1
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Cui Q, Zhu Y, Jiang J, Cui P, Yang H, Chang K, Wang K. Anatomy of Hidden Dzyaloshinskii-Moriya Interactions and Topological Spin Textures in Centrosymmetric Crystals. NANO LETTERS 2024. [PMID: 38739551 DOI: 10.1021/acs.nanolett.4c01486] [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
The Dzyaloshinskii-Moriya interaction (DMI) is understood to be forbidden by the symmetry of centrosymmetric systems, thus restricting the candidate types for investigating many correlated physical phenomena. Here, we report the hidden DMI existing in centrosymmetric magnets driven by the local inversion symmetry breaking of specific spin sublattices. The opposite DMI spatially localized on the inverse spin sublattice favors the separated spin spiral with opposite chirality. Furthermore, we elucidate that hidden DMI widely exists in many potential candidates, from the first-principles calculations on the mature crystal database. Interestingly, novel topological spin configurations, such as the anti-chirality-locked merons and antiferromagnetic-ferromagnetic meron chains, are stabilized as a consequence of hidden DMI. Our understanding enables the effective control of DMI by symmetry operations at the atomic level and enlarges the range of currently useful magnets for topological magnetism.
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Affiliation(s)
- Qirui Cui
- Center for Quantum Matter, School of Physics, Zhejiang University, Hangzhou 310027, Zhejiang, China
- State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China
- Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201, China
| | - Yingmei Zhu
- Key Laboratory of Spintronics Materials, Devices and Systems of Zhejiang Province, Hangzhou 311305, China
| | - Jiawei Jiang
- Center for Quantum Matter, School of Physics, Zhejiang University, Hangzhou 310027, Zhejiang, China
| | - Ping Cui
- Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201, China
- Yongjiang Laboratory, Ningbo 315202, China
| | - Hongxin Yang
- Center for Quantum Matter, School of Physics, Zhejiang University, Hangzhou 310027, Zhejiang, China
| | - Kai Chang
- Center for Quantum Matter, School of Physics, Zhejiang University, Hangzhou 310027, Zhejiang, China
| | - Kaiyou Wang
- State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
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2
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Jani H, Harrison J, Hooda S, Prakash S, Nandi P, Hu J, Zeng Z, Lin JC, Godfrey C, Omar GJ, Butcher TA, Raabe J, Finizio S, Thean AVY, Ariando A, Radaelli PG. Spatially reconfigurable antiferromagnetic states in topologically rich free-standing nanomembranes. NATURE MATERIALS 2024; 23:619-626. [PMID: 38374414 PMCID: PMC11068574 DOI: 10.1038/s41563-024-01806-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2023] [Accepted: 01/11/2024] [Indexed: 02/21/2024]
Abstract
Antiferromagnets hosting real-space topological textures are promising platforms to model fundamental ultrafast phenomena and explore spintronics. However, they have only been epitaxially fabricated on specific symmetry-matched substrates, thereby preserving their intrinsic magneto-crystalline order. This curtails their integration with dissimilar supports, restricting the scope of fundamental and applied investigations. Here we circumvent this limitation by designing detachable crystalline antiferromagnetic nanomembranes of α-Fe2O3. First, we show-via transmission-based antiferromagnetic vector mapping-that flat nanomembranes host a spin-reorientation transition and rich topological phenomenology. Second, we exploit their extreme flexibility to demonstrate the reconfiguration of antiferromagnetic states across three-dimensional membrane folds resulting from flexure-induced strains. Finally, we combine these developments using a controlled manipulator to realize the strain-driven non-thermal generation of topological textures at room temperature. The integration of such free-standing antiferromagnetic layers with flat/curved nanostructures could enable spin texture designs via magnetoelastic/geometric effects in the quasi-static and dynamical regimes, opening new explorations into curvilinear antiferromagnetism and unconventional computing.
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Affiliation(s)
- Hariom Jani
- Clarendon Laboratory, Department of Physics, University of Oxford, Oxford, UK.
- Department of Physics, National University of Singapore, Singapore, Singapore.
| | - Jack Harrison
- Clarendon Laboratory, Department of Physics, University of Oxford, Oxford, UK
| | - Sonu Hooda
- Department of Electrical and Computer Engineering, National University of Singapore, Singapore, Singapore
| | - Saurav Prakash
- Department of Physics, National University of Singapore, Singapore, Singapore
| | - Proloy Nandi
- Department of Physics, National University of Singapore, Singapore, Singapore
| | - Junxiong Hu
- Department of Physics, National University of Singapore, Singapore, Singapore.
| | - Zhiyang Zeng
- Clarendon Laboratory, Department of Physics, University of Oxford, Oxford, UK
| | - Jheng-Cyuan Lin
- Clarendon Laboratory, Department of Physics, University of Oxford, Oxford, UK
| | - Charles Godfrey
- Clarendon Laboratory, Department of Physics, University of Oxford, Oxford, UK
| | - Ganesh Ji Omar
- Department of Physics, National University of Singapore, Singapore, Singapore
| | - Tim A Butcher
- Swiss Light Source, Paul Scherrer Institut, Villigen, Switzerland
| | - Jörg Raabe
- Swiss Light Source, Paul Scherrer Institut, Villigen, Switzerland
| | - Simone Finizio
- Swiss Light Source, Paul Scherrer Institut, Villigen, Switzerland.
| | - Aaron Voon-Yew Thean
- Department of Electrical and Computer Engineering, National University of Singapore, Singapore, Singapore
- Integrative Sciences and Engineering Programme, National University of Singapore, Singapore, Singapore
| | - A Ariando
- Department of Physics, National University of Singapore, Singapore, Singapore.
- Integrative Sciences and Engineering Programme, National University of Singapore, Singapore, Singapore.
| | - Paolo G Radaelli
- Clarendon Laboratory, Department of Physics, University of Oxford, Oxford, UK.
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3
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Wang Y, Xing J, Zhao Y, Wang Y, Zhao J, Jiang X. Alloying Driven Antiferromagnetic Skyrmions on NiPS 3 Monolayer: A First-Principles Calculation. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2024:e2401048. [PMID: 38647400 DOI: 10.1002/advs.202401048] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2024] [Revised: 03/25/2024] [Indexed: 04/25/2024]
Abstract
Topological magnetic states are promising information carriers for ultrahigh-density and high-efficiency magnetic storage. Recent advances in two-dimensional (2D) magnets provide powerful platforms for stabilizing various nanometer-size topological spin textures within a wide range of magnetic field and temperature. However, non-centrosymmetric 2D magnets with broken inversion symmetry are scarce in nature, making direct observations of the chiral spin structure difficult, especially for antiferromagnetic (AFM) skyrmions. In this work, it is theoretically predicted that intrinsic AFM skyrmions can be easily triggered in XY-type honeycomb magnet NiPS3 monolayer by alloying of Cr atoms, due to the presence of a sizable Dzyaloshinskii-Moriya interaction. More interestingly, the diameter of the AFM skyrmions in Ni3/4Cr1/4PS3 decreases from 12 to 4.4 nm as the external magnetic field increases and the skyrmion phases remain stable up to an external magnetic field of 4 T. These results highlight an effective strategy to generate and modulate the topological spin texture in 2D magnets by alloying with magnetic element.
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Affiliation(s)
- Yanxia Wang
- Key Laboratory of Materials Modification by Laser, Ion and Electron Beams, Dalian University of Technology, Ministry of Education, Dalian, 116024, China
| | - Jianpei Xing
- Key Laboratory of Materials Modification by Laser, Ion and Electron Beams, Dalian University of Technology, Ministry of Education, Dalian, 116024, China
| | - Ying Zhao
- Key Laboratory of Materials Modification by Laser, Ion and Electron Beams, Dalian University of Technology, Ministry of Education, Dalian, 116024, China
| | - Yi Wang
- Key Laboratory of Materials Modification by Laser, Ion and Electron Beams, Dalian University of Technology, Ministry of Education, Dalian, 116024, China
| | - Jijun Zhao
- Key Laboratory of Materials Modification by Laser, Ion and Electron Beams, Dalian University of Technology, Ministry of Education, Dalian, 116024, China
- Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials, School of Physics, South China Normal University, Guangzhou, 510006, China
- Guangdong-Hong Kong Joint Laboratory of Quantum Matter, Frontier Research Institute for Physics, South China Normal University, Guangzhou, 510006, China
| | - Xue Jiang
- Key Laboratory of Materials Modification by Laser, Ion and Electron Beams, Dalian University of Technology, Ministry of Education, Dalian, 116024, China
- Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials, School of Physics, South China Normal University, Guangzhou, 510006, China
- Guangdong-Hong Kong Joint Laboratory of Quantum Matter, Frontier Research Institute for Physics, South China Normal University, Guangzhou, 510006, China
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4
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Pham VT, Sisodia N, Di Manici I, Urrestarazu-Larrañaga J, Bairagi K, Pelloux-Prayer J, Guedas R, Buda-Prejbeanu LD, Auffret S, Locatelli A, Menteş TO, Pizzini S, Kumar P, Finco A, Jacques V, Gaudin G, Boulle O. Fast current-induced skyrmion motion in synthetic antiferromagnets. Science 2024; 384:307-312. [PMID: 38635712 DOI: 10.1126/science.add5751] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Accepted: 03/14/2024] [Indexed: 04/20/2024]
Abstract
Magnetic skyrmions are topological magnetic textures that hold great promise as nanoscale bits of information in memory and logic devices. Although room-temperature ferromagnetic skyrmions and their current-induced manipulation have been demonstrated, their velocity has been limited to about 100 meters per second. In addition, their dynamics are perturbed by the skyrmion Hall effect, a motion transverse to the current direction caused by the skyrmion topological charge. Here, we show that skyrmions in compensated synthetic antiferromagnets can be moved by current along the current direction at velocities of up to 900 meters per second. This can be explained by the cancellation of the net topological charge leading to a vanishing skyrmion Hall effect. Our results open an important path toward the realization of logic and memory devices based on the fast manipulation of skyrmions in tracks.
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Affiliation(s)
- Van Tuong Pham
- Université Grenoble Alpes, CNRS, CEA, SPINTEC, 38054 Grenoble, France
- Université Grenoble Alpes, CNRS, Institut Néel, 38042 Grenoble, France
| | - Naveen Sisodia
- Université Grenoble Alpes, CNRS, CEA, SPINTEC, 38054 Grenoble, France
- Department of Physics, Indian Institute of Technology Gandhinagar, Gandhinagar 382355, Gujarat, India
| | - Ilaria Di Manici
- Université Grenoble Alpes, CNRS, CEA, SPINTEC, 38054 Grenoble, France
| | | | - Kaushik Bairagi
- Université Grenoble Alpes, CNRS, CEA, SPINTEC, 38054 Grenoble, France
| | | | - Rodrigo Guedas
- Université Grenoble Alpes, CNRS, CEA, SPINTEC, 38054 Grenoble, France
- Instituto de Sistemas Optoelectrónicos y Microtecnología (ISOM), Universidad Politécnica de Madrid, 28040 Madrid, Spain
| | | | - Stéphane Auffret
- Université Grenoble Alpes, CNRS, CEA, SPINTEC, 38054 Grenoble, France
| | - Andrea Locatelli
- Elettra-Sincrotrone Trieste S.C.p.A., 34149 Basovizza, Trieste, Italy
| | | | - Stefania Pizzini
- Université Grenoble Alpes, CNRS, Institut Néel, 38042 Grenoble, France
| | - Pawan Kumar
- Laboratoire Charles Coulomb, Université de Montpellier, CNRS, 34095 Montpellier, France
| | - Aurore Finco
- Laboratoire Charles Coulomb, Université de Montpellier, CNRS, 34095 Montpellier, France
| | - Vincent Jacques
- Laboratoire Charles Coulomb, Université de Montpellier, CNRS, 34095 Montpellier, France
| | - Gilles Gaudin
- Université Grenoble Alpes, CNRS, CEA, SPINTEC, 38054 Grenoble, France
| | - Olivier Boulle
- Université Grenoble Alpes, CNRS, CEA, SPINTEC, 38054 Grenoble, France
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5
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Lv X, Lv H, Huang Y, Zhang R, Qin G, Dong Y, Liu M, Pei K, Cao G, Zhang J, Lai Y, Che R. Distinct skyrmion phases at room temperature in two-dimensional ferromagnet Fe 3GaTe 2. Nat Commun 2024; 15:3278. [PMID: 38627376 PMCID: PMC11021542 DOI: 10.1038/s41467-024-47579-9] [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: 01/04/2024] [Accepted: 04/03/2024] [Indexed: 04/19/2024] Open
Abstract
Distinct skyrmion phases at room temperature hosted by one material offer additional degree of freedom for the design of topology-based compact and energetically-efficient spintronic devices. The field has been extended to low-dimensional magnets with the discovery of magnetism in two-dimensional van der Waals magnets. However, creating multiple skyrmion phases in 2D magnets, especially above room temperature, remains a major challenge. Here, we report the experimental observation of mixed-type skyrmions, exhibiting both Bloch and hybrid characteristics, in a room-temperature ferromagnet Fe3GaTe2. Analysis of the magnetic intensities under varied imaging conditions coupled with complementary simulations reveal that spontaneous Bloch skyrmions exist as the magnetic ground state with the coexistence of hybrid stripes domain, on account of the interplay between the dipolar interaction and the Dzyaloshinskii-Moriya interaction. Moreover, hybrid skyrmions are created and their coexisting phases with Bloch skyrmions exhibit considerably high thermostability, enduring up to 328 K. The findings open perspectives for 2D spintronic devices incorporating distinct skyrmion phases at room temperature.
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Affiliation(s)
- Xiaowei Lv
- Laboratory of Advanced Materials, Shanghai Key Lab of Molecular Catalysis and Innovative Materials, Academy for Engineering & Technology, Fudan University, Shanghai, 200438, PR China
| | - Hualiang Lv
- Shanghai Frontiers Science Research Base of Intelligent Optoelectronics and Perception, Institute of Optoelectronics, Fudan University, Shanghai, 200433, PR China
| | - Yalei Huang
- Materials Genome Institute, Shanghai University, Shanghai, 200444, China
| | | | - Guanhua Qin
- Zhejiang Laboratory, Hangzhou, 311100, China
| | - Yihui Dong
- Materials Genome Institute, Shanghai University, Shanghai, 200444, China
| | - Min Liu
- Laboratory of Advanced Materials, Shanghai Key Lab of Molecular Catalysis and Innovative Materials, Academy for Engineering & Technology, Fudan University, Shanghai, 200438, PR China
| | - Ke Pei
- Laboratory of Advanced Materials, Shanghai Key Lab of Molecular Catalysis and Innovative Materials, Academy for Engineering & Technology, Fudan University, Shanghai, 200438, PR China
| | - Guixin Cao
- Materials Genome Institute, Shanghai University, Shanghai, 200444, China.
- Zhejiang Laboratory, Hangzhou, 311100, China.
| | | | - Yuxiang Lai
- Pico Electron Microscopy Center, Innovation Institute for Ocean Materials Characterization, Center for Advanced Studies in Precision Instruments, Hainan University, Haikou, 570228, China
| | - Renchao Che
- Laboratory of Advanced Materials, Shanghai Key Lab of Molecular Catalysis and Innovative Materials, Academy for Engineering & Technology, Fudan University, Shanghai, 200438, PR China.
- Zhejiang Laboratory, Hangzhou, 311100, China.
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6
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Lee J, Park HR, Jin KH, Kim JS, Cheong SW, Yeom HW. Topological Complex Charge Conservation in Nontrivial Z 2 × Z 2 Domain Walls. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024:e2313803. [PMID: 38482920 DOI: 10.1002/adma.202313803] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2023] [Revised: 02/14/2024] [Indexed: 03/22/2024]
Abstract
Localized topological modes such as solitons, Majorana Fermions, and skyrmions are attracting great interest as robust information carriers for future devices. Here, a novel conserved quantity for topological domain wall networks of a Z2 × Z2 order generated with spin-polarized current in Sr2VO3FeAs is discovered. Domain walls are mobilized by the scanning tunneling current, which also observes in atomic scale active dynamics of domain wall vertices including merge, bifurcation, pair creation, and annihilation. Within this dynamics, the product of the topological complex charges defined for domain wall vertices is conserved with a novel boundary-charge correspondence rule. These results may open an avenue toward topological electronics based on domain wall vertices in generic Z2 × Z2 systems.
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Affiliation(s)
- Jhinhwan Lee
- Center for Artificial Low Dimensional Electronic Systems, Institute for Basic Science (IBS), Pohang, 37673, Republic of Korea
| | - Hae-Ryong Park
- Center for Artificial Low Dimensional Electronic Systems, Institute for Basic Science (IBS), Pohang, 37673, Republic of Korea
- Department of Physics, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea
| | - Kyung-Hwan Jin
- Center for Artificial Low Dimensional Electronic Systems, Institute for Basic Science (IBS), Pohang, 37673, Republic of Korea
| | - Jun Sung Kim
- Center for Artificial Low Dimensional Electronic Systems, Institute for Basic Science (IBS), Pohang, 37673, Republic of Korea
- Department of Physics, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea
| | - Sang-Wook Cheong
- Rutgers Center for Emergent Materials and Department of Physics and Astronomy, Rutgers University, Piscataway, NJ, 08854, USA
| | - Han-Woong Yeom
- Center for Artificial Low Dimensional Electronic Systems, Institute for Basic Science (IBS), Pohang, 37673, Republic of Korea
- Department of Physics, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea
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7
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Gao B, Zhou Z, Deng S, Lee K, Fukuda M, Hu L, Azuma M, Liu H, Chen J. Emergent Three-Dimensional Electric Dipole Sinewave in Bulk Perovskite Oxides. NANO LETTERS 2024; 24:3118-3124. [PMID: 38421801 DOI: 10.1021/acs.nanolett.3c04957] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/02/2024]
Abstract
The magnetic and electric dipoles of ferroics play a central role in their fascinating properties. In particular, topological configurations have shown promising potential for use in novel electromechanical and electronic devices. Magnetic configurations from simple collinear to complex topological are well-documented. In contrast, many complex topological features in the electric counterpart remain unexplored. Here, we report the first example of three-dimensional electric dipole sinewave topological structure in a PbZrO3-based bulk perovskite, which presents an interesting triple-hysteresis loop macroscopically. This polar configuration consists of two orthogonal sinewave electric dipole modulations decoded from a polar incommensurate phase by advanced diffraction and atomic-resolution imaging techniques. The resulting topology is unraveled to be the competition between the antiferroelectric and ferroelectric states, stabilized by the modulation of the Pb 6s2 lone pair and the antiferrodistortive effect. These findings further reinforce the similarity of the magnetic and electric topologies.
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Affiliation(s)
- Botao Gao
- Beijing Advanced Innovation Center for Materials Genome Engineering, Department of Physical Chemistry, University of Science and Technology Beijing, Beijing 100083, China
- Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 201899, China
| | - Zhengyang Zhou
- Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 201899, China
| | - Shiqing Deng
- Beijing Advanced Innovation Center for Materials Genome Engineering, Department of Physical Chemistry, University of Science and Technology Beijing, Beijing 100083, China
| | - Koomok Lee
- Laboratory for Materials and Structures, Tokyo Institute of Technology, Yokohama 226-8503, Japan
| | - Masayuki Fukuda
- Laboratory for Materials and Structures, Tokyo Institute of Technology, Yokohama 226-8503, Japan
| | - Lei Hu
- State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, Xi'an 710049, China
| | - Masaki Azuma
- Laboratory for Materials and Structures, Tokyo Institute of Technology, Yokohama 226-8503, Japan
| | - Hui Liu
- Beijing Advanced Innovation Center for Materials Genome Engineering, Department of Physical Chemistry, University of Science and Technology Beijing, Beijing 100083, China
| | - Jun Chen
- Beijing Advanced Innovation Center for Materials Genome Engineering, Department of Physical Chemistry, University of Science and Technology Beijing, Beijing 100083, China
- Hainan University, Haikou 570228, China
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8
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Chen S, Lourembam J, Ho P, Toh AKJ, Huang J, Chen X, Tan HK, Yap SLK, Lim RJJ, Tan HR, Suraj TS, Sim MI, Toh YT, Lim I, Lim NCB, Zhou J, Chung HJ, Lim ST, Soumyanarayanan A. All-electrical skyrmionic magnetic tunnel junction. Nature 2024; 627:522-527. [PMID: 38509277 DOI: 10.1038/s41586-024-07131-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2023] [Accepted: 01/25/2024] [Indexed: 03/22/2024]
Abstract
Topological whirls or 'textures' of spins such as magnetic skyrmions represent the smallest realizable emergent magnetic entities1-5. They hold considerable promise as robust, nanometre-scale, mobile bits for sustainable computing6-8. A longstanding roadblock to unleashing their potential is the absence of a device enabling deterministic electrical readout of individual spin textures9,10. Here we present the wafer-scale realization of a nanoscale chiral magnetic tunnel junction (MTJ) hosting a single, ambient skyrmion. Using a suite of electrical and multimodal imaging techniques, we show that the MTJ nucleates skyrmions of fixed polarity, whose large readout signal-20-70% relative to uniformly magnetized states-corresponds directly to skyrmion size. The MTJ exploits complementary nucleation mechanisms to stabilize distinctly sized skyrmions at zero field, thereby realizing three non-volatile electrical states. Crucially, it can electrically write and delete skyrmions to both uniform states with switching energies 1,000 times lower than the state of the art. Here, the applied voltage emulates a magnetic field and, in contrast to conventional MTJs, it reshapes both the energetics and kinetics of the switching transition, enabling deterministic bidirectional switching. Our stack platform enables large readout and efficient switching, and is compatible with lateral manipulation of skyrmionic bits, providing the much-anticipated backbone for all-electrical skyrmionic device architectures9,10. Its wafer-scale realizability provides a springboard to harness chiral spin textures for multibit memory and unconventional computing8,11.
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Affiliation(s)
- Shaohai Chen
- Institute of Materials Research and Engineering (IMRE), Agency for Science, Technology and Research (A*STAR), Singapore, Singapore
| | - James Lourembam
- Institute of Materials Research and Engineering (IMRE), Agency for Science, Technology and Research (A*STAR), Singapore, Singapore
| | - Pin Ho
- Institute of Materials Research and Engineering (IMRE), Agency for Science, Technology and Research (A*STAR), Singapore, Singapore
| | - Alexander K J Toh
- Institute of Materials Research and Engineering (IMRE), Agency for Science, Technology and Research (A*STAR), Singapore, Singapore
| | - Jifei Huang
- Department of Physics, National University of Singapore, Singapore, Singapore
| | - Xiaoye Chen
- Institute of Materials Research and Engineering (IMRE), Agency for Science, Technology and Research (A*STAR), Singapore, Singapore
| | - Hang Khume Tan
- Institute of Materials Research and Engineering (IMRE), Agency for Science, Technology and Research (A*STAR), Singapore, Singapore
| | - Sherry L K Yap
- Institute of Materials Research and Engineering (IMRE), Agency for Science, Technology and Research (A*STAR), Singapore, Singapore
| | - Royston J J Lim
- Institute of Materials Research and Engineering (IMRE), Agency for Science, Technology and Research (A*STAR), Singapore, Singapore
| | - Hui Ru Tan
- Institute of Materials Research and Engineering (IMRE), Agency for Science, Technology and Research (A*STAR), Singapore, Singapore
| | - T S Suraj
- Department of Physics, National University of Singapore, Singapore, Singapore
| | - May Inn Sim
- Department of Physics, National University of Singapore, Singapore, Singapore
| | - Yeow Teck Toh
- Institute of Materials Research and Engineering (IMRE), Agency for Science, Technology and Research (A*STAR), Singapore, Singapore
| | - Idayu Lim
- Institute of Materials Research and Engineering (IMRE), Agency for Science, Technology and Research (A*STAR), Singapore, Singapore
| | - Nelson C B Lim
- Institute of Materials Research and Engineering (IMRE), Agency for Science, Technology and Research (A*STAR), Singapore, Singapore
| | - Jing Zhou
- Institute of Materials Research and Engineering (IMRE), Agency for Science, Technology and Research (A*STAR), Singapore, Singapore
| | - Hong Jing Chung
- Institute of Materials Research and Engineering (IMRE), Agency for Science, Technology and Research (A*STAR), Singapore, Singapore
| | - Sze Ter Lim
- Institute of Materials Research and Engineering (IMRE), Agency for Science, Technology and Research (A*STAR), Singapore, Singapore
| | - Anjan Soumyanarayanan
- Institute of Materials Research and Engineering (IMRE), Agency for Science, Technology and Research (A*STAR), Singapore, Singapore.
- Department of Physics, National University of Singapore, Singapore, Singapore.
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9
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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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10
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He B, Jin H, Zheng D, Liu Y, Li J, Hu Y, Wang Y, Zhang J, Peng Y, Wan C, Zhu T, Han X, Zhang S, Yu G. Creation of Room-Temperature Sub-100 nm Antiferromagnetic Skyrmions in an Antiferromagnet IrMn through Interfacial Exchange Coupling. NANO LETTERS 2024; 24:2196-2202. [PMID: 38329428 DOI: 10.1021/acs.nanolett.3c04221] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/09/2024]
Abstract
Antiferromagnetic (AFM) skyrmions are magnetic vortices composed of antiparallell-aligned neighboring spins. In stark contrast to conventional skyrmions based on ferromagnetic order, AFM skyrmions have vanished stray fields, higher response frequencies, and rectified translational motion driven by an external force. Therefore, AFM skyrmions promise highly efficient spintronics devices with high bit mobility and density. Nevertheless, the experimental realization of intrinsic AFM skyrmions remains elusive. Here, we show that AFM skyrmions can be nucleated via interfacial exchange coupling at the surface of a room-temperature AFM material, IrMn, exploiting the particular response from uncompensated moments to the thermal annealing and imprinting effects. Further systematic magnetic characterizations validate the existence of such an AFM order at the IrMn/CoFeB interfaces. Such AFM skyrmions have a typical size of 100 nm, which presents pronounced robustness against field and temperature. Our work opens new pathways for magnetic topological devices based on AFM skyrmions.
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Affiliation(s)
- Bin He
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Haonan Jin
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China
- ShanghaiTech Laboratory for Topological Physics, ShanghaiTech University, Shanghai 200031, China
| | - Dongfeng Zheng
- Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, China
| | - Yizhou Liu
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Jialiang Li
- Spallation Neutron Source Science Center, Dongguan 523803, China
| | - Yue Hu
- Key Laboratory for Magnetism and Magnetic Materials of Ministry of Education, Lanzhou University, Lanzhou 730000, China
| | - Yuqiang Wang
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Junwei Zhang
- Key Laboratory for Magnetism and Magnetic Materials of Ministry of Education, Lanzhou University, Lanzhou 730000, China
| | - Yong Peng
- Key Laboratory for Magnetism and Magnetic Materials of Ministry of Education, Lanzhou University, Lanzhou 730000, China
| | - Caihua Wan
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, China
| | - Tao Zhu
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, China
- Spallation Neutron Source Science Center, Dongguan 523803, China
| | - Xiufeng Han
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, China
| | - Shilei Zhang
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China
- ShanghaiTech Laboratory for Topological Physics, ShanghaiTech University, Shanghai 200031, China
| | - Guoqiang Yu
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, China
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11
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Ukleev V, Ajejas F, Devishvili A, Vorobiev A, Steinke NJ, Cubitt R, Luo C, Abrudan RM, Radu F, Cros V, Reyren N, White JS. Observation by SANS and PNR of pure Néel-type domain wall profiles and skyrmion suppression below room temperature in magnetic [Pt/CoFeB/Ru] 10 multilayers. SCIENCE AND TECHNOLOGY OF ADVANCED MATERIALS 2024; 25:2315015. [PMID: 38455384 PMCID: PMC10919321 DOI: 10.1080/14686996.2024.2315015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/28/2023] [Accepted: 01/29/2024] [Indexed: 03/09/2024]
Abstract
We report investigations of the magnetic textures in periodic multilayers [Pt(1 nm)/(CoFeB(0.8 nm)/Ru(1.4 nm)]10 using polarised neutron reflectometry (PNR) and small-angle neutron scattering (SANS). The multilayers are known to host skyrmions stabilized by Dzyaloshinskii-Moriya interactions induced by broken inversion symmetry and spin-orbit coupling at the asymmetric interfaces. From depth-dependent PNR measurements, we observed well-defined structural features and obtained the layer-resolved magnetization profiles. The in-plane magnetization of the CoFeB layers calculated from fitting of the PNR profiles is found to be in excellent agreement with magnetometry data. Using SANS as a bulk probe of the entire multilayer, we observe long-period magnetic stripe domains and skyrmion ensembles with full orientational disorder at room temperature. No sign of skyrmions is found below 250 K, which we suggest is due to an increase of an effective magnetic anisotropy in the CoFeB layer on cooling that suppresses skyrmion stability. Using polarised SANS at room temperature, we prove the existence of pure Néel-type windings in both stripe domain and skyrmion regimes. No Bloch-type winding admixture, i.e. an indication for hybrid windings, is detected within the measurement sensitivity, in good agreement with expectations according to our micromagnetic modelling of the multilayers. Our findings using neutron techniques provide valuable microscopic insights into the rich magnetic behavior of skyrmion-hosting multilayers, which are essential for the advancement of future skyrmion-based spintronic devices.
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Affiliation(s)
- Victor Ukleev
- Laboratory for Neutron Scattering and Imaging (LNS), Paul Scherrer Institute (PSI), Villigen, Switzerland
- Helmholtz-Zentrum Berlin für Materialien und Energie, Berlin, Germany
| | - Fernando Ajejas
- Laboratoire Albert Fert, CNRS, Thales, Université Paris-Saclay, Palaiseau, France
| | | | - Alexei Vorobiev
- Institut Laue-Langevin, Grenoble, France
- Department of Physics, Uppsala University, Uppsala, Sweden
| | | | | | - Chen Luo
- Helmholtz-Zentrum Berlin für Materialien und Energie, Berlin, Germany
| | | | - Florin Radu
- Helmholtz-Zentrum Berlin für Materialien und Energie, Berlin, Germany
| | - Vincent Cros
- Laboratoire Albert Fert, CNRS, Thales, Université Paris-Saclay, Palaiseau, France
| | - Nicolas Reyren
- Laboratoire Albert Fert, CNRS, Thales, Université Paris-Saclay, Palaiseau, France
| | - Jonathan S. White
- Laboratory for Neutron Scattering and Imaging (LNS), Paul Scherrer Institute (PSI), Villigen, Switzerland
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12
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Darwin E, Tomasello R, Shepley PM, Satchell N, Carpentieri M, Finocchio G, Hickey BJ. Antiferromagnetic interlayer exchange coupled Co 68B 32/Ir/Pt multilayers. Sci Rep 2024; 14:95. [PMID: 38168577 PMCID: PMC10761723 DOI: 10.1038/s41598-023-49976-4] [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: 06/21/2023] [Accepted: 12/14/2023] [Indexed: 01/05/2024] Open
Abstract
Synthetic antiferromagnetic structures can exhibit the advantages of high velocity similarly to antiferromagnets with the additional benefit of being imaged and read-out through techniques applied to ferromagnets. Here, we explore the potential and limits of synthetic antiferromagnets to uncover ways to harness their valuable properties for applications. Two synthetic antiferromagnetic systems have been engineered and systematically investigated to provide an informed basis for creating devices with maximum potential for data storage, logic devices, and skyrmion racetrack memories. The two systems considered are (system 1) CoB/Ir/Pt of N repetitions with Ir inducing the negative coupling between the ferromagnetic layers and (system 2) two ferromagnetically coupled multilayers of CoB/Ir/Pt, coupled together antiferromagnetically with an Ir layer. From the hysteresis, it is found that system 1 shows stable antiferromagnetic interlayer exchange coupling between each magnetic layer up to N = 7. Using Kerr imaging, the two ferromagnetic multilayers in system 2 are shown to undergo separate maze-like switches during hysteresis. Both systems are also studied as a function of temperature and show different behaviors. Micromagnetic simulations predict that in both systems the skyrmion Hall angle is suppressed with the skyrmion velocity five times higher in system 1 than system 2.
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Affiliation(s)
- Emily Darwin
- School of Physics and Astronomy, University of Leeds, Leeds, LS2 9JT, UK
- Department of Electrical and Information Engineering, Politecnico Di Bari, Via E. Orabona 4, 70125, Bari, Italy
| | - Riccardo Tomasello
- Department of Electrical and Information Engineering, Politecnico Di Bari, Via E. Orabona 4, 70125, Bari, Italy
| | - Philippa M Shepley
- School of Physics and Astronomy, University of Leeds, Leeds, LS2 9JT, UK
| | - Nathan Satchell
- School of Physics and Astronomy, University of Leeds, Leeds, LS2 9JT, UK
- Department of Physics, Texas State University, San Marcos, TX, 78666, USA
| | - Mario Carpentieri
- Department of Electrical and Information Engineering, Politecnico Di Bari, Via E. Orabona 4, 70125, Bari, Italy
| | - Giovanni Finocchio
- Department of Mathematical and Computer Sciences, Physical Sciences and Earth Sciences, University of Messina, 98166, Messina, Italy.
| | - B J Hickey
- School of Physics and Astronomy, University of Leeds, Leeds, LS2 9JT, UK.
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13
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Raj RK, Bindal N, Kaushik BK. Skyrmion motion under temperature gradient and application in logic devices. NANOTECHNOLOGY 2023; 35:075703. [PMID: 38014695 DOI: 10.1088/1361-6528/acfd33] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/21/2023] [Accepted: 09/25/2023] [Indexed: 11/29/2023]
Abstract
Under the presence of temperature gradient (TG) on a nanotrack, it is necessary to investigate the skyrmion dynamics in various magnetic systems under the combined effect of forces due to magnonic spin transfer torque(μSTT),thermal STT (τSTT), entropic difference(dS),as well as thermal induced dipolar field (DF). Hence, in this work, the dynamics of skyrmions in ferromagnets (FM), synthetic antiferromagnets (SAF), and antiferromagnets (AFM) have been studied under different TGs and damping constants (αG). It is observed thatαGplays a major role in deciding the direction of skyrmion motion either towards the hotter or colder side in different magnetic structures. Later, FM skyrmion based logic device is proposed that consists of a cross-coupled nanotrack, where the skyrmions on horizontal and vertical nanotrack are controlled by exploiting TG and electrical STT (eSTT), respectively by taking the advantages of thermal induced skyrmion Hall effect (SkHE). The proposed device performs AND and OR logic functionalities simultaneously, when the applied current density is2×1011Am-2.Moreover, the proposed device is also able to exhibit the half adder functionality by tuning the applied current density to3×1011Am-2.The total energy consumption for AND and OR logic operation and half adder are 33.63 fJ and 25.06 fJ, respectively. This paves the way for the development of energy-efficient logic devices with ultra-high storage density.
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Affiliation(s)
- Ravish Kumar Raj
- Department of Electronics and Communication Engineering, Indian Institute of Technology, Roorkee 247667, India
| | - Namita Bindal
- Department of Electronics and Communication Engineering, Indian Institute of Technology, Roorkee 247667, India
| | - Brajesh Kumar Kaushik
- Department of Electronics and Communication Engineering, Indian Institute of Technology, Roorkee 247667, India
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14
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Aldarawsheh A, Sallermann M, Abusaa M, Lounis S. Intrinsic Néel Antiferromagnetic Multimeronic Spin Textures in Ultrathin Films. J Phys Chem Lett 2023; 14:8970-8978. [PMID: 37773009 PMCID: PMC10577774 DOI: 10.1021/acs.jpclett.3c02419] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Accepted: 09/27/2023] [Indexed: 09/30/2023]
Abstract
Topological antiferromagnetism is a vibrant and captivating research field, generating considerable enthusiasm with the aim of identifying topologically protected magnetic states of key importance in the hybrid realm of topology, magnetism, and spintronics. While topological antiferromagnetic (AFM) solitons bear various advantages with respect to their ferromagnetic cousins, their observation is scarce. Utilizing first-principles simulations, here we predict new chiral particles in the realm of AFM topological magnetism, exchange-frustrated multimeronic spin textures hosted by a Néel magnetic state, arising universally in single Mn layers directly grown on an Ir(111) surface or interfaced with Pd-based films. These nanoscale topological structures are intrinsic; i.e. they form in a single AFM material, can carry distinct topological charges, and can combine in various multimeronic sequences with enhanced stability against external magnetic fields. We envision the frustrated Néel AFM multimerons as exciting highly sought after AFM solitons having the potential to be utilized in novel spintronic devices hinging on nonsynthetic AFM quantum materials, further advancing the frontiers of nanotechnology and nanophysics.
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Affiliation(s)
- Amal Aldarawsheh
- Peter
Grünberg Institute and Institute for Advanced Simulation, Forschungszentrum Jülich and JARA, D-52425 Jülich, Germany
- Faculty
of Physics, University of Duisburg-Essen
and CENIDE, 47053 Duisburg, Germany
| | - Moritz Sallermann
- Peter
Grünberg Institute and Institute for Advanced Simulation, Forschungszentrum Jülich and JARA, D-52425 Jülich, Germany
- RWTH
Aachen University, 52056 Aachen, Germany
- Science
Institute and Faculty of Physical Sciences, University of Iceland, VR-III, 107 Reykjavík, Iceland
| | - Muayad Abusaa
- Department
of Physics, Arab American University, 240 Jenin, Palestine
| | - Samir Lounis
- Peter
Grünberg Institute and Institute for Advanced Simulation, Forschungszentrum Jülich and JARA, D-52425 Jülich, Germany
- Faculty
of Physics, University of Duisburg-Essen
and CENIDE, 47053 Duisburg, Germany
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15
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Dohi T, Weißenhofer M, Kerber N, Kammerbauer F, Ge Y, Raab K, Zázvorka J, Syskaki MA, Shahee A, Ruhwedel M, Böttcher T, Pirro P, Jakob G, Nowak U, Kläui M. Enhanced thermally-activated skyrmion diffusion with tunable effective gyrotropic force. Nat Commun 2023; 14:5424. [PMID: 37696785 PMCID: PMC10495465 DOI: 10.1038/s41467-023-40720-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Accepted: 08/07/2023] [Indexed: 09/13/2023] Open
Abstract
Magnetic skyrmions, topologically-stabilized spin textures that emerge in magnetic systems, have garnered considerable interest due to a variety of electromagnetic responses that are governed by the topology. The topology that creates a microscopic gyrotropic force also causes detrimental effects, such as the skyrmion Hall effect, which is a well-studied phenomenon highlighting the influence of topology on the deterministic dynamics and drift motion. Furthermore, the gyrotropic force is anticipated to have a substantial impact on stochastic diffusive motion; however, the predicted repercussions have yet to be demonstrated, even qualitatively. Here we demonstrate enhanced thermally-activated diffusive motion of skyrmions in a specifically designed synthetic antiferromagnet. Suppressing the effective gyrotropic force by tuning the angular momentum compensation leads to a more than 10 times enhanced diffusion coefficient compared to that of ferromagnetic skyrmions. Consequently, our findings not only demonstrate the gyro-force dependence of the diffusion coefficient but also enable ultimately energy-efficient unconventional stochastic computing.
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Affiliation(s)
- Takaaki Dohi
- Institut für Physik, Johannes Gutenberg-Universität Mainz, Staudingerweg 7, 55128, Mainz, Germany.
- Laboratory for Nanoelectronics and Spintronics, Research Institute of Electrical Communication, Tohoku University, Sendai, 980-8577, Japan.
| | - Markus Weißenhofer
- Fachbereich Physik, Universität Konstanz, DE-78457, Konstanz, Germany.
- Department of Physics and Astronomy, Uppsala University, P.O. Box 516, S-751 20, Uppsala, Sweden.
- Department of Physics, Freie Universität Berlin, Arnimallee 14, D-14195, Berlin, Germany.
| | - Nico Kerber
- Institut für Physik, Johannes Gutenberg-Universität Mainz, Staudingerweg 7, 55128, Mainz, Germany
- Graduate School of Excellence Materials Science in Mainz, Staudingerweg 9, 55128, Mainz, Germany
| | - Fabian Kammerbauer
- Institut für Physik, Johannes Gutenberg-Universität Mainz, Staudingerweg 7, 55128, Mainz, Germany
| | - Yuqing Ge
- Institut für Physik, Johannes Gutenberg-Universität Mainz, Staudingerweg 7, 55128, Mainz, Germany
| | - Klaus Raab
- Institut für Physik, Johannes Gutenberg-Universität Mainz, Staudingerweg 7, 55128, Mainz, Germany
| | - Jakub Zázvorka
- Institute of Physics, Faculty of Mathematics and Physics, Charles University, Ke Karlovu 5, Prague, 12116, Czech Republic
| | - Maria-Andromachi Syskaki
- Institut für Physik, Johannes Gutenberg-Universität Mainz, Staudingerweg 7, 55128, Mainz, Germany
- Singulus Technologies AG, 63796, Kahl am Main, Germany
| | - Aga Shahee
- Institut für Physik, Johannes Gutenberg-Universität Mainz, Staudingerweg 7, 55128, Mainz, Germany
| | - Moritz Ruhwedel
- Fachbereich Physik and Landesforschungszentrum OPTIMAS, Technische Universität Kaiserslautern, Gottlieb-Daimler-Straße 46, 67663, Kaiserslautern, Germany
| | - Tobias Böttcher
- Graduate School of Excellence Materials Science in Mainz, Staudingerweg 9, 55128, Mainz, Germany
- Fachbereich Physik and Landesforschungszentrum OPTIMAS, Technische Universität Kaiserslautern, Gottlieb-Daimler-Straße 46, 67663, Kaiserslautern, Germany
| | - Philipp Pirro
- Fachbereich Physik and Landesforschungszentrum OPTIMAS, Technische Universität Kaiserslautern, Gottlieb-Daimler-Straße 46, 67663, Kaiserslautern, Germany
| | - Gerhard Jakob
- Institut für Physik, Johannes Gutenberg-Universität Mainz, Staudingerweg 7, 55128, Mainz, Germany
- Graduate School of Excellence Materials Science in Mainz, Staudingerweg 9, 55128, Mainz, Germany
| | - Ulrich Nowak
- Fachbereich Physik, Universität Konstanz, DE-78457, Konstanz, Germany
| | - Mathias Kläui
- Institut für Physik, Johannes Gutenberg-Universität Mainz, Staudingerweg 7, 55128, Mainz, Germany.
- Graduate School of Excellence Materials Science in Mainz, Staudingerweg 9, 55128, Mainz, Germany.
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16
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Yagan R, Cheghabouri AM, Onbasli MC. Stabilization and adiabatic control of antiferromagnetically coupled skyrmions without the topological Hall effect. NANOSCALE ADVANCES 2023; 5:4470-4479. [PMID: 37638152 PMCID: PMC10448311 DOI: 10.1039/d3na00236e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Accepted: 07/26/2023] [Indexed: 08/29/2023]
Abstract
Synthetic antiferromagnetically coupled (SAF) multilayers provide different physics of stabilizing skyrmions while eliminating the topological Hall effect (THE), enabling efficient and stable control. The effects of material parameters, external current drive, and a magnetic field on the skyrmion equilibrium and propagation characteristics are largely unresolved. Here, we present a computational and theoretical demonstration of the large window of material parameters that stabilize SAF skyrmions determined by saturation magnetization, uniaxial anisotropy, and Dzyaloshinskii-Moriya interaction. Current-driven SAF skyrmion velocities reach ∼200 m s-1 without the THE. The SAF velocities are about 3-10 times greater than the typical ferromagnetic skyrmion velocities. The current densities needed for driving SAF skyrmions could be reduced to 108 A m-2, while 1011 A m-2 or above is needed for ferromagnetic skyrmions. By reducing the SAF skyrmion drive current by 3 orders, Joule heating is reduced by 6 orders of magnitude. These results pave the way for new SAF interfaces with improved equilibrium, dynamics, and power savings in THE-free skyrmionics.
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Affiliation(s)
- Rawana Yagan
- Department of Electrical and Electronics Engineering, Koç University Sarıyer Istanbul 34450 Turkey
| | | | - Mehmet C Onbasli
- Department of Electrical and Electronics Engineering, Koç University Sarıyer Istanbul 34450 Turkey
- Department of Physics, Koç University Sarıyer Istanbul 34450 Turkey
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17
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Tambovtsev IM, Lobanov IS, Kiselev AD, Uzdin VM. Pair interaction of localized topological structures in confined chiral media. Phys Rev E 2023; 108:024705. [PMID: 37723750 DOI: 10.1103/physreve.108.024705] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Accepted: 08/08/2023] [Indexed: 09/20/2023]
Abstract
We study pairwise interactions between localized topological structures in chiral magnetic and cholesteric liquid crystal (CLC) systems confined in the planar geometry. Our calculations for magnetics are based on the lattice model that takes into account the bulk and surface anisotropies along with the exchange and the Dzyaloshinskii-Moriya interactions. In CLC cells, these anisotropies describe the energy of interaction with an external magnetic or electric field and the anchoring energy assuming that the magnetic or electric anisotropy is negative and the boundary conditions are homeotropic. We have selected the region of the phase diagram, where various localized solitonlike structures, including skyrmion tubes, torons, and leeches, embedded in the ground state of the z-cone (conical phase) coexist, and carried out numerical analysis of the distance dependencies of the effective intersoliton interaction potentials. For skyrmions and torons, the potentials are found to be attractive in the large separation region. It turned out that for these potentials, the effects of axial asymmetry are negligible. By contrast, it turned out that for the intermediate structures between the skyrmions and torons known as the leeches, the leech-leech potentials generally depend on the orientation of the intersoliton separation vector and their large distance parts may become repulsive at certain directions of the vector. All the potentials have the short distance repulsive parts and the local minima located at the equilibrium separations. It is found that the skyrmion-skyrmion potential has an additional metastable configuration shifted towards the short-distance region.
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Affiliation(s)
- I M Tambovtsev
- Faculty of Physics, ITMO University, 197101 St. Petersburg, Russia
- Department of Physics, St. Petersburg State University, St. Petersburg 198504, Russia
- Science Institute and Faculty of Physical Sciences, University of Iceland, 107 Reykjavík, Iceland
| | - I S Lobanov
- Faculty of Physics, ITMO University, 197101 St. Petersburg, Russia
| | - Alexei D Kiselev
- Laboratory of Quantum Processes and Measurements, ITMO University, 199034 Saint Petersburg, Russia
| | - V M Uzdin
- Faculty of Physics, ITMO University, 197101 St. Petersburg, Russia
- Department of Physics, St. Petersburg State University, St. Petersburg 198504, Russia
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18
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Chen R, Chen C, Han L, Liu P, Su R, Zhu W, Zhou Y, Pan F, Song C. Ordered creation and motion of skyrmions with surface acoustic wave. Nat Commun 2023; 14:4427. [PMID: 37481619 PMCID: PMC10363109 DOI: 10.1038/s41467-023-40131-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Accepted: 07/04/2023] [Indexed: 07/24/2023] Open
Abstract
Magnetic skyrmions with a well-defined spin texture have shown unprecedented potential for various spintronic applications owning to their topologically non-trivial and quasiparticle properties. To put skyrmions into practical technology, efficient manipulation, especially the inhibition of skyrmion Hall effect (SkHE) has been intensively pursued. In spite of the recent progress made on reducing SkHE in several substituted systems, such as ferrimagnets and synthetic antiferromagnets, the organized creation and current driven motion of skyrmions with negligible SkHE in ferromagnets remain challenging. Here, by embedding the [Co/Pd] multilayer into a surface acoustic wave (SAW) delay line where the longitudinal leaky SAW is excited to provide both the strain and thermal effect, we experimentally realized the ordered generation of magnetic skyrmions. The resultant current-induced skyrmions movement with negligible SkHE was observed, which can be attributed to the energy redistribution of the system during the excitation of SAW. Our findings open up an unprecedentedly new perspective for manipulating topological solitons, which could possibly trigger the future discoveries in skyrmionics and spin acousto-electronics.
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Affiliation(s)
- Ruyi Chen
- Key Laboratory of Advanced Materials (MOE), School of Materials Science and Engineering, Beijing Innovation Center for Future Chip, Tsinghua University, Beijing, 100084, China
| | - Chong Chen
- Key Laboratory of Advanced Materials (MOE), School of Materials Science and Engineering, Beijing Innovation Center for Future Chip, Tsinghua University, Beijing, 100084, China
| | - Lei Han
- Key Laboratory of Advanced Materials (MOE), School of Materials Science and Engineering, Beijing Innovation Center for Future Chip, Tsinghua University, Beijing, 100084, China
| | - Peisen Liu
- Key Laboratory of Advanced Materials (MOE), School of Materials Science and Engineering, Beijing Innovation Center for Future Chip, Tsinghua University, Beijing, 100084, China
| | - Rongxuan Su
- Key Laboratory of Advanced Materials (MOE), School of Materials Science and Engineering, Beijing Innovation Center for Future Chip, Tsinghua University, Beijing, 100084, China
| | - Wenxuan Zhu
- Key Laboratory of Advanced Materials (MOE), School of Materials Science and Engineering, Beijing Innovation Center for Future Chip, Tsinghua University, Beijing, 100084, China
| | - Yongjian Zhou
- Key Laboratory of Advanced Materials (MOE), School of Materials Science and Engineering, Beijing Innovation Center for Future Chip, Tsinghua University, Beijing, 100084, China
| | - Feng Pan
- Key Laboratory of Advanced Materials (MOE), School of Materials Science and Engineering, Beijing Innovation Center for Future Chip, Tsinghua University, Beijing, 100084, China
| | - Cheng Song
- Key Laboratory of Advanced Materials (MOE), School of Materials Science and Engineering, Beijing Innovation Center for Future Chip, Tsinghua University, Beijing, 100084, China.
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19
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Burgos-Parra E, Sassi Y, Legrand W, Ajejas F, Léveillé C, Gargiani P, Valvidares M, Reyren N, Cros V, Jaouen N, Flewett S. Probing of three-dimensional spin textures in multilayers by field dependent X-ray resonant magnetic scattering. Sci Rep 2023; 13:11711. [PMID: 37474533 PMCID: PMC10359410 DOI: 10.1038/s41598-023-38029-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Accepted: 06/30/2023] [Indexed: 07/22/2023] Open
Abstract
In multilayers of magnetic thin films with perpendicular anisotropy, domain walls can take on hybrid configurations in the vertical direction which minimize the domain wall energy, with Néel walls in the top or bottom layers and Bloch walls in some central layers. These types of textures are theoretically predicted, but their observation has remained challenging until recently, with only a few techniques capable of realizing a three dimensional characterization of their magnetization distribution. Here we perform a field dependent X-ray resonant magnetic scattering measurements on magnetic multilayers exploiting circular dichroism contrast to investigate such structures. Using a combination of micromagnetic and X-ray resonant magnetic scattering simulations along with our experimental results, we characterize the three-dimensional magnetic texture of domain walls, notably the thickness resolved characterization of the size and position of the Bloch part in hybrid walls. We also take a step in advancing the resonant scattering methodology by using measurements performed off the multilayer Bragg angle in order to calibrate the effective absorption of the X-rays, and permitting a quantitative evaluation of the out of plane (z) structure of our samples. Beyond hybrid domain walls, this approach can be used to characterize other periodic chiral structures such as skyrmions, antiskyrmions or even magnetic bobbers or hopfions, in both static and dynamic experiments.
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Affiliation(s)
- Erick Burgos-Parra
- Synchrotron SOLEIL, L'Orme des Merisiers, 91192, Gif-sur-Yvette, France.
- Unité Mixte de Physique, CNRS, Thales, Université Paris-Saclay, 91767, Palaiseau, France.
- University of Santiago de Chile, Avenida Víctor Jara 3493, Estación Central, Santiago, Chile.
| | - Yanis Sassi
- Unité Mixte de Physique, CNRS, Thales, Université Paris-Saclay, 91767, Palaiseau, France
| | - William Legrand
- Unité Mixte de Physique, CNRS, Thales, Université Paris-Saclay, 91767, Palaiseau, France
| | - Fernando Ajejas
- Unité Mixte de Physique, CNRS, Thales, Université Paris-Saclay, 91767, Palaiseau, France
| | - Cyril Léveillé
- Synchrotron SOLEIL, L'Orme des Merisiers, 91192, Gif-sur-Yvette, France
| | - Pierluigi Gargiani
- ALBA Synchrotron Light Source, Cerdanyola del Vallès, 08290, Barcelona, Spain
| | - Manuel Valvidares
- ALBA Synchrotron Light Source, Cerdanyola del Vallès, 08290, Barcelona, Spain
| | - Nicolas Reyren
- Unité Mixte de Physique, CNRS, Thales, Université Paris-Saclay, 91767, Palaiseau, France
| | - Vincent Cros
- Unité Mixte de Physique, CNRS, Thales, Université Paris-Saclay, 91767, Palaiseau, France
| | - Nicolas Jaouen
- Synchrotron SOLEIL, L'Orme des Merisiers, 91192, Gif-sur-Yvette, France
| | - Samuel Flewett
- Pontificia Universidad Católica de Valparaíso, Avenida Universidad 330, Valparaiso, Chile
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20
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Xu T, Zhang Y, Wang Z, Bai H, Song C, Liu J, Zhou Y, Je SG, N'Diaye AT, Im MY, Yu R, Chen Z, Jiang W. Systematic Control of Ferrimagnetic Skyrmions via Composition Modulation in Pt/Fe 1-xTb x/Ta Multilayers. ACS NANO 2023; 17:7920-7928. [PMID: 37010987 DOI: 10.1021/acsnano.3c02006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
Magnetic skyrmions are topological spin textures that can be used as memory and logic components for advancing the next generation spintronics. In this regard, control of nanoscale skyrmions, including their sizes and densities, is of particular importance for enhancing the storage capacity of skyrmionic devices. Here, we propose a viable route for engineering ferrimagnetic skyrmions via tuning the magnetic properties of the involved ferrimagnets Fe1-xTbx. Via tuning the composition of Fe1-xTbx that alters the magnetic anisotropy and the saturation magnetization, the size of the ferrimagnetic skyrmion (ds) and the average density (ηs) can be effectively tailored in [Pt/Fe1-xTbx/Ta]10 multilayers. In particular, a stabilization of sub-50 nm skyrmions with a high density is demonstrated at room temperature. Our work provides an effective approach for designing ferrimagnetic skyrmions with the desired size and density, which could be useful for enabling high-density ferrimagnetic skyrmionics.
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Affiliation(s)
- Teng Xu
- State Key Laboratory of Low-Dimensional Quantum Physics and Department of Physics, Tsinghua University, Beijing 100084, China
- Frontier Science Center for Quantum Information, Tsinghua University, Beijing 100084, China
| | - Yuxuan Zhang
- School of Materials Science and Engineering, The State Key Laboratory of New Ceramics and Fine Processing, MOE Key Laboratory of Advanced Materials, Tsinghua University, Beijing 100084, China
| | - Zidong Wang
- State Key Laboratory of Low-Dimensional Quantum Physics and Department of Physics, Tsinghua University, Beijing 100084, China
- Frontier Science Center for Quantum Information, Tsinghua University, Beijing 100084, China
- School of Science and Engineering, The Chinese University of Hong Kong, Shenzhen, Guangdong 518172, China
| | - Hao Bai
- State Key Laboratory of Low-Dimensional Quantum Physics and Department of Physics, Tsinghua University, Beijing 100084, China
- Frontier Science Center for Quantum Information, Tsinghua University, Beijing 100084, China
| | - Chengkun Song
- State Key Laboratory of Low-Dimensional Quantum Physics and Department of Physics, Tsinghua University, Beijing 100084, China
- Frontier Science Center for Quantum Information, Tsinghua University, Beijing 100084, China
| | - Jiahao Liu
- State Key Laboratory of Low-Dimensional Quantum Physics and Department of Physics, Tsinghua University, Beijing 100084, China
- Frontier Science Center for Quantum Information, Tsinghua University, Beijing 100084, China
| | - Yan Zhou
- School of Science and Engineering, The Chinese University of Hong Kong, Shenzhen, Guangdong 518172, China
| | - Soong-Geun Je
- Lawrence Berkeley National Laboratory, Cyclotron Road, Berkeley, California 94720, United States
| | - Alpha T N'Diaye
- Lawrence Berkeley National Laboratory, Cyclotron Road, Berkeley, California 94720, United States
| | - Mi-Young Im
- Lawrence Berkeley National Laboratory, Cyclotron Road, Berkeley, California 94720, United States
| | - Rong Yu
- School of Materials Science and Engineering, The State Key Laboratory of New Ceramics and Fine Processing, MOE Key Laboratory of Advanced Materials, Tsinghua University, Beijing 100084, China
| | - Zhen Chen
- School of Materials Science and Engineering, The State Key Laboratory of New Ceramics and Fine Processing, MOE Key Laboratory of Advanced Materials, Tsinghua University, Beijing 100084, China
| | - Wanjun Jiang
- State Key Laboratory of Low-Dimensional Quantum Physics and Department of Physics, Tsinghua University, Beijing 100084, China
- Frontier Science Center for Quantum Information, Tsinghua University, Beijing 100084, China
- Collaborative Innovation Center of Quantum Matter, Beijing 100084, China
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21
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Luo X, Wang Y, Liu S, Guo T, Han X, Yu G. Unusual spin-orbit torque switching in perpendicular synthetic antiferromagnets with strong interlayer exchange coupling. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2023; 35:264004. [PMID: 36958042 DOI: 10.1088/1361-648x/acc711] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/30/2022] [Accepted: 03/23/2023] [Indexed: 06/18/2023]
Abstract
Synthetic antiferromagnet (SAF) is an outstanding system for controlling magnetic coupling via tuning the layer thickness and material composition. Here, we control the interlayer exchange coupling (IEC) in a perpendicularly magnetized SAF Pt/Co/Ir/CoFeB/MgO multilayer, which is tuned by varying the nonmagnetic layer Ir thickness and the magnetic layer Co thickness. And we study the spin-orbit torque (SOT) driven magnetization switching of the SAF. In the SAF with a weak IEC, the SOT-driven switching behavior is similar to that of a single ferromagnet system, which is dominated by the external magnetic field. In contrast, in the SAF with an ultra-strong IEC, the saturation magnetic field is large than 50 kOe, and the SOT-driven switching behavior is decided by the effective magnetic field. The effective field is correlated to the external magnetic field, the IEC field, magnetic moments of CoFeB and Co, and magnetic anisotropy. These results may advance the understanding of SOT switching of perpendicular SAFs and promote the applications of SAFs with low stray fields and lower power in spintronic devices.
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Affiliation(s)
- Xuming Luo
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, People's Republic of China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
| | - Yuqiang Wang
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, People's Republic of China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
| | - Shiqiang Liu
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, People's Republic of China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
| | - Tengyu Guo
- Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, People's Republic of China
| | - Xiufeng Han
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, People's Republic of China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, People's Republic of China
| | - Guoqiang Yu
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, People's Republic of China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, People's Republic of China
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22
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Deng P, Zhuo F, Li H, Cheng Z. Mirroring Skyrmions in Synthetic Antiferromagnets via Modular Design. NANOMATERIALS (BASEL, SWITZERLAND) 2023; 13:859. [PMID: 36903736 PMCID: PMC10004772 DOI: 10.3390/nano13050859] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/28/2022] [Revised: 02/18/2023] [Accepted: 02/24/2023] [Indexed: 06/18/2023]
Abstract
Skyrmions are promising for the next generation of spintronic devices, which involves the production and transfer of skyrmions. The creation of skyrmions can be realized by a magnetic field, electric field, or electric current while the controllable transfer of skyrmions is hindered by the skyrmion Hall effect. Here, we propose utilizing the interlayer exchange coupling induced by the Ruderman-Kittel-Kasuya-Yoshida interactions to create skyrmions through hybrid ferromagnet/synthetic antiferromagnet structures. An initial skyrmion in ferromagnetic regions could create a mirroring skyrmion with an opposite topological charge in antiferromagnetic regions driven by the current. Furthermore, the created skyrmions could be transferred in synthetic antiferromagnets without deviations away from the main trajectories due to the suppression of the skyrmion Hall effect in comparison to the transfer of the skyrmion in ferromagnets. The interlayer exchange coupling can be tuned, and the mirrored skyrmions can be separated when they reach the desired locations. Using this approach, the antiferromagnetic coupled skyrmions can be repeatedly created in hybrid ferromagnet/synthetic antiferromagnet structures. Our work not only supplies a highly efficient approach to create isolated skyrmions and correct the errors in the process of skyrmion transport, but also paves the way to a vital information writing technique based on the motion of skyrmions for skyrmion-based data storage and logic devices.
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Affiliation(s)
- Panluo Deng
- School of Physics and Electronics, Henan University, Kaifeng 475004, China
| | - Fengjun Zhuo
- School of Physics Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Hang Li
- School of Physics and Electronics, Henan University, Kaifeng 475004, China
| | - Zhenxiang Cheng
- Institute for Superconducting and Electronic Materials, Australian Institute of Innovative Materials, Innovation Campus, University of Wollongong, Squires Way, North Wollongong, NSW 2500, Australia
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23
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Kossak AE, Huang M, Reddy P, Wolf D, Beach GS. Voltage control of magnetic order in RKKY coupled multilayers. SCIENCE ADVANCES 2023; 9:eadd0548. [PMID: 36598984 PMCID: PMC9812395 DOI: 10.1126/sciadv.add0548] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/23/2022] [Accepted: 11/23/2022] [Indexed: 06/17/2023]
Abstract
In the field of antiferromagnetic (AFM) spintronics, there is a substantial effort present to make AFMs viable active components for efficient and fast devices. Typically, this is done by manipulating the AFM Néel vector. Here, we establish a method of enabling AFM active components by directly controlling the magnetic order. We show that magneto-ionic gating of hydrogen enables dynamic control of the Ruderman-Kittel-Kasuya-Yosida (RKKY) interaction in solid-state synthetic AFM multilayer devices. Using a gate voltage, we tune the RKKY interaction to drive continuous transitions from AFM to FM and vice versa. The switching is submillisecond at room temperature and fully reversible. We validate the utility of this method by demonstrating that magneto-ionic gating of the RKKY interaction allows for 180° field-free deterministic switching. This dynamic method of controlling a fundamental exchange interaction can engender the manipulation of a broader array of spin textures, e.g., chiral domain walls and skyrmions.
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Affiliation(s)
- Alexander E. Kossak
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Mantao Huang
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Pooja Reddy
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Daniel Wolf
- Leibniz IFW Dresden Helmholtzstrasse 20, Dresden 01069, Germany
| | - Geoffrey S. D. Beach
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
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24
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Xie X, Wang X, Wang W, Zhao X, Bai L, Chen Y, Tian Y, Yan S. Engineering Spin Configurations of Synthetic Antiferromagnet by Controlling Long-Range Oscillatory Interlayer Coupling and Neighboring Ferrimagnetic Coupling. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2208275. [PMID: 36268544 DOI: 10.1002/adma.202208275] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2022] [Revised: 10/07/2022] [Indexed: 06/16/2023]
Abstract
Controllable manipulation of specific spin configurations of magnetic materials is the key to constructing functional spintronic devices. Here, it is demonstrated by integrating the merits of ferromagnetic, ferrimagnetic, and antiferromagnetic spin configurations into one synthetic antiferromagnetic (SAF) heterostructure by controlling both long-range oscillatory interlayer coupling and neighboring ferrimagnetic coupling. A controllable manipulation of four types of spin configurations of the Pt/[Co/Pt/Co]/Ru/CoTb SAF heterostructures composed of ferromagnetic Co/Pt/Co and ferrimagnetic CoTb layers is successfully achieved. In particular, the compensated magnetization, enhanced anomalous Hall resistance in the remanence state, wide-temperature spin-orbit torque switching of magnetization, and high immunity to the external magnetic field are simultaneously obtained in one of the SAF heterojunctions with macroscopic interlayer antiferromagnetic coupling. This design concept of engineering spin configurations may enable efficient spin manipulation for customized memory and logic applications.
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Affiliation(s)
- Xuejie Xie
- School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan, 250100, P. R. China
| | - Xiujuan Wang
- School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan, 250100, P. R. China
| | - Wei Wang
- School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan, 250100, P. R. China
| | - Xiaonan Zhao
- School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan, 250100, P. R. China
| | - Lihui Bai
- School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan, 250100, P. R. China
| | - Yanxue Chen
- School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan, 250100, P. R. China
| | - Yufeng Tian
- School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan, 250100, P. R. China
| | - Shishen Yan
- School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan, 250100, P. R. China
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25
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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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26
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Yu X, Iakoubovskii KV, Yasin FS, Peng L, Nakajima K, Schneider S, Karube K, Arima T, Taguchi Y, Tokura Y. Real-Space Observations of Three-Dimensional Antiskyrmions and Skyrmion Strings. NANO LETTERS 2022; 22:9358-9364. [PMID: 36383503 PMCID: PMC9756337 DOI: 10.1021/acs.nanolett.2c03142] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Revised: 10/26/2022] [Indexed: 06/16/2023]
Abstract
Nanometric topological spin textures, such as skyrmions (Sks) and antiskyrmions (antiSks), have attracted much attention recently. However, most studies have focused on two-dimensional spin textures in films with inherent or synthetic antisymmetric spin-exchange interaction, termed Dzyaloshinskii-Moriya interaction, although three-dimensional (3D) topological spin textures, such as antiSks composed of alternating Bloch- and Néel-type spin spirals, chiral bobbers carrying emergent magnetic monopoles, and deformed Sk strings, are ubiquitous. To elucidate these textures, we have developed a 3D nanometric magnetic imaging technique, tomographic Lorentz transmission electron microscopy (TEM). The approach enables the visualization of the 3D shape of magnetic objects and their 3D vector field mapping. Here we report 3D vector field maps of deformed Sk-strings and antiSk using the technique. This research approach will lead to discoveries and understanding of fertile 3D magnetic structures in a broad class of magnets, providing insight into 3D topological magnetism.
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Affiliation(s)
- Xiuzhen Yu
- RIKEN
Center for Emergent Matter Science (CEMS), Wako 351-0198, Japan
| | | | - Fehmi Sami Yasin
- RIKEN
Center for Emergent Matter Science (CEMS), Wako 351-0198, Japan
| | - Licong Peng
- RIKEN
Center for Emergent Matter Science (CEMS), Wako 351-0198, Japan
| | - Kiyomi Nakajima
- RIKEN
Center for Emergent Matter Science (CEMS), Wako 351-0198, Japan
| | | | - Kosuke Karube
- RIKEN
Center for Emergent Matter Science (CEMS), Wako 351-0198, Japan
| | - Takahisa Arima
- RIKEN
Center for Emergent Matter Science (CEMS), Wako 351-0198, Japan
- Department
of Advanced Materials Science, University
of Tokyo, Kashiwa 277-8561, Japan
| | - Yasujiro Taguchi
- RIKEN
Center for Emergent Matter Science (CEMS), Wako 351-0198, Japan
| | - 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
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27
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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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28
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One RA, Mican S, CimpoesȖu AG, Joldos M, Tetean R, Tiușan CV. Micromagnetic Design of Skyrmionic Materials and Chiral Magnetic Configurations in Patterned Nanostructures for Neuromorphic and Qubit Applications. NANOMATERIALS (BASEL, SWITZERLAND) 2022; 12:4411. [PMID: 36558263 PMCID: PMC9782460 DOI: 10.3390/nano12244411] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Revised: 12/02/2022] [Accepted: 12/06/2022] [Indexed: 06/17/2023]
Abstract
Our study addresses the problematics of magnetic skyrmions, nanometer-size vortex-like swirling topological defects, broadly studied today for applications in classic, neuromorphic and quantum information technologies. We tackle some challenging issues of material properties versus skyrmion stability and manipulation within a multiple-scale modeling framework, involving complementary ab-initio and micromagnetic frameworks. Ab-initio calculations provide insight into the anatomy of the magnetic anisotropy, the Dzyaloshinskii-Moriya asymmetric exchange interaction (DMI) and their response to a gating electric field. Various multi-layered heterostructures were specially designed to provide electric field tunable perpendicular magnetization and sizeable DMI, which are required for skyrmion occurrence. Landau-Lifshitz-Gilbert micromagnetic calculations in nanometric disks allowed the extraction of material parameter phase diagrams in which magnetic textures were classified according to their topological charge. We identified suitable ranges of magnetic anisotropy, DMI and saturation magnetization for stabilizing skyrmionic ground states or writing/manipulating them using either a spin-transfer torque of a perpendicular current or the electric field. From analyzing the different contributions to the total magnetic free energy, we point out some critical properties influencing the skyrmions' stability. Finally, we discuss some experimental issues related to the choice of materials or the design of novel magnetic materials compatible with skyrmionic applications.
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Affiliation(s)
- Roxana-Alina One
- Department of Condensed Matter Physics and Advanced Technologies, Faculty of Physics, Babeș-Bolyai University of Cluj-Napoca, 400084 Cluj-Napoca, Romania
| | - Sever Mican
- Department of Condensed Matter Physics and Advanced Technologies, Faculty of Physics, Babeș-Bolyai University of Cluj-Napoca, 400084 Cluj-Napoca, Romania
| | - Angela-Georgiana CimpoesȖu
- Department of Condensed Matter Physics and Advanced Technologies, Faculty of Physics, Babeș-Bolyai University of Cluj-Napoca, 400084 Cluj-Napoca, Romania
| | - Marius Joldos
- Computer Science Department, Faculty of Automation and Computer Science, Technical University of Cluj-Napoca, 400027 Cluj-Napoca, Romania
| | - Romulus Tetean
- Department of Condensed Matter Physics and Advanced Technologies, Faculty of Physics, Babeș-Bolyai University of Cluj-Napoca, 400084 Cluj-Napoca, Romania
| | - Coriolan Viorel Tiușan
- Department of Condensed Matter Physics and Advanced Technologies, Faculty of Physics, Babeș-Bolyai University of Cluj-Napoca, 400084 Cluj-Napoca, Romania
- National Center of Scientific Research, 54500 Vandoeuvre-lès-Nancy, France
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29
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Aldarawsheh A, Fernandes IL, Brinker S, Sallermann M, Abusaa M, Blügel S, Lounis S. Emergence of zero-field non-synthetic single and interchained antiferromagnetic skyrmions in thin films. Nat Commun 2022; 13:7369. [DOI: 10.1038/s41467-022-35102-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Accepted: 11/15/2022] [Indexed: 12/02/2022] Open
Abstract
AbstractAntiferromagnetic (AFM) skyrmions are envisioned as ideal localized topological magnetic bits in future information technologies. In contrast to ferromagnetic (FM) skyrmions, they are immune to the skyrmion Hall effect, might offer potential terahertz dynamics while being insensitive to external magnetic fields and dipolar interactions. Although observed in synthetic AFM structures and as complex meronic textures in intrinsic AFM bulk materials, their realization in non-synthetic AFM films, of crucial importance in racetrack concepts, has been elusive. Here, we unveil their presence in a row-wise AFM Cr film deposited on PdFe bilayer grown on fcc Ir(111) surface. Using first principles, we demonstrate the emergence of single and strikingly interpenetrating chains of AFM skyrmions, which can co-exist with the rich inhomogeneous exchange field, including that of FM skyrmions, hosted by PdFe. Besides the identification of an ideal platform of materials for intrinsic AFM skyrmions, we anticipate the uncovered knotted solitons to be promising building blocks in AFM spintronics.
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30
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Dou K, Du W, He Z, Dai Y, Huang B, Ma Y. Theoretical Prediction of Antiferromagnetic Skyrmion Crystal in Janus Monolayer CrSi 2N 2As 2. ACS NANO 2022; 17:1144-1152. [PMID: 36448916 DOI: 10.1021/acsnano.2c08544] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
An antiferromagnetic skyrmion crystal (AF-SkX), a regular array of antiferromagnetic skyrmions, is a fundamental phenomenon in the field of condensed-matter physics. So far, very few proposals have been made to realize the AF-SkX, and most have been based on three-dimensional (3D) materials. Herein, using first-principles calculations and Monte Carlo simulations, we report the identification of AF-SkX in a two-dimensional lattice of the Janus monolayer CrSi2N2As2. Arising from the broken inversion symmetry and strong spin-orbit coupling, a large Dzyaloshinskii-Moriya interaction is obtained in the Janus monolayer CrSi2N2As2. This, combined with the geometric frustration of its triangular lattice, gives rise to the skyrmion physics and long-sought AF-SkX in the presence of an external magnetic field. More intriguingly, this system presents two different antiferromagnetic skyrmion phases, and such a phenomenon is distinct from those reported in 3D systems. Furthermore, by contacting with Sc2CO2, the creation and annihilation of AF-SkX in Janus monolayer CrSi2N2As2 can be achieved through ferroelectricity. These findings greatly enrich the research on antiferromagnetic skyrmions.
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Affiliation(s)
- Kaiying Dou
- School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Shandanan Str. 27, Jinan250100, People's Republic of China
| | - Wenhui Du
- School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Shandanan Str. 27, Jinan250100, People's Republic of China
| | - Zhonglin He
- School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Shandanan Str. 27, Jinan250100, People's Republic of China
| | - Ying Dai
- School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Shandanan Str. 27, Jinan250100, People's Republic of China
| | - Baibiao Huang
- School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Shandanan Str. 27, Jinan250100, People's Republic of China
| | - Yandong Ma
- School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Shandanan Str. 27, Jinan250100, People's Republic of China
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31
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Hassan M, Laureti S, Rinaldi C, Fagiani F, Barucca G, Casoli F, Mezzi A, Bolli E, Kaciulis S, Fix M, Ullrich A, Albrecht M, Varvaro G. Thin-Film Heterostructures Based on Co/Ni Synthetic Antiferromagnets on Polymer Tapes: Toward Sustainable Flexible Spintronics. ACS APPLIED MATERIALS & INTERFACES 2022; 14:51496-51509. [PMID: 36318544 DOI: 10.1021/acsami.2c14000] [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
Synthetic antiferromagnets with perpendicular magnetic anisotropy (PMA-SAFs) have gained growing attention for both conventional and next-generation spin-based technologies. While the progress of PMA-SAF spintronic devices on rigid substrates has been remarkable, only few examples of flexible thin-film heterostructures are reported in the literature, all containing platinum group metals (PGMs). Systems based on Co/Ni may offer additional advantages with respect to devices containing PGMs, i.e., low damping and high spin polarization. Moreover, limiting the use of PGMs may relieve the demand for critical raw materials and reduce the environmental impact of related technologies, thus contributing to the transition toward a more sustainable future. Here, we discuss for the first time the realization of Co/Ni-based PMA-SAFs on polymer tapes and exploit it to obtain flexible giant magneto-resistive spin valves (GMR-SVs) with perpendicular magnetic anisotropy. Several combinations of buffer and capping layers (i.e., Pt, Pd, and Cu/Ta) are also investigated. High-quality flexible SAFs with a fully compensated antiferromagnetic region and SVs with a sizable GMR ratio (up to 4.4%), in line with the values reported in the literature for similar systems on rigid substrates, were obtained in all cases. However, we demonstrate that PGMs allows achieving the best results when used as a buffer layer, while Cu is the best choice as a capping layer to optimize the properties of the stacks. We justify the role of buffer and capping layers in terms of different interdiffusion mechanisms occurring at the interface between the metallic layers. These results, along with the high robustness of the samples' properties against bending (up to 180°), indicate that complex and bendable Co/Ni-based heterostructures with reduced content of PGMs can be obtained on flexible tapes, allowing for the development of novel flexible and sustainable spintronic devices for applications in many fields including wearable electronics, soft robotics, and biomedicine.
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Affiliation(s)
- Mariam Hassan
- ISM-CNR, nM2-Lab, Area della Ricerca Roma 1, Monterotondo Scalo (Roma)00015, Italy
- Institute of Physics, University of Augsburg, Universitätsstraße 1 Nord, D-86159Augsburg, Germany
| | - Sara Laureti
- ISM-CNR, nM2-Lab, Area della Ricerca Roma 1, Monterotondo Scalo (Roma)00015, Italy
| | - Christian Rinaldi
- Department of Physics, Politecnico di Milano, via G. Colombo 81, Milano20133, Italy
| | - Federico Fagiani
- Department of Physics, Politecnico di Milano, via G. Colombo 81, Milano20133, Italy
| | - Gianni Barucca
- Department SIMAU, University Politecnica delle Marche, via Brecce Bianche, Ancona60131, Italy
| | | | - Alessio Mezzi
- ISMN-CNR, Area della Ricerca Roma 1, Monterotondo Scalo (Roma)00015, Italy
| | - Eleonora Bolli
- ISMN-CNR, Area della Ricerca Roma 1, Monterotondo Scalo (Roma)00015, Italy
| | - Saulius Kaciulis
- ISMN-CNR, Area della Ricerca Roma 1, Monterotondo Scalo (Roma)00015, Italy
| | - Mario Fix
- Institute of Physics, University of Augsburg, Universitätsstraße 1 Nord, D-86159Augsburg, Germany
| | - Aladin Ullrich
- Institute of Physics, University of Augsburg, Universitätsstraße 1 Nord, D-86159Augsburg, Germany
| | - Manfred Albrecht
- Institute of Physics, University of Augsburg, Universitätsstraße 1 Nord, D-86159Augsburg, Germany
| | - Gaspare Varvaro
- ISM-CNR, nM2-Lab, Area della Ricerca Roma 1, Monterotondo Scalo (Roma)00015, Italy
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32
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Bellizotti Souza JC, Vizarim NP, Reichhardt CJO, Reichhardt C, Venegas PA. Magnus induced diode effect for skyrmions in channels with periodic potentials. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2022; 51:015804. [PMID: 36272354 DOI: 10.1088/1361-648x/ac9cc5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2022] [Accepted: 10/21/2022] [Indexed: 06/16/2023]
Abstract
Using a particle based model, we investigate the skyrmion dynamical behavior in a channel where the upper wall contains divots of one depth and the lower wall contains divots of a different depth. Under an applied driving force, skyrmions in the channels move with a finite skyrmion Hall angle that deflects them toward the upper wall for -xdirection driving and the lower wall for +xdirection driving. When the upper divots have zero height, the skyrmions are deflected against the flat upper wall for -xdirection driving and the skyrmion velocity depends linearly on the drive. For +xdirection driving, the skyrmions are pushed against the lower divots and become trapped, giving reduced velocities and a nonlinear velocity-force response. When there are shallow divots on the upper wall and deep divots on the lower wall, skyrmions get trapped for both driving directions; however, due to the divot depth difference, skyrmions move more easily under -xdirection driving, and become strongly trapped for +xdirection driving. The preferred -xdirection motion produces what we call a Magnus diode effect since it vanishes in the limit of zero Magnus force, unlike the diode effects observed for asymmetric sawtooth potentials. We show that the transport curves can exhibit a series of jumps or dips, negative differential conductivity, and reentrant pinning due to collective trapping events. We also discuss how our results relate to recent continuum modeling on a similar skyrmion diode system.
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Affiliation(s)
- J C Bellizotti Souza
- Departamento de Física, Faculdade de Ciências, Unesp-Universidade Estadual Paulista, CP 473, 17033-360 Bauru, SP, Brazil
| | - N P Vizarim
- POSMAT-Programa de Pós-Graduação em Ciência e Tecnologia de Materiais, Faculdade de Ciências, Universidade Estadual Paulista-UNESP, CP 473, 17033-360 Bauru, SP, Brazil
- Department of Physics, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp, Belgium
| | - C J O Reichhardt
- Theoretical Division and Center for Nonlinear Studies, Los Alamos National Laboratory, Los Alamos, NM 87545, United States of America
| | - C Reichhardt
- Theoretical Division and Center for Nonlinear Studies, Los Alamos National Laboratory, Los Alamos, NM 87545, United States of America
| | - P A Venegas
- Departamento de Física, Faculdade de Ciências, Unesp-Universidade Estadual Paulista, CP 473, 17033-360 Bauru, SP, Brazil
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33
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Li D, Haldar S, Heinze S. Strain-Driven Zero-Field Near-10 nm Skyrmions in Two-Dimensional van der Waals Heterostructures. NANO LETTERS 2022; 22:7706-7713. [PMID: 36121771 DOI: 10.1021/acs.nanolett.2c03287] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Magnetic skyrmions─localized chiral spin structures─show great promise for spintronic applications. The recent discovery of two-dimensional (2D) magnets opened new opportunities for topological spin structures in atomically thin van der Waals (vdW) materials. Despite recent progress in stabilizing metastable skyrmions in 2D magnets, their lifetime, essential for applications, has not been explored yet. Here, using first-principles calculations and atomistic spin simulations, we predict that compressive strain leads to stabilizing zero-field skyrmions with diameters close to 10 nm in a Fe3GeTe2/germanene vdW heterostructure. The origin of these unique skyrmions is attributed to the high tunability of Dzyaloshinskii-Moriya interaction and magnetocrystalline anisotropy energy by strain, which generally holds for Fe3GeTe2 heterostructures with buckled substrates. Furthermore, we calculate the energy barriers protecting skyrmions against annihilation and their lifetimes using transition-state theory. We show that nanoscale skyrmions in strained Fe3GeTe2/germanene can be stable for hours at temperatures up to 20 K.
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Affiliation(s)
- Dongzhe Li
- CEMES, Université de Toulouse, CNRS, 29 rue Jeanne Marvig, F-31055 Toulouse, France
| | - Soumyajyoti Haldar
- Institute of Theoretical Physics and Astrophysics, University of Kiel, Leibnizstrasse 15, 24098 Kiel, Germany
| | - Stefan Heinze
- Institute of Theoretical Physics and Astrophysics, University of Kiel, Leibnizstrasse 15, 24098 Kiel, Germany
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34
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Miller JS. Artificial Antiferromagnets Possessing Extended Zero‐, One‐, Two‐, and Three‐Dimensional Structures. Chemistry 2022; 28:e202201342. [DOI: 10.1002/chem.202201342] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2022] [Indexed: 11/10/2022]
Affiliation(s)
- Joel S. Miller
- Department of Chemistry University of Utah 84112-0850 Salt Lake City UT USA
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35
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Juge R, Sisodia N, Larrañaga JU, Zhang Q, Pham VT, Rana KG, Sarpi B, Mille N, Stanescu S, Belkhou R, Mawass MA, Novakovic-Marinkovic N, Kronast F, Weigand M, Gräfe J, Wintz S, Finizio S, Raabe J, Aballe L, Foerster M, Belmeguenai M, Buda-Prejbeanu LD, Pelloux-Prayer J, Shaw JM, Nembach HT, Ranno L, Gaudin G, Boulle O. Skyrmions in synthetic antiferromagnets and their nucleation via electrical current and ultra-fast laser illumination. Nat Commun 2022; 13:4807. [PMID: 35974009 PMCID: PMC9381802 DOI: 10.1038/s41467-022-32525-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Accepted: 08/03/2022] [Indexed: 11/09/2022] Open
Abstract
Magnetic skyrmions are topological spin textures that hold great promise as nanoscale information carriers in non-volatile memory and logic devices. While room-temperature magnetic skyrmions and their current-induced motion were recently demonstrated, the stray field resulting from their finite magnetisation and their topological charge limit their minimum size and reliable motion. Antiferromagnetic skyrmions allow to lift these limitations owing to their vanishing magnetisation and net zero topological charge, promising ultra-small and ultra-fast skyrmions. Here, we report on the observation of isolated skyrmions in compensated synthetic antiferromagnets at zero field and room temperature using X-ray magnetic microscopy. Micromagnetic simulations and an analytical model confirm the chiral antiferromagnetic nature of these skyrmions and allow the identification of the physical mechanisms controlling their size and stability. Finally, we demonstrate the nucleation of synthetic antiferromagnetic skyrmions via local current injection and ultra-fast laser excitation.
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Affiliation(s)
- Roméo Juge
- Univ. Grenoble Alpes, CNRS, CEA, SPINTEC, 38000, Grenoble, France
| | - Naveen Sisodia
- Univ. Grenoble Alpes, CNRS, CEA, SPINTEC, 38000, Grenoble, France
| | | | - Qiang Zhang
- Univ. Grenoble Alpes, CNRS, CEA, SPINTEC, 38000, Grenoble, France
| | - Van Tuong Pham
- Univ. Grenoble Alpes, CNRS, CEA, SPINTEC, 38000, Grenoble, France
| | | | - Brice Sarpi
- Synchrotron SOLEIL, L'Orme des Merisiers, 91190, Saint-Aubin, France
| | - Nicolas Mille
- Synchrotron SOLEIL, L'Orme des Merisiers, 91190, Saint-Aubin, France
| | - Stefan Stanescu
- Synchrotron SOLEIL, L'Orme des Merisiers, 91190, Saint-Aubin, France
| | - Rachid Belkhou
- Synchrotron SOLEIL, L'Orme des Merisiers, 91190, Saint-Aubin, France
| | - Mohamad-Assaad Mawass
- Helmholtz-Zentrum Berlin für Materialien und Energie, Albert-Einstein-Straße 15, 12489, Berlin, Germany
| | - Nina Novakovic-Marinkovic
- Helmholtz-Zentrum Berlin für Materialien und Energie, Albert-Einstein-Straße 15, 12489, Berlin, Germany
| | - Florian Kronast
- Helmholtz-Zentrum Berlin für Materialien und Energie, Albert-Einstein-Straße 15, 12489, Berlin, Germany
| | - Markus Weigand
- Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Hahn-Meitner-Platz 1, D-14109, Berlin, Germany
| | - Joachim Gräfe
- Max Planck Institute for Intelligent Systems, Heisenbergstraße 3, 70569, Stuttgart, Germany
| | - Sebastian Wintz
- Max Planck Institute for Intelligent Systems, Heisenbergstraße 3, 70569, Stuttgart, Germany
| | - Simone Finizio
- Swiss Light Source, Paul Scherrer Institut, 5232, Villigen, Switzerland
| | - Jörg Raabe
- Swiss Light Source, Paul Scherrer Institut, 5232, Villigen, Switzerland
| | - Lucia Aballe
- ALBA Synchrotron Light Facility, 08290, Cerdanyola del Vallès, Barcelona, Spain
| | - Michael Foerster
- ALBA Synchrotron Light Facility, 08290, Cerdanyola del Vallès, Barcelona, Spain
| | - Mohamed Belmeguenai
- Laboratoire des Sciences des Procedés et des Matériaux, CNRS, Univ. Paris 13, 93430, Villetaneuse, France
| | | | | | - Justin M Shaw
- Quantum Electromagnetics Division, National Institute of Standards and Technology, Boulder, CO, 80309, USA
| | - Hans T Nembach
- Quantum Electromagnetics Division, National Institute of Standards and Technology, Boulder, CO, 80309, USA.,Department of Physics, University of Colorado, Boulder, CO, 80309, USA
| | - Laurent Ranno
- Univ. Grenoble Alpes, CNRS, Institut Néel, 38042, Grenoble, France
| | - Gilles Gaudin
- Univ. Grenoble Alpes, CNRS, CEA, SPINTEC, 38000, Grenoble, France
| | - Olivier Boulle
- Univ. Grenoble Alpes, CNRS, CEA, SPINTEC, 38000, Grenoble, France.
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36
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Yıldırım O, Tomasello R, Feng Y, Carlotti G, Tacchi S, Vaghefi PM, Giordano A, Dutta T, Finocchio G, Hug HJ, Mandru AO. Tuning the Coexistence Regime of Incomplete and Tubular Skyrmions in Ferromagnetic/Ferrimagnetic/Ferromagnetic Trilayers. ACS APPLIED MATERIALS & INTERFACES 2022; 14:34002-34010. [PMID: 35830277 DOI: 10.1021/acsami.2c06608] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
The development of skyrmionic devices requires a suitable tuning of material parameters to stabilize skyrmions and control their density. It has been demonstrated recently that different skyrmion types can be simultaneously stabilized at room temperature in heterostructures involving ferromagnets, ferrimagnets, and heavy metals, offering a new platform of coding binary information in the type of skyrmion instead of the presence/absence of skyrmions. Here, we tune the energy landscape of the two skyrmion types in such heterostructures by engineering the geometrical and material parameters of the individual layers. We find that a fine adjustment of the ferromagnetic layer thickness, and thus its magnetic anisotropy, allows the trilayer system to support either one of the skyrmion types or the coexistence of both and with varying densities.
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Affiliation(s)
- Oğuz Yıldırım
- Empa, Swiss Federal Laboratories for Materials Science and Technology, CH-8600 Dübendorf, Switzerland
| | - Riccardo Tomasello
- Department of Electrical and Information Engineering, Politecnico di Bari, 70125 Bari, Italy
| | - Yaoxuan Feng
- Empa, Swiss Federal Laboratories for Materials Science and Technology, CH-8600 Dübendorf, Switzerland
| | - Giovanni Carlotti
- Dipartimento di Fisica e Geologia, Università di Perugia, 06123 Perugia, Italy
| | - Silvia Tacchi
- Istituto Officina dei Materiali del CNR (CNR-IOM), Sede Secondaria di Perugia, c/o Dipartimento di Fisica e Geologia, Università di Perugia, 06123 Perugia, Italy
| | - Pegah Mirzadeh Vaghefi
- Empa, Swiss Federal Laboratories for Materials Science and Technology, CH-8600 Dübendorf, Switzerland
| | - Anna Giordano
- Department of Mathematical and Computer Sciences, Physical Sciences and Earth Sciences, University of Messina, I-98166 Messina, Italy
| | - Tanmay Dutta
- Empa, Swiss Federal Laboratories for Materials Science and Technology, CH-8600 Dübendorf, Switzerland
| | - Giovanni Finocchio
- Department of Mathematical and Computer Sciences, Physical Sciences and Earth Sciences, University of Messina, I-98166 Messina, Italy
| | - Hans J Hug
- Empa, Swiss Federal Laboratories for Materials Science and Technology, CH-8600 Dübendorf, Switzerland
- Department of Physics, University of Basel, CH-4056 Basel, Switzerland
| | - Andrada-Oana Mandru
- Empa, Swiss Federal Laboratories for Materials Science and Technology, CH-8600 Dübendorf, Switzerland
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37
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Liu L, Chen W, Zheng Y. Flexoresponses of Synthetic Antiferromagnetic Systems Hosting Skyrmions. PHYSICAL REVIEW LETTERS 2022; 128:257201. [PMID: 35802441 DOI: 10.1103/physrevlett.128.257201] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2022] [Accepted: 06/02/2022] [Indexed: 06/15/2023]
Abstract
While strain gradients break lattice centrosymmetry, ferromagnetism is a time-reversal symmetry breaking product. Flexomagnetic effect in ferromagnets is usually indirect and weak. In this Letter, we reveal a topologically enhanced flexomagnetic effect in synthetic antiferromagnetic systems based on Dzyaloshinskii-Moriya interaction and the large deformability of skyrmion. Moreover, the synthetic antiferromagnetic skyrmion exhibits an unexpected Hall effect under strain gradient. We propose that this flexo-Hall effect originates from a geometric Magnus force related to the asymmetric deformation of skyrmion. Our results shed new insights into the flexoresponses in systems hosting topological structures and may open up a new field-"flexoskyrmionics".
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Affiliation(s)
- Linjie Liu
- Guangdong Provincial Key Laboratory of Magnetoelectric Physics and Devices, School of Physics, Sun Yat-sen University, Guangzhou 510275, China
- State Key Laboratory of Optoelectronic Materials and Technologies, School of Physics, Sun Yat-sen University, 510275 Guangzhou, China
- Centre for Physical Mechanics and Biophysics, School of Physics, Sun Yat-sen University, 510275 Guangzhou, China
| | - Weijin Chen
- Guangdong Provincial Key Laboratory of Magnetoelectric Physics and Devices, School of Physics, Sun Yat-sen University, Guangzhou 510275, China
- State Key Laboratory of Optoelectronic Materials and Technologies, School of Physics, Sun Yat-sen University, 510275 Guangzhou, China
- Centre for Physical Mechanics and Biophysics, School of Physics, Sun Yat-sen University, 510275 Guangzhou, China
- School of Materials, Sun Yat-sen University, 518107 Shenzhen, China
| | - Yue Zheng
- Guangdong Provincial Key Laboratory of Magnetoelectric Physics and Devices, School of Physics, Sun Yat-sen University, Guangzhou 510275, China
- State Key Laboratory of Optoelectronic Materials and Technologies, School of Physics, Sun Yat-sen University, 510275 Guangzhou, China
- Centre for Physical Mechanics and Biophysics, School of Physics, Sun Yat-sen University, 510275 Guangzhou, China
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38
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Abstract
A key issue for skyrmion dynamics and devices are pinning effects present in real systems. While posing a challenge for the realization of conventional skyrmionics devices, exploiting pinning effects can enable non-conventional computing approaches if the details of the pinning in real samples are quantified and understood. We demonstrate that using thermal skyrmion dynamics, we can characterize the pinning of a sample and we ascertain the spatially resolved energy landscape. To understand the mechanism of the pinning, we probe the strong skyrmion size and shape dependence of the pinning. Magnetic microscopy imaging demonstrates that in contrast to findings in previous investigations, for large skyrmions the pinning originates at the skyrmion boundary and not at its core. The boundary pinning is strongly influenced by the very complex pinning energy landscape that goes beyond the conventional effective rigid quasi-particle description. This gives rise to complex skyrmion shape distortions and allows for dynamic switching of pinning sites and flexible tuning of the pinning. Skyrmions, topological spin textures, can be pinned by defects present in the material that hosts them, influencing their motion. Here, Gruber et al show that the skyrmions are pinned at their boundary where the finite size of the skyrmions governs their pinning, and they demonstrate that certain pinning sites can switched on and off in-situ.
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39
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Wang QH, Bedoya-Pinto A, Blei M, Dismukes AH, Hamo A, Jenkins S, Koperski M, Liu Y, Sun QC, Telford EJ, Kim HH, Augustin M, Vool U, Yin JX, Li LH, Falin A, Dean CR, Casanova F, Evans RFL, Chshiev M, Mishchenko A, Petrovic C, He R, Zhao L, Tsen AW, Gerardot BD, Brotons-Gisbert M, Guguchia Z, Roy X, Tongay S, Wang Z, Hasan MZ, Wrachtrup J, Yacoby A, Fert A, Parkin S, Novoselov KS, Dai P, Balicas L, Santos EJG. The Magnetic Genome of Two-Dimensional van der Waals Materials. ACS NANO 2022; 16:6960-7079. [PMID: 35442017 PMCID: PMC9134533 DOI: 10.1021/acsnano.1c09150] [Citation(s) in RCA: 54] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Accepted: 02/23/2022] [Indexed: 05/23/2023]
Abstract
Magnetism in two-dimensional (2D) van der Waals (vdW) materials has recently emerged as one of the most promising areas in condensed matter research, with many exciting emerging properties and significant potential for applications ranging from topological magnonics to low-power spintronics, quantum computing, and optical communications. In the brief time after their discovery, 2D magnets have blossomed into a rich area for investigation, where fundamental concepts in magnetism are challenged by the behavior of spins that can develop at the single layer limit. However, much effort is still needed in multiple fronts before 2D magnets can be routinely used for practical implementations. In this comprehensive review, prominent authors with expertise in complementary fields of 2D magnetism (i.e., synthesis, device engineering, magneto-optics, imaging, transport, mechanics, spin excitations, and theory and simulations) have joined together to provide a genome of current knowledge and a guideline for future developments in 2D magnetic materials research.
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Affiliation(s)
- Qing Hua Wang
- Materials
Science and Engineering, School for Engineering of Matter, Transport
and Energy, Arizona State University, Tempe, Arizona 85287, United States
| | - Amilcar Bedoya-Pinto
- NISE
Department, Max Planck Institute of Microstructure
Physics, 06120 Halle, Germany
- Instituto
de Ciencia Molecular (ICMol), Universitat
de València, 46980 Paterna, Spain
| | - Mark Blei
- Materials
Science and Engineering, School for Engineering of Matter, Transport
and Energy, Arizona State University, Tempe, Arizona 85287, United States
| | - Avalon H. Dismukes
- Department
of Chemistry, Columbia University, New York, New York 10027, United States
| | - Assaf Hamo
- Department
of Physics, Harvard University, Cambridge, Massachusetts 02138, United States
| | - Sarah Jenkins
- Twist
Group,
Faculty of Physics, University of Duisburg-Essen, Campus Duisburg, 47057 Duisburg, Germany
| | - Maciej Koperski
- Institute
for Functional Intelligent Materials, National
University of Singapore, 117544 Singapore
| | - Yu Liu
- Condensed
Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, New York 11973, United States
| | - Qi-Chao Sun
- Physikalisches
Institut, University of Stuttgart, 70569 Stuttgart, Germany
| | - Evan J. Telford
- Department
of Chemistry, Columbia University, New York, New York 10027, United States
- Department
of Physics, Columbia University, New York, New York 10027, United States
| | - Hyun Ho Kim
- School
of Materials Science and Engineering, Department of Energy Engineering
Convergence, Kumoh National Institute of
Technology, Gumi 39177, Korea
| | - Mathias Augustin
- Institute
for Condensed Matter Physics and Complex Systems, School of Physics
and Astronomy, The University of Edinburgh, Edinburgh, EH9 3FD, United Kingdom
- Donostia
International Physics Center (DIPC), 20018 Donostia-San Sebastián, Basque Country, Spain
| | - Uri Vool
- Department
of Physics, Harvard University, Cambridge, Massachusetts 02138, United States
- John Harvard
Distinguished Science Fellows Program, Harvard
University, Cambridge, Massachusetts 02138, United States
| | - Jia-Xin Yin
- Laboratory
for Topological Quantum Matter and Spectroscopy, Department of Physics, Princeton University, Princeton, New Jersey 08544, United States
| | - Lu Hua Li
- Institute
for Frontier Materials, Deakin University, Geelong Waurn Ponds Campus, Waurn Ponds, Victoria 3216, Australia
| | - Alexey Falin
- Institute
for Frontier Materials, Deakin University, Geelong Waurn Ponds Campus, Waurn Ponds, Victoria 3216, Australia
| | - Cory R. Dean
- Department
of Physics, Columbia University, New York, New York 10027, United States
| | - Fèlix Casanova
- CIC nanoGUNE
BRTA, 20018 Donostia - San Sebastián, Basque
Country, Spain
- IKERBASQUE,
Basque Foundation for Science, 48013 Bilbao, Basque Country, Spain
| | - Richard F. L. Evans
- Department
of Physics, University of York, Heslington, York YO10 5DD, United Kingdom
| | - Mairbek Chshiev
- Université
Grenoble Alpes, CEA, CNRS, Spintec, 38000 Grenoble, France
- Institut
Universitaire de France, 75231 Paris, France
| | - Artem Mishchenko
- Department
of Physics and Astronomy, University of
Manchester, Manchester, M13 9PL, United Kingdom
- National
Graphene Institute, University of Manchester, Manchester, M13 9PL, United Kingdom
| | - Cedomir Petrovic
- Condensed
Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, New York 11973, United States
| | - Rui He
- Department
of Electrical and Computer Engineering, Texas Tech University, 910 Boston Avenue, Lubbock, Texas 79409, United
States
| | - Liuyan Zhao
- Department
of Physics, University of Michigan, 450 Church Street, Ann Arbor, Michigan 48109, United States
| | - Adam W. Tsen
- Institute
for Quantum Computing and Department of Chemistry, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
| | - Brian D. Gerardot
- SUPA, Institute
of Photonics and Quantum Sciences, Heriot-Watt
University, Edinburgh EH14 4AS, United Kingdom
| | - Mauro Brotons-Gisbert
- SUPA, Institute
of Photonics and Quantum Sciences, Heriot-Watt
University, Edinburgh EH14 4AS, United Kingdom
| | - Zurab Guguchia
- Laboratory
for Muon Spin Spectroscopy, Paul Scherrer
Institute, CH-5232 Villigen PSI, Switzerland
| | - Xavier Roy
- Department
of Chemistry, Columbia University, New York, New York 10027, United States
| | - Sefaattin Tongay
- Materials
Science and Engineering, School for Engineering of Matter, Transport
and Energy, Arizona State University, Tempe, Arizona 85287, United States
| | - Ziwei Wang
- Department
of Physics and Astronomy, University of
Manchester, Manchester, M13 9PL, United Kingdom
- National
Graphene Institute, University of Manchester, Manchester, M13 9PL, United Kingdom
| | - M. Zahid Hasan
- Materials
Sciences Division, Lawrence Berkeley National
Laboratory, Berkeley, California 94720, United States
- Princeton
Institute for Science and Technology of Materials, Princeton University, Princeton, New Jersey 08544, United States
- National
High Magnetic Field Laboratory, Florida
State University, Tallahassee, Florida 32310, United States
| | - Joerg Wrachtrup
- Physikalisches
Institut, University of Stuttgart, 70569 Stuttgart, Germany
- Max Planck
Institute for Solid State Research, 70569 Stuttgart, Germany
| | - Amir Yacoby
- Department
of Physics, Harvard University, Cambridge, Massachusetts 02138, United States
- John A.
Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, United States
| | - Albert Fert
- Donostia
International Physics Center (DIPC), 20018 Donostia-San Sebastián, Basque Country, Spain
- Unité
Mixte de Physique, CNRS, Thales, Université Paris-Saclay, 91767 Palaiseau, France
- Department
of Materials Physics UPV/EHU, 20018 Donostia - San Sebastián, Basque Country, Spain
| | - Stuart Parkin
- NISE
Department, Max Planck Institute of Microstructure
Physics, 06120 Halle, Germany
| | - Kostya S. Novoselov
- Institute
for Functional Intelligent Materials, National
University of Singapore, 117544 Singapore
| | - Pengcheng Dai
- Department
of Physics and Astronomy, Rice University, Houston, Texas 77005, United States
| | - Luis Balicas
- National
High Magnetic Field Laboratory, Florida
State University, Tallahassee, Florida 32310, United States
- Department
of Physics, Florida State University, Tallahassee, Florida 32306, United States
| | - Elton J. G. Santos
- Institute
for Condensed Matter Physics and Complex Systems, School of Physics
and Astronomy, The University of Edinburgh, Edinburgh, EH9 3FD, United Kingdom
- Donostia
International Physics Center (DIPC), 20018 Donostia-San Sebastián, Basque Country, Spain
- Higgs Centre
for Theoretical Physics, The University
of Edinburgh, Edinburgh EH9 3FD, United Kingdom
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40
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Cui Q, Zhu Y, Ga Y, Liang J, Li P, Yu D, Cui P, Yang H. Anisotropic Dzyaloshinskii-Moriya Interaction and Topological Magnetism in Two-Dimensional Magnets Protected by P4̅ m2 Crystal Symmetry. NANO LETTERS 2022; 22:2334-2341. [PMID: 35266723 DOI: 10.1021/acs.nanolett.1c04803] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
As a fundamental magnetic parameter, Dzyaloshinskii-Moriya interaction (DMI), has gained a great deal of attention in the last two decades due to its critical role in formation of magnetic skyrmions. Recent discoveries of two-dimensional (2D) van der Waals (vdW) magnets has also gained a great deal of attention due to appealing physical properties, such as gate tunability, flexibility, and miniaturization. Intensive studies have shown that isotropic DMI stabilizes ferromagnetic (FM) topological spin textures in 2D magnets or their corresponding heterostructures. However, the investigation of anisotropic DMI and antiferromagnetic (AFM) topological spin configurations remains elusive. Here, we propose and demonstrate a family of 2D magnets with P4m2 symmetry-protected anisotropic DMI. More interestingly, various topological spin configurations, including FM/AFM antiskyrmion and AFM vortex-antivortex pair, emerge in this family. These results give a general method to design anisotropic DMI and pave the way toward topological magnetism in 2D materials using crystal symmetry.
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Affiliation(s)
- Qirui Cui
- Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201, China
- Faculty of Science and Engineering, University of Nottingham Ningbo China, Ningbo 315100, China
| | - Yingmei Zhu
- Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201, China
| | - Yonglong Ga
- Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201, China
| | - Jinghua Liang
- Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201, China
| | - Peng Li
- Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201, China
| | - Dongxing Yu
- Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201, China
| | - Ping Cui
- Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201, China
- Faculty of Science and Engineering, University of Nottingham Ningbo China, Ningbo 315100, China
| | - Hongxin Yang
- Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201, China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
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41
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De A, Arekapudi SSPK, Koch L, Samad F, Panda SN, Böhm B, Hellwig O, Barman A. Magnetic Configuration Driven Femtosecond Spin Dynamics in Synthetic Antiferromagnets. ACS APPLIED MATERIALS & INTERFACES 2022; 14:13970-13979. [PMID: 35275629 DOI: 10.1021/acsami.2c01555] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Ultrafast demagnetization in diverse materials has sparked immense research activities due to its captivating richness and contested underlying mechanisms. Among these, the two most celebrated mechanisms have been the spin-flip scattering (SFS) and spin transport (ST) of optically excited carriers. In this work, we have investigated femtosecond laser-induced ultrafast demagnetization in perpendicular magnetic anisotropy-based synthetic antiferromagnets (p-SAFs) where [Co/Pt]n-1/Co multilayer blocks are separated by Ru or Ir spacers. Our investigation conclusively shows that the ST of optically excited carriers can have a significant contribution to the ultrafast demagnetization in addition to SFS processes. Moreover, we have also achieved an active control over the individual mechanisms by specially designing the SAF samples and altering the external magnetic field and excitation fluence. Our study provides a vital understanding of the underlying mechanism of ultrafast demagnetization in synthetic antiferromagnets, which will be crucial in future research and applications of antiferromagnetic spintronics.
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Affiliation(s)
- Anulekha De
- Department of Condensed Matter Physics and Material Sciences, S. N. Bose National Centre for Basic Sciences, Block JD, Sector-III, Salt Lake, Kolkata 700 106, India
| | | | - Leopold Koch
- Institute of Physics, Chemnitz University of Technology, Reichenhainer Straße 70, D-09107 Chemnitz, Germany
- Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, 01328 Dresden, Germany
| | - Fabian Samad
- Institute of Physics, Chemnitz University of Technology, Reichenhainer Straße 70, D-09107 Chemnitz, Germany
- Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, 01328 Dresden, Germany
| | - Surya Narayan Panda
- Department of Condensed Matter Physics and Material Sciences, S. N. Bose National Centre for Basic Sciences, Block JD, Sector-III, Salt Lake, Kolkata 700 106, India
| | - Benny Böhm
- Institute of Physics, Chemnitz University of Technology, Reichenhainer Straße 70, D-09107 Chemnitz, Germany
| | - Olav Hellwig
- Institute of Physics, Chemnitz University of Technology, Reichenhainer Straße 70, D-09107 Chemnitz, Germany
- Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, 01328 Dresden, Germany
| | - Anjan Barman
- Department of Condensed Matter Physics and Material Sciences, S. N. Bose National Centre for Basic Sciences, Block JD, Sector-III, Salt Lake, Kolkata 700 106, India
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42
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Yu Z, Gong B, Xiong L, Du X, Wei C, Xiong R, Lu Z, Zhang Y. Domain wall motion driven by a wide range of current in coupled soft/hard ferromagnetic nanowires. NANOSCALE ADVANCES 2022; 4:1545-1550. [PMID: 36134365 PMCID: PMC9417525 DOI: 10.1039/d1na00540e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/05/2021] [Accepted: 01/15/2022] [Indexed: 06/16/2023]
Abstract
Racetrack memory with the advantages of small size and high reading speed is proposed based on current-induced domain wall (DW) motion in a ferromagnetic (FM) nanowire. Walker breakdown that restricts the enhancement of DW velocity in a single FM nanowire can be depressed by inter-wire magnetostatic coupling in a double FM nanowire system. However, this magnetostatic coupling also limits the working current density in a small range. In the present work, based on micromagnetic calculation, we have found that when there is a moderate difference of magnetic anisotropy constant between two FM nanowires, the critical current density for triggering the DW motion can be reduced while that for breaking the inter-wire coupling can be enhanced significantly to a magnitude of 1013 A m-2, which is far above the working current density in current electronic devices. The manipulation of working current density is relevant to the modification of DW structure and inter-wire magnetostatic coupling due to the difference of the anisotropy constants between the two nanowires and paves a way to develop racetrack memory that can work in a wide range of current.
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Affiliation(s)
- Ziyang Yu
- Hubei Key Laboratory of Optical Information and Pattern Recognition, School of Optical Information and Energy Engineering, Wuhan Institute of Technology Wuhan 430205 P. R. China
| | - Bin Gong
- Hubei Key Laboratory of Optical Information and Pattern Recognition, School of Optical Information and Energy Engineering, Wuhan Institute of Technology Wuhan 430205 P. R. China
| | - Lun Xiong
- Hubei Key Laboratory of Optical Information and Pattern Recognition, School of Optical Information and Energy Engineering, Wuhan Institute of Technology Wuhan 430205 P. R. China
| | - Xinran Du
- Hubei Provincial Key Laboratory of Green Materials for Light Industry, Hubei University of Technology Wuhan 430068 China
| | - Chenhuinan Wei
- Hubei Provincial Key Laboratory of Green Materials for Light Industry, Hubei University of Technology Wuhan 430068 China
| | - Rui Xiong
- Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education, School of Physics and Technology, Wuhan University Wuhan 430072 China
| | - Zhihong Lu
- The State Key Laboratory of Refractories and Metallurgy, School of Materials and Metallurgy, Wuhan University of Science and Technology Wuhan 430081 China
| | - Yue Zhang
- School of Optical and Electronic Information, Huazhong University of Science and Technology Wuhan 430074 China
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43
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Tambovtsev IM, Leonov AO, Lobanov IS, Kiselev AD, Uzdin VM. Topological structures in chiral media: Effects of confined geometry. Phys Rev E 2022; 105:034701. [PMID: 35428094 DOI: 10.1103/physreve.105.034701] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2022] [Accepted: 02/25/2022] [Indexed: 06/14/2023]
Abstract
We theoretically study orientational structures in chiral magnetics and cholesteric liquid crystal (CLC) nanosystems confined in the slab geometry. Our analysis is based on the model that, in addition to the exchange and the Dzyaloshinskii-Moriya interactions, takes into account the bulk and surface anisotropies. In CLC films, these anisotropies describe the energy of interaction with external magnetic/electric field and the anchoring energy assuming that magnetic/electric anisotropy is negative and the boundary conditions are homeotropic. We have computed the phase diagram and found that the ground state of the film is represented by various delocalized structures depending on the bulk and surface anisotropy parameters, κ^{b} and κ^{s}. These include the z helix and the z cone states, the oblique, and the x helicoids. The minimum energy paths connecting the ground state and metastable helicoids and the energy barriers separating these states are evaluated. We have shown that there is a variety of localized topological structures such as the skyrmion tube, the toron, and the bobber that can be embedded in different ground states including the z cone (conical phase) and tilted fingerprint states. We have also found the structure called the leech that can be viewed as an intermediate state between the toron and the skyrmion tube.
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Affiliation(s)
- I M Tambovtsev
- Department of Physics, St. Petersburg State University, St. Petersburg 198504, Russia and Faculty of Physics, ITMO University, 197101 St. Petersburg, Russia
| | - A O Leonov
- Department of Chemistry, Faculty of Science, Hiroshima University Kagamiyama, Higashi Hiroshima, Hiroshima 739-8526, Japan and IFW Dresden, Postfach 270016, D-01171 Dresden, Germany
| | - I S Lobanov
- Faculty of Physics, ITMO University, 197101 St. Petersburg, Russia
| | - Alexei D Kiselev
- Laboratory of Quantum Processes and Measurements, ITMO University, 199034 St. Petersburg, Russia
| | - V M Uzdin
- Faculty of Physics, ITMO University, 197101 St. Petersburg, Russia and Department of Physics, St. Petersburg State University, St. Petersburg 198504, Russia
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44
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Chen X, Lin M, Kong JF, Tan HR, Tan AK, Je S, Tan HK, Khoo KH, Im M, Soumyanarayanan A. Unveiling the Emergent Traits of Chiral Spin Textures in Magnetic Multilayers. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2022; 9:e2103978. [PMID: 34978165 PMCID: PMC8867163 DOI: 10.1002/advs.202103978] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Indexed: 05/16/2023]
Abstract
Magnetic skyrmions are topologically wound nanoscale textures of spins whose ambient stability and electrical manipulation in multilayer films have led to an explosion of research activities. While past efforts focused predominantly on isolated skyrmions, recently ensembles of chiral spin textures, consisting of skyrmions and magnetic stripes, are shown to possess rich interactions with potential for device applications. However, several fundamental aspects of chiral spin texture phenomenology remain to be elucidated, including their domain wall (DW) structure, thermodynamic stability, and morphological transitions. Here the evolution of these textural characteristics are unveiled on a tunable multilayer platform-wherein chiral interactions governing spin texture energetics can be widely varied-using a combination of full-field electron and soft X-ray microscopies with numerical simulations. With increasing chiral interactions, the emergence of Néel helicity, followed by a marked reduction in domain compressibility, and finally a transformation in the skyrmion formation mechanism are demonstrated. Together with an analytical model, these experiments establish a comprehensive microscopic framework for investigating and tailoring chiral spin texture character in multilayer films.
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Affiliation(s)
- Xiaoye Chen
- Institute of Materials Research & EngineeringAgency for ScienceTechnology & Research (A*STAR)Singapore138634Singapore
- Data Storage InstituteAgency for ScienceTechnology & Research (A*STAR)Singapore138634Singapore
| | - Ming Lin
- Institute of Materials Research & EngineeringAgency for ScienceTechnology & Research (A*STAR)Singapore138634Singapore
| | - Jian Feng Kong
- Institute of High Performance ComputingAgency for ScienceTechnology & Research (A*STAR)Singapore138632Singapore
| | - Hui Ru Tan
- Institute of Materials Research & EngineeringAgency for ScienceTechnology & Research (A*STAR)Singapore138634Singapore
| | - Anthony K.C. Tan
- Data Storage InstituteAgency for ScienceTechnology & Research (A*STAR)Singapore138634Singapore
| | - Soong‐Geun Je
- Center for X‐Ray OpticsLawrence Berkeley National LaboratoryBerkeleyCA94720USA
| | - Hang Khume Tan
- Institute of Materials Research & EngineeringAgency for ScienceTechnology & Research (A*STAR)Singapore138634Singapore
- Data Storage InstituteAgency for ScienceTechnology & Research (A*STAR)Singapore138634Singapore
| | - Khoong Hong Khoo
- Institute of High Performance ComputingAgency for ScienceTechnology & Research (A*STAR)Singapore138632Singapore
| | - Mi‐Young Im
- Center for X‐Ray OpticsLawrence Berkeley National LaboratoryBerkeleyCA94720USA
| | - Anjan Soumyanarayanan
- Institute of Materials Research & EngineeringAgency for ScienceTechnology & Research (A*STAR)Singapore138634Singapore
- Data Storage InstituteAgency for ScienceTechnology & Research (A*STAR)Singapore138634Singapore
- Department of PhysicsNational University of SingaporeSingapore117551Singapore
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45
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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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46
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Sud A, Tacchi S, Sagkovits D, Barton C, Sall M, Diez LH, Stylianidis E, Smith N, Wright L, Zhang S, Zhang X, Ravelosona D, Carlotti G, Kurebayashi H, Kazakova O, Cubukcu M. Tailoring interfacial effect in multilayers with Dzyaloshinskii-Moriya interaction by helium ion irradiation. Sci Rep 2021; 11:23626. [PMID: 34880294 PMCID: PMC8654828 DOI: 10.1038/s41598-021-02902-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2021] [Accepted: 11/23/2021] [Indexed: 11/13/2022] Open
Abstract
We show a method to control magnetic interfacial effects in multilayers with Dzyaloshinskii-Moriya interaction (DMI) using helium (He[Formula: see text]) ion irradiation. We report results from SQUID magnetometry, ferromagnetic resonance as well as Brillouin light scattering results on multilayers with DMI as a function of irradiation fluence to study the effect of irradiation on the magnetic properties of the multilayers. Our results show clear evidence of the He[Formula: see text] irradiation effects on the magnetic properties which is consistent with interface modification due to the effects of the He[Formula: see text] irradiation. This external degree of freedom offers promising perspectives to further improve the control of magnetic skyrmions in multilayers, that could push them towards integration in future technologies.
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Affiliation(s)
- A. Sud
- grid.83440.3b0000000121901201London Centre for Nanotechnology, University College London, 17-19 Gordon Street, London, WC1H 0AH UK
| | - S. Tacchi
- grid.9027.c0000 0004 1757 3630Istituto Officina dei Materiali del CNR (CNR-IOM), Sede Secondaria di Perugia, c/o Dipartimento di Fisica e Geologia, Università di Perugia, 06123 Perugia, Italy
| | - D. Sagkovits
- grid.83440.3b0000000121901201London Centre for Nanotechnology, University College London, 17-19 Gordon Street, London, WC1H 0AH UK ,grid.410351.20000 0000 8991 6349National Physical Laboratory, Hampton Road, Teddington, TW11 0LW UK
| | - C. Barton
- grid.410351.20000 0000 8991 6349National Physical Laboratory, Hampton Road, Teddington, TW11 0LW UK
| | - M. Sall
- Spin-Ion Technologies, Palaiseau, France
| | - L. H. Diez
- grid.503099.6Centre de Nanosciences et de Nanotechnologies, Orsay, l̂le-de-France France
| | - E. Stylianidis
- grid.83440.3b0000000121901201London Centre for Nanotechnology, University College London, 17-19 Gordon Street, London, WC1H 0AH UK
| | - N. Smith
- grid.410351.20000 0000 8991 6349National Physical Laboratory, Hampton Road, Teddington, TW11 0LW UK
| | - L. Wright
- grid.410351.20000 0000 8991 6349National Physical Laboratory, Hampton Road, Teddington, TW11 0LW UK
| | - S. Zhang
- grid.45672.320000 0001 1926 5090King Abdullah University of Science and Technology Physical Sciences and Engineering Division, Thuwal, Mecca, Saudi Arabia
| | - X. Zhang
- grid.45672.320000 0001 1926 5090King Abdullah University of Science and Technology Physical Sciences and Engineering Division, Thuwal, Mecca, Saudi Arabia
| | - D. Ravelosona
- Spin-Ion Technologies, Palaiseau, France ,grid.503099.6Centre de Nanosciences et de Nanotechnologies, Orsay, l̂le-de-France France
| | - G. Carlotti
- grid.9027.c0000 0004 1757 3630Dipartimento di Fisica e Geologia, Università di Perugia, Via Pascoli, 06123 Perugia, Italy
| | - H. Kurebayashi
- grid.83440.3b0000000121901201London Centre for Nanotechnology, University College London, 17-19 Gordon Street, London, WC1H 0AH UK
| | - O. Kazakova
- grid.410351.20000 0000 8991 6349National Physical Laboratory, Hampton Road, Teddington, TW11 0LW UK
| | - M. Cubukcu
- grid.83440.3b0000000121901201London Centre for Nanotechnology, University College London, 17-19 Gordon Street, London, WC1H 0AH UK ,grid.410351.20000 0000 8991 6349National Physical Laboratory, Hampton Road, Teddington, TW11 0LW UK
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47
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Da Browski M, Scott JN, Hendren WR, Forbes CM, Frisk A, Burn DM, Newman DG, Sait CRJ, Keatley PS, N'Diaye AT, Hesjedal T, van der Laan G, Bowman RM, Hicken RJ. Transition Metal Synthetic Ferrimagnets: Tunable Media for All-Optical Switching Driven by Nanoscale Spin Current. NANO LETTERS 2021; 21:9210-9216. [PMID: 34699234 DOI: 10.1021/acs.nanolett.1c03081] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
All-optical switching of magnetization has great potential for use in future ultrafast and energy efficient nanoscale magnetic storage devices. So far, research has been almost exclusively focused on rare-earth based materials, which limits device tunability and scalability. Here, we show that a perpendicularly magnetized synthetic ferrimagnet composed of two distinct transition metal ferromagnetic layers, Ni3Pt and Co, can exhibit helicity independent magnetization switching. Switching occurs between two equivalent remanent states with antiparallel alignment of the Ni3Pt and Co magnetic moments and is observable over a broad temperature range. Time-resolved measurements indicate that the switching is driven by a spin-polarized current passing through the subnanometer Ir interlayer. The magnetic properties of this model system may be tuned continuously via subnanoscale changes in the constituent layer thicknesses as well as growth conditions, allowing the underlying mechanisms to be elucidated and paving the way to a new class of data storage devices.
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Affiliation(s)
- Maciej Da Browski
- Department of Physics and Astronomy, University of Exeter, Exeter EX4 4QL, United Kingdom
| | - Jade N Scott
- School of Mathematics and Physics, Queen's University Belfast, Belfast BT7 1NN, United Kingdom
| | - William R Hendren
- School of Mathematics and Physics, Queen's University Belfast, Belfast BT7 1NN, United Kingdom
| | - Colin M Forbes
- School of Mathematics and Physics, Queen's University Belfast, Belfast BT7 1NN, United Kingdom
| | - Andreas Frisk
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot OX11 0DE, United Kingdom
| | - David M Burn
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot OX11 0DE, United Kingdom
| | - David G Newman
- Department of Physics and Astronomy, University of Exeter, Exeter EX4 4QL, United Kingdom
| | - Connor R J Sait
- Department of Physics and Astronomy, University of Exeter, Exeter EX4 4QL, United Kingdom
| | - Paul S Keatley
- Department of Physics and Astronomy, University of Exeter, Exeter EX4 4QL, United Kingdom
| | - Alpha T N'Diaye
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Thorsten Hesjedal
- Department of Physics, Clarendon Laboratory, University of Oxford, Oxford OX1 3PU, United Kingdom
| | - Gerrit van der Laan
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot OX11 0DE, United Kingdom
| | - Robert M Bowman
- School of Mathematics and Physics, Queen's University Belfast, Belfast BT7 1NN, United Kingdom
| | - Robert J Hicken
- Department of Physics and Astronomy, University of Exeter, Exeter EX4 4QL, United Kingdom
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48
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Yang S, Moon KW, Ju TS, Kim C, Kim HJ, Kim J, Tran BX, Hong JI, Hwang C. Electrical Generation and Deletion of Magnetic Skyrmion-Bubbles via Vertical Current Injection. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2021; 33:e2104406. [PMID: 34569658 DOI: 10.1002/adma.202104406] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Revised: 08/28/2021] [Indexed: 06/13/2023]
Abstract
The magnetic skyrmion is a topologically protected spin texture that has attracted much attention as a promising information carrier because of its distinct features of suitability for high-density storage, low power consumption, and stability. One of the skyrmion devices proposed so far is the skyrmion racetrack memory, which is the skyrmion version of the domain-wall racetrack memory. For application in devices, skyrmion racetrack memory requires electrical generation, deletion, and displacement of isolated skyrmions. Despite the progress in experimental demonstrations of skyrmion generation, deletion, and displacement, these three operations have yet to be realized in one device. Here, a route for generating and deleting isolated skyrmion-bubbles through vertical current injection with an explanation of its microscopic origin is presented. By combining the proposed skyrmion-bubble generation/deletion method with the spin-orbit-torque-driven skyrmion shift, a proof-of-concept experimental demonstration of the skyrmion racetrack memory operation in a three-terminal device structure is provided.
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Affiliation(s)
- Seungmo Yang
- Quantum Spin Team, Korea Research Institute of Standards and Science, Daejeon, 34113, Republic of Korea
| | - Kyoung-Woong Moon
- Quantum Spin Team, Korea Research Institute of Standards and Science, Daejeon, 34113, Republic of Korea
| | - Tae-Seong Ju
- Quantum Spin Team, Korea Research Institute of Standards and Science, Daejeon, 34113, Republic of Korea
| | - Changsoo Kim
- Quantum Spin Team, Korea Research Institute of Standards and Science, Daejeon, 34113, Republic of Korea
| | - Hyun-Joong Kim
- Quantum Spin Team, Korea Research Institute of Standards and Science, Daejeon, 34113, Republic of Korea
| | - Juran Kim
- Quantum Spin Team, Korea Research Institute of Standards and Science, Daejeon, 34113, Republic of Korea
| | - Bao Xuan Tran
- Department of Emerging Materials Science, DGIST, Daegu, 42988, Republic of Korea
| | - Jung-Il Hong
- Department of Emerging Materials Science, DGIST, Daegu, 42988, Republic of Korea
| | - Chanyong Hwang
- Quantum Spin Team, Korea Research Institute of Standards and Science, Daejeon, 34113, Republic of Korea
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49
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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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50
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Li Z, Su J, Lin SZ, Liu D, Gao Y, Wang S, Wei H, Zhao T, Zhang Y, Cai J, Shen B. Field-free topological behavior in the magnetic domain wall of ferrimagnetic GdFeCo. Nat Commun 2021; 12:5604. [PMID: 34556648 PMCID: PMC8460835 DOI: 10.1038/s41467-021-25926-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Accepted: 09/09/2021] [Indexed: 11/22/2022] Open
Abstract
Exploring and controlling topological textures such as merons and skyrmions has attracted enormous interests from the perspective of fundamental research and spintronic applications. It has been predicted theoretically and proved experimentally that the lattice form of topological meron-skyrmion transformation can be realized with the requirement of external magnetic fields in chiral ferromagnets. However, such topological transition behavior has yet to be verified in other materials. Here, we report real-space observation of magnetic topology transformation between meron pairs and skyrmions in the localized domain wall of ferrimagnetic GdFeCo films without the need of magnetic fields. The topological transformation in the domain wall of ferrimagnet is introduced by temperature-induced spin reorientation transition (SRT) and the underlying mechanism is revealed by micromagnetic simulations. The convenient electric-controlling topology transformation and driving motion along the confined domain wall is further anticipated, which will enable advanced application in magnetic devices. Merons and Skyrmions, two topological spin-textures, have attracted a lot of interests due to their potential use in information storage. Here, the authors demonstrate the transformation of Meron pairs into Skyrmions without an applied magnetic field within domain walls of GdFeCo films.
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Affiliation(s)
- Zhuolin Li
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, 100190, Beijing, China.,School of Physical Sciences, University of Chinese Academy of Sciences, 100049, Beijing, China
| | - Jian Su
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, 100190, Beijing, China.,School of Physical Sciences, University of Chinese Academy of Sciences, 100049, Beijing, China
| | - Shi-Zeng Lin
- Theoretical Division, Los Alamos National Laboratory, Los Alamos, NM, 87545, USA
| | - Dan Liu
- Department of Physics, Beijing Technology and Business University, 100048, Beijing, China
| | - Yang Gao
- Institute of Advanced Materials, Beijing Normal University, 100875, Beijing, China
| | - Shouguo Wang
- Institute of Advanced Materials, Beijing Normal University, 100875, Beijing, China
| | - Hongxiang Wei
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, 100190, Beijing, China
| | - Tongyun Zhao
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, 100190, Beijing, China
| | - Ying Zhang
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, 100190, Beijing, China. .,Songshan Lake Materials Laboratory, Dongguan, 523808, Guangdong, China.
| | - Jianwang Cai
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, 100190, Beijing, China.,School of Physical Sciences, University of Chinese Academy of Sciences, 100049, Beijing, China
| | - Baogen Shen
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, 100190, Beijing, China.,School of Physical Sciences, University of Chinese Academy of Sciences, 100049, Beijing, China
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