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Li Z, Yin Q, Lv W, Shen J, Wang S, Zhao T, Cai J, Lei H, Lin SZ, Zhang Y, Shen B. Electron-Assisted Generation and Straight Movement of Skyrmion Bubble in Kagome TbMn 6Sn 6. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024; 36:e2309538. [PMID: 38366361 DOI: 10.1002/adma.202309538] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2023] [Revised: 12/31/2023] [Indexed: 02/18/2024]
Abstract
Topological magnetic textures are promising candidates as binary data units for the next-generation memory device. The precise generation and convenient control of nontrivial spin topology at zero field near room temperature endows the critical advantages in skyrmionic devices but is not simultaneously integrated into one material. Here, in the Kagome plane of quantum TbMn6Sn6, the expedient generation of the skyrmion bubbles in versatile forms of lattice, chain, and isolated one by converging the electron beam, where the electron intensity gradient contributes to the dynamic generation from local anisotropy variation near spin reorientation transition (SRT) is reported. Encouragingly, by utilizing the dynamic shift of the SRT domain interface, the straight movement is actualized with the skyrmion bubble slave to the SRT domain interface forming an elastic composite object, avoiding the usual deflection from the skyrmion Hall effect. The critical contribution of the SRT domain interface via conveniently electron-assisted heating is further theoretically validated in micromagnetic simulation, highlighting the compatible application possibility in advanced devices.
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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
- Department of Physics and Beijing Key Laboratory of Optoelectronic Functional Materials & MicroNano Devices, Renmin University of China, Beijing, 100872, China
- Key Laboratory of Quantum State Construction and Manipulation (Ministry of Education), Renmin University of China, Beijing, 100872, China
| | - Wenxin Lv
- Department of Physics and Beijing Key Laboratory of Optoelectronic Functional Materials & MicroNano Devices, Renmin University of China, Beijing, 100872, China
- Key Laboratory of Quantum State Construction and Manipulation (Ministry of Education), Renmin University of China, Beijing, 100872, China
| | - Jun Shen
- Department of Energy and Power Engineering, School of Mechanical Engineering, Beijing Institute of Technology, Beijing, 100081, China
| | - Shouguo Wang
- Anhui Key Laboratory of Magnetic Functional Materials and Devices, School of Materials Science and Engineering, Anhui University, Hefei, 230601, 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
- Department of Physics and Beijing Key Laboratory of Optoelectronic Functional Materials & MicroNano Devices, Renmin University of China, Beijing, 100872, China
- Key Laboratory of Quantum State Construction and Manipulation (Ministry of Education), Renmin University of China, Beijing, 100872, China
| | - Shi-Zeng Lin
- Theoretical Division and Center for Integrated Nanotechnologies, Los Alamos National Laboratory, Los Alamos, New Mexico, 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
- Open Access Research Infrastrucure, 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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2
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Zhang Y, Tang J, Wu Y, Shi M, Xu X, Wang S, Tian M, Du H. Stable skyrmion bundles at room temperature and zero magnetic field in a chiral magnet. Nat Commun 2024; 15:3391. [PMID: 38649678 PMCID: PMC11035646 DOI: 10.1038/s41467-024-47730-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2023] [Accepted: 04/10/2024] [Indexed: 04/25/2024] Open
Abstract
Topological spin textures are characterized by magnetic topological charges, Q, which govern their electromagnetic properties. Recent studies have achieved skyrmion bundles with arbitrary integer values of Q, opening possibilities for exploring topological spintronics based on Q. However, the realization of stable skyrmion bundles in chiral magnets at room temperature and zero magnetic field - the prerequisite for realistic device applications - has remained elusive. Here, through the combination of pulsed currents and reversed magnetic fields, we experimentally achieve skyrmion bundles with different integer Q values - reaching a maximum of 24 at above room temperature and zero magnetic field - in the chiral magnet Co8Zn10Mn2. We demonstrate the field-driven annihilation of high-Q bundles and present a phase diagram as a function of temperature and field. Our experimental findings are consistently corroborated by micromagnetic simulations, which reveal the nature of the skyrmion bundle as that of skyrmion tubes encircled by a fractional Hopfion.
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Grants
- This work was supported by the National Key R&D Program of China, Grant No. 2022YFA1403603 (H.D.); the Natural Science Foundation of China, Grants No. 12174396 (J.T.), 12104123 (Y.W.), and 12241406 (H.D.); the National Natural Science Funds for Distinguished Young Scholar, Grant No. 52325105 (H.D.); the Anhui Provincial Natural Science Foundation, Grant No. 2308085Y32 (J.T.); the Natural Science Project of Colleges and Universities in Anhui Province, Grant No. 2022AH030011 (J.T.); the Strategic Priority Research Program of Chinese Academy of Sciences, Grant No. XDB33030100 (H.D.); CAS Project for Young Scientists in Basic Research, Grant No. YSBR-084 (H.D.); Systematic Fundamental Research Program Leveraging Major Scientific and Technological Infrastructure, Chinese Academy of Sciences, Grant No. JZHKYPT-2021-08 (H.D.);Anhui Province Excellent Young Teacher Training Project Grant No. YQZD2023067 (Y.W.); and the China Postdoctoral Science Foundation Grant No. 2023M743543 (Y.W.).
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Affiliation(s)
- Yongsen Zhang
- Science Island Branch, Graduate School of USTC, Hefei, 230026, China
- Anhui Province Key Laboratory of Low-Energy Quantum Materials and Devices, High Magnetic Field Laboratory, HFIPS, Chinese Academy of Sciences, Hefei, 230031, China
| | - Jin Tang
- School of Physics and Optoelectronic Engineering, Anhui University, Hefei, 230601, China.
| | - Yaodong Wu
- School of Physics and Materials Engineering, Hefei Normal University, Hefei, 230601, China
| | - Meng Shi
- Science Island Branch, Graduate School of USTC, Hefei, 230026, China
- Anhui Province Key Laboratory of Low-Energy Quantum Materials and Devices, High Magnetic Field Laboratory, HFIPS, Chinese Academy of Sciences, Hefei, 230031, China
| | - Xitong Xu
- Anhui Province Key Laboratory of Low-Energy Quantum Materials and Devices, High Magnetic Field Laboratory, HFIPS, Chinese Academy of Sciences, Hefei, 230031, China
| | - Shouguo Wang
- Anhui Key Laboratory of Magnetic Functional Materials and Devices, School of Materials Science and Engineering, Anhui University, Hefei, 230601, China
| | - Mingliang Tian
- Anhui Province Key Laboratory of Low-Energy Quantum Materials and Devices, High Magnetic Field Laboratory, HFIPS, Chinese Academy of Sciences, Hefei, 230031, China
- School of Physics and Optoelectronic Engineering, Anhui University, Hefei, 230601, China
| | - Haifeng Du
- Anhui Province Key Laboratory of Low-Energy Quantum Materials and Devices, High Magnetic Field Laboratory, HFIPS, Chinese Academy of Sciences, Hefei, 230031, China.
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3
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Pohl D, Lee Y, Kriegner D, Beckert S, Schneider S, Rellinghaus B, Thomas A. Probing magnetic properties at the nanoscale: in-situ Hall measurements in a TEM. Sci Rep 2023; 13:14871. [PMID: 37684274 PMCID: PMC10491587 DOI: 10.1038/s41598-023-41985-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Accepted: 09/04/2023] [Indexed: 09/10/2023] Open
Abstract
We report on advanced in-situ magneto-transport measurements in a transmission electron microscope. The approach allows for concurrent magnetic imaging and high resolution structural and chemical characterization of the same sample. Proof-of-principle in-situ Hall measurements on presumably undemanding nickel thin films supported by micromagnetic simulations reveal that in samples with non-trivial structures and/or compositions, detailed knowledge of the latter is indispensable for a thorough understanding and reliable interpretation of the magneto-transport data. The proposed in-situ approach is thus expected to contribute to a better understanding of the Hall signatures in more complex magnetic textures.
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Affiliation(s)
- Darius Pohl
- Dresden Center for Nanoanalysis (DCN), cfaed, TU Dresden, 01062, Dresden, Germany.
| | - Yejin Lee
- Leibniz Institute for Solid State and Materials Research, IFW Dresden, 01062, Dresden, Germany
| | - Dominik Kriegner
- Institute of Physics, Academy of Sciences of the Czech Republic, Cukrovarnická 10, 162 00, Praha 6, Czech Republic
- Institute of Solid State and Materials Physics, TU Dresden, 01062, Dresden, Germany
| | - Sebastian Beckert
- Institute of Solid State and Materials Physics, TU Dresden, 01062, Dresden, Germany
| | - Sebastian Schneider
- Dresden Center for Nanoanalysis (DCN), cfaed, TU Dresden, 01062, Dresden, Germany
| | - Bernd Rellinghaus
- Dresden Center for Nanoanalysis (DCN), cfaed, TU Dresden, 01062, Dresden, Germany.
| | - Andy Thomas
- Leibniz Institute for Solid State and Materials Research, IFW Dresden, 01062, Dresden, Germany.
- Institute of Solid State and Materials Physics, TU Dresden, 01062, Dresden, Germany.
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4
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He Z, Du W, Dou K, Dai Y, Huang B, Ma Y. Ferroelectrically tunable magnetic skyrmions in two-dimensional multiferroics. MATERIALS HORIZONS 2023; 10:3450-3457. [PMID: 37345913 DOI: 10.1039/d3mh00572k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/23/2023]
Abstract
Magnetic skyrmions are topologically protected entities that are promising for information storage and processing. Currently, an essential challenge for future advances of skyrmionic devices lies in achieving effective control of skyrmion properties. Here, through first-principles and Monte-Carlo simulations, we report the identification of nontrivial topological magnetism in two-dimensional multiferroics of Co2NF2. Because of ferroelectricity, monolayer Co2NF2 exhibits a large Dzyaloshinskii-Moriya interaction. This together with exchange interaction can stabilize magnetic skyrmions with the size of sub-10 nm under a moderate magnetic field. Importantly, arising from the magnetoelectric coupling effect, the chirality of magnetic skyrmions is ferroelectrically tunable, producing the four-fold degenerate skyrmions. When interfacing with monolayer MoSe2, the creation and annihilation of magnetic skyrmions, as well as phase transition between skyrmion and skyrmion lattice, can be realized in a ferroelectrically controllable fashion. A dimensionless parameter κ' is further proposed as the criterion for stabilizing magnetic skyrmions in such multiferroic lattices. Our work greatly enriches the two-dimensional skyrmionics and multiferroics research.
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Affiliation(s)
- Zhonglin He
- School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Shandanan Street 27, Jinan 250100, China.
| | - Wenhui Du
- School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Shandanan Street 27, Jinan 250100, China.
| | - Kaiying Dou
- School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Shandanan Street 27, Jinan 250100, China.
| | - Ying Dai
- School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Shandanan Street 27, Jinan 250100, China.
| | - Baibiao Huang
- School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Shandanan Street 27, Jinan 250100, China.
| | - Yandong Ma
- School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Shandanan Street 27, Jinan 250100, China.
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5
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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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6
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Abstract
Writing, erasing and computing are three fundamental operations required by any working electronic device. Magnetic skyrmions could be essential bits in promising in emerging topological spintronic devices. In particular, skyrmions in chiral magnets have outstanding properties like compact texture, uniform size, and high mobility. However, creating, deleting, and driving isolated skyrmions, as prototypes of aforementioned basic operations, have been a grand challenge in chiral magnets ever since the discovery of skyrmions, and achieving all these three operations in a single device is even more challenging. Here, by engineering chiral magnet Co8Zn10Mn2 into the customized micro-devices for in-situ Lorentz transmission electron microscopy observations, we implement these three operations of skyrmions using nanosecond current pulses with a low current density of about 1010 A·m−2 at room temperature. A notched structure can create or delete magnetic skyrmions depending on the direction and magnitude of current pulses. We further show that the magnetic skyrmions can be deterministically shifted step-by-step by current pulses, allowing the establishment of the universal current-velocity relationship. These experimental results have immediate significance towards the skyrmion-based memory or logic devices. There has been much interest in using skyrmions for new approaches to compution, however, creating, deleting and driving skyrmions remains a challenge. Here, Wang et al demonstrate all three operations for skyrmions in tailored Co8Zn10Mn2 nanodevices using tailored current pulses.
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7
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Hou Z, Wang Y, Lan X, Li S, Wan X, Meng F, Hu Y, Fan Z, Feng C, Qin M, Zeng M, Zhang X, Liu X, Fu X, Yu G, Zhou G, Zhou Y, Zhao W, Gao X, Liu JM. Controlled Switching of the Number of Skyrmions in a Magnetic Nanodot by Electric Fields. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2022; 34:e2107908. [PMID: 34969153 DOI: 10.1002/adma.202107908] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2021] [Revised: 12/18/2021] [Indexed: 06/14/2023]
Abstract
Magnetic skyrmions are topological swirling spin configurations that hold promise for building future magnetic memories and logic circuits. Skyrmionic devices typically rely on the electrical manipulation of a single skyrmion, but controllably manipulating a group of skyrmions can lead to more compact and memory-efficient devices. Here, an electric-field-driven cascading transition of skyrmion clusters in a nanostructured ferromagnetic/ferroelectric multiferroic heterostructure is reported, which allows a continuous multilevel transition of the number of skyrmions in a one-by-one manner. Most notably, the transition is non-volatile and reversible, which is crucial for multi-bit memory applications. Combined experiments and theoretical simulations reveal that the switching of skyrmion clusters is induced by the strain-mediated modification of both the interfacial Dzyaloshinskii-Moriya interaction and effective uniaxial anisotropy. The results not only open up a new direction for constructing low-power-consuming, non-volatile, and multi-bit skyrmionic devices, but also offer valuable insights into the fundamental physics underlying the voltage manipulation of skyrmion clusters.
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Affiliation(s)
- 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, P. R. China
| | - Yadong Wang
- 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, P. R. China
| | - Xiaoming Lan
- School of Materials Science and Engineering, Dongguan University of Technology, Dongguan, 523808, P. R. China
| | - Sai Li
- Fert Beijing Institute, School of Integrated Circuit Science and Engineering, Beihang University, Beijing, 100191, P. R. China
| | - Xuejin Wan
- School of Materials Science and Engineering, Dongguan University of Technology, Dongguan, 523808, P. R. China
| | - Fei Meng
- Department of Materials Physics and Chemistry, University of Science and Technology Beijing, Beijing, 100083, P. R. China
| | - Yangfan Hu
- School of Materials Science and Engineering, Dongguan University of Technology, Dongguan, 523808, P. R. China
| | - Zhen Fan
- 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, P. R. China
| | - Chun Feng
- Department of Materials Physics and Chemistry, University of Science and Technology Beijing, Beijing, 100083, P. R. China
| | - Minghui Qin
- 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, P. R. China
| | - Min Zeng
- 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, P. R. China
| | - Xichao Zhang
- Department of Electrical and Computer Engineering, Shinshu University, 4-17-1 Wakasato, Nagano, 380-8553, Japan
| | - Xiaoxi Liu
- Department of Electrical and Computer Engineering, Shinshu University, 4-17-1 Wakasato, Nagano, 380-8553, Japan
| | - Xuewen Fu
- Ultrafast Electron Microscopy Laboratory, School of Physics, Nankai University, Tianjin, 300071, P. R. China
| | - Guanghua Yu
- Department of Materials Physics and Chemistry, University of Science and Technology Beijing, Beijing, 100083, P. R. China
| | - Guofu Zhou
- 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, P. R. China
| | - Yan Zhou
- School of Science and Engineering, The Chinese University of Hong Kong, Shenzhen, Guangdong, 518172, P. R. China
| | - Weisheng Zhao
- Fert Beijing Institute, School of Integrated Circuit Science and Engineering, Beihang University, Beijing, 100191, P. R. China
| | - Xingsen Gao
- 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, P. R. China
| | - Jun-Ming Liu
- 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, P. R. China
- Laboratory of Solid State Microstructures and Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, 211102, P. R. China
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8
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Dynamic transition of current-driven single-skyrmion motion in a room-temperature chiral-lattice magnet. Nat Commun 2021; 12:6797. [PMID: 34819505 PMCID: PMC8613223 DOI: 10.1038/s41467-021-27073-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2021] [Accepted: 11/03/2021] [Indexed: 11/08/2022] Open
Abstract
Driving and controlling single-skyrmion motion promises skyrmion-based spintronic applications. Recently progress has been made in moving skyrmionic bubbles in thin-film heterostructures and low-temperature chiral skyrmions in the FeGe helimagnet by electric current. Here, we report the motion tracking and control of a single skyrmion at room temperature in the chiral-lattice magnet Co9Zn9Mn2 using nanosecond current pulses. We have directly observed that the skyrmion Hall motion reverses its direction upon the reversal of skyrmion topological number using Lorentz transmission electron microscopy. Systematic measurements of the single-skyrmion trace as a function of electric current reveal a dynamic transition from the static pinned state to the linear flow motion via a creep event, in agreement with the theoretical prediction. We have clarified the role of skyrmion pinning and evaluated the intrinsic skyrmion Hall angle and the skyrmion velocity in the course of the dynamic transition. Our results pave a way to skyrmion applications in spintronic devices. Skyrmions, topological spin textures, have attracted interest for use in spin-based information processing. Here, Peng et al analyse the current driven motion of a single skyrmion at room temperature in a chiral-lattice magnet, tracking the motion using Lorentz transmission electron microscopy.
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9
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Kúkoľová A, Dimitrievska M, Litvinchuk AP, Ramanandan SP, Tappy N, Menon H, Borg M, Grundler D, Fontcuberta I Morral A. Cubic, hexagonal and tetragonal FeGe x phases ( x = 1, 1.5, 2): Raman spectroscopy and magnetic properties. CrystEngComm 2021; 23:6506-6517. [PMID: 34602862 PMCID: PMC8474057 DOI: 10.1039/d1ce00970b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2021] [Accepted: 08/20/2021] [Indexed: 11/30/2022]
Abstract
There is currently an emerging drive towards computational materials design and fabrication of predicted novel materials. One of the keys to developing appropriate fabrication methods is determination of the composition and phase. Here we explore the FeGe system and establish reference Raman signatures for the distinction between FeGe hexagonal and cubic structures, as well as FeGe2 and Fe2Ge3 phases. The experimental results are substantiated by first principles lattice dynamics calculations as well as by complementary structural characterization such as transmission electron microscopy and X-ray diffraction, along with magnetic measurements.
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Affiliation(s)
- A Kúkoľová
- Laboratory of Semiconductor Materials, Institute of Materials, School of Engineering, Ecole Polytechnique Fédérale de Lausanne (EPFL) 1015 Lausanne Switzerland
- Laboratory of Nanoscale Magnetic Materials and Magnonics, Institute of Materials, Ecole Polytechnique Fédérale de Lausanne (EPFL) 1015 Lausanne Switzerland
| | - M Dimitrievska
- Laboratory of Semiconductor Materials, Institute of Materials, School of Engineering, Ecole Polytechnique Fédérale de Lausanne (EPFL) 1015 Lausanne Switzerland
| | - A P Litvinchuk
- Texas Center for Superconductivity at UH, Department of Physics, University of Houston USA
| | - S P Ramanandan
- Laboratory of Semiconductor Materials, Institute of Materials, School of Engineering, Ecole Polytechnique Fédérale de Lausanne (EPFL) 1015 Lausanne Switzerland
| | - N Tappy
- Laboratory of Semiconductor Materials, Institute of Materials, School of Engineering, Ecole Polytechnique Fédérale de Lausanne (EPFL) 1015 Lausanne Switzerland
| | - H Menon
- Electrical and Information Technology, Lund University Lund Sweden
- NanoLund, Lund University Lund Sweden
| | - M Borg
- Electrical and Information Technology, Lund University Lund Sweden
- NanoLund, Lund University Lund Sweden
| | - D Grundler
- Laboratory of Nanoscale Magnetic Materials and Magnonics, Institute of Materials, Ecole Polytechnique Fédérale de Lausanne (EPFL) 1015 Lausanne Switzerland
- Institute of Electrical and Micro Engineering, School of Engineering, Ecole Polytechnique Fédérale de Lausanne (EPFL) 1015 Lausanne Switzerland
| | - A Fontcuberta I Morral
- Laboratory of Semiconductor Materials, Institute of Materials, School of Engineering, Ecole Polytechnique Fédérale de Lausanne (EPFL) 1015 Lausanne Switzerland
- Institute of Physics, School of Basic Sciences, Ecole Polytechnique Fédérale de Lausanne (EPFL) 1015 Lausanne Switzerland
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10
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Wang B, Wu PK, Bagués Salguero N, Zheng Q, Yan J, Randeria M, McComb DW. Stimulated Nucleation of Skyrmions in a Centrosymmetric Magnet. ACS NANO 2021; 15:13495-13503. [PMID: 34374281 DOI: 10.1021/acsnano.1c04053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Understanding the dynamics of skyrmion nucleation and manipulation is important for applications in spintronic devices. In this contribution, the spin textures at magnetic domain-boundaries stimulated by application of in-plane magnetic fields in a centrosymmetric kagome ferromagnet, Fe3Sn2, with thickness gradient are investigated using Lorentz transmission electron microscopy. Switching of the in-plane magnetic field is shown to induce a reversible transformation from magnetic stripes to skyrmions, or vice versa, at the interface between differently oriented domains. Micromagnetic simulations combined with experiments reveal that the rotatable anisotropy and thickness dependence of the response to the external in-plane field are the critical factors for the skyrmion formation. In addition, it is shown that the helicity of skyrmions can also be controlled using this dynamic process. The results suggest that magnetic materials with rotatable anisotropy are potential skyrmionic systems and provides a different approach for nucleation and manipulation of skyrmions in spintronic devices.
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Affiliation(s)
- Binbin Wang
- Department of Materials Science and Engineering, The Ohio State University, Columbus, Ohio 43212, United States
- Center for Electron Microscopy and Analysis, The Ohio State University, Columbus, Ohio 43212, United States
| | - Po-Kuan Wu
- Department of Physics, The Ohio State University, Columbus, Ohio 43210, United States
| | - Núria Bagués Salguero
- Department of Materials Science and Engineering, The Ohio State University, Columbus, Ohio 43212, United States
- Center for Electron Microscopy and Analysis, The Ohio State University, Columbus, Ohio 43212, United States
| | - Qiang Zheng
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
- Department of Materials Science and Engineering, University of Tennessee, Knoxville, Tennessee 37996, United States
| | - Jiaqiang Yan
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
- Department of Materials Science and Engineering, University of Tennessee, Knoxville, Tennessee 37996, United States
| | - Mohit Randeria
- Department of Physics, The Ohio State University, Columbus, Ohio 43210, United States
| | - David W McComb
- Department of Materials Science and Engineering, The Ohio State University, Columbus, Ohio 43212, United States
- Center for Electron Microscopy and Analysis, The Ohio State University, Columbus, Ohio 43212, United States
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11
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Tyukalova E, Vimal Vas J, Ignatans R, Mueller AD, Medwal R, Imamura M, Asada H, Fukuma Y, Rawat RS, Tileli V, Duchamp M. Challenges and Applications to Operando and In Situ TEM Imaging and Spectroscopic Capabilities in a Cryogenic Temperature Range. Acc Chem Res 2021; 54:3125-3135. [PMID: 34339603 DOI: 10.1021/acs.accounts.1c00078] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
ConspectusIn this Account, we describe the challenges and promising applications of transmission electron microscopy (TEM) imaging and spectroscopy at cryogenic temperatures. Our work focuses on two areas of application: the delay of electron-beam-induced degradation and following low-temperature phenomena in a continuous and variable temperature range. For the former, we present a study of LiMn1.5Ni0.5O4 lithium ion battery cathode material that undergoes electron beam-induced degradation when studied at room temperature by TEM. Cryogenic imaging reveals the true structure of LiMn1.5Ni0.5O4 nanoparticles in their discharged state. Improved stability under electron beam irradiation was confirmed by following the evolution of the O K-edge fine structure by electron energy-loss spectroscopy. Our results demonstrate that the effect of radiation damage on discharged LiMn1.5Ni0.5O4 was previously underestimated and that atomic-resolution imaging at cryogenic temperature has a potential to be generalized to most of the Li-based materials and beyond. For the latter, we present two studies in the imaging of low-temperature phenomena on the local scale, namely, the evolution of ferroelectric and ferromagnetic domains walls, in BaTiO3 and Y3Fe5O12 systems, respectively, in a continuous and variable temperature range. Continuous imaging of the phase transition in BaTiO3, a prototypical ferroelectric system, from the low-temperature orthorhombic phase continuously up to the centrosymmetric high-temperature phase is shown to be possible inside a TEM. Similarly, the propagation of domain walls in Y3Fe5O12, a magnetic insulator, is studied from ∼120 to ∼400 K and combined with the application of a magnetic field and electrical current pulses to mimic the operando conditions as in domain wall memory and logic devices for information technology. Such studies are promising for studying the pinning of the ferroelectric and magnetic domains versus temperature, spin-polarized current, and externally applied magnetic field to better manipulate the domain walls. The capability of combining operando TEM stimuli such as current, voltage, and/or magnetic field with in situ TEM imaging in a continuous cryogenic temperature range will allow the uncovering of fundamental phenomena on the nanometer scale. These studies were made possible using a MEMS-based TEM holder that allowed an electron-transparent sample to be transferred and electrically contacted on a MEMS chip. The six-contact double-tilt holder allows the alignment of the specimen into its zone axis while simultaneously using four electrical contacts to regulate the temperature and two contacts to apply the electrical stimuli, i.e., operando TEM imaging. This Account leads to the demonstration of (i) the high-resolution imaging and spectroscopy of nanoparticles oriented in the desired [110] zone-axis direction at cryogenic temperatures to mitigate the electron beam degradation, (ii) imaging of low-temperature transitions with accurate and continuous control of the temperature that allowed single-frame observation of the presence of both the orthorhombic and tetragonal phases in the BaTiO3 system, and (iii) magnetic domain wall propagation as a function of temperature, magnetic field, and current pulses (100 ns with a 100 kHz repetition rate) in the Y3Fe5O12 system.
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Affiliation(s)
| | | | - Reinis Ignatans
- Institute of Materials, École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland
| | | | | | - Masaaki Imamura
- Department of Electrical Engineering, Fukuoka Institute of Technology, Fukuoka 811-0295, Japan
| | - Hironori Asada
- Graduate School of Sciences and Technology for Innovation, Yamaguchi University, Ube 755-8611, Japan
| | - Yasuhiro Fukuma
- Department of Physics and Information Technology, Kyushu Institute of Technology, Iizuka 820-8502, Japan
- Research Center for Neuromorphic AI Hardwares, Kyushu Institute of Technology, Kitakyushu 808-0196, Japan
| | | | - Vasiliki Tileli
- Institute of Materials, École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland
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12
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Controlling bimerons as skyrmion analogues by ferroelectric polarization in 2D van der Waals multiferroic heterostructures. Nat Commun 2020; 11:5930. [PMID: 33230183 PMCID: PMC7683542 DOI: 10.1038/s41467-020-19779-6] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Accepted: 10/30/2020] [Indexed: 11/08/2022] Open
Abstract
Atom-thick van der Waals heterostructures with nontrivial physical properties tunable via the magnetoelectric coupling effect are highly desirable for the future advance of multiferroic devices. In this work on LaCl/In2Se3 heterostructure consisting of a 2D ferromagnetic layer and a 2D ferroelectric layer, reversible switch of the easy axis and the Curie temperature of the magnetic LaCl layer has been enabled by switching of ferroelectric polarization in In2Se3. More importantly, magnetic skyrmions in the bimerons form have been discovered in the LaCl/In2Se3 heterostructure and can be driven by an electric current. The creation and annihilation of bimerons in LaCl magnetic nanodisks were achieved by polarization switching. It thus proves to be a feasible approach to achieve purely electric control of skyrmions in 2D van der Waals heterostructures. Such nonvolatile and tunable magnetic skyrmions are promising candidates for information carriers in future data storage and logic devices operated under small electrical currents.
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13
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Diehle P, Kovács A, Duden T, Speen R, Žagar Soderžnik K, Dunin-Borkowski RE. A cartridge-based turning specimen holder with wireless tilt angle measurement for magnetic induction mapping in the transmission electron microscope. Ultramicroscopy 2020; 220:113098. [PMID: 33161222 DOI: 10.1016/j.ultramic.2020.113098] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2020] [Revised: 07/26/2020] [Accepted: 08/26/2020] [Indexed: 10/23/2022]
Abstract
Magnetic induction mapping in the transmission electron microscope using phase contrast techniques such as off-axis electron holography and differential phase contrast imaging often requires the separation of the magnetic contribution to the recorded signal from the electrostatic contribution. When using off-axis electron holography, one of the experimental approaches that can be used to achieve this separation is to evaluate half of the difference between phase shift images that have been recorded before and after turning the sample over. Here, we introduce a cartridge-based sample mounting system, which is based on an existing on-axis tomography specimen holder and can be used to turn a sample over inside the electron microscope, thereby avoiding the need to remove the holder from the microscope to turn the sample over manually. We present three cartridge designs, which are compatible with all pole piece designs and can be used to support conventional 3-mm-diameter sample grids, Si3N4-based membrane chips and needle-shaped specimens. We make use of a wireless inclinometer that has a precision of 0.1° to monitor the sample holder tilt angle independently of the microscope goniometer readout. We also highlight the need to remove geometrical image distortions when aligning pairs of phase shift images that have been recorded before and after turning the sample over. The capabilities of the cartridge-based specimen holder and the turning approach are demonstrated by using off-axis electron holography to record magnetic induction maps of lithographically-patterned soft magnetic Co elements, a focused ion beam milled hard magnetic Nd-Fe-B lamella and an array of four Fe3O4 nanocrystals.
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Affiliation(s)
- Patrick Diehle
- Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons and Peter Grünberg Institute, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany; Fraunhofer Institute for Microstructure of Materials and Systems IMWS, Walter-Hülse-Strasse 1, 06120 Halle, Germany.
| | - András Kovács
- Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons and Peter Grünberg Institute, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany.
| | - Thomas Duden
- Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons and Peter Grünberg Institute, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
| | - Rolf Speen
- Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons and Peter Grünberg Institute, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
| | | | - Rafal E Dunin-Borkowski
- Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons and Peter Grünberg Institute, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
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14
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Wang Y, Wang L, Xia J, Lai Z, Tian G, Zhang X, Hou Z, Gao X, Mi W, Feng C, Zeng M, Zhou G, Yu G, Wu G, Zhou Y, Wang W, Zhang XX, Liu J. Electric-field-driven non-volatile multi-state switching of individual skyrmions in a multiferroic heterostructure. Nat Commun 2020; 11:3577. [PMID: 32681004 PMCID: PMC7367868 DOI: 10.1038/s41467-020-17354-7] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2019] [Accepted: 06/26/2020] [Indexed: 11/09/2022] Open
Abstract
Electrical manipulation of skyrmions attracts considerable attention for its rich physics and promising applications. To date, such a manipulation is realized mainly via spin-polarized current based on spin-transfer torque or spin-orbital torque effect. However, this scheme is energy consuming and may produce massive Joule heating. To reduce energy dissipation and risk of heightened temperatures of skyrmion-based devices, an effective solution is to use electric field instead of current as stimulus. Here, we realize an electric-field manipulation of skyrmions in a nanostructured ferromagnetic/ferroelectrical heterostructure at room temperature via an inverse magneto-mechanical effect. Intriguingly, such a manipulation is non-volatile and exhibits a multistate feature. Numerical simulations indicate that the electric-field manipulation of skyrmions originates from strain-mediated modification of effective magnetic anisotropy and Dzyaloshinskii-Moriya interaction. Our results open a direction for constructing low-energy-dissipation, non-volatile, and multistate skyrmion-based spintronic devices.
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Affiliation(s)
- Yadong Wang
- 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
| | - Lei Wang
- School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing, 100083, China
| | - Jing Xia
- School of Science and Engineering, The Chinese University of Hong Kong, Shenzhen, Guangdong, 518172, China
| | - Zhengxun Lai
- Colleage of Science, Tianjin University, Tianjin, 300392, China
| | - Guo Tian
- 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
| | - Xichao Zhang
- School of Science and Engineering, The Chinese University of Hong Kong, Shenzhen, Guangdong, 518172, 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.
| | - Xingsen Gao
- 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.
| | - Wenbo Mi
- Colleage of Science, Tianjin University, Tianjin, 300392, China
| | - Chun Feng
- School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing, 100083, China.
| | - Min Zeng
- 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
| | - Guofu Zhou
- 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
| | - Guanghua Yu
- School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing, 100083, China
| | - Guangheng Wu
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
| | - Yan Zhou
- School of Science and Engineering, The Chinese University of Hong Kong, Shenzhen, Guangdong, 518172, China
| | - Wenhong Wang
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
| | - Xi-Xiang Zhang
- Physical Science and Engineering Division, King Abdullah University of Science and Technology, Thuwal, 23955-6900, Saudi Arabia
| | - Junming Liu
- Laboratory of Solid State Microstructures and Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, 211102, China
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15
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Yu XZ, Morikawa D, Nakajima K, Shibata K, Kanazawa N, Arima T, Nagaosa N, Tokura Y. Motion tracking of 80-nm-size skyrmions upon directional current injections. SCIENCE ADVANCES 2020; 6:eaaz9744. [PMID: 32596450 PMCID: PMC7299614 DOI: 10.1126/sciadv.aaz9744] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2019] [Accepted: 05/05/2020] [Indexed: 05/29/2023]
Abstract
Nanometer-scale skyrmions are prospective candidates for information bits in low-power consumption devices owing to their topological nature and controllability with low current density. Studies on skyrmion dynamics in different classes of materials have exploited the topological Hall effect and current-driven fast motion of skyrmionic bubbles. However, the small current track motion of a single skyrmion and few-skyrmion aggregates remains elusive. Here, we report the tracking of creation and extinction and motion of 80-nm-size skyrmions upon directional one-current pulse excitations at low current density of the order of 109 A m-2 in designed devices with the notched hole. The Hall motion of a single skyrmion and the torque motions of few-skyrmion aggregates have been directly revealed. The results exemplify low-current density controls of skyrmions, which will pave the way for the application of skyrmions.
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Affiliation(s)
- X. Z. Yu
- RIKEN Center for Emergent Matter Science (CEMS), Wako 351-0198, Japan
| | - D. Morikawa
- RIKEN Center for Emergent Matter Science (CEMS), Wako 351-0198, Japan
| | - K. Nakajima
- RIKEN Center for Emergent Matter Science (CEMS), Wako 351-0198, Japan
| | - K. Shibata
- RIKEN Center for Emergent Matter Science (CEMS), Wako 351-0198, Japan
| | - N. Kanazawa
- Department of Applied Physics, University of Tokyo, Tokyo 113-8656, Japan
| | - T. Arima
- RIKEN Center for Emergent Matter Science (CEMS), Wako 351-0198, Japan
- Department of Advanced Materials Science, University of Tokyo, Kashiwa 277-8561, Japan
| | - N. Nagaosa
- RIKEN Center for Emergent Matter Science (CEMS), Wako 351-0198, Japan
- Department of Applied Physics, University of Tokyo, Tokyo 113-8656, Japan
| | - Y. 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
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16
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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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17
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Ding B, Li Z, Xu G, Li H, Hou Z, Liu E, Xi X, Xu F, Yao Y, Wang W. Observation of Magnetic Skyrmion Bubbles in a van der Waals Ferromagnet Fe 3GeTe 2. NANO LETTERS 2020; 20:868-873. [PMID: 31869236 DOI: 10.1021/acs.nanolett.9b03453] [Citation(s) in RCA: 75] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Two-dimensional (2D) van der Waals (vdW) magnetic materials have recently been introduced as a new horizon in materials science, and they enable potential applications for next-generation spintronic devices. Here, in this communication, the observations of stable Bloch-type magnetic skyrmions in single crystals of 2D vdW Fe3GeTe2 (FGT) are reported by using in situ Lorentz transmission electron microscopy (TEM). We find the ground-state magnetic stripe domains in FGT transform into skyrmion bubbles when an external magnetic field is applied perpendicularly to the (001) thin plate with temperatures below the Curie temperature TC. Most interestingly, a hexagonal lattice of skyrmion bubbles is obtained via field-cooling manipulation with magnetic field applied along the [001] direction. Owing to their topological stability, the skyrmion bubble lattices are stable to large field-cooling tilted angles and further reproduced by utilizing the micromagnetic simulations. These observations directly demonstrate that the 2D vdW FGT possesses a rich variety of topological spin textures, being of great promise for future applications in the field of spintronics.
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Affiliation(s)
- Bei Ding
- Beijing National Laboratory for Condensed Matter Physics , Institute of Physics, Chinese Academy of Sciences , Beijing 100190 , China
- University of Chinese Academy of Sciences , Beijing 100049 , China
| | - Zefang Li
- Beijing National Laboratory for Condensed Matter Physics , Institute of Physics, Chinese Academy of Sciences , Beijing 100190 , China
- University of Chinese Academy of Sciences , Beijing 100049 , China
| | - Guizhou Xu
- School of Materials Science and Engineering , Nanjing University of Science and Technology , Nanjing 210094 , China
| | - Hang Li
- Beijing National Laboratory for Condensed Matter Physics , Institute of Physics, Chinese Academy of Sciences , Beijing 100190 , China
- University of Chinese Academy of Sciences , Beijing 100049 , China
| | - Zhipeng Hou
- South China Academy of Advanced Optoelectronics , South China Normal University , Guangzhou 510006 , China
| | - Enke Liu
- Beijing National Laboratory for Condensed Matter Physics , Institute of Physics, Chinese Academy of Sciences , Beijing 100190 , China
| | - Xuekui Xi
- 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
| | - Wenhong Wang
- Beijing National Laboratory for Condensed Matter Physics , Institute of Physics, Chinese Academy of Sciences , Beijing 100190 , China
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18
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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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19
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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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Yu XZ, Koshibae W, Tokunaga Y, Shibata K, Taguchi Y, Nagaosa N, Tokura Y. Transformation between meron and skyrmion topological spin textures in a chiral magnet. Nature 2018; 564:95-98. [DOI: 10.1038/s41586-018-0745-3] [Citation(s) in RCA: 183] [Impact Index Per Article: 30.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2018] [Accepted: 10/11/2018] [Indexed: 11/09/2022]
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Leroux M, Stolt MJ, Jin S, Pete DV, Reichhardt C, Maiorov B. Skyrmion Lattice Topological Hall Effect near Room Temperature. Sci Rep 2018; 8:15510. [PMID: 30341339 PMCID: PMC6195581 DOI: 10.1038/s41598-018-33560-2] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2018] [Accepted: 09/28/2018] [Indexed: 11/16/2022] Open
Abstract
Magnetic skyrmions are stable nanosized spin structures that can be displaced at low electrical current densities. Because of these properties, they have been proposed as building blocks of future electronic devices with unprecedentedly high information density and low energy consumption. The electrical detection of an ordered skyrmion lattice via the Topological Hall Effect (THE) in a bulk crystal, has so far been demonstrated only at cryogenic temperatures in the MnSi family of compounds. Here, we report the observation of a skyrmion lattice Topological Hall Effect near room temperature (276 K) in a mesoscopic lamella carved from a bulk crystal of FeGe. This region coincides with the skyrmion lattice location revealed by neutron scattering. We provide clear evidence of a re-entrant helicoid magnetic phase adjacent to the skyrmion phase, and discuss the large THE amplitude (5 nΩ.cm) in view of the ordinary Hall Effect.
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Affiliation(s)
- Maxime Leroux
- Materials Physics and Applications Division, Los Alamos National Laboratory, Los Alamos, New Mexico, 87545, USA
| | - Matthew J Stolt
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, Wisconsin, 53706, USA
| | - Song Jin
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, Wisconsin, 53706, USA
| | - Douglas V Pete
- Centre for Integrated Nanotechnologies, Sandia National Laboratories, Albuquerque, New Mexico, 87185, USA
| | - Charles Reichhardt
- Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico, 87545, USA
| | - Boris Maiorov
- Materials Physics and Applications Division, Los Alamos National Laboratory, Los Alamos, New Mexico, 87545, USA.
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22
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Shibata K, Tanigaki T, Akashi T, Shinada H, Harada K, Niitsu K, Shindo D, Kanazawa N, Tokura Y, Arima TH. Current-Driven Motion of Domain Boundaries between Skyrmion Lattice and Helical Magnetic Structure. NANO LETTERS 2018; 18:929-933. [PMID: 29345472 DOI: 10.1021/acs.nanolett.7b04312] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
To utilize magnetic skyrmions, nanoscale vortex-like magnetic structures, experimental elucidation of their dynamics against current application in various circumstances such as in confined structure and mixture of different magnetic phases is indispensable. Here, we investigate the current-induced dynamics of the coexistence state of magnetic skyrmions and helical magnetic structure in a thin plate of B20-type helimagnet FeGe in terms of in situ real-space observation using Lorentz transmission electron microscopy. Current pulses with various heights and widths were applied, and the change of the magnetic domain distribution was analyzed using a machine-learning technique. The observed average driving direction of the two-magnetic-state domain boundary is opposite to the applied electric current, indicating ferromagnetic s-d exchange coupling in the spin-transfer torque mechanism. The evaluated driving distance tends to increase with increasing the pulse duration time, current density (>1 × 109 A/m2), and sample temperature, providing valuable information about hitherto unknown current-induced dynamics of the skyrmion-lattice ensemble.
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Affiliation(s)
- Kiyou Shibata
- RIKEN Center for Emergent Matter Science (CEMS) , Wako 351-0198, Japan
| | - Toshiaki Tanigaki
- Research and Development Group, Hitachi Ltd., Hatoyama 350-0395, Japan
| | - Tetsuya Akashi
- Research and Development Group, Hitachi Ltd., Hatoyama 350-0395, Japan
| | - Hiroyuki Shinada
- Research and Development Group, Hitachi Ltd., Hatoyama 350-0395, Japan
| | - Ken Harada
- RIKEN Center for Emergent Matter Science (CEMS) , Wako 351-0198, Japan
| | - Kodai Niitsu
- RIKEN Center for Emergent Matter Science (CEMS) , Wako 351-0198, Japan
| | - Daisuke Shindo
- RIKEN Center for Emergent Matter Science (CEMS) , Wako 351-0198, Japan
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University , Sendai 980-8577, Japan
| | - Naoya Kanazawa
- Department of Applied Physics, the University of Tokyo , Tokyo 113-8656, Japan
| | - Yoshinori Tokura
- RIKEN Center for Emergent Matter Science (CEMS) , Wako 351-0198, Japan
- Department of Applied Physics, the University of Tokyo , Tokyo 113-8656, Japan
| | - Taka-Hisa Arima
- RIKEN Center for Emergent Matter Science (CEMS) , Wako 351-0198, Japan
- Department of Advanced Materials Science, the University of Tokyo , Kashiwa 277-8561, Japan
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23
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Stier M, Häusler W, Posske T, Gurski G, Thorwart M. Skyrmion-Anti-Skyrmion Pair Creation by in-Plane Currents. PHYSICAL REVIEW LETTERS 2017; 118:267203. [PMID: 28707922 DOI: 10.1103/physrevlett.118.267203] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2017] [Indexed: 06/07/2023]
Abstract
Magnetic Skyrmions can be considered as localized vortexlike spin textures which are topologically protected in continuous systems. Because of their stability, their small size, and the possibility to move them by low electric currents, they are promising candidates for spintronic devices. Without changing the topological charge, it is possible to create Skyrmion-anti-Skyrmion pairs. We derive a Skyrmion equation of motion which reveals how spin-polarized charge currents create Skyrmion-anti-Skyrmion pairs. It allows us to identify general prerequisites for the pair creation process. We corroborate these general principles by numerical simulations. On a lattice, where the concept of topological protection has to be replaced by that of a finite energy barrier, the anti-Skyrmion partner of the pairs is annihilated and only the Skyrmion survives. This eventually changes the total Skyrmion number and yields a new way of creating and controlling Skyrmions.
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Affiliation(s)
- Martin Stier
- I. Institut für Theoretische Physik, Universität Hamburg, Jungiusstraße 9, 20355 Hamburg, Germany
| | - Wolfgang Häusler
- I. Institut für Theoretische Physik, Universität Hamburg, Jungiusstraße 9, 20355 Hamburg, Germany
- Institut für Physik, Universität Augsburg, 86135 Augsburg, Germany
| | - Thore Posske
- I. Institut für Theoretische Physik, Universität Hamburg, Jungiusstraße 9, 20355 Hamburg, Germany
| | - Gregor Gurski
- I. Institut für Theoretische Physik, Universität Hamburg, Jungiusstraße 9, 20355 Hamburg, Germany
| | - Michael Thorwart
- I. Institut für Theoretische Physik, Universität Hamburg, Jungiusstraße 9, 20355 Hamburg, Germany
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