| | - Chengbao Jiang
- School of Materials Science and Engineering, Beihang University, Beijing100191, P. R. China
| | - Baogen Shen
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing100190, P. R. China
- Ningbo Institute of Materials Technology & Engineering, Chinese Academy of Sciences, Ningbo, Zhejiang315201, P. R. China
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13
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Zuo S, Qiao K, Zhang Y, Li Z, Zhao T, Jiang C, Shen B. Spontaneous Topological States and Their Mutual Transformations in a Rare-Earth Ferrimagnet. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2023; 10:e2205574. [PMID: 36403248 PMCID: PMC9875609 DOI: 10.1002/advs.202205574] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/11/2022] [Revised: 11/02/2022] [Indexed: 06/16/2023]
Abstract
Nontrivial chiral spin textures with nanometric sizes and novel characteristics (e.g., magnetic skyrmions) are promising for encoding information bits in future energy-efficient and high-density spintronic devices. Because of antiferromagnetic exchange coupling, skyrmions in ferrimagnetic materials exhibit many advantages in terms of size and efficient manipulation, which allow them to overcome the limitations of ferromagnetic skyrmions. Despite recent progress, ferrimagnetic skyrmions have been observed only in few films in the presence of external fields, while those in ferrimagnetic bulks remain elusive. This study reports on spontaneously generated zero-field ground-state magnetic skyrmions and their subsequent transformation into traditional magnetic bubbles via intermediate states of (bi-)target bubbles during a magnetic anisotropy change in the rare-earth ferrimagnetic crystal DyFe11 Ti. Spontaneous reversible topological transformation driven by a temperature-induced spin reorientation transition is directly distinguished using Lorentz transmission electron microscopy. The spontaneous generation of magnetic skyrmions and successive topological transformations in ferrimagnetic DyFe11 Ti are expected to advance the design of topological spin textures with versatile properties and potential applications in rare-earth magnets.
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Affiliation(s)
- Shulan Zuo
- Key Laboratory of Aerospace Materials and Performance (Ministry of Education)School of Materials Science and EngineeringBeihang UniversityBeijing100191P. R. China
| | - Kaiming Qiao
- School of Materials Science and EngineeringUniversity of Science and Technology BeijingBeijing100083P. R. China
| | - Ying Zhang
- Beijing National Laboratory for Condensed Matter PhysicsInstitute of PhysicsChinese Academy of SciencesBeijing100190P. R. China
- Songshan Lake Materials LaboratoryDongguanGuangdong523808P. R. China
| | - Zhuolin Li
- Beijing National Laboratory for Condensed Matter PhysicsInstitute of PhysicsChinese Academy of SciencesBeijing100190P. R. China
| | - Tongyun Zhao
- Beijing National Laboratory for Condensed Matter PhysicsInstitute of PhysicsChinese Academy of SciencesBeijing100190P. R. China
| | - Chengbao Jiang
- Key Laboratory of Aerospace Materials and Performance (Ministry of Education)School of Materials Science and EngineeringBeihang UniversityBeijing100191P. R. China
| | - Baogen Shen
- Beijing National Laboratory for Condensed Matter PhysicsInstitute of PhysicsChinese Academy of SciencesBeijing100190P. R. China
- Ningbo Institute of Materials Technology & EngineeringChinese Academy of SciencesNingboZhejiang315201P. R. China
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14
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Iroulart E, Rosales HD. Skyrmion-skyrmion interaction induced by itinerant electrons in a ferromagnetic strip. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2022; 35:045601. [PMID: 36541515 DOI: 10.1088/1361-648x/aca5dc] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Accepted: 11/24/2022] [Indexed: 06/17/2023]
Abstract
Magnetic skyrmions are promising spin textures for building next-generation magnetic memories and spintronic devices. Nevertheless, one of the major challenges in realizing skyrmion-based devices is the stabilization of ordered arrays of these spin textures in different geometries. Here we numerically study the skyrmion-skyrmion interaction potential that arises due to the dynamics of itinerant electrons coupled to the magnetic texture in a ferromagnetic background with racetrack geometry. We consider different topological textures (ferromagnetic (FM) and antiferromagnetic (AFM)), namely: skyrmions, antiskyrmions and biskyrmions. We show that at low electron filling, for sufficiently short separation, the skyrmions strongly couple each other yielding a bound-state bound by electronic dynamics. However, when the filling is increased, the interaction potential energy presents local minima at specific values of the skyrmion-skyrmion distance. Each of these local minima corresponds to energetically stable positions of skyrmions which are 'protected' by well-defined energy barriers. By inspecting the local charge density, we find that in the case of AFM skyrmions, the local antiferromagnetic nature prevents electronic penetration into the core, allowing the AFM skyrmions to be seen as infinite potential barriers for electrons.
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Affiliation(s)
- E Iroulart
- Instituto de Física de Líquidos y Sistemas Biológicos, CONICET, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, 1900 La Plata, Argentina
- Departamento de Física, FCE, UNLP, La Plata, Argentina
| | - H D Rosales
- Instituto de Física de Líquidos y Sistemas Biológicos, CONICET, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, 1900 La Plata, Argentina
- Departamento de Ciencias Básicas, Facultad de Ingeniería, UNLP, La Plata, Argentina
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15
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Liu K, Kang C, Tian J, Song Y, She L, Liu X, Zhang W. Canonical Spin Glass and the Anomalous Hall Effect in a Centrosymmetric Ferrimagnet. J Phys Chem Lett 2022; 13:10048-10055. [PMID: 36264631 DOI: 10.1021/acs.jpclett.2c02646] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Centrosymmetric ferro/ferrimagnets provide an ideal arena for fundamental research due to their fascinating magnetic and structural characters. In this work, the Co0.8MnSn compound with a single hexagonal phase was successfully synthesized, and the magnetic phase transition and magnetic and electronic properties have been systematically investigated. Interestingly, Arrott plots and normalized magnetic entropy changes derived from the isothermal magnetizing curves may imply the first-order nature of the magnetic ordering transition around TC ∼ 121 K. The AC susceptibility analysis and detailed nonequilibrium dynamical studies (including magnetic aging, rejuvenation, and memory effects) reveal the canonical spin-glass state of Co0.8MnSn at lower temperature. Further, negative magnetoresistance and the anomalous Hall effect dominated by a commonly intrinsic term are obtained. Moreover, the field-dependent AC susceptibility data indicated that complicated and nontrivial magnetic spin textures should exist in the compound. These studies may open up further research opportunities in exploring emergent physical phenomena and potential applications in centrosymmetric magnets.
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Affiliation(s)
- Kai Liu
- Henan Key Lab of Photovoltaic Materials and Center for Topological Functional Materials, Henan University, Kaifeng475004, China
| | - Chaoyang Kang
- Henan Key Lab of Photovoltaic Materials and Center for Topological Functional Materials, Henan University, Kaifeng475004, China
| | - Jianjun Tian
- Henan Key Lab of Photovoltaic Materials and Center for Topological Functional Materials, Henan University, Kaifeng475004, China
| | - Yeheng Song
- Henan Key Lab of Photovoltaic Materials and Center for Topological Functional Materials, Henan University, Kaifeng475004, China
| | - Limin She
- Henan Key Lab of Photovoltaic Materials and Center for Topological Functional Materials, Henan University, Kaifeng475004, China
| | - Xiansheng Liu
- Henan Key Lab of Photovoltaic Materials and Center for Topological Functional Materials, Henan University, Kaifeng475004, China
| | - Weifeng Zhang
- Henan Key Lab of Photovoltaic Materials and Center for Topological Functional Materials, Henan University, Kaifeng475004, China
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16
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Qin G, Zhang R, Yang C, Lv X, Pei K, Yang L, Liu X, Zhang X, Che R. Magnetic-Field-Assisted Diffusion Motion of Magnetic Skyrmions. ACS NANO 2022; 16:15927-15934. [PMID: 36166823 DOI: 10.1021/acsnano.2c03046] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Studies of the diffusion dynamics of magnetic skyrmions have generated widespread interest in both fundamental physics and spintronics applications. Here we report the magnetic-field-assisted diffusion motion of skyrmions in a microstructured chiral FeGe magnet. We demonstrate the enhancement of diffusion motion of magnetic skyrmions that is manipulated and driven by an oscillatory magnetic field. Further, the directed diffusion of skyrmions is observed when an in-plane field was introduced to break the symmetry of the system. Finally, we demonstrate the application of a magnetic field can induce an arrangements transition of skyrmions assemble in microstructure, that is, from a stiff hexagonal lattice to a weak interactional isotropic state. By using a step-ascended magnetic field we finished the observation of a particle-like diffusive motion for magnetic skyrmions that transport from high-concentration regions to low-concentration regions and the diffusion flux is proportional to the concentration gradient followed Fick's law.
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Affiliation(s)
- Gang Qin
- Laboratory of Advanced Materials, Shanghai Key Lab of Molecular Catalysis and Innovative Materials, Department of Materials Science, Fudan University, Shanghai 200438, P. R. China
| | - Ruixuan Zhang
- Laboratory of Advanced Materials, Shanghai Key Lab of Molecular Catalysis and Innovative Materials, Department of Materials Science, Fudan University, Shanghai 200438, P. R. China
| | - Chendi Yang
- Laboratory of Advanced Materials, Shanghai Key Lab of Molecular Catalysis and Innovative Materials, Department of Materials Science, Fudan University, Shanghai 200438, P. R. China
| | - Xiaowei Lv
- Laboratory of Advanced Materials, Shanghai Key Lab of Molecular Catalysis and Innovative Materials, Department of Materials Science, Fudan University, Shanghai 200438, P. R. China
| | - Ke Pei
- Laboratory of Advanced Materials, Shanghai Key Lab of Molecular Catalysis and Innovative Materials, Department of Materials Science, Fudan University, Shanghai 200438, P. R. China
| | - Liting Yang
- Laboratory of Advanced Materials, Shanghai Key Lab of Molecular Catalysis and Innovative Materials, Department of Materials Science, Fudan University, Shanghai 200438, P. R. China
| | - Xianhu Liu
- Laboratory of Advanced Materials, Shanghai Key Lab of Molecular Catalysis and Innovative Materials, Department of Materials Science, Fudan University, Shanghai 200438, P. R. China
| | - Xuefeng Zhang
- Laboratory of Advanced Materials, Shanghai Key Lab of Molecular Catalysis and Innovative Materials, Department of Materials Science, Fudan University, Shanghai 200438, P. R. China
| | - Renchao Che
- Laboratory of Advanced Materials, Shanghai Key Lab of Molecular Catalysis and Innovative Materials, Department of Materials Science, Fudan University, Shanghai 200438, P. R. China
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17
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Zhang C, Liu C, Zhang S, Zhou B, Guan C, Ma Y, Algaidi H, Zheng D, Li Y, He X, Zhang J, Li P, Hou Z, Yin G, Liu K, Peng Y, Zhang XX. Magnetic Skyrmions with Unconventional Helicity Polarization in a Van Der Waals Ferromagnet. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2022; 34:e2204163. [PMID: 35975291 DOI: 10.1002/adma.202204163] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Revised: 08/10/2022] [Indexed: 06/15/2023]
Abstract
Skyrmion helicity, which defines the spin swirling direction, is a fundamental parameter that may be utilized to encode data bits in future memory devices. Generally, in centrosymmetric ferromagnets, dipole skyrmions with helicity of -π/2 and π/2 are degenerate in energy, leading to equal populations of both helicities. On the other hand, in chiral materials where the Dzyaloshinskii-Moriya interaction (DMI) prevails and the dipolar interaction is negligible, only a preferred helicity is selected by the type of DMI. However, whether there is a rigid boundary between these two regimes remains an open question. Herein, the observation of dipole skyrmions with unconventional helicity polarization in a van der Waals ferromagnet, Fe5- δ GeTe2 , is reported. Combining magnetometry, Lorentz transmission electron microscopy, electrical transport measurements, and micromagnetic simulations, the short-range superstructures in Fe5- δ GeTe2 resulting in a localized DMI contribution, which breaks the degeneracy of the opposite helicities and leads to the helicity polarization, is demonstrated. Therefore, the helicity feature in Fe5- δ GeTe2 is controlled by both the dipolar interaction and DMI that the former leads to Bloch-type skyrmions with helicity of ±π/2 whereas the latter breaks the helicity degeneracy. This work provides new insights into the skyrmion topology in van der Waals materials.
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Affiliation(s)
- Chenhui Zhang
- Physical Science and Engineering Division (PSE), King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Saudi Arabia
| | - Chen Liu
- Physical Science and Engineering Division (PSE), King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Saudi Arabia
| | - Senfu Zhang
- Key Laboratory for Magnetism and Magnetic Materials of Ministry of Education, School of Physical Science and Technology, Lanzhou University, Lanzhou, 730000, China
| | - Bojian Zhou
- School of Materials and Energy and Electron Microscopy Centre of Lanzhou University, Lanzhou University, Lanzhou, 730000, China
| | - Chaoshuai Guan
- School of Materials and Energy and Electron Microscopy Centre of Lanzhou University, Lanzhou University, Lanzhou, 730000, China
| | - Yinchang Ma
- Physical Science and Engineering Division (PSE), King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Saudi Arabia
| | - Hanin Algaidi
- Physical Science and Engineering Division (PSE), King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Saudi Arabia
| | - Dongxing Zheng
- Physical Science and Engineering Division (PSE), King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Saudi Arabia
| | - Yan Li
- Physical Science and Engineering Division (PSE), King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Saudi Arabia
| | - Xin He
- Physical Science and Engineering Division (PSE), King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Saudi Arabia
| | - Junwei Zhang
- School of Materials and Energy and Electron Microscopy Centre of Lanzhou University, Lanzhou University, Lanzhou, 730000, China
| | - Peng Li
- State Key Laboratory of Electronic Thin Film and Integrated Devices, University of Electronic Science and Technology of China, Chengdu, 610054, China
| | - Zhipeng Hou
- Guangdong Provincial Key Laboratory of Optical Information Materials and Technology & Institute for Advanced Materials, South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou, 510006, China
- National Center for International Research on Green Optoelectronics, South China Normal University, Guangzhou, 510006, China
| | - Gen Yin
- Physics Department, Georgetown University, Washington, DC, 20057, USA
| | - Kai Liu
- Physics Department, Georgetown University, Washington, DC, 20057, USA
| | - Yong Peng
- School of Materials and Energy and Electron Microscopy Centre of Lanzhou University, Lanzhou University, Lanzhou, 730000, China
| | - Xi-Xiang Zhang
- Physical Science and Engineering Division (PSE), King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Saudi Arabia
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18
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Liu J, Ding B, Liang J, Li X, Yao Y, Wang W. Magnetic Skyrmionic Bubbles at Room Temperature and Sign Reversal of the Topological Hall Effect in a Layered Ferromagnet Cr 0.87Te. ACS NANO 2022; 16:13911-13918. [PMID: 36000915 DOI: 10.1021/acsnano.2c02928] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
The search for materials that exhibit topologically protected spin configurations, such as magnetic skyrmions, continues to be fueled by the promise of outstanding candidate components for spin-based applications. In this study, in situ Lorentz transmission electron microscopy directly images Bloch-type magnetic skyrmionic bubbles in a layered ferromagnet Cr0.87Te single crystal. Owing to the competition between a magnetic dipole interaction and uniaxial easy axis anisotropy, nanoscale magnetic bubbles with random chirality can be observed in a wide temperature range covering room temperature when the external magnetic field is applied along the out-of-plane direction. Moreover, high-density and stable skyrmionic bubbles are successfully realized at zero magnetic field by appropriate field-cooling manipulation. Additionally, a sign reversal of the Hall effect and the derived topological Hall effect is observed and discussed. As quasi-two-dimensional materials, the binary chromium tellurides hosting magnetic skyrmions could have many applications in low-dimensional skyrmion-based spintronic devices in an ambient atmosphere.
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Affiliation(s)
- Jun Liu
- Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Bei Ding
- Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Jinjing Liang
- Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xue Li
- Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yuan Yao
- Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
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19
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Chauhan HC, Kumar B, Ghosh S. Origin of metamagnetism in skyrmion host Cu[Formula: see text]OSeO[Formula: see text]. Sci Rep 2022; 12:15971. [PMID: 36153357 PMCID: PMC9509362 DOI: 10.1038/s41598-022-20038-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2022] [Accepted: 09/07/2022] [Indexed: 11/30/2022] Open
Abstract
Skyrmion host chiral Cu[Formula: see text]OSeO[Formula: see text] has attracted researchers due to several intriguing properties. Observation of metamagnetism in low-temperature and low-field makes the magnetic properties of Cu[Formula: see text]OSeO[Formula: see text] more complex. Here, we present an investigation on metamagnetism in Cu[Formula: see text]OSeO[Formula: see text] by analyzing its structural and magnetic properties. Study of magnetic properties reveal spin-flip of one of the Cu[Formula: see text] ions, embedded in square pyramidal CuO[Formula: see text] polyhedra, due to the development of strain in low-temperature and low-field regime. The spin-flip is found to be the main reason for field-induced first-order metamagnetic transition. Magnetic phase diagram of Cu[Formula: see text]OSeO[Formula: see text] has been constructed with the help of magnetization analyses. It is argued that the metamagnetic hysteretic field region may be low-temperature skyrmion phase with additional spiral and tilted-conical phases. A tricritical point has been observed in the phase diagram at which first-order metamagnetic hysteretic field range ceases to exist.
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Affiliation(s)
| | - Birendra Kumar
- School of Physical Sciences, Jawaharlal Nehru University, New Delhi, 110067 India
| | - Subhasis Ghosh
- School of Physical Sciences, Jawaharlal Nehru University, New Delhi, 110067 India
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20
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Xu C, Li X, Chen P, Zhang Y, Xiang H, Bellaiche L. Assembling Diverse Skyrmionic Phases in Fe 3 GeTe 2 Monolayers. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2022; 34:e2107779. [PMID: 35023226 DOI: 10.1002/adma.202107779] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Revised: 01/05/2022] [Indexed: 06/14/2023]
Abstract
Skyrmionic magnetic states are promising in advanced spintronics. This topic is experiencing recent progress in 2D magnets, with, for example, a near 300 K Curie temperature observed in Fe3 GeTe2 . However, despite previous studies reporting skyrmions in Fe3 GeTe2 , such a system remains elusive, since it has been reported to host either Néel-type or Bloch-type textures, while a net Dzyaloshinskii-Moriya interaction (DMI) cannot occur in this compound for symmetry reasons. It is thus desirable to develop an accurate model to deeply understand Fe3 GeTe2 . Here, a newly developed method adopting spin invariants is applied to build a first-principle-based Hamiltonian, which predicts colorful topological defects assembled from the unit of Bloch lines, and reveals the critical role of specific forms of fourth-order interactions in Fe3 GeTe2 . Rather than the DMI, it is the multiple fourth-order interactions, with symmetry and spin-orbit couplings considered, that stabilize both Néel-type and Bloch-type skyrmions, as well as antiskyrmions, without any preference for clockwise versus counterclockwise spin rotation. This study also demonstrates that spin invariants can be used as a general approach to study complex magnetic interactions.
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Affiliation(s)
- Changsong Xu
- Key Laboratory of Computational Physical Sciences (Ministry of Education), Institute of Computational Physical Sciences, State Key Laboratory of Surface Physics, and Department of Physics, Fudan University, Shanghai, 200433, China
- Shanghai Qi Zhi Institute, Shanghai, 200232, China
- Physics Department and Institute for Nanoscience and Engineering, University of Arkansas, Fayetteville, AR, 72701, USA
| | - Xueyang Li
- Key Laboratory of Computational Physical Sciences (Ministry of Education), Institute of Computational Physical Sciences, State Key Laboratory of Surface Physics, and Department of Physics, Fudan University, Shanghai, 200433, China
- Shanghai Qi Zhi Institute, Shanghai, 200232, China
| | - Peng Chen
- Physics Department and Institute for Nanoscience and Engineering, University of Arkansas, Fayetteville, AR, 72701, USA
| | - Yun Zhang
- Physics Department and Institute for Nanoscience and Engineering, University of Arkansas, Fayetteville, AR, 72701, USA
- Department of Physics and Information Technology, Baoji University of Arts and Sciences, Baoji, 721016, China
| | - Hongjun Xiang
- Key Laboratory of Computational Physical Sciences (Ministry of Education), Institute of Computational Physical Sciences, State Key Laboratory of Surface Physics, and Department of Physics, Fudan University, Shanghai, 200433, China
- Shanghai Qi Zhi Institute, Shanghai, 200232, China
| | - Laurent Bellaiche
- Physics Department and Institute for Nanoscience and Engineering, University of Arkansas, Fayetteville, AR, 72701, USA
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21
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Stepanova M, Masell J, Lysne E, Schoenherr P, Köhler L, Paulsen M, Qaiumzadeh A, Kanazawa N, Rosch A, Tokura Y, Brataas A, Garst M, Meier D. Detection of Topological Spin Textures via Nonlinear Magnetic Responses. NANO LETTERS 2022; 22:14-21. [PMID: 34935368 PMCID: PMC8759079 DOI: 10.1021/acs.nanolett.1c02723] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Revised: 11/29/2021] [Indexed: 06/14/2023]
Abstract
Topologically nontrivial spin textures, such as skyrmions and dislocations, display emergent electrodynamics and can be moved by spin currents over macroscopic distances. These unique properties and their nanoscale size make them excellent candidates for the development of next-generation race-track memory and unconventional computing. A major challenge for these applications and the investigation of nanoscale magnetic structures in general is the realization of suitable detection schemes. We study magnetic disclinations, dislocations, and domain walls in FeGe and reveal pronounced responses that distinguish them from the helimagnetic background. A combination of magnetic force microscopy (MFM) and micromagnetic simulations links the response to the local magnetic susceptibility, that is, characteristic changes in the spin texture driven by the MFM tip. On the basis of the findings, which we explain using nonlinear response theory, we propose a read-out scheme using superconducting microcoils, presenting an innovative approach for detecting topological spin textures and domain walls in device-relevant geometries.
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Affiliation(s)
- Mariia Stepanova
- Department
of Materials Science and Engineering, Norwegian
University of Science and Technology (NTNU), Trondheim 7491, Norway
- Center
for Quantum Spintronics, Department of Physics,
Norwegian University of Science and Technology (NTNU), Trondheim 7491, Norway
| | - Jan Masell
- RIKEN
Center for Emergent Matter Science (CEMS), Wako 351-0198, Japan
| | - Erik Lysne
- Department
of Materials Science and Engineering, Norwegian
University of Science and Technology (NTNU), Trondheim 7491, Norway
- Center
for Quantum Spintronics, Department of Physics,
Norwegian University of Science and Technology (NTNU), Trondheim 7491, Norway
| | - Peggy Schoenherr
- School
of Materials Science and Engineering, University
of New South Wales, Sydney, Sydney New South Wales 2052, Australia
- ARC
Centre of Excellence in Future Low-Energy Electronics Technologies
(FLEET), UNSW Sydney, Sydney, NSW 2052, Australia
| | - Laura Köhler
- Institute
of Theoretical Solid State Physics, Karlsruhe
Institute of Technology, 76049 Karlsruhe, Germany
| | - Michael Paulsen
- Physikalisch-Technische
Bundesanstalt (PTB), Berlin 10587, Germany
| | - Alireza Qaiumzadeh
- Center
for Quantum Spintronics, Department of Physics,
Norwegian University of Science and Technology (NTNU), Trondheim 7491, Norway
| | - Naoya Kanazawa
- Department
of Applied Physics, University of Tokyo, Tokyo 113-8656, Japan
| | - Achim Rosch
- Institute
for Theoretical Physics, University of Cologne, Cologne 50937, Germany
| | - Yoshinori Tokura
- RIKEN
Center for Emergent Matter Science (CEMS), Wako 351-0198, Japan
- Department
of Applied Physics, University of Tokyo, Tokyo 113-8656, Japan
- Tokyo
College, University of Tokyo, Tokyo 113−8656, Japan
| | - Arne Brataas
- Center
for Quantum Spintronics, Department of Physics,
Norwegian University of Science and Technology (NTNU), Trondheim 7491, Norway
| | - Markus Garst
- Institute
of Theoretical Solid State Physics, Karlsruhe
Institute of Technology, 76049 Karlsruhe, Germany
- Institute
for Quantum Materials and Technology, Karlsruhe
Institute of Technology, 76021 Karlsruhe, Germany
| | - Dennis Meier
- Department
of Materials Science and Engineering, Norwegian
University of Science and Technology (NTNU), Trondheim 7491, Norway
- Center
for Quantum Spintronics, Department of Physics,
Norwegian University of Science and Technology (NTNU), Trondheim 7491, Norway
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22
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Zhang H, Zhu XY, Xu Y, Gawryluk DJ, Xie W, Ju SL, Shi M, Shiroka T, Zhan QF, Pomjakushina E, Shang T. Giant magnetoresistance and topological Hall effect in the EuGa 4antiferromagnet. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2021; 34:034005. [PMID: 34666329 DOI: 10.1088/1361-648x/ac3102] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2021] [Accepted: 10/19/2021] [Indexed: 06/13/2023]
Abstract
We report on systematic temperature- and magnetic field-dependent studies of the EuGa4binary compound, which crystallizes in a centrosymmetric tetragonal BaAl4-type structure with space groupI4/mmm. The electronic properties of EuGa4single crystals, with an antiferromagnetic (AFM) transition atTN∼ 16.4 K, were characterized via electrical resistivity and magnetization measurements. A giant nonsaturating magnetoresistance was observed at low temperatures, reaching∼7×104% at 2 K in a magnetic field of 9 T. In the AFM state, EuGa4undergoes a series of metamagnetic transitions in an applied magnetic field, clearly manifested in its field-dependent electrical resistivity. BelowTN, in the ∼4-7 T field range, we observe also a clear hump-like anomaly in the Hall resistivity which is part of the anomalous Hall resistivity. We attribute such a hump-like feature to the topological Hall effect, usually occurring in noncentrosymmetric materials known to host topological spin textures (as e.g., magnetic skyrmions). Therefore, the family of materials with a tetragonal BaAl4-type structure, to which EuGa4and EuAl4belong, seems to comprise suitable candidates on which one can study the interplay among correlated-electron phenomena (such as charge-density wave or exotic magnetism) with topological spin textures and topologically nontrivial bands.
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Affiliation(s)
- H Zhang
- Key Laboratory of Polar Materials and Devices (MOE), School of Physics and Electronic Science, East China Normal University, Shanghai 200241, People's Republic of China
| | - X Y Zhu
- Key Laboratory of Polar Materials and Devices (MOE), School of Physics and Electronic Science, East China Normal University, Shanghai 200241, People's Republic of China
| | - Y Xu
- Key Laboratory of Polar Materials and Devices (MOE), School of Physics and Electronic Science, East China Normal University, Shanghai 200241, People's Republic of China
| | - D J Gawryluk
- Laboratory for Multiscale Materials Experiments, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
| | - W Xie
- DESY, Notkestraβe 85, D-22607 Hamburg, Germany
| | - S L Ju
- Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
| | - M Shi
- Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
| | - T Shiroka
- Laboratory for Muon-Spin Spectroscopy, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
- Laboratorium für Festkörperphysik, ETH Zürich, CH-8093 Zurich, Switzerland
| | - Q F Zhan
- Key Laboratory of Polar Materials and Devices (MOE), School of Physics and Electronic Science, East China Normal University, Shanghai 200241, People's Republic of China
| | | | - T Shang
- Key Laboratory of Polar Materials and Devices (MOE), School of Physics and Electronic Science, East China Normal University, Shanghai 200241, People's Republic of China
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23
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Kumar B, Tiwari JK, Chauhan HC, Ghosh S. Multiple magnetic phase transitions with different universality classes in bilayer La[Formula: see text]Sr[Formula: see text]Mn[Formula: see text]O[Formula: see text] manganite. Sci Rep 2021; 11:21184. [PMID: 34707160 PMCID: PMC8551313 DOI: 10.1038/s41598-021-00544-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Accepted: 10/05/2021] [Indexed: 11/10/2022] Open
Abstract
Here, we report three magnetic transitions at 101 K (T[Formula: see text]), 246 K (T[Formula: see text]) and 295 K (T[Formula: see text]) in bilayer La[Formula: see text]Sr[Formula: see text]Mn[Formula: see text]O[Formula: see text]. The second order phase transitions have been identified at these transition points with the help of change in entropy analysis and modified Arrott plots (MAPs). The critical behavior around T[Formula: see text], T[Formula: see text] and T[Formula: see text] have been studied by MAPs and Kouvel-Fisher method. Based on these analyses four magnetic phases are: (1) 2D Ising ferromagnetic (FM) below T[Formula: see text],(2) 2D Heisenberg canted antiferromagnetic (CAFM-I) and FM clusters in temperature range T[Formula: see text] < T < T[Formula: see text], (3) 2D Heisenberg CAFM-II and FM clusters with non magnetically interacting planes in temperature range T[Formula: see text] < T < T[Formula: see text] and (4) paramagnetic for T > T[Formula: see text].
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Affiliation(s)
- Birendra Kumar
- School of Physical Sciences, Jawaharlal Nehru University, New Delhi, 110067 India
| | | | | | - Subhasis Ghosh
- School of Physical Sciences, Jawaharlal Nehru University, New Delhi, 110067 India
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24
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Zuo S, Liu J, Qiao K, Zhang Y, Chen J, Su N, Liu Y, Cao J, Zhao T, Wang J, Hu F, Sun J, Jiang C, Shen B. Spontaneous Topological Magnetic Transitions in NdCo 5 Rare-Earth Magnets. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2021; 33:e2103751. [PMID: 34402532 DOI: 10.1002/adma.202103751] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Revised: 06/28/2021] [Indexed: 06/13/2023]
Abstract
Particle-like magnetic textures with nanometric sizes, such as skyrmions, are potentially suitable for designing high-efficiency information bits in future spintronics devices. In general, the Dzyaloshinskii-Moriya interactions and dipolar interactions are the dominant factors for generating nonlinear spin configurations. However, to stabilize the topological skyrmions, an external magnetic field is usually required. In this study, the spontaneous emergence of skyrmions is directly observed, together with the unique successive topological domain evolution during the spin reorientation transition in a neodymium-cobalt (NdCo5 ) rare-earth magnet. On decreasing the temperature, nanometric skyrmion lattices evolve into enclosed in-plane domains (EIPDs) similar to mini bar-magnets with size below 120 nm. The internal magnetization rotates with magnetic anisotropy, demonstrating the ability to manipulate the mini bar-magnets. The nanoscale EIPD lattices remain robust over the wide temperature range of 241-167 K, indicating the possibility of high-density in-plane magnetic information storage. The generation of spontaneous magnetic skyrmions and the successive domain transformation in the traditional NdCo5 rare-earth magnet may prompt application exploration for topological magnetic spin textures with novel physical mechanisms in versatile magnets.
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Affiliation(s)
- Shulan Zuo
- Key Laboratory of Aerospace Materials and Performance (Ministry of Education), School of Materials Science and Engineering, Beihang University, Beijing, 100191, China
| | - Jun Liu
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
| | - Kaiming Qiao
- School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing, 100083, China
| | - Ying Zhang
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
| | - Jie Chen
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
| | - Na Su
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
| | - Yanli Liu
- School of Science, Inner Mongolia University of Science and Technology, Baotou, 014010, China
| | - Jun Cao
- Key Laboratory of Aerospace Materials and Performance (Ministry of Education), School of Materials Science and Engineering, Beihang University, Beijing, 100191, China
| | - Tongyun Zhao
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
| | - Jingmin Wang
- Key Laboratory of Aerospace Materials and Performance (Ministry of Education), School of Materials Science and Engineering, Beihang University, Beijing, 100191, China
| | - Fengxia Hu
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
| | - Jirong Sun
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
| | - Chengbao Jiang
- Key Laboratory of Aerospace Materials and Performance (Ministry of Education), School of Materials Science and Engineering, Beihang University, Beijing, 100191, China
| | - Baogen Shen
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
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25
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Xu M, Meng D, Zhang J, Li R, Jiang G, Zhang Z. Suppression of the repulsion phenomenon of magnetic skyrmions at the end of synthetic antiferromagnetic racetracks. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2021; 33:495801. [PMID: 34505579 DOI: 10.1088/1361-648x/ac2532] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Accepted: 09/09/2021] [Indexed: 06/13/2023]
Abstract
The synthetic antiferromagnetic (SAF) racetracks can perfectly suppress the skyrmion Hall effect, but the congestion phenomenon of the skyrmions at the end of the racetracks will seriously hinder the development of the skyrmion-based magnetic storage technology. In this paper, we have designed and investigated three racetrack structures of double-layer triangular notch, single-layer triangular notch (SLTN) and square hole-triangular notch (SHTN) in SAF racetracks by micromagnetic simulations. The critical current density that annihilates skyrmions in a racetrack with triangular notches is closely related to the angle of the triangular notches and decreases with the decrease of the angles. If a skyrmion in the top ferromagnetic (FM) layer of SLTN structure is annihilated, its counterpart in the bottom FM layer will also be annihilated due to the interlayer antiferromagnetic exchange coupling. Compared with the critical current density of 3.0 × 1012 A m-2in a normal racetrack, the critical current density of SHTN structure can be dropped to 6.0 × 1010 A m-2. The results reveal that all the three structures can significantly reduce the critical current density, which can effectively solve the skyrmion congestion at the end of the racetracks.
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Affiliation(s)
- Min Xu
- Key Laboratory for Anisotropy and Texture of Materials (MOE), School of Materials Science and Engineering, Northeastern University, Shenyang, 110819, People's Republic of China
| | - Dexiang Meng
- Key Laboratory for Anisotropy and Texture of Materials (MOE), School of Materials Science and Engineering, Northeastern University, Shenyang, 110819, People's Republic of China
| | - Jinyu Zhang
- Key Laboratory for Anisotropy and Texture of Materials (MOE), School of Materials Science and Engineering, Northeastern University, Shenyang, 110819, People's Republic of China
| | - Runshui Li
- Key Laboratory for Anisotropy and Texture of Materials (MOE), School of Materials Science and Engineering, Northeastern University, Shenyang, 110819, People's Republic of China
| | - Guiqian Jiang
- Key Laboratory for Anisotropy and Texture of Materials (MOE), School of Materials Science and Engineering, Northeastern University, Shenyang, 110819, People's Republic of China
| | - Zhiyu Zhang
- Key Laboratory for Anisotropy and Texture of Materials (MOE), School of Materials Science and Engineering, Northeastern University, Shenyang, 110819, People's Republic of China
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26
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Amoroso D, Barone P, Picozzi S. Interplay between Single-Ion and Two-Ion Anisotropies in Frustrated 2D Semiconductors and Tuning of Magnetic Structures Topology. NANOMATERIALS 2021; 11:nano11081873. [PMID: 34443704 PMCID: PMC8397980 DOI: 10.3390/nano11081873] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Revised: 07/15/2021] [Accepted: 07/16/2021] [Indexed: 01/14/2023]
Abstract
The effects of competing magnetic interactions in stabilizing different spin configurations are drawing renewed attention in order to unveil emerging topological spin textures and to highlight microscopic mechanisms leading to their stabilization. The possible key role of the two-site exchange anisotropy in selecting specific helicity and vorticity of skyrmionic lattices has only recently been proposed. In this work, we explore the phase diagram of a frustrated localized magnet characterized by a two-dimensional centrosymmetric triangular lattice, focusing on the interplay between the two-ion anisotropy and the single-ion anisotropy. The effects of an external magnetic field applied perpendicularly to the magnetic layer, are also investigated. By means of Monte Carlo simulations, we find an abundance of different spin configurations, going from trivial to high-order Q skyrmionic and meronic lattices. In closer detail, we find that a dominant role is played by the two-ion over the single-ion anisotropy in determining the planar spin texture; the strength and the sign of single ion anisotropy, together with the magnitude of the magnetic field, tune the perpendicular spin components, mostly affecting the polarity (and, in turn, the topology) of the spin texture. Our analysis confirms the crucial role of the anisotropic symmetric exchange in systems with dominant short-range interactions; at the same time, we predict a rich variety of complex magnetic textures, which may arise from a fine tuning of competing anisotropic mechanisms.
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Affiliation(s)
- Danila Amoroso
- Consiglio Nazionale delle Ricerche CNR-SPIN, c/o Università degli Studi “G. D’Annunzio”, I-66100 Chieti, Italy;
- Correspondence:
| | - Paolo Barone
- Consiglio Nazionale delle Ricerche CNR-SPIN, Area della Ricerca di Tor Vergata, Via del Fosso del Cavaliere 100, I-00133 Rome, Italy;
| | - Silvia Picozzi
- Consiglio Nazionale delle Ricerche CNR-SPIN, c/o Università degli Studi “G. D’Annunzio”, I-66100 Chieti, Italy;
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27
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Magnetism in quasi-two-dimensional tri-layer La 2.1Sr 1.9Mn 3O 10 manganite. Sci Rep 2021; 11:14117. [PMID: 34238952 PMCID: PMC8266891 DOI: 10.1038/s41598-021-93290-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Accepted: 06/16/2021] [Indexed: 11/24/2022] Open
Abstract
The tri-layer La\documentclass[12pt]{minimal}
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\begin{document}$$_{10}$$\end{document}10 manganites of Ruddlesden–Popper (RP) series are naturally arranged layered structure with alternate stacking of ω-MnO\documentclass[12pt]{minimal}
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\begin{document}$$_2$$\end{document}2 along c-axis. The dimensionality of the RP series manganites depends on the number of perovskite layers and significantly affects the magnetic and transport properties of the system. Generally, when a ferromagnetic material undergoes a magnetic phase transition from ferromagnetic to paramagnetic state, the magnetic moment of the system becomes zero above the transition temperature (T\documentclass[12pt]{minimal}
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\begin{document}$$_{10}$$\end{document}10 shows non-zero magnetic moment above T\documentclass[12pt]{minimal}
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\begin{document}$$ _{C} $$\end{document}C and also another transition at higher temperature T\documentclass[12pt]{minimal}
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\begin{document}$$ ^{*} \approx $$\end{document}∗≈ 263 K. The non-zero magnetization above T\documentclass[12pt]{minimal}
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\begin{document}$$_{10}$$\end{document}10 not a ferromagnetic to paramagnetic state. We show here the non-zero magnetic moment above T\documentclass[12pt]{minimal}
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\begin{document}$$_{10}$$\end{document}10 manganite. The scaling of the magnetic entropy change confirms the second-order phase transition and the critical behavior of phase transition has been studied around T\documentclass[12pt]{minimal}
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\begin{document}$$_{10}$$\end{document}10. We have obtained the critical exponents for tri-layer La\documentclass[12pt]{minimal}
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\begin{document}$$_{10}$$\end{document}10, which belong to the short-range two-dimensional (2D)-Ising universality class. The low dimensional magnetism in tri-layer La\documentclass[12pt]{minimal}
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\begin{document}$$_{10}$$\end{document}10 manganite is also explained with the help of renormalization group theoretical approach for short-range 2D-Ising systems. It has been shown that the layered structure of tri-layer La\documentclass[12pt]{minimal}
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\begin{document}$$_{10}$$\end{document}10 results in three different types of interactions intra-planer (\documentclass[12pt]{minimal}
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\begin{document}$$ J_{c} $$\end{document}Jc) and inter-tri-layer (\documentclass[12pt]{minimal}
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\begin{document}$$ J_{ab}> J_{c}>> J' $$\end{document}Jab>Jc>>J′ and competition among these give rise to the canted antiferromagnetic spin structure above T\documentclass[12pt]{minimal}
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\begin{document}$$ _{C} $$\end{document}C. Based on the similar magnetic interaction in bi-layer manganite, we propose that the tri-layer La\documentclass[12pt]{minimal}
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\begin{document}$$_{10}$$\end{document}10 should be able to host the skyrmion below T\documentclass[12pt]{minimal}
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\begin{document}$$ _{C} $$\end{document}C due to its strong anisotropy and layered structure.
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28
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Bera S, Mandal SS. Skyrmions at vanishingly small Dzyaloshinskii-Moriya interaction or zero magnetic field. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2021; 33:255801. [PMID: 33848984 DOI: 10.1088/1361-648x/abf783] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2021] [Accepted: 04/13/2021] [Indexed: 06/12/2023]
Abstract
By introducing biquadratic together with usual bilinear ferromagnetic nearest neighbor exchange interaction in a square lattice, we find that the energy of the spin-wave mode is minimized at a finite wavevector for a vanishingly small Dzyaloshinskii-Moriya interaction (DMI), supporting a ground state with spin-spiral structure whose pitch length is unusually short as found in some of the experiments. Apart from reproducing the magnetic structures that can be obtained in a canonical model with nearest neighbor exchange interaction only, a numerical simulation of this model with further introduction of magnetic anisotropy and magnetic field predicts many other magnetic structures some of which are already observed in the experiments. Among many observed structures, nanoscale skyrmion even at vanishingly small DMI is found for the first time in a model. The model provides the nanoscale skyrmions of unit topological charge at zero magnetic field as well. We obtain phase diagrams for all the magnetic structures predicted in the model.
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Affiliation(s)
- Sandip Bera
- Department of Physics, Indian Institute of Technology, Kharagpur, West Bengal 721302, India
| | - Sudhansu S Mandal
- Department of Physics, Indian Institute of Technology, Kharagpur, West Bengal 721302, India
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29
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Eilmsteiner D, Wang XG, Chotorlishvili L, Paischer S, Hoffmann M, Buczek P, Ernst A. Asymmetry in the propagation of vortex domain wall artificial skyrmion composite system. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2021; 33:185803. [PMID: 33711837 DOI: 10.1088/1361-648x/abee39] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Accepted: 03/12/2021] [Indexed: 06/12/2023]
Abstract
We studied the propagation of an artificial skyrmion coupled to the vortex domain wall (VDW). We discovered the following effect: depending on the propagation's direction, the dynamics of the coupled skyrmion VDW can be faster than the isolated VDW's velocity. The reason for such behavior is the structural distortion that occurs in the coupled system. We interpret the numerical results in terms of the modified Thiele's equation. In particular, increasing the Thiele's equation counteractive coefficient leads to the perfect fitting with the micromagnetic simulation results.
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Affiliation(s)
- D Eilmsteiner
- Institute for Theoretical Physics, Johannes Kepler University Linz, 4040 Linz, Austria
| | - Xi-Guang Wang
- School of Physics and Electronics, Central South University, Changsha 410083, People's Republic of China
| | - L Chotorlishvili
- Institute für Physik, Martin-Luther Universität Halle-Wittenberg, D-06120 Halle/Saale, Germany
| | - S Paischer
- Institute for Theoretical Physics, Johannes Kepler University Linz, 4040 Linz, Austria
| | - M Hoffmann
- Institute for Theoretical Physics, Johannes Kepler University Linz, 4040 Linz, Austria
| | - P Buczek
- Department of Engineering and Computer Sciences, Hamburg University of Applied Sciences, Berliner Tor 7, 20099 Hamburg, Germany
| | - A Ernst
- Institute for Theoretical Physics, Johannes Kepler University Linz, 4040 Linz, Austria
- Max Planck Institute of Microstructure Physics, 06120 Halle, Germany
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30
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Streubel R, Bouma DS, Bruni F, Chen X, Ercius P, Ciston J, N'Diaye AT, Roy S, Kevan SD, Fischer P, Hellman F. Chiral Spin Textures in Amorphous Iron-Germanium Thick Films. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2021; 33:e2004830. [PMID: 33432657 DOI: 10.1002/adma.202004830] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Revised: 12/02/2020] [Indexed: 06/12/2023]
Abstract
Topological solitary fields, such as magnetic and polar skyrmions, are envisioned to revolutionize microelectronics. These configurations have been stabilized in solid-state materials with a global inversion symmetry breaking, which translates in magnetic materials into a vector spin exchange known as the Dzyaloshinskii-Moriya interaction (DMI), as well as spin chirality selection and isotropic solitons. This work reports experimental evidence of 3D chiral spin textures, such as helical spins and skyrmions with different chirality and topological charge, stabilized in amorphous Fe-Ge thick films. These results demonstrate that structurally and chemically disordered materials with a random DMI can resemble inversion symmetry broken systems with similar magnetic properties, moments, and states. Disordered systems are distinguished from systems with global inversion symmetry breaking by their degenerate spin chirality that allows for forming isotropic and anisotropic topological spin textures at remanence, while offering greater flexibility in materials synthesis, voltage, and strain manipulation.
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Affiliation(s)
- Robert Streubel
- Department of Physics and Astronomy, and Nebraska, Center for Materials and Nanoscience, University of Nebraska-Lincoln, Lincoln, NE, 68588, USA
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - D Simca Bouma
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
- Department of Physics, University of California Berkeley, Berkeley, CA, 94720, USA
| | - Frank Bruni
- Department of Physics, University of California Berkeley, Berkeley, CA, 94720, USA
| | - Xiaoqian Chen
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Peter Ercius
- National Center for Electron Microscopy, Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Jim Ciston
- National Center for Electron Microscopy, Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Alpha T N'Diaye
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Sujoy Roy
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Steve D Kevan
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Peter Fischer
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Frances Hellman
- Department of Physics, University of California Berkeley, Berkeley, CA, 94720, USA
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31
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Turnbull LA, Birch MT, Laurenson A, Bukin N, Burgos-Parra EO, Popescu H, Wilson MN, Stefančič A, Balakrishnan G, Ogrin FY, Hatton PD. Tilted X-Ray Holography of Magnetic Bubbles in MnNiGa Lamellae. ACS NANO 2021; 15:387-395. [PMID: 33119252 DOI: 10.1021/acsnano.0c07392] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Nanoscopic lamellae of centrosymmetric ferromagnetic alloys have recently been reported to host the biskyrmion spin texture; however, this has been disputed as the misidentication of topologically trivial type-II magnetic bubbles. Here we demonstrate resonant soft X-ray holographic imaging of topological magnetic states in lamellae of the centrosymmetric alloy (Mn1-xNix)0.65Ga0.35 (x = 0.5), showing the presence of magnetic stripes evolving into single core magnetic bubbles. We observe rotation of the stripe phase via the nucleation and destruction of disclination defects. This indicates the system behaves as a conventional uniaxial ferromagnet. By utilizing the holography with extended reference by autocorrelation linear differential operator (HERALDO) method, we show tilted holographic images at 30° incidence confirming the presence of type-II magnetic bubbles in this system. This study demonstrates the utility of X-ray imaging techniques in identifying the topology of localized structures in nanoscale magnetism.
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Affiliation(s)
- Luke A Turnbull
- Centre for Materials Physics, Durham University, Durham, DH1 3LE United Kingdom
| | - Max T Birch
- Centre for Materials Physics, Durham University, Durham, DH1 3LE United Kingdom
- Diamond Light Source, Didcot, OX11 0DE United Kingdom
| | - Angus Laurenson
- School of Physics and Astronomy, University of Exeter, Exeter, EX4 4QL United Kingdom
| | - Nick Bukin
- School of Physics and Astronomy, University of Exeter, Exeter, EX4 4QL United Kingdom
| | | | - Horia Popescu
- Synchrotron SOLEIL, Saint Aubin, BP 48, 91192 Gif-sur-Yvette, France
| | - Murray N Wilson
- Centre for Materials Physics, Durham University, Durham, DH1 3LE United Kingdom
| | - Aleš Stefančič
- Department of Physics, University of Warwick, Coventry, CV4 7AL United Kingdom
| | - Geetha Balakrishnan
- Department of Physics, University of Warwick, Coventry, CV4 7AL United Kingdom
| | - Feodor Y Ogrin
- School of Physics and Astronomy, University of Exeter, Exeter, EX4 4QL United Kingdom
| | - Peter D Hatton
- Centre for Materials Physics, Durham University, Durham, DH1 3LE United Kingdom
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32
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Gao Y, Yin Q, Wang Q, Li Z, Cai J, Zhao T, Lei H, Wang S, Zhang Y, Shen B. Spontaneous (Anti)meron Chains in the Domain Walls of van der Waals Ferromagnetic Fe 5- x GeTe 2. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2020; 32:e2005228. [PMID: 33118243 DOI: 10.1002/adma.202005228] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2020] [Revised: 10/03/2020] [Indexed: 06/11/2023]
Abstract
The promise of topologically vortex-like magnetic spin textures hinges on the intriguing physical properties and theories in fundamental research and their distinguished roles as high-efficiency information units in future spintronics. The exploration of such magnetic states with unique spin configurations has never ceased. In this study, the emergence of unconventional (anti)meron chains from a domain wall pair is directly observed at zero field in 2D ferromagnetic Fe5- x GeTe2 , closely correlated with significant enhancement of the in-plane magnetization and weak van der Waals interactions. The simultaneous appearance of a large topological Hall effect is observed at the same temperature range as that of the abnormal magnetic transition. Moreover, the distinctive features of the (anti)meron chains and their collective dynamic behavior under external fields may provide concrete experimental evidence for the recent theoretical prediction of the magnetic-domain-wall topology and endorse a broader range of possibilities for electronics, spintronics, condensed matter physics, etc.
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Affiliation(s)
- Yang Gao
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
- Institute of Advanced Materials, Beijing Normal University, Beijing, 100875, China
| | - Qiangwei Yin
- Department of Physics and Beijing Key Laboratory of Opto-Electronic Functional Materials & Micro-Nano Devices, Renmin University of China, Beijing, 100872, China
| | - Qi Wang
- Department of Physics and Beijing Key Laboratory of Opto-Electronic Functional Materials & Micro-Nano Devices, Renmin University of China, Beijing, 100872, China
| | - Zhuolin Li
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Jianwang Cai
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
| | - Tongyun Zhao
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
| | - Hechang Lei
- Department of Physics and Beijing Key Laboratory of Opto-Electronic Functional Materials & Micro-Nano Devices, Renmin University of China, Beijing, 100872, China
| | - Shouguo Wang
- Institute of Advanced Materials, Beijing Normal University, Beijing, 100875, China
| | - Ying Zhang
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong, 523808, China
| | - Baogen Shen
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China
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33
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Spontaneous skyrmionic lattice from anisotropic symmetric exchange in a Ni-halide monolayer. Nat Commun 2020; 11:5784. [PMID: 33188198 PMCID: PMC7666143 DOI: 10.1038/s41467-020-19535-w] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Accepted: 10/02/2020] [Indexed: 11/09/2022] Open
Abstract
Topological spin structures, such as magnetic skyrmions, hold great promises for data storage applications, thanks to their inherent stability. In most cases, skyrmions are stabilized by magnetic fields in non-centrosymmetric systems displaying the chiral Dzyaloshinskii-Moriya exchange interaction, while spontaneous skyrmion lattices have been reported in centrosymmetric itinerant magnets with long-range interactions. Here, a spontaneous anti-biskyrmion lattice with unique topology and chirality is predicted in the monolayer of a semiconducting and centrosymmetric metal halide, NiI2. Our first-principles and Monte Carlo simulations reveal that the anisotropies of the short-range symmetric exchange, when combined with magnetic frustration, can lead to an emergent chiral interaction that is responsible for the predicted topological spin structures. The proposed mechanism finds a prototypical manifestation in two-dimensional magnets, thus broadening the class of materials that can host spontaneous skyrmionic states.
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Yang M, Li Q, Chopdekar RV, Dhall R, Turner J, Carlström JD, Ophus C, Klewe C, Shafer P, N'Diaye AT, Choi JW, Chen G, Wu YZ, Hwang C, Wang F, Qiu ZQ. Creation of skyrmions in van der Waals ferromagnet Fe 3GeTe 2 on (Co/Pd) n superlattice. SCIENCE ADVANCES 2020; 6:6/36/eabb5157. [PMID: 32917619 PMCID: PMC7473669 DOI: 10.1126/sciadv.abb5157] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Accepted: 07/15/2020] [Indexed: 05/27/2023]
Abstract
Magnetic skyrmions are topological spin textures, which usually exist in noncentrosymmetric materials where the crystal inversion symmetry breaking generates the so-called Dzyaloshinskii-Moriya interaction. This requirement unfortunately excludes many important magnetic material classes, including the recently found two-dimensional van der Waals (vdW) magnetic materials, which offer unprecedented opportunities for spintronic technology. Using photoemission electron microscopy and Lorentz transmission electron microscopy, we investigated and stabilized Néel-type magnetic skyrmion in vdW ferromagnetic Fe3GeTe2 on top of (Co/Pd) n in which the Fe3GeTe2 has a centrosymmetric crystal structure. We demonstrate that the magnetic coupling between the Fe3GeTe2 and the (Co/Pd) n could create skyrmions in Fe3GeTe2 without the need of an external magnetic field. Our results open exciting opportunities in spintronic research and the engineering of topologically protected nanoscale features by expanding the group of skyrmion host materials to include these previously unknown vdW magnets.
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Affiliation(s)
- M Yang
- Department of Physics, University of California, Berkeley, CA 94720, USA
| | - Q Li
- Department of Physics, University of California, Berkeley, CA 94720, USA.
| | - R V Chopdekar
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - R Dhall
- Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - J Turner
- Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - J D Carlström
- Department of Physics, University of California, Berkeley, CA 94720, USA
| | - C Ophus
- Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - C Klewe
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - P Shafer
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - A T N'Diaye
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - J W Choi
- Center for Spintronics, Korea Institute of Science and Technology, Seoul 02792, Republic of Korea
| | - G Chen
- Department of Physics, University of California, Davis, CA 95616, USA
| | - Y Z Wu
- Department of Physics and State Key Laboratory of Surface Physics, Fudan University, Shanghai 200433, China
| | - C Hwang
- Korea Research Institute of Standards and Science, Yuseong, Daejeon 305-340, Republic of Korea
| | - F Wang
- Department of Physics, University of California, Berkeley, CA 94720, USA
| | - Z Q Qiu
- Department of Physics, University of California, Berkeley, CA 94720, USA.
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35
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Capic D, Garanin DA, Chudnovsky EM. Skyrmion-skyrmion interaction in a magnetic film. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2020; 32:415803. [PMID: 32526724 DOI: 10.1088/1361-648x/ab9bc8] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Accepted: 06/11/2020] [Indexed: 06/11/2023]
Abstract
Interaction of two skyrmions stabilized by the ferromagnetic exchange, Dzyaloshinskii-Moriya interaction (DMI), and external magnetic field has been studied numerically on a 2D lattice of size large compared to the separation,d, between the skyrmions. We show that two skyrmions of the same chirality (determined by the symmetry of the crystal) repel. In accordance with earlier analytical results, their long-range pair interaction falls out with the separation as exp(-d/δH), whereδHis the magnetic screening length, independent of the DMI. The prefactor in this expression depends on the DMI that drives the repulsion. The latter results in the spiral motion of the two skyrmions around each other, with the separation between them growing logarithmically with time. When two skyrmions of the total topological chargeQ= 2 are pushed close to each other, the discreteness of the atomic lattice makes them collapse into one skyrmion of chargeQ= 1 below a critical separation. Experiment is proposed that would allow one to measure the interaction between two skyrmions by holding them in positions with two magnetic tips. Our findings should be of value for designing topologically protected magnetic memory based upon skyrmions.
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Affiliation(s)
- D Capic
- Physics Department, Herbert H. Lehman College and Graduate School, The City University of New York, 250 Bedford Park Boulevard West, Bronx, New York 10468-1589, United States of America
| | - D A Garanin
- Physics Department, Herbert H. Lehman College and Graduate School, The City University of New York, 250 Bedford Park Boulevard West, Bronx, New York 10468-1589, United States of America
| | - E M Chudnovsky
- Physics Department, Herbert H. Lehman College and Graduate School, The City University of New York, 250 Bedford Park Boulevard West, Bronx, New York 10468-1589, United States of America
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Ma T, Sharma AK, Saha R, Srivastava AK, Werner P, Vir P, Kumar V, Felser C, Parkin SSP. Tunable Magnetic Antiskyrmion Size and Helical Period from Nanometers to Micrometers in a D 2d Heusler Compound. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2020; 32:e2002043. [PMID: 32484269 DOI: 10.1002/adma.202002043] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Revised: 04/27/2020] [Indexed: 06/11/2023]
Abstract
Skyrmions and antiskyrmions are magnetic nano-objects with distinct chiral, noncollinear spin textures that are found in various magnetic systems with crystal symmetries that give rise to specific Dzyaloshinskii-Moriya exchange vectors. These magnetic nano-objects are associated with closely related helical spin textures that can form in the same material. The skyrmion size and the period of the helix are generally considered as being determined, in large part, by the ratio of the magnitude of the Heisenberg to that of the Dzyaloshinskii-Moriya exchange interaction. In this work, it is shown by real-space magnetic imaging that the helix period λ and the size of the antiskyrmion daSk in the D2d compound Mn1.4 PtSn can be systematically tuned by more than an order of magnitude from ≈100 nm to more than 1.1 µm by varying the thickness of the lamella in which they are observed. The chiral spin texture is verified to be preserved even up to micrometer-thick layers. This extreme size tunability is shown to arise from long-range magnetodipolar interactions, which typically play a much less important role for B20 skyrmions. This tunability in size makes antiskyrmions very attractive for technological applications.
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Affiliation(s)
- Tianping Ma
- Max Planck Institute of Microstructure Physics, Weinberg 2, Halle (Saale), D-06120, Germany
- Institute of Physics, Martin Luther University, Halle-Wittenberg, Halle (Saale), D-06120, Germany
| | - Ankit K Sharma
- Max Planck Institute of Microstructure Physics, Weinberg 2, Halle (Saale), D-06120, Germany
- Institute of Physics, Martin Luther University, Halle-Wittenberg, Halle (Saale), D-06120, Germany
| | - Rana Saha
- Max Planck Institute of Microstructure Physics, Weinberg 2, Halle (Saale), D-06120, Germany
| | - Abhay K Srivastava
- Max Planck Institute of Microstructure Physics, Weinberg 2, Halle (Saale), D-06120, Germany
- Institute of Physics, Martin Luther University, Halle-Wittenberg, Halle (Saale), D-06120, Germany
| | - Peter Werner
- Max Planck Institute of Microstructure Physics, Weinberg 2, Halle (Saale), D-06120, Germany
| | - Praveen Vir
- Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Straβe 40, Dresden, 01187, Germany
| | - Vivek Kumar
- Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Straβe 40, Dresden, 01187, Germany
| | - Claudia Felser
- Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Straβe 40, Dresden, 01187, Germany
| | - Stuart S P Parkin
- Max Planck Institute of Microstructure Physics, Weinberg 2, Halle (Saale), D-06120, Germany
- Institute of Physics, Martin Luther University, Halle-Wittenberg, Halle (Saale), D-06120, Germany
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Wang S, Zeng Q, Liu D, Zhang H, Ma L, Xu G, Liang Y, Zhang Z, Wu H, Che R, Han X, Huang Q. Giant Topological Hall Effect and Superstable Spontaneous Skyrmions below 330 K in a Centrosymmetric Complex Noncollinear Ferromagnet NdMn 2Ge 2. ACS APPLIED MATERIALS & INTERFACES 2020; 12:24125-24132. [PMID: 32363848 DOI: 10.1021/acsami.0c04632] [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
Skyrmions with topologically nontrivial spin textures are promising information carriers in next-generation ultralow power consumption and high-density spintronic devices. To promote their further development and utilization, the search for new room temperature skyrmion-hosting materials is crucial. Considering that most of the previous skyrmion-hosting materials are noncollinear magnets, here, the detection of the topological Hall effect (THE) and the discovery of skyrmions at room temperature are first reported in a centrosymmetric complex noncollinear ferromagnet NdMn2Ge2. Below 330 K, the compound can host stable Bloch-type skyrmions with about 75 nm diameter in a wide window of magnetic field and temperature, including zero magnetic field and room temperature. Moreover, the skyrmions can induce a giant topological Hall effect in a wide temperature range with a maximum value of -2.05 μΩ cm. These features make the compound attractive for both fundamental research and potential application in novel spintronic devices.
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Affiliation(s)
- Shaobo Wang
- Beijing Key Laboratory of Microstructure and Properties of Advanced Material, Institute of Microstructure and Property of Advanced Materials, Beijing University of Technology, Beijing 100124, China
| | - Qingwen Zeng
- Laboratory of Advanced Materials, Department of Materials Science, Collaborative Innovation Center of Chemistry for Energy Materials, Fudan University, Shanghai 200438, China
| | - Danmin Liu
- Beijing Key Laboratory of Microstructure and Properties of Advanced Material, Institute of Microstructure and Property of Advanced Materials, Beijing University of Technology, Beijing 100124, China
| | - Hongguo Zhang
- Key Laboratory of Advanced Functional Materials, Education Ministry of China, College of Materials Science and Engineering, Beijing University of Technology, Beijing 100124, China
| | - Lin Ma
- Key Laboratory of Advanced Functional Materials, Education Ministry of China, College of Materials Science and Engineering, Beijing University of Technology, Beijing 100124, China
| | - Guoliang Xu
- Beijing Key Laboratory of Microstructure and Properties of Advanced Material, Institute of Microstructure and Property of Advanced Materials, Beijing University of Technology, Beijing 100124, China
| | - Yuntian Liang
- Beijing Key Laboratory of Microstructure and Properties of Advanced Material, Institute of Microstructure and Property of Advanced Materials, Beijing University of Technology, Beijing 100124, China
| | - Zhenlu Zhang
- Beijing Key Laboratory of Microstructure and Properties of Advanced Material, Institute of Microstructure and Property of Advanced Materials, Beijing University of Technology, Beijing 100124, China
| | - Hui Wu
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, United States
| | - Renchao Che
- Laboratory of Advanced Materials, Department of Materials Science, Collaborative Innovation Center of Chemistry for Energy Materials, Fudan University, Shanghai 200438, China
| | - Xiaodong Han
- Beijing Key Laboratory of Microstructure and Properties of Advanced Material, Institute of Microstructure and Property of Advanced Materials, Beijing University of Technology, Beijing 100124, China
| | - Qingzhen Huang
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, United States
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38
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Wang Z, Su Y, Lin SZ, Batista CD. Skyrmion Crystal from RKKY Interaction Mediated by 2D Electron Gas. PHYSICAL REVIEW LETTERS 2020; 124:207201. [PMID: 32501075 DOI: 10.1103/physrevlett.124.207201] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Revised: 02/13/2020] [Accepted: 05/05/2020] [Indexed: 06/11/2023]
Abstract
We consider a C_{6} invariant lattice of magnetic moments coupled via a Kondo exchange J with a 2D electron gas (2DEG). The effective Ruderman-Kittel-Kasuya-Yosida interaction between the moments stabilizes a magnetic skyrmion crystal in the presence of magnetic field and easy-axis anisotropy. An attractive aspect of this mechanism is that the magnitude of the magnetic ordering wave vectors, Q_{ν} (ν=1, 2, 3), is dictated by the Fermi wave number k_{F}: |Q_{ν}|=2k_{F}. Consequently, the topological contribution to the Hall conductivity of the 2DEG becomes of the order of the quantized value, e^{2}/h, when J is comparable to the Fermi energy ε_{F}.
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Affiliation(s)
- Zhentao Wang
- Department of Physics and Astronomy, The University of Tennessee, Knoxville, Tennessee 37996, USA
| | - Ying Su
- Theoretical Division, T-4 and CNLS, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - Shi-Zeng Lin
- Theoretical Division, T-4 and CNLS, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - Cristian D Batista
- Department of Physics and Astronomy, The University of Tennessee, Knoxville, Tennessee 37996, USA
- Quantum Condensed Matter Division and Shull-Wollan Center, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
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39
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Kumar Tiwari J, Chandr Chauhan H, Kumar B, Ghosh S. 3D-Ising like ferromagnetism in skyrmionic-bubbles host infinite-layer La 0.825Sr 0.175MnO 3 manganite perovskite. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2020; 32:195803. [PMID: 31952061 DOI: 10.1088/1361-648x/ab6d14] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The critical behavior of infinite-layer La0.825Sr0.175MnO3 of Ruddlesden-Popper series manganite has been studied around the transition temperature ([Formula: see text]). To reveal the universality class that explains the critical behavior in La0.825Sr0.175MnO3 several methods, such as modified Arrott plots, Kouvel-Fisher, entropy and critical isotherm analysis have been employed. The critical exponent [Formula: see text] for infinite-layer is obtained independently from critical magnetization isotherm and found to satisfy the Widom scaling relation [Formula: see text]. The universality class of the critical phenomenon in infinite-layer La0.825Sr0.175MnO3 manganite can be explained with the help of renormalization group theory approach for three dimensional (3D) systems. We have shown that a short-range 3D-Ising type interaction is responsible for ferromagnetic and second-order phase transition to paramagnetic phase.
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40
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Zhang X, Zhou Y, Mee Song K, Park TE, Xia J, Ezawa M, Liu X, Zhao W, Zhao G, Woo S. Skyrmion-electronics: writing, deleting, reading and processing magnetic skyrmions toward spintronic applications. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2020; 32:143001. [PMID: 31689688 DOI: 10.1088/1361-648x/ab5488] [Citation(s) in RCA: 59] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The field of magnetic skyrmions has been actively investigated across a wide range of topics during the last decades. In this topical review, we mainly review and discuss key results and findings in skyrmion research since the first experimental observation of magnetic skyrmions in 2009. We particularly focus on the theoretical, computational and experimental findings and advances that are directly relevant to the spintronic applications based on magnetic skyrmions, i.e. their writing, deleting, reading and processing driven by magnetic field, electric current and thermal energy. We then review several potential applications including information storage, logic computing gates and non-conventional devices such as neuromorphic computing devices. Finally, we discuss possible future research directions on magnetic skyrmions, which also cover rich topics on other topological textures such as antiskyrmions and bimerons in antiferromagnets and frustrated magnets.
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Affiliation(s)
- Xichao Zhang
- School of Science and Engineering, The Chinese University of Hong Kong, Shenzhen, Guangdong 518172, People's Republic of China
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41
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Srivastava AK, Devi P, Sharma AK, Ma T, Deniz H, Meyerheim HL, Felser C, Parkin SSP. Observation of Robust Néel Skyrmions in Metallic PtMnGa. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2020; 32:e1904327. [PMID: 31880023 DOI: 10.1002/adma.201904327] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2019] [Revised: 11/03/2019] [Indexed: 06/10/2023]
Abstract
Over the past decade the family of chiral noncollinear spin textures has continued to expand with the observation in metallic compounds of Bloch-like skyrmions in several B20 compounds, and antiskyrmions in a tetragonal inverse Heusler. Néel like skyrmions in bulk crystals with broken inversion symmetry have recently been seen in two distinct nonmetallic compounds, GaV4 S8 and VOSe2 O5 at low temperatures (below ≈13 K) only. Here, the first observation of bulk Néel skyrmions in a metallic compound PtMnGa and, moreover, at high temperatures up to ≈220 K is reported. Lorentz transmission electron microscopy reveals the chiral Néel character of the skyrmions. A strong variation is reported of the size of the skyrmions on the thickness of the lamella in which they are confined, varying by a factor of 7 as the thickness is varied from ≈90 nm to ≈4 µm. Moreover, the skyrmions are highly robust to in-plane magnetic fields and can be stabilized in a zero magnetic field using suitable field-cooling protocols over a very broad temperature range to as low as 5 K. These properties, together with the possibility of manipulating skyrmions in metallic PtMnGa via current induced spin-orbit torques, make them extremely exciting for future spintronic applications.
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Affiliation(s)
- Abhay K Srivastava
- Max Planck Institute of Microstructure Physics, Weinberg 2, Halle (Saale), D-06120, Germany
- Institute of Physics, Martin Luther University, Halle-Wittenberg, Halle (Saale), D-06120, Germany
| | - Parul Devi
- Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Straβe 40, 01187, Dresden, Germany
| | - Ankit K Sharma
- Max Planck Institute of Microstructure Physics, Weinberg 2, Halle (Saale), D-06120, Germany
- Institute of Physics, Martin Luther University, Halle-Wittenberg, Halle (Saale), D-06120, Germany
| | - Tianping Ma
- Max Planck Institute of Microstructure Physics, Weinberg 2, Halle (Saale), D-06120, Germany
- Institute of Physics, Martin Luther University, Halle-Wittenberg, Halle (Saale), D-06120, Germany
| | - Hakan Deniz
- Max Planck Institute of Microstructure Physics, Weinberg 2, Halle (Saale), D-06120, Germany
| | - Holger L Meyerheim
- Max Planck Institute of Microstructure Physics, Weinberg 2, Halle (Saale), D-06120, Germany
| | - Claudia Felser
- Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Straβe 40, 01187, Dresden, Germany
| | - Stuart S P Parkin
- Max Planck Institute of Microstructure Physics, Weinberg 2, Halle (Saale), D-06120, Germany
- Institute of Physics, Martin Luther University, Halle-Wittenberg, Halle (Saale), D-06120, Germany
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42
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Shen L, Xia J, Zhang X, Ezawa M, Tretiakov OA, Liu X, Zhao G, Zhou Y. Current-Induced Dynamics and Chaos of Antiferromagnetic Bimerons. PHYSICAL REVIEW LETTERS 2020; 124:037202. [PMID: 32031830 DOI: 10.1103/physrevlett.124.037202] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2019] [Revised: 11/01/2019] [Indexed: 06/10/2023]
Abstract
A magnetic bimeron is a topologically nontrivial spin texture carrying an integer topological charge, which can be regarded as the counterpart of the skyrmion in easy-plane magnets. The controllable creation and manipulation of bimerons are crucial for practical applications based on topological spin textures. Here, we analytically and numerically study the dynamics of an antiferromagnetic bimeron driven by a spin current. Numerical simulations demonstrate that the spin current can create an isolated bimeron in the antiferromagnetic thin film via the dampinglike spin torque. The spin current can also effectively drive the antiferromagnetic bimeron without a transverse drift. The steady motion of an antiferromagnetic bimeron is analytically derived and is in good agreement with the simulation results. Also, we find that the alternating-current-induced motion of the antiferromagnetic bimeron can be described by the Duffing equation due to the presence of the nonlinear boundary-induced force. The associated chaotic behavior of the bimeron is analyzed in terms of the Lyapunov exponents. Our results demonstrate the inertial dynamics of an antiferromagnetic bimeron, and may provide useful guidelines for building future bimeron-based spintronic devices.
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Affiliation(s)
- Laichuan Shen
- School of Science and Engineering, The Chinese University of Hong Kong, Shenzhen, Guangdong 518172, China
- College of Physics and Electronic Engineering, Sichuan Normal University, Chengdu 610068, China
| | - Jing Xia
- School of Science and Engineering, The Chinese University of Hong Kong, Shenzhen, Guangdong 518172, China
| | - Xichao Zhang
- School of Science and Engineering, The Chinese University of Hong Kong, Shenzhen, Guangdong 518172, China
| | - Motohiko Ezawa
- Department of Applied Physics, The University of Tokyo, 7-3-1 Hongo, Tokyo 113-8656, Japan
| | - Oleg A Tretiakov
- School of Physics, The University of New South Wales, Sydney 2052, Australia
| | - Xiaoxi Liu
- Department of Electrical and Computer Engineering, Shinshu University, 4-17-1 Wakasato, Nagano 380-8553, Japan
| | - Guoping Zhao
- College of Physics and Electronic Engineering, Sichuan Normal University, Chengdu 610068, China
| | - Yan Zhou
- School of Science and Engineering, The Chinese University of Hong Kong, Shenzhen, Guangdong 518172, China
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43
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Puphal P, Pomjakushin V, Kanazawa N, Ukleev V, Gawryluk DJ, Ma J, Naamneh M, Plumb NC, Keller L, Cubitt R, Pomjakushina E, White JS. Topological Magnetic Phase in the Candidate Weyl Semimetal CeAlGe. PHYSICAL REVIEW LETTERS 2020; 124:017202. [PMID: 31976692 DOI: 10.1103/physrevlett.124.017202] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Revised: 11/01/2019] [Indexed: 06/10/2023]
Abstract
We report the discovery of topological magnetism in the candidate magnetic Weyl semimetal CeAlGe. Using neutron scattering we find this system to host several incommensurate, square-coordinated multi-k[over →] magnetic phases below T_{N}. The topological properties of a phase stable at intermediate magnetic fields parallel to the c axis are suggested by observation of a topological Hall effect. Our findings highlight CeAlGe as an exceptional system for exploiting the interplay between the nontrivial topologies of the magnetization in real space and Weyl nodes in momentum space.
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Affiliation(s)
- Pascal Puphal
- Laboratory for Multiscale Materials Experiments (LMX), Paul Scherrer Institute (PSI), CH-5232 Villigen, Switzerland
| | - Vladimir Pomjakushin
- Laboratory for Neutron Scattering and Imaging (LNS), Paul Scherrer Institute (PSI), CH-5232 Villigen, Switzerland
| | - Naoya Kanazawa
- Department of Applied Physics, University of Tokyo, Tokyo 113-8656, Japan
| | - Victor Ukleev
- Laboratory for Neutron Scattering and Imaging (LNS), Paul Scherrer Institute (PSI), CH-5232 Villigen, Switzerland
| | - Dariusz J Gawryluk
- Laboratory for Multiscale Materials Experiments (LMX), Paul Scherrer Institute (PSI), CH-5232 Villigen, Switzerland
| | - Junzhang Ma
- Swiss Light Source (SLS), Paul Scherrer Institute (PSI), CH-5232 Villigen PSI, Switzerland
| | - Muntaser Naamneh
- Swiss Light Source (SLS), Paul Scherrer Institute (PSI), CH-5232 Villigen PSI, Switzerland
| | - Nicholas C Plumb
- Swiss Light Source (SLS), Paul Scherrer Institute (PSI), CH-5232 Villigen PSI, Switzerland
| | - Lukas Keller
- Laboratory for Neutron Scattering and Imaging (LNS), Paul Scherrer Institute (PSI), CH-5232 Villigen, Switzerland
| | - Robert Cubitt
- Institut Laue-Langevin (ILL), 71 avenue des Martyrs, CS 20156, 38042 Grenoble cedex 9, France
| | - Ekaterina Pomjakushina
- Laboratory for Multiscale Materials Experiments (LMX), Paul Scherrer Institute (PSI), CH-5232 Villigen, Switzerland
| | - Jonathan S White
- Laboratory for Neutron Scattering and Imaging (LNS), Paul Scherrer Institute (PSI), CH-5232 Villigen, Switzerland
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44
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Hou Z, Zhang Q, Zhang X, Xu G, Xia J, Ding B, Li H, Zhang S, Batra NM, Costa PMFJ, Liu E, Wu G, Ezawa M, Liu X, Zhou Y, Zhang X, Wang W. Current-Induced Helicity Reversal of a Single Skyrmionic Bubble Chain in a Nanostructured Frustrated Magnet. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2020; 32:e1904815. [PMID: 31746047 DOI: 10.1002/adma.201904815] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2019] [Revised: 10/14/2019] [Indexed: 06/10/2023]
Abstract
Helicity indicates the in-plane magnetic-moment swirling direction of a skyrmionic configuration. The ability to reverse the helicity of a skyrmionic bubble via purely electrical means has been predicted in frustrated magnetic systems; however, it has been challenging to observe this experimentally. The current-driven helicity reversal of the skyrmionic bubble in a nanostructured frustrated Fe3 Sn2 magnet is experimentally demonstrated. The critical current density required to trigger the helicity reversal is 109 -1010 A m-2 , with a corresponding pulse-width varying from 1 µs to 100 ns. Computational simulations reveal that both the pinning effect and dipole-dipole interaction play a crucial role in the helicity reversal process.
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Affiliation(s)
- Zhipeng Hou
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
- Institute for Advanced Materials, Guangdong Provincial Key Laboratory of Optical Information Materials and Technology, South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou, 510006, China
| | - Qiang Zhang
- Physical Science and Engineering Division, King Abdullah University of Science and Technology, Thuwal, 23955-6900, Saudi Arabia
| | - Xichao Zhang
- School of Science and Engineering, The Chinese University of Hong Kong, Shenzhen, Guangdong, 518172, China
| | - Guizhou Xu
- School of Materials Science and Engineering, Nanjing University of Science and Technology, Nanjing, 210094, China
| | - Jing Xia
- School of Science and Engineering, The Chinese University of Hong Kong, Shenzhen, Guangdong, 518172, China
| | - Bei Ding
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
| | - Hang Li
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
| | - Senfu Zhang
- Physical Science and Engineering Division, King Abdullah University of Science and Technology, Thuwal, 23955-6900, Saudi Arabia
| | - Nitin M Batra
- Physical Science and Engineering Division, King Abdullah University of Science and Technology, Thuwal, 23955-6900, Saudi Arabia
| | - Pedro M F J Costa
- Physical Science and Engineering Division, King Abdullah University of Science and Technology, Thuwal, 23955-6900, Saudi Arabia
| | - Enke Liu
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
| | - Guangheng Wu
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
| | - Motohiko Ezawa
- Department of Applied Physics, The University of Tokyo, 7-3-1 Hongo, Tokyo, 113-8656, Japan
| | - Xiaoxi Liu
- Department of Electrical and Computer Engineering, Shinshu University, 4-17-1 Wakasato, Nagano, 380-8553, Japan
| | - Yan Zhou
- School of Science and Engineering, The Chinese University of Hong Kong, Shenzhen, Guangdong, 518172, China
| | - Xixiang Zhang
- Physical Science and Engineering Division, King Abdullah University of Science and Technology, Thuwal, 23955-6900, Saudi Arabia
| | - Wenhong Wang
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
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45
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Göbel B, Henk J, Mertig I. Forming individual magnetic biskyrmions by merging two skyrmions in a centrosymmetric nanodisk. Sci Rep 2019; 9:9521. [PMID: 31266991 PMCID: PMC6606756 DOI: 10.1038/s41598-019-45965-8] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Accepted: 06/17/2019] [Indexed: 11/25/2022] Open
Abstract
When two magnetic skyrmions - whirl-like, topologically protected quasiparticles - form a bound pair, a biskyrmion state with a topological charge of NSk = ±2 is constituted. Recently, especially the case of two partially overlapping skyrmions has brought about great research interest. Since for its formation the individual skyrmions need to posses opposite in-plane magnetizations, such a biskyrmion cannot be stabilized by the Dzyaloshinskii-Moriya-interaction (DMI), which is the interaction that typically stabilizes skyrmions in non-centrosymmetric materials and at interfaces. Here, we show that these biskyrmions can be stabilized by the dipole-dipole interaction in centrosymmetric materials in which the DMI is forbidden. Analytical considerations indicate that the bound state of a biskyrmion is energetically preferable over two individual skyrmions. As a result, when starting from two skyrmions in a micromagnetic simulation, a biskyrmion is formed upon relaxation. We propose a scheme that allows to control this biskyrmion formation in nanodisks and analyze the individual steps.
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Affiliation(s)
- Börge Göbel
- Max-Planck-Institut für Mikrostrukturphysik, Halle (Saale), 06120, Germany.
| | - Jürgen Henk
- Martin-Luther-Universität Halle-Wittenberg, Institut für Physik, Halle (Saale), 06099, Germany
| | - Ingrid Mertig
- Max-Planck-Institut für Mikrostrukturphysik, Halle (Saale), 06120, Germany
- Martin-Luther-Universität Halle-Wittenberg, Institut für Physik, Halle (Saale), 06099, Germany
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46
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Loudon JC, Twitchett‐Harrison AC, Cortés‐Ortuño D, Birch MT, Turnbull LA, Štefančič A, Ogrin FY, Burgos‐Parra EO, Bukin N, Laurenson A, Popescu H, Beg M, Hovorka O, Fangohr H, Midgley PA, Balakrishnan G, Hatton PD. Do Images of Biskyrmions Show Type-II Bubbles? ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2019; 31:e1806598. [PMID: 30844122 PMCID: PMC9285551 DOI: 10.1002/adma.201806598] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/11/2018] [Revised: 01/31/2019] [Indexed: 06/09/2023]
Abstract
The intense research effort investigating magnetic skyrmions and their applications for spintronics has yielded reports of more exotic objects including the biskyrmion, which consists of a bound pair of counter-rotating vortices of magnetization. Biskyrmions have been identified only from transmission electron microscopy images and have not been observed by other techniques, nor seen in simulations carried out under realistic conditions. Here, quantitative Lorentz transmission electron microscopy, X-ray holography, and micromagnetic simulations are combined to search for biskyrmions in MnNiGa, a material in which they have been reported. Only type-I and type-II magnetic bubbles are found and images purported to show biskyrmions can be explained as type-II bubbles viewed at an angle to their axes. It is not the magnetization but the magnetic flux density resulting from this object that forms the counter-rotating vortices.
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Affiliation(s)
- James C. Loudon
- Department of Materials Science and MetallurgyUniversity of Cambridge27 Charles Babbage RoadCambridgeCB3 0FSUK
| | | | - David Cortés‐Ortuño
- Faculty of Engineering and Physical SciencesUniversity of SouthamptonSouthamptonSO17 1BJUK
| | - Max T. Birch
- Department of PhysicsUniversity of DurhamDurhamDH1 3LEUK
| | | | - Aleš Štefančič
- Department of PhysicsUniversity of WarwickCoventryCV4 7ALUK
| | - Feodor Y. Ogrin
- School of Physics and AstronomyUniversity of ExeterExeterEX4 4QLUK
| | | | - Nicholas Bukin
- School of Physics and AstronomyUniversity of ExeterExeterEX4 4QLUK
| | - Angus Laurenson
- School of Physics and AstronomyUniversity of ExeterExeterEX4 4QLUK
| | - Horia Popescu
- Synchrotron SOLEILSaint Aubin, BP 4891192Gif‐sur‐YvetteFrance
| | - Marijan Beg
- Faculty of Engineering and Physical SciencesUniversity of SouthamptonSouthamptonSO17 1BJUK
- European XFEL GmbHHolzkoppel 422869SchenefeldGermany
| | - Ondrej Hovorka
- Faculty of Engineering and Physical SciencesUniversity of SouthamptonSouthamptonSO17 1BJUK
| | - Hans Fangohr
- Faculty of Engineering and Physical SciencesUniversity of SouthamptonSouthamptonSO17 1BJUK
- European XFEL GmbHHolzkoppel 422869SchenefeldGermany
| | - Paul A. Midgley
- Department of Materials Science and MetallurgyUniversity of Cambridge27 Charles Babbage RoadCambridgeCB3 0FSUK
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47
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Li X, Zhang S, Li H, Venero DA, White JS, Cubitt R, Huang Q, Chen J, He L, van der Laan G, Wang W, Hesjedal T, Wang F. Oriented 3D Magnetic Biskyrmions in MnNiGa Bulk Crystals. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2019; 31:e1900264. [PMID: 30866107 DOI: 10.1002/adma.201900264] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2019] [Revised: 02/15/2019] [Indexed: 06/09/2023]
Abstract
A biskyrmion consists of two bound, topologically stable, skyrmion spin textures. These coffee-bean-shaped objects are observed in real space in thin plates using Lorentz transmission electron microscopy (LTEM). From LTEM imaging alone, it is not clear whether biskyrmions are surface-confined objects, or, analogous to skyrmions in noncentrosymmetric helimagnets, 3D tube-like structures in a bulk sample. Here, the biskyrmion form factor is investigated in single- and polycrystalline-MnNiGa samples using small-angle neutron scattering. It is found that biskyrmions are not long-range ordered, not even in single crystals. Surprisingly all of the disordered biskyrmions have their in-plane symmetry axis aligned along certain directions, governed by the magnetocrystalline anisotropy. This anisotropic nature of biskyrmions may be further exploited to encode information.
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Affiliation(s)
- Xiyang Li
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, 101408, China
| | - Shilei Zhang
- Department of Physics, Clarendon Laboratory, University of Oxford, Oxford, OX1 3PU, UK
| | - Hang Li
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, 101408, China
| | - Diego Alba Venero
- ISIS, STFC Rutherford Appleton Laboratory, Chilton, Didcot, OX11 0QX, UK
| | - Jonathan S White
- Laboratory for Neutron Scattering and Imaging, Paul Scherrer Institute, CH-5232, Villigen, Switzerland
| | - Robert Cubitt
- Institut Laue-Langevin, 6 rue Jules Horowitz, 38042, Grenoble, France
| | - Qingzhen Huang
- NIST Center for Neutron Research, National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, MD, 20899, USA
| | - Jie Chen
- China Spallation Neutron Source, Dongguan, 523808, China
| | - Lunhua He
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
- Songshan Lake Materials Laboratory, Dongguan, 523808, China
| | | | - Wenhong Wang
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, 101408, China
- Songshan Lake Materials Laboratory, Dongguan, 523808, China
| | - Thorsten Hesjedal
- Department of Physics, Clarendon Laboratory, University of Oxford, Oxford, OX1 3PU, UK
| | - Fangwei Wang
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, 101408, China
- Songshan Lake Materials Laboratory, Dongguan, 523808, China
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48
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Zuo S, Liu Y, Zhang Y, Xiong J, Liu J, Qiao K, Liang F, Zhao T, Hu F, Sun J, Shen B. In situ TEM study on diversified martensitic transition behaviour in Ni 50Mn 35In 15 alloys. NANOSCALE 2019; 11:4999-5004. [PMID: 30839014 DOI: 10.1039/c8nr10209k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Ni-Mn-In magnetic shape-memory alloys are attractive materials due to their important functional properties relating to the martensitic transition. Understanding the complex martensitic magnetism and the transition process is of crucial importance not only from a fundamental but also from a technological point of view. Here, we demonstrate the dynamic magnetic domains and microstructures during the martensitic transition in the bulk and melt-spun ribbons of Ni50Mn35In15via in situ Lorentz transmission electron microscopy. The significant evolutionary differences in correlation with the temperature dependence of magnetization are identified between the bulk and ribbons. For a bulk alloy with L21 crystal structure at room temperature, the complete martensite with 7 M modulation in the paramagnetic state and the successive stripe magnetic domains in ferromagnetic martensite develop with a further decrease in the temperature. The stripe domains evolve into biskyrmion-like spin configurations when a perpendicular magnetic field is applied. In contrast, the partial austenitic phase always coexists with the martensitic phase in the ribbons even far below the martensitic transition temperatures and the martensitic phase presents a dominant twinning stack morphology with 5 M modulation and various magnetic domains. During the subsequent reheating-cooling cycles, the thermal hysteresis behavior and the transition reversibility in the bulk and ribbons are represented via the microstructural evolution.
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Affiliation(s)
- Shulan Zuo
- State Key Laboratory of Magnetism, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, P. R. China.
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49
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Hou Z, Zhang Q, Xu G, Zhang S, Gong C, Ding B, Li H, Xu F, Yao Y, Liu E, Wu G, Zhang XX, Wang W. Manipulating the Topology of Nanoscale Skyrmion Bubbles by Spatially Geometric Confinement. ACS NANO 2019; 13:922-929. [PMID: 30605309 DOI: 10.1021/acsnano.8b09689] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The discovery of magnetic skyrmion bubbles in centrosymmetric magnets has been receiving increasing interest from the research community, due to the fascinating physics of topological spin textures and its possible applications to spintronics. However, key challenges remain, such as how to manipulate the nucleation of skyrmion bubbles to exclude the trivial bubbles or metastable skyrmion bubbles that usually coexist with skyrmion bubbles in the centrosymmetric magnets. Here, we report having performed this task by applying spatially geometric confinement to a centrosymmetric frustrated Fe3Sn2 magnet. We demonstrate that the spatially geometric confinement can indeed stabilize the skyrmion bubbles by effectively suppressing the formation of trivial bubbles and metastable skyrmion bubbles. We also show that the critical magnetic field for the nucleation of the skyrmion bubbles in the confined Fe3Sn2 nanostripes is drastically less, by an order of magnitude, than that required in the thin plate without geometrical confinement. By analyzing how the width and thickness of the nanostripes affect the spin textures of skyrmion bubbles, we infer that the topological transition of skyrmion bubbles is closely related to the dipole-dipole interaction, which we find is consistent with theoretical simulations. The results presented here bring us closer to achieving the fabrication of skyrmion-based racetrack memory devices.
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Affiliation(s)
- Zhipeng Hou
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics , Chinese Academy of Sciences , Beijing 100190 , China
- Physical Science and Engineering , King Abdullah University of Science and Technology (KAUST) , Thuwal 23955-6900 , Saudi Arabia
| | - Qiang Zhang
- Physical Science and Engineering , King Abdullah University of Science and Technology (KAUST) , Thuwal 23955-6900 , Saudi Arabia
| | - Guizhou Xu
- School of Materials Science and Engineering , Nanjing University of Science and Technology , Nanjing 210094 , China
| | - Senfu Zhang
- Physical Science and Engineering , King Abdullah University of Science and Technology (KAUST) , Thuwal 23955-6900 , Saudi Arabia
| | - Chen Gong
- Physical Science and Engineering , King Abdullah University of Science and Technology (KAUST) , Thuwal 23955-6900 , Saudi Arabia
| | - Bei Ding
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics , Chinese Academy of Sciences , Beijing 100190 , China
| | - Hang Li
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics , Chinese Academy of Sciences , Beijing 100190 , China
| | - Feng Xu
- School of Materials Science and Engineering , Nanjing University of Science and Technology , Nanjing 210094 , China
| | - Yuan Yao
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics , Chinese Academy of Sciences , Beijing 100190 , China
| | - Enke Liu
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics , Chinese Academy of Sciences , Beijing 100190 , China
| | - Guangheng Wu
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics , Chinese Academy of Sciences , Beijing 100190 , China
| | - Xi-Xiang Zhang
- Physical Science and Engineering , King Abdullah University of Science and Technology (KAUST) , Thuwal 23955-6900 , Saudi Arabia
| | - Wenhong Wang
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics , Chinese Academy of Sciences , Beijing 100190 , China
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50
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Hou Z, Zhang Q, Xu G, Gong C, Ding B, Wang Y, Li H, Liu E, Xu F, Zhang H, Yao Y, Wu G, Zhang XX, Wang W. Creation of Single Chain of Nanoscale Skyrmion Bubbles with Record-High Temperature Stability in a Geometrically Confined Nanostripe. NANO LETTERS 2018; 18:1274-1279. [PMID: 29299928 DOI: 10.1021/acs.nanolett.7b04900] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Nanoscale topologically nontrivial spin textures, such as magnetic skyrmions, have been identified as promising candidates for the transport and storage of information for spintronic applications, notably magnetic racetrack memory devices. The design and realization of a single skyrmion chain at room temperature (RT) and above in the low-dimensional nanostructures are of great importance for future practical applications. Here, we report the creation of a single skyrmion bubble chain in a geometrically confined Fe3Sn2 nanostripe with a width comparable to the featured size of a skyrmion bubble. Systematic investigations on the thermal stability have revealed that the single chain of skyrmion bubbles can keep stable at temperatures varying from RT up to a record-high temperature of 630 K. This extreme stability can be ascribed to the weak temperature-dependent magnetic anisotropy and the formation of edge states at the boundaries of the nanostripes. The realization of the highly stable skyrmion bubble chain in a geometrically confined nanostructure is a very important step toward the application of skyrmion-based spintronic devices.
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Affiliation(s)
- Zhipeng Hou
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences , Beijing 100190, China
- Physical Science and Engineering, King Abdullah University of Science and Technology (KAUST) , Thuwal 23955-6900, Saudi Arabia
| | - Qiang Zhang
- Physical Science and Engineering, King Abdullah University of Science and Technology (KAUST) , Thuwal 23955-6900, Saudi Arabia
| | - Guizhou Xu
- School of Materials Science and Engineering, Nanjing University of Science and Technology , Nanjing 210094, China
| | - Chen Gong
- Physical Science and Engineering, King Abdullah University of Science and Technology (KAUST) , Thuwal 23955-6900, Saudi Arabia
| | - Bei Ding
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences , Beijing 100190, China
| | - Yue Wang
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences , Beijing 100190, China
| | - Hang Li
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences , Beijing 100190, China
| | - Enke Liu
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences , Beijing 100190, China
| | - Feng Xu
- School of Materials Science and Engineering, Nanjing University of Science and Technology , Nanjing 210094, China
| | - Hongwei Zhang
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences , Beijing 100190, China
| | - Yuan Yao
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences , Beijing 100190, China
| | - Guangheng Wu
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences , Beijing 100190, China
| | - Xi-Xiang Zhang
- Physical Science and Engineering, King Abdullah University of Science and Technology (KAUST) , Thuwal 23955-6900, Saudi Arabia
| | - Wenhong Wang
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences , Beijing 100190, China
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