1
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Littlehales MT, Moody SH, Turnbull LA, Huddart BM, Brereton BA, Balakrishnan G, Fan R, Steadman P, Hatton PD, Wilson MN. Demonstration of Controlled Skyrmion Injection Across a Thickness Step. NANO LETTERS 2024. [PMID: 38781191 DOI: 10.1021/acs.nanolett.4c01605] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2024]
Abstract
Spintronic devices incorporating magnetic skyrmions have attracted significant interest recently. Such devices traditionally focus on controlling magnetic textures in 2D thin films. However, enhanced performance of spintronic properties through the exploitation of higher dimensionalities motivates the investigation of variable-thickness skyrmion devices. We report the demonstration of a skyrmion injection mechanism that utilizes charge currents to drive skyrmions across a thickness step and, consequently, a metastability barrier. Our measurements show that under certain temperature and field conditions skyrmions can be reversibly injected from a thin region of an FeGe lamella, where they exist as an equilibrium state, into a thicker region, where they can only persist as a metastable state. This injection is achieved with a current density of 3 × 108 A m-2, nearly 3 orders of magnitude lower than required to move magnetic domain walls. This highlights the possibility to use such an element as a skyrmion source/drain within future spintronic devices.
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Affiliation(s)
- Matthew T Littlehales
- Durham University, Department of Physics, South Road, Durham, DH1 3LE, United Kingdom
- ISIS Neutron and Muon Source, Rutherford Appleton Laboratory, Didcot, OX11 0QX, United Kingdom
| | - Samuel H Moody
- Durham University, Department of Physics, South Road, Durham, DH1 3LE, United Kingdom
- Laboratory for Neutron Scattering and Imaging, Paul Scherrer Institute, Villigen, CH-5232, Switzerland
| | - Luke A Turnbull
- Durham University, Department of Physics, South Road, Durham, DH1 3LE, United Kingdom
- Max Planck Institute for Chemical Physics of Solids, Noethnitzer Str. 40, 01187 Dresden, Germany
| | - Benjamin M Huddart
- Durham University, Department of Physics, South Road, Durham, DH1 3LE, United Kingdom
- Department of Physics, Clarendon Laboratory, University of Oxford, Parks Road, Oxford, OX1 3PU, United Kingdom
| | - Ben A Brereton
- Durham University, Department of Physics, South Road, Durham, DH1 3LE, United Kingdom
| | - Geetha Balakrishnan
- University of Warwick, Department of Physics, Coventry, CV4 7AL, United Kingdom
| | - Raymond Fan
- Diamond Light Source, Didcot, OX11 0DE, United Kingdom
| | - Paul Steadman
- Diamond Light Source, Didcot, OX11 0DE, United Kingdom
| | - Peter D Hatton
- Durham University, Department of Physics, South Road, Durham, DH1 3LE, United Kingdom
| | - Murray N Wilson
- Durham University, Department of Physics, South Road, Durham, DH1 3LE, United Kingdom
- Memorial University of Newfoundland, Department of Physics and Physical Oceanography, St John's, Newfoundland, A1B 3X7, Canada
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2
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Kitaori A, White JS, Ukleev V, Peng L, Nakajima K, Kanazawa N, Yu X, Ōnuki Y, Tokura Y. Enhanced emergent electromagnetic inductance in Tb 5Sb 3 due to highly disordered helimagnetism. COMMUNICATIONS PHYSICS 2024; 7:159. [PMID: 38779470 PMCID: PMC11106002 DOI: 10.1038/s42005-024-01656-z] [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: 12/23/2023] [Accepted: 05/08/2024] [Indexed: 05/25/2024]
Abstract
In helimagnetic metals, ac current-driven spin motions can generate emergent electric fields acting on conduction electrons, leading to emergent electromagnetic induction (EEMI). Recent experiments reveal the EEMI signal generally shows a strongly current-nonlinear response. In this study, we investigate the EEMI of Tb5Sb3, a short-period helimagnet. Using small angle neutron scattering we show that Tb5Sb3 hosts highly disordered helimagnetism with a distribution of spin-helix periodicity. The current-nonlinear dynamics of the disordered spin helix in Tb5Sb3 indeed shows up as the nonlinear electrical resistivity (real part of ac resistivity), and even more clearly as a nonlinear and huge EEMI (imaginary part of ac resistivity) response. The magnitude of the EEMI reaches as large as several tens of μH for Tb5Sb3 devices on the scale of several tens of μm, originating to noncollinear spin textures possibly even without long-range helimagnetic order.
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Affiliation(s)
- Aki Kitaori
- Institute of Engineering Innovation, The University of Tokyo, Tokyo, 113-0032 Japan
- Department of Applied Physics, The University of Tokyo, Tokyo, 113-8656 Japan
- RIKEN Center for Emergent Matter Science (CEMS), Wako, 351-0198 Japan
| | - Jonathan S. White
- Laboratory for Neutron Scattering and Imaging (LNS), Paul Scherrer Institute (PSI), CH-5232 Villigen, Switzerland
| | - Victor Ukleev
- Laboratory for Neutron Scattering and Imaging (LNS), Paul Scherrer Institute (PSI), CH-5232 Villigen, Switzerland
- Helmholtz-Zentrum Berlin für Materialien und Energie, D-14109 Berlin, Germany
| | - 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
| | - Naoya Kanazawa
- Institute of Industrial Science, The University of Tokyo, Tokyo, 153-8505 Japan
| | - Xiuzhen Yu
- RIKEN Center for Emergent Matter Science (CEMS), Wako, 351-0198 Japan
| | - Yoshichika Ōnuki
- RIKEN Center for Emergent Matter Science (CEMS), Wako, 351-0198 Japan
| | - Yoshinori Tokura
- Department of Applied Physics, The University of Tokyo, Tokyo, 113-8656 Japan
- RIKEN Center for Emergent Matter Science (CEMS), Wako, 351-0198 Japan
- Tokyo College, The University of Tokyo, Tokyo, 113-8656 Japan
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3
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Liyanage WLNC, Tang N, Dally RL, Quigley LJ, Buchanan CC, Shu GJ, Butch NP, Krycka K, Bleuel M, Borchers JA, Debeer-Schmitt L, Gilbert DA. Skyrmion lattice formation and destruction mechanisms probed with TR-SANS. NANOSCALE 2024. [PMID: 38712993 DOI: 10.1039/d4nr00858h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2024]
Abstract
Magnetic skyrmions are topologically protected, nanoscale whirls of the spin configuration that tend to form hexagonally ordered arrays. As a topologically non-trivial structure, the nucleation and annihilation of the skyrmion, as well as the interaction between skyrmions, varies from conventional magnetic systems. Recent works have suggested that the ordering kinetics in these materials occur over millisecond or longer timescales, which is unusually slow for magnetic dynamics. The current work investigates the skyrmion ordering kinetics, particularly during lattice formation and destruction, using time-resolved small angle neutron scattering (TR-SANS). Evaluating the time-resolved structure and intensity of the neutron diffraction pattern reveals the evolving real-space structure of the skyrmion lattice and the timeframe of the formation. Measurements were performed on three prototypical skyrmion materials: MnSi, (Fe,Co)Si, and Cu2OSeO3. To probe lattice formation and destruction kinetics, the systems were prepared in the stable skyrmion state, and then a square-wave magnetic field modulation was applied. The measurements show that the skyrmions quickly form ordered domains, with a significant distribution in lattice parameters, which then converge to the final structure; the results confirm the slow kinetics, with formation times between 10 ms and 99 ms. Comparisons are made between the measured formation times and the fundamental material properties, suggesting the ordering temperature, saturation magnetization and magnetocrystalline anisotropy may be driving the timeframes. Micromagnetic simulations were also performed and support a scaling of the kinetics with sample volume, a behavior which is caused by the reconciling of misaligned domains.
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Affiliation(s)
- W L N C Liyanage
- Department of Physics and Astronomy, University of Tennessee, Knoxville, TN 37996, USA.
| | - Nan Tang
- Materials Science Department, University of Tennessee, Knoxville, TN 37996, USA
| | - Rebecca L Dally
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA
| | - Lizabeth J Quigley
- Materials Science Department, University of Tennessee, Knoxville, TN 37996, USA
| | | | - Guo-Jiun Shu
- Center for Condensed Matter Sciences, National Taiwan University, Taipei 10617, Taiwan
- Department of Materials and Mineral Resources Engineering, Institute of Mineral Resources Engineering, National Taipei University of Technology, Taipei 10608, Taiwan
| | - Nicholas P Butch
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA
- Center for Nanophysics and Advanced Materials, Department of Physics, University of Maryland, College Park, MD 20742, USA
| | - Kathryn Krycka
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA
| | - Markus Bleuel
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA
- Department of Materials Science and Engineering, University of Maryland, College Park, MD 20742, USA
| | - Julie A Borchers
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA
| | - Lisa Debeer-Schmitt
- High Flux Isotope Reactor, Oak Ridge National Laboratory, Oak Ridge, TN 37830, USA
| | - Dustin A Gilbert
- Department of Physics and Astronomy, University of Tennessee, Knoxville, TN 37996, USA.
- Materials Science Department, University of Tennessee, Knoxville, TN 37996, USA
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4
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Wang ZQ, Xue F, Qiu L, Wang Z, Wu R, Hou Y. Switching Intrinsic Magnetic Skyrmions with Controllable Magnetic Anisotropy in van der Waals Multiferroic Heterostructures. NANO LETTERS 2024; 24:4117-4123. [PMID: 38509030 DOI: 10.1021/acs.nanolett.3c05024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/22/2024]
Abstract
Magnetic skyrmions, topologically nontrivial whirling spin textures at nanometer scales, have emerged as potential information carriers for spintronic devices. The ability to efficiently create and erase magnetic skyrmions is vital yet challenging for such applications. Based on first-principles studies, we find that switching between intrinsic magnetic skyrmion and high-temperature ferromagnetic states can be achieved in the two-dimensional van der Waals (vdW) multiferroic heterostructure CrSeI/In2Te3 by reversing the ferroelectric polarization of In2Te3. The core mechanism of this switching is traced to the controllable magnetic anisotropy of CrSeI influenced by the ferroelectric polarization of In2Te3. We propose a useful descriptor linking the presence of magnetic skyrmions to magnetic parameters and validate this connection through studies of a variety of similar vdW multiferroic heterostructures. Our work demonstrates that manipulating magnetic skyrmions via tunable magnetic anisotropies in vdW multiferroic heterostructures represents a highly promising and energy-efficient strategy for the future development of spintronics.
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Affiliation(s)
- Ze-Quan Wang
- Guangdong Provincial Key Laboratory of Magnetoelectric Physics and Devices, Center for Neutron Science and Technology, School of Physics, Sun Yat-Sen University, Guangzhou 510275, China
| | - Feng Xue
- Department of Physics, College of Physics & Optoelectronic Engineering, Jinan University, Guangzhou, Guangdong 510632, China
| | - Liang Qiu
- Guangdong Provincial Key Laboratory of Magnetoelectric Physics and Devices, Center for Neutron Science and Technology, School of Physics, Sun Yat-Sen University, Guangzhou 510275, China
| | - Zhe Wang
- Department of Physics and Astronomy, University of California, Irvine, Irvine, California 92697-4575, United States
| | - Ruqian Wu
- Department of Physics and Astronomy, University of California, Irvine, Irvine, California 92697-4575, United States
| | - Yusheng Hou
- Guangdong Provincial Key Laboratory of Magnetoelectric Physics and Devices, Center for Neutron Science and Technology, School of Physics, Sun Yat-Sen University, Guangzhou 510275, China
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5
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Yu J, Liu Y, Ke Y, Su J, Cao J, Li Z, Sun B, Bai H, Wang W. Observation of Topological Hall Effect in a Chemically Complex Alloy. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024; 36:e2308415. [PMID: 38265890 DOI: 10.1002/adma.202308415] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2023] [Revised: 12/28/2023] [Indexed: 01/26/2024]
Abstract
The topological Hall effect (THE) is the transport response of chiral spin textures and thus can serve as a powerful probe for detecting and understanding these unconventional magnetic orders. So far, the THE is only observed in either noncentrosymmetric systems where spin chirality is stabilized by Dzyaloshinskii-Moriya interactions, or triangular-lattice magnets with Ruderman-Kittel-Kasuya-Yosida-type interactions. Here, a pronounced THE is observed in a Fe-Co-Ni-Mn chemically complex alloy with a simple face-centered cubic (fcc) structure across a wide range of temperatures and magnetic fields. The alloy is shown to have a strong magnetic frustration owing to the random occupation of magnetic atoms on the close-packed fcc lattice and the direct Heisenberg exchange interaction among atoms, as evidenced by the appearance of a reentrant spin glass state in the low-temperature regime and the first principles calculations. Consequently, THE is attributed to the nonvanishing spin chirality created by strong spin frustration under the external magnetic field, which is distinct from the mechanism responsible for the skyrmion systems, as well as geometrically frustrated magnets.
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Affiliation(s)
- Jihao Yu
- 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
| | - Yuying Liu
- School of Physical Science and Technology, Guangxi University, Nanning, 530004, China
| | - Yubin Ke
- Spallation Neutron Source Science Center, Dongguan, 523803, China
- Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, 100049, China
| | - Jiaqi Su
- School of Physical Science and Technology, Guangxi University, Nanning, 530004, China
| | - Jingshan Cao
- 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
| | - Zian Li
- School of Physical Science and Technology, Guangxi University, Nanning, 530004, China
| | - Baoan Sun
- 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
| | - Haiyang Bai
- 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
| | - Weihua Wang
- 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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6
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Urrestarazu Larrañaga J, Sisodia N, Guedas R, Pham VT, Di Manici I, Masseboeuf A, Garello K, Disdier F, Fernandez B, Wintz S, Weigand M, Belmeguenai M, Pizzini S, Sousa RC, Buda-Prejbeanu LD, Gaudin G, Boulle O. Electrical Detection and Nucleation of a Magnetic Skyrmion in a Magnetic Tunnel Junction Observed via Operando Magnetic Microscopy. NANO LETTERS 2024; 24:3557-3565. [PMID: 38499397 DOI: 10.1021/acs.nanolett.4c00316] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/20/2024]
Abstract
Magnetic skyrmions are topological spin textures which are envisioned as nanometer scale information carriers in magnetic memory and logic devices. The recent demonstrations of room temperature skyrmions and their current induced manipulation in ultrathin films were first steps toward the realization of such devices. However, important challenges remain regarding the electrical detection and the low-power nucleation of skyrmions, which are required for the read and write operations. Here, we demonstrate, using operando magnetic microscopy experiments, the electrical detection of a single magnetic skyrmion in a magnetic tunnel junction (MTJ) and its nucleation and annihilation by gate voltage via voltage control of magnetic anisotropy. The nucleated skyrmion can be manipulated by both gate voltages and external magnetic fields, leading to tunable intermediate resistance states. Our results unambiguously demonstrate the readout and voltage controlled write operations in a single MTJ device, which is a major milestone for low power skyrmion based technologies.
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Affiliation(s)
| | - Naveen Sisodia
- Univ. Grenoble Alpes, CNRS, CEA, Grenoble INP, SPINTEC, 38000 Grenoble, France
| | - Rodrigo Guedas
- Univ. Grenoble Alpes, CNRS, CEA, Grenoble INP, SPINTEC, 38000 Grenoble, France
| | - Van Tuong Pham
- Univ. Grenoble Alpes, CNRS, CEA, Grenoble INP, SPINTEC, 38000 Grenoble, France
- Univ. Grenoble Alpes, CNRS, Institut Néel, 38042 Grenoble, France
| | - Ilaria Di Manici
- Univ. Grenoble Alpes, CNRS, CEA, Grenoble INP, SPINTEC, 38000 Grenoble, France
| | - Aurélien Masseboeuf
- Univ. Grenoble Alpes, CNRS, CEA, Grenoble INP, SPINTEC, 38000 Grenoble, France
| | - Kevin Garello
- Univ. Grenoble Alpes, CNRS, CEA, Grenoble INP, SPINTEC, 38000 Grenoble, France
| | - Florian Disdier
- Univ. Grenoble Alpes, CNRS, CEA, Grenoble INP, SPINTEC, 38000 Grenoble, France
| | - Bruno Fernandez
- Univ. Grenoble Alpes, CNRS, Institut Néel, 38042 Grenoble, France
| | - Sebastian Wintz
- Max Planck Institute for Intelligent Systems, Heisenbergstraße 3, 70569 Stuttgart, Germany
- Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, D-14109 Berlin, Germany
| | - Markus Weigand
- Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, D-14109 Berlin, Germany
| | - Mohamed Belmeguenai
- LSPM (CNRS-UPR 3407), Université Paris 13, Sorbonne Paris Cité, 99 Avenue Jean-Baptiste Clément, 93430 Villetaneuse, France
| | - Stefania Pizzini
- Univ. Grenoble Alpes, CNRS, Institut Néel, 38042 Grenoble, France
| | - Ricardo C Sousa
- Univ. Grenoble Alpes, CNRS, CEA, Grenoble INP, SPINTEC, 38000 Grenoble, France
| | | | - Gilles Gaudin
- Univ. Grenoble Alpes, CNRS, CEA, Grenoble INP, SPINTEC, 38000 Grenoble, France
| | - Olivier Boulle
- Univ. Grenoble Alpes, CNRS, CEA, Grenoble INP, SPINTEC, 38000 Grenoble, France
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7
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Feng X, Yan S, Zhang X, Yin L, Wang H, Wen Y, Yao J, Wang H, Cheng R, Li Z, He J. Spontaneous Skyrmion Bubbles in an Iron-Silicon Alloy with Uniaxial Magnetic Anisotropy. ACS NANO 2024; 18:8475-8483. [PMID: 38456704 DOI: 10.1021/acsnano.4c00658] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/09/2024]
Abstract
The magnetic skyrmions exhibit intriguing topological behaviors, holding promise for future applications in the realm of spintronic devices. Despite recent advancements, achieving spontaneous magnetic skyrmions and topological transitions in magnets featuring uniaxial magnetic anisotropy, particularly at elevated temperatures (>100 K), remains a challenging endeavor. Here, single-crystal Fe5Si3 nanorods with the central symmetry and uniaxial magnetic anisotropy were successfully synthesized on a mica substrate through chemical vapor deposition, which exhibit a high Curie temperature (TC) of about 372 K. The real-time observation, facilitated by Lorentz transmission electron microscopy, revealed the spontaneous formation of magnetic skyrmions and evolution of domains in focused ion beam-prepared Fe5Si3 thin foils. Moreover, Fe5Si3 device transport measurements expose notable magnetoresistance (MR) effects, enabling the interchange between positive and negative MR across specific temperature settings. These results offer various potential avenues for exploring diverse topological spin textures and their formation mechanisms, indicating inventive applications for iron-silicon alloy in the realm of spintronics.
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Affiliation(s)
- Xiaoqiang Feng
- Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education, and School of Physics and Technology, Wuhan University, Wuhan 430072, China
| | - Shanshan Yan
- State Key Laboratory of Featured Metal Materials and Life-cycle Safety for Composite Structures, and School of Physical Science and Technology, Guangxi University, Nanning 530004, China
| | - Xiaolin Zhang
- Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education, and School of Physics and Technology, Wuhan University, Wuhan 430072, China
| | - Lei Yin
- Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education, and School of Physics and Technology, Wuhan University, Wuhan 430072, China
| | - Hao Wang
- Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education, and School of Physics and Technology, Wuhan University, Wuhan 430072, China
| | - Yao Wen
- Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education, and School of Physics and Technology, Wuhan University, Wuhan 430072, China
| | - Jiayi Yao
- Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education, and School of Physics and Technology, Wuhan University, Wuhan 430072, China
| | - Hao Wang
- Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education, and School of Physics and Technology, Wuhan University, Wuhan 430072, China
| | - Ruiqing Cheng
- Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education, and School of Physics and Technology, Wuhan University, Wuhan 430072, China
- Hubei Luojia Laboratory, Wuhan 430072, China
| | - Zian Li
- State Key Laboratory of Featured Metal Materials and Life-cycle Safety for Composite Structures, and School of Physical Science and Technology, Guangxi University, Nanning 530004, China
| | - Jun He
- Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education, and School of Physics and Technology, Wuhan University, Wuhan 430072, China
- Hubei Luojia Laboratory, Wuhan 430072, China
- Wuhan Institute of Quantum Technology, Wuhan 430206, China
- Institute of Semiconductors, Henan Academy of Sciences, Zhengzhou 450046, China
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8
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Oh T, Nagaosa N. Emergent Inductance from Spin Fluctuations in Strongly Correlated Magnets. PHYSICAL REVIEW LETTERS 2024; 132:116501. [PMID: 38563933 DOI: 10.1103/physrevlett.132.116501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2023] [Revised: 02/16/2024] [Accepted: 02/22/2024] [Indexed: 04/04/2024]
Abstract
Recently, the intriguing phenomenon of emergent inductance has been theoretically proposed and experimentally observed in nanoscale spiral spin systems subjected to oscillating currents. Building upon these recent developments, we put forward the concept of emergent inductance in strongly correlated magnets in the normal state with spin fluctuations. It is argued that the inductance shows a positive peak at temperatures above the ordering temperature. As for the frequency dependence, in systems featuring a single-band structure or a gapped multiband, we observe a Drude-type inductance, while in gapless multiband systems, a non-Drude inductance with a sharp dip near zero frequency. These results offer valuable insights into the behavior of strongly correlated magnets and open up new possibilities for harnessing emergent inductance in practical applications.
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Affiliation(s)
- Taekoo Oh
- RIKEN Center for Emergent Matter Science (CEMS), Wako, Saitama 351-0198, Japan
| | - Naoto Nagaosa
- RIKEN Center for Emergent Matter Science (CEMS), Wako, Saitama 351-0198, Japan
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9
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Masuda H, Seki T, Ohe JI, Nii Y, Masuda H, Takanashi K, Onose Y. Room temperature chirality switching and detection in a helimagnetic MnAu 2 thin film. Nat Commun 2024; 15:1999. [PMID: 38453940 PMCID: PMC10920692 DOI: 10.1038/s41467-024-46326-4] [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: 12/23/2022] [Accepted: 02/22/2024] [Indexed: 03/09/2024] Open
Abstract
Helimagnetic structures, in which the magnetic moments are spirally ordered, host an internal degree of freedom called chirality corresponding to the handedness of the helix. The chirality seems quite robust against disturbances and is therefore promising for next-generation magnetic memory. While the chirality control was recently achieved by the magnetic field sweep with the application of an electric current at low temperature in a conducting helimagnet, problems such as low working temperature and cumbersome control and detection methods have to be solved in practical applications. Here we show chirality switching by electric current pulses at room temperature in a thin-film MnAu2 helimagnetic conductor. Moreover, we have succeeded in detecting the chirality at zero magnetic fields by means of simple transverse resistance measurement utilizing the spin Berry phase in a bilayer device composed of MnAu2 and a spin Hall material Pt. These results may pave the way to helimagnet-based spintronics.
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Affiliation(s)
- Hidetoshi Masuda
- Institute for Materials Research, Tohoku University, Sendai, Japan.
| | - Takeshi Seki
- Institute for Materials Research, Tohoku University, Sendai, Japan.
| | - Jun-Ichiro Ohe
- Department of Physics, Toho University, Funabashi, Japan
| | - Yoichi Nii
- Institute for Materials Research, Tohoku University, Sendai, Japan
- PRESTO, Japan Science and Technology Agency, Kawaguchi, Japan
| | - Hiroto Masuda
- Institute for Materials Research, Tohoku University, Sendai, Japan
| | - Koki Takanashi
- Institute for Materials Research, Tohoku University, Sendai, Japan
- Center for Science and Innovation in Spintronics, Tohoku University, Sendai, Japan
- Advanced Science Research Center, Japan Atomic Energy Agency, Ibaraki, Japan
| | - Yoshinori Onose
- Institute for Materials Research, Tohoku University, Sendai, Japan.
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10
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Simeth W, Rahn MC, Bauer A, Meven M, Pfleiderer C. Topological aspects of multi- kantiferromagnetism in cubic rare-earth compounds. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2024; 36:215602. [PMID: 38295434 DOI: 10.1088/1361-648x/ad24bb] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/08/2023] [Accepted: 01/31/2024] [Indexed: 02/02/2024]
Abstract
We advertise rare-earth intermetallics with high-symmetry crystal structures and competing interactions as a possible materials platform hosting spin structures with non-trivial topological properties. Focusing on the series of cubicRCu compounds, whereR= Ho, Er, Tm, the bulk properties of these systems display exceptionally rich magnetic phase diagrams hosting an abundance of different phase pockets characteristic of antiferromagnetic order in the presence of delicately balanced interactions. The electrical transport properties exhibit large anomalous contributions suggestive of topologically non-trivial winding in the electronic and magnetic structures. Neutron diffraction identifies spontaneous long-range magnetic order in terms of commensurate and incommensurate variations of(ππ0)antiferromagnetism with the possibility for various multi-kconfigurations. Motivated by general trends in these materials, we discuss the possible existence of topologically non-trivial winding in real and reciprocal space in the class ofRCu compounds including antiferromagnetic skyrmion lattices. Putatively bringing together different limits of non-trivial topological winding in the same material, the combination of properties inRCu systems promises access to advanced functionalities.
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Affiliation(s)
- W Simeth
- Physik-Department, Technical University of Munich, D-85748 Garching, Germany
- Paul Scherrer Institut, Forschungsstrasse 111, CH-5232 Villigen, Switzerland
| | - M C Rahn
- Physik-Department, Technical University of Munich, D-85748 Garching, Germany
- Institute for Solid State and Materials Physics, Technical University of Dresden, D-01062 Dresden, Germany
| | - A Bauer
- Physik-Department, Technical University of Munich, D-85748 Garching, Germany
- Centre for Quantum Engineering (ZQE), Technical University of Munich, D-85748 Garching, Germany
| | - M Meven
- Forschungszentrum Jülich GmbH, Jülich Centre for Neutron Science (JCNS) at Heinz Maier-Leibnitz Zentrum (MLZ), D-85748 Garching, Germany
- Institut für Kristallographie, RWTH Aachen, D-52056 Aachen, Germany
| | - C Pfleiderer
- Physik-Department, Technical University of Munich, D-85748 Garching, Germany
- Centre for Quantum Engineering (ZQE), Technical University of Munich, D-85748 Garching, Germany
- Munich Center for Quantum Science and Technology (MCQST), Technical University of Munich, D-85748 Garching, Germany
- Heinz Maier-Leibnitz Zentrum (MLZ), Technical University of Munich, D-85748 Garching, Germany
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11
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Cheng E, Yan L, Shi X, Lou R, Fedorov A, Behnami M, Yuan J, Yang P, Wang B, Cheng JG, Xu Y, Xu Y, Xia W, Pavlovskii N, Peets DC, Zhao W, Wan Y, Burkhardt U, Guo Y, Li S, Felser C, Yang W, Büchner B. Tunable positions of Weyl nodes via magnetism and pressure in the ferromagnetic Weyl semimetal CeAlSi. Nat Commun 2024; 15:1467. [PMID: 38368411 PMCID: PMC10874455 DOI: 10.1038/s41467-024-45658-5] [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: 01/10/2023] [Accepted: 01/30/2024] [Indexed: 02/19/2024] Open
Abstract
The noncentrosymmetric ferromagnetic Weyl semimetal CeAlSi with simultaneous space-inversion and time-reversal symmetry breaking provides a unique platform for exploring novel topological states. Here, by employing multiple experimental techniques, we demonstrate that ferromagnetism and pressure can serve as efficient parameters to tune the positions of Weyl nodes in CeAlSi. At ambient pressure, a magnetism-facilitated anomalous Hall/Nernst effect (AHE/ANE) is uncovered. Angle-resolved photoemission spectroscopy (ARPES) measurements demonstrated that the Weyl nodes with opposite chirality are moving away from each other upon entering the ferromagnetic phase. Under pressure, by tracing the pressure evolution of AHE and band structure, we demonstrate that pressure could also serve as a pivotal knob to tune the positions of Weyl nodes. Moreover, multiple pressure-induced phase transitions are also revealed. These findings indicate that CeAlSi provides a unique and tunable platform for exploring exotic topological physics and electron correlations, as well as catering to potential applications, such as spintronics.
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Affiliation(s)
- Erjian Cheng
- Leibniz Institute for Solid State and Materials Research (IFW-Dresden), 01069, Dresden, Germany.
- Max Planck Institute for Chemical Physics of Solids, 01187, Dresden, Germany.
| | - Limin Yan
- Center for High Pressure Science and Technology Advanced Research, 201203, Shanghai, China
- State Key Laboratory of Superhard Materials, Department of Physics, Jilin University, 130012, Changchun, China
| | - Xianbiao Shi
- State Key Laboratory of Advanced Welding & Joining, Harbin Institute of Technology, 150001, Harbin, China
- Flexible Printed Electronics Technology Center, Harbin Institute of Technology (Shenzhen), 518055, Shenzhen, China
| | - Rui Lou
- Leibniz Institute for Solid State and Materials Research (IFW-Dresden), 01069, Dresden, Germany.
- Helmholtz-Zentrum Berlin für Materialien und Energie, Albert-Einstein-Straße 15, 12489, Berlin, Germany.
- Joint Laboratory "Functional Quantum Materials" at BESSY II, 12489, Berlin, Germany.
| | - Alexander Fedorov
- Leibniz Institute for Solid State and Materials Research (IFW-Dresden), 01069, Dresden, Germany
- Helmholtz-Zentrum Berlin für Materialien und Energie, Albert-Einstein-Straße 15, 12489, Berlin, Germany
- Joint Laboratory "Functional Quantum Materials" at BESSY II, 12489, Berlin, Germany
| | - Mahdi Behnami
- Leibniz Institute for Solid State and Materials Research (IFW-Dresden), 01069, Dresden, Germany
| | - Jian Yuan
- School of Physical Science and Technology, ShanghaiTech University, 200031, Shanghai, China
| | - Pengtao Yang
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, 100190, Beijing, China
- School of Physical Sciences, University of Chinese Academy of Sciences, 100190, Beijing, China
| | - Bosen Wang
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, 100190, Beijing, China
- School of Physical Sciences, University of Chinese Academy of Sciences, 100190, Beijing, China
| | - Jin-Guang Cheng
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, 100190, Beijing, China
- School of Physical Sciences, University of Chinese Academy of Sciences, 100190, Beijing, China
| | - Yuanji Xu
- Institute for Applied Physics, University of Science and Technology Beijing, 100083, Beijing, China
| | - Yang Xu
- Key Laboratory of Polar Materials and Devices (MOE), School of Physics and Electronic Science, East China Normal University, 200241, Shanghai, China
| | - Wei Xia
- School of Physical Science and Technology, ShanghaiTech University, 200031, Shanghai, China
| | - Nikolai Pavlovskii
- Institute of Solid State and Materials Physics, Technische Universität Dresden, 01069, Dresden, Germany
| | - Darren C Peets
- Institute of Solid State and Materials Physics, Technische Universität Dresden, 01069, Dresden, Germany
| | - Weiwei Zhao
- State Key Laboratory of Advanced Welding & Joining, Harbin Institute of Technology, 150001, Harbin, China
- Flexible Printed Electronics Technology Center, Harbin Institute of Technology (Shenzhen), 518055, Shenzhen, China
| | - Yimin Wan
- State Key Laboratory of Surface Physics, and Department of Physics, Fudan University, 200438, Shanghai, China
| | - Ulrich Burkhardt
- Max Planck Institute for Chemical Physics of Solids, 01187, Dresden, Germany
| | - Yanfeng Guo
- School of Physical Science and Technology, ShanghaiTech University, 200031, Shanghai, China
| | - Shiyan Li
- State Key Laboratory of Surface Physics, and Department of Physics, Fudan University, 200438, Shanghai, China
- Collaborative Innovation Center of Advanced Microstructures, 210093, Nanjing, China
- Shanghai Research Center for Quantum Sciences, 201315, Shanghai, China
| | - Claudia Felser
- Max Planck Institute for Chemical Physics of Solids, 01187, Dresden, Germany
| | - Wenge Yang
- Center for High Pressure Science and Technology Advanced Research, 201203, Shanghai, China.
| | - Bernd Büchner
- Leibniz Institute for Solid State and Materials Research (IFW-Dresden), 01069, Dresden, Germany.
- Institute of Solid State and Materials Physics and Würzburg-Dresden Cluster of Excellence-ct.qmat, Technische Universität Dresden, 01062, Dresden, Germany.
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12
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Meng Y, Meng F, Hou M, Zheng Q, Wang B, Zhu R, Feng C, Yu G. Regulation of interfacial Dzyaloshinskii-Moriya interaction in ferromagnetic multilayers. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2024; 36:193001. [PMID: 38286006 DOI: 10.1088/1361-648x/ad2386] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2023] [Accepted: 01/29/2024] [Indexed: 01/31/2024]
Abstract
Interfacial Dzyaloshinskii-Moriya interaction (i-DMI) exists in the film materials with inversion symmetry breaking, which can stabilize a series of nonlinear spin structures and control their chirality, such as Néel-type domain wall, magnetic skyrmion and spin spiral. In addition, the strength and chirality of i-DMI are directly related to the dynamic behavior of these nonlinear spin structures. Therefore, regulating the strength and chirality of i-DMI not only has an important scientific significance for enriching spintronics and topological physics, but also has a significant practical value for constructing a new generation of memorizer, logic gate, and brain-like devices with low-power. This review summarizes the research progress on the regulation of i-DMI in ferromagnetic films and provides some prospects for future research.
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Affiliation(s)
- Yufei Meng
- School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, People's Republic of China
| | - Fei Meng
- School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, People's Republic of China
| | - Mingxuan Hou
- School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, People's Republic of China
| | - Qianqi Zheng
- School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, People's Republic of China
| | - Boyi Wang
- School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, People's Republic of China
| | - Ronggui Zhu
- School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, People's Republic of China
| | - Chun Feng
- School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, People's Republic of China
| | - Guanghua Yu
- School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, People's Republic of China
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13
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Moon A, Li Y, McKeever C, Casas BW, Bravo M, Zheng W, Macy J, Petford-Long AK, McCandless GT, Chan JY, Phatak C, Santos EJG, Balicas L. Writing and Detecting Topological Charges in Exfoliated Fe 5-xGeTe 2. ACS NANO 2024; 18:4216-4228. [PMID: 38262067 DOI: 10.1021/acsnano.3c09234] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2024]
Abstract
Fe5-xGeTe2 is a promising two-dimensional (2D) van der Waals (vdW) magnet for practical applications, given its magnetic properties. These include Curie temperatures above room temperature, and topological spin textures─TST (both merons and skyrmions), responsible for a pronounced anomalous Hall effect (AHE) and its topological counterpart (THE), which can be harvested for spintronics. Here, we show that both the AHE and THE can be amplified considerably by just adjusting the thickness of exfoliated Fe5-xGeTe2, with THE becoming observable even in zero magnetic field due to a field-induced unbalance in topological charges. Using a complementary suite of techniques, including electronic transport, Lorentz transmission electron microscopy, and micromagnetic simulations, we reveal the emergence of substantial coercive fields upon exfoliation, which are absent in the bulk, implying thickness-dependent magnetic interactions that affect the TST. We detected a "magic" thickness t ≈ 30 nm where the formation of TST is maximized, inducing large magnitudes for the topological charge density (∼6.45 × 1020 cm-2), and the concomitant anomalous (ρxyA,max ≃22.6 μΩ cm) and topological (ρxyu,T 1≃5 μΩ cm) Hall resistivities at T ≈ 120 K. These values for ρxyA,max and ρxyu,T are higher than those found in magnetic topological insulators and, so far, the largest reported for 2D magnets. The hitherto unobserved THE under zero magnetic field could provide a platform for the writing and electrical detection of TST aiming at energy-efficient devices based on vdW ferromagnets.
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Affiliation(s)
- Alex Moon
- National High Magnetic Field Laboratory, 1800 E. Paul Dirac Dr., Tallahassee, Florida 32310, United States
- Department of Physics, Florida State University, 77 Chieftan Way, Tallahassee, Florida 32306, United States
| | - Yue Li
- Materials Science Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
| | - Conor McKeever
- Institute for Condensed Matter and Complex Systems, School of Physics and Astronomy, The University of Edinburgh, Edinburgh EH9 3FD, U.K
| | - Brian W Casas
- National High Magnetic Field Laboratory, 1800 E. Paul Dirac Dr., Tallahassee, Florida 32310, United States
| | - Moises Bravo
- Department of Chemistry and Biochemistry, Baylor University, Waco, Texas 76798, United States
| | - Wenkai Zheng
- National High Magnetic Field Laboratory, 1800 E. Paul Dirac Dr., Tallahassee, Florida 32310, United States
- Department of Physics, Florida State University, 77 Chieftan Way, Tallahassee, Florida 32306, United States
| | - Juan Macy
- National High Magnetic Field Laboratory, 1800 E. Paul Dirac Dr., Tallahassee, Florida 32310, United States
- Department of Physics, Florida State University, 77 Chieftan Way, Tallahassee, Florida 32306, United States
| | - Amanda K Petford-Long
- Materials Science Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
- Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208, United States
| | - Gregory T McCandless
- Department of Chemistry and Biochemistry, Baylor University, Waco, Texas 76798, United States
| | - Julia Y Chan
- Department of Chemistry and Biochemistry, Baylor University, Waco, Texas 76798, United States
| | - Charudatta Phatak
- Materials Science Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
- Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208, United States
| | - Elton J G Santos
- Institute for Condensed Matter and Complex Systems, School of Physics and Astronomy, The University of Edinburgh, Edinburgh EH9 3FD, U.K
- Higgs Centre for Theoretical Physics, The University of Edinburgh, Edinburgh EH9 3FD, U.K
| | - Luis Balicas
- National High Magnetic Field Laboratory, 1800 E. Paul Dirac Dr., Tallahassee, Florida 32310, United States
- Department of Physics, Florida State University, 77 Chieftan Way, Tallahassee, Florida 32306, United States
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14
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Li Z, Zhang H, Li G, Guo J, Wang Q, Deng Y, Hu Y, Hu X, Liu C, Qin M, Shen X, Yu R, Gao X, Liao Z, Liu J, Hou Z, Zhu Y, Fu X. Room-temperature sub-100 nm Néel-type skyrmions in non-stoichiometric van der Waals ferromagnet Fe 3-xGaTe 2 with ultrafast laser writability. Nat Commun 2024; 15:1017. [PMID: 38310096 PMCID: PMC10838308 DOI: 10.1038/s41467-024-45310-2] [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: 08/08/2023] [Accepted: 01/19/2024] [Indexed: 02/05/2024] Open
Abstract
Realizing room-temperature magnetic skyrmions in two-dimensional van der Waals ferromagnets offers unparalleled prospects for future spintronic applications. However, due to the intrinsic spin fluctuations that suppress atomic long-range magnetic order and the inherent inversion crystal symmetry that excludes the presence of the Dzyaloshinskii-Moriya interaction, achieving room-temperature skyrmions in 2D magnets remains a formidable challenge. In this study, we target room-temperature 2D magnet Fe3GaTe2 and unveil that the introduction of iron-deficient into this compound enables spatial inversion symmetry breaking, thus inducing a significant Dzyaloshinskii-Moriya interaction that brings about room-temperature Néel-type skyrmions with unprecedentedly small size. To further enhance the practical applications of this finding, we employ a homemade in-situ optical Lorentz transmission electron microscopy to demonstrate ultrafast writing of skyrmions in Fe3-xGaTe2 using a single femtosecond laser pulse. Our results manifest the Fe3-xGaTe2 as a promising building block for realizing skyrmion-based magneto-optical functionalities.
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Grants
- This work was supported by the National Key Research and Development Program of China at grant No. 2020YFA0309300, Science and Technology Projects in Guangzhou (grant No. 202201000008), the National Natural Science Foundation of China (NSFC) at grant No. 12304146, 11974191, 12127803, 52322108, 52271178, U22A20117 and 12241403, China Postdoctoral Science Foundation (2023M741828), Guangdong Basic and Applied Basic Research Foundation (grant No. 2021B1515120047 and 2023B1515020112), the Natural Science Foundation of Tianjin at grant No. 20JCJQJC00210, the 111 Project at grant No. B23045, and the “Fundamental Research Funds for the Central Universities”, Nankai University (grant No. 63213040, C029211101, C02922101, ZB22000104 and DK2300010207). This work was supported by the Synergetic Extreme Condition User Facility (SECUF).
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Affiliation(s)
- Zefang Li
- Ultrafast Electron Microscopy Laboratory, The MOE Key Laboratory of Weak-Light Nonlinear Photonics, School of Physics, Nankai University, Tianjin, China
| | - Huai Zhang
- Guangdong Provincial Key Laboratory of Optical Information Materials and Technology, Institute for Advanced Materials, South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou, China
| | - Guanqi Li
- School of Integrated Circuits, Guangdong University of Technology, Guangzhou, China
| | - Jiangteng Guo
- Ultrafast Electron Microscopy Laboratory, The MOE Key Laboratory of Weak-Light Nonlinear Photonics, School of Physics, Nankai University, Tianjin, China
| | - Qingping Wang
- School of Physics and Electronic and Electrical Engineering, Aba Teachers University, Wenchuan, China
| | - Ying Deng
- Ultrafast Electron Microscopy Laboratory, The MOE Key Laboratory of Weak-Light Nonlinear Photonics, School of Physics, Nankai University, Tianjin, China
| | - Yue Hu
- Ultrafast Electron Microscopy Laboratory, The MOE Key Laboratory of Weak-Light Nonlinear Photonics, School of Physics, Nankai University, Tianjin, China
| | - Xuange Hu
- Ultrafast Electron Microscopy Laboratory, The MOE Key Laboratory of Weak-Light Nonlinear Photonics, School of Physics, Nankai University, Tianjin, China
| | - Can Liu
- Ultrafast Electron Microscopy Laboratory, The MOE Key Laboratory of Weak-Light Nonlinear Photonics, School of Physics, Nankai University, Tianjin, China
| | - Minghui Qin
- Guangdong Provincial Key Laboratory of Optical Information Materials and Technology, Institute for Advanced Materials, South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou, China
| | - Xi Shen
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, China
| | - Richeng Yu
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, China
| | - Xingsen Gao
- Guangdong Provincial Key Laboratory of Optical Information Materials and Technology, Institute for Advanced Materials, South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou, China
| | - Zhimin Liao
- State Key Laboratory for Mesoscopic Physics and Frontiers Science Center for Nano-optoelectronics, School of Physics, Peking University, Beijing, China
| | - Junming Liu
- Guangdong Provincial Key Laboratory of Optical Information Materials and Technology, Institute for Advanced Materials, South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou, China
- Laboratory of Solid State Microstructures and Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, China
| | - Zhipeng Hou
- Guangdong Provincial Key Laboratory of Optical Information Materials and Technology, Institute for Advanced Materials, South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou, China.
| | - Yimei Zhu
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, New York, USA.
| | - Xuewen Fu
- Ultrafast Electron Microscopy Laboratory, The MOE Key Laboratory of Weak-Light Nonlinear Photonics, School of Physics, Nankai University, Tianjin, China.
- School of Materials Science and Engineering, Smart Sensing Interdisciplinary Science Center, Nankai University, Tianjin, China.
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15
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Gong B, Wang L, Wang S, Yu Z, Xiong L, Xiong R, Liu Q, Zhang Y. Optimizing skyrmionium movement and stability via stray magnetic fields in trilayer nanowire constructs. Phys Chem Chem Phys 2024; 26:4716-4723. [PMID: 38251958 DOI: 10.1039/d3cp05340g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2024]
Abstract
Skyrmioniums, known for their unique transport and regulatory properties, are emerging as potential cornerstones for future data storage systems. However, the stability of skyrmionium movement faces considerable challenges due to the skyrmion Hall effect, which is induced by deformation. In response, our research introduces an innovative solution: we utilized micro-magnetic simulations to create a sandwiched trilayer nanowire structure augmented with a stray magnetic field. This combination effectively guides the skyrmionium within the ferromagnetic (FM) layer. Our empirical investigations reveal that the use of a stray magnetic field not only reduces the size of the skyrmionium but also amplifies its stability. This dual-effect proficiently mitigates the deformation of skyrmionium movement and boosts their thermal stability. We find these positive outcomes are most pronounced at a particular intensity of the stray magnetic field. Importantly, the required stray magnetic field can be generated using a heavy metal (HM1) layer of suitable thickness, rendering the practical application of this approach plausible in real-world experiments. Additionally, we analyze the functioning mechanism based on the Landau-Lifshitz-Gilbert (LLG) equation and energy variation. We also develop a deep spiking neural network (DSNN), which achieves a remarkable recognition accuracy of 97%. This achievement is realized through supervised learning via the spike timing dependent plasticity rule (STDP), considering the nanostructure as an artificial synapse device that corresponds to the electrical properties of the nanostructure. In conclusion, our study provides invaluable insights for the design of innovative information storage devices utilizing skyrmionium technology. By tackling the issues presented by the skyrmion Hall effect, we outline a feasible route for the practical application of this advanced technology. Our research, therefore, serves as a robust platform for continued investigations in this field.
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Affiliation(s)
- 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.
- Fujian Provincial Key Laboratory of Semiconductors and Applications, Collaborative Innovation Center for Optoelectronic Semiconductors and Efficient Devices, Department of Physics, Xiamen University, Xiamen 361005, P. R. China
| | - Luowen Wang
- 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.
| | - Sunan Wang
- 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.
| | - 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.
| | - 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.
| | - Rui Xiong
- Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education, School of Physics and Technology, Wuhan University, Wuhan 430072, China
| | - Qingbo Liu
- 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.
| | - Yue Zhang
- School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan, 430074, China
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16
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Takeda H, Kawano M, Tamura K, Akazawa M, Yan J, Waki T, Nakamura H, Sato K, Narumi Y, Hagiwara M, Yamashita M, Hotta C. Magnon thermal Hall effect via emergent SU(3) flux on the antiferromagnetic skyrmion lattice. Nat Commun 2024; 15:566. [PMID: 38263303 PMCID: PMC10805809 DOI: 10.1038/s41467-024-44793-3] [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: 03/26/2023] [Accepted: 01/02/2024] [Indexed: 01/25/2024] Open
Abstract
Complexity of quantum phases of matter is often understood theoretically by using gauge structures, as is recognized by the [Formula: see text] and U(1) gauge theory description of spin liquids in frustrated magnets. Anomalous Hall effect of conducting electrons can intrinsically arise from a U(1) gauge expressing the spatial modulation of ferromagnetic moments or from an SU(2) gauge representing the spin-orbit coupling effect. Similarly, in insulating ferro and antiferromagnets, the magnon contribution to anomalous transports is explained in terms of U(1) and SU(2) fluxes present in the ordered magnetic structure. Here, we report thermal Hall measurements of MnSc2S4 in an applied field up to 14 T, for which we consider an emergent higher rank SU(3) flux, controlling the magnon transport. The thermal Hall coefficient takes a substantial value when the material enters a three-sublattice antiferromagnetic skyrmion phase, which is in agreement with the linear spin-wave theory. In our description, magnons are dressed with SU(3) gauge field, which is a mixture of three species of U(1) gauge fields originating from the slowly varying magnetic moments on these sublattices.
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Affiliation(s)
- Hikaru Takeda
- Institute for Solid State Physics, University of Tokyo, Kashiwa, 277-8581, Japan.
| | - Masataka Kawano
- Department of Physics, Technical University of Munich, 85748, Garching, Germany.
| | - Kyo Tamura
- Institute for Solid State Physics, University of Tokyo, Kashiwa, 277-8581, Japan
| | - Masatoshi Akazawa
- Institute for Solid State Physics, University of Tokyo, Kashiwa, 277-8581, Japan
| | - Jian Yan
- Institute for Solid State Physics, University of Tokyo, Kashiwa, 277-8581, Japan
| | - Takeshi Waki
- Department of Materials Science and Engineering, Kyoto University, Kyoto, 606-8501, Japan
| | - Hiroyuki Nakamura
- Department of Materials Science and Engineering, Kyoto University, Kyoto, 606-8501, Japan
| | - Kazuki Sato
- Center for Advanced High Magnetic Field Science (AHMF), Graduate School of Science, Osaka University, Toyonaka, Osaka, 560-0043, Japan
| | - Yasuo Narumi
- Center for Advanced High Magnetic Field Science (AHMF), Graduate School of Science, Osaka University, Toyonaka, Osaka, 560-0043, Japan
| | - Masayuki Hagiwara
- Center for Advanced High Magnetic Field Science (AHMF), Graduate School of Science, Osaka University, Toyonaka, Osaka, 560-0043, Japan
| | - Minoru Yamashita
- Institute for Solid State Physics, University of Tokyo, Kashiwa, 277-8581, Japan
| | - Chisa Hotta
- Department of Basic Science, University of Tokyo, Meguro-ku, Tokyo, 153-8902, Japan
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17
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Gao L, Prokhorenko S, Nahas Y, Bellaiche L. Dynamical Control of Topology in Polar Skyrmions via Twisted Light. PHYSICAL REVIEW LETTERS 2024; 132:026902. [PMID: 38277608 DOI: 10.1103/physrevlett.132.026902] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Revised: 09/23/2023] [Accepted: 11/08/2023] [Indexed: 01/28/2024]
Abstract
Twisted light carries a nonzero orbital angular momentum, that can be transferred from light to electrons and particles ranging from nanometers to micrometers. Up to now, the interplay between twisted light with dipolar systems has scarcely been explored, though the latter bear abundant forms of topologies such as skyrmions and embrace strong light-matter coupling. Here, using first-principles-based simulations, we show that twisted light can excite and drive dynamical polar skyrmions and transfer its nonzero winding number to ferroelectric ultrathin films. The skyrmion is successively created and annihilated alternately at the two interfaces, and experiences a periodic transition from a markedly "Bloch" to "Néel" character, accompanied with the emergence of a "Bloch point" topological defect with vanishing polarization. The dynamical evolution of skyrmions is connected to a constant jump of topological number between "0" and "1" over time. These intriguing phenomena are found to have an electrostatic origin. Our study thus demonstrates that, and explains why this unique light-matter interaction can be very powerful in creating and manipulating topological solitons in functional materials.
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Affiliation(s)
- Lingyuan Gao
- Physics Department and Institute for Nanoscience and Engineering, University of Arkansas, Fayetteville, Arkansas 72701, USA
| | - Sergei Prokhorenko
- Physics Department and Institute for Nanoscience and Engineering, University of Arkansas, Fayetteville, Arkansas 72701, USA
| | - Yousra Nahas
- Physics Department and Institute for Nanoscience and Engineering, University of Arkansas, Fayetteville, Arkansas 72701, USA
| | - Laurent Bellaiche
- Physics Department and Institute for Nanoscience and Engineering, University of Arkansas, Fayetteville, Arkansas 72701, USA
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18
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Lu C, Wang B, Fang X, Tsai DP, Zhu W, Song Q, Deng X, He T, Gong X, Luo H, Wang Z, Dai X, Shi Y, Cheng X. Nanoparticle Deep-Subwavelength Dynamics Empowered by Optical Meron-Antimeron Topology. NANO LETTERS 2024; 24:104-113. [PMID: 37943097 DOI: 10.1021/acs.nanolett.3c03351] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2023]
Abstract
Optical meron is a type of nonplanar topological texture mainly observed in surface plasmon polaritons and highly symmetric points of photonic crystals in the reciprocal space. Here, we report Poynting-vector merons formed at the real space of a photonic crystal for a Γ-point illumination. Optical merons can be utilized for subwavelength-resolution manipulation of nanoparticles, resembling a topological Hall effect on electrons via magnetic merons. In particular, staggered merons and antimerons impose strong radiation pressure on large gold nanoparticles (AuNPs), while focused hot spots in antimerons generate dominant optical gradient forces on small AuNPs. Synergistically, differently sized AuNPs in a still environment can be trapped or orbit in opposite directions, mimicking a coupled galaxy system. They can also be separated with a 10 nm precision when applying a flow velocity of >1 mm/s. Our study unravels a novel way to exploit topological textures for optical manipulation with deep-subwavelength precision and switchable topology in a lossless environment.
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Affiliation(s)
- Chengfeng Lu
- Institute of Precision Optical Engineering, School of Physics Science and Engineering, Tongji University, Shanghai 200092, China
- Technology Innovation Center of Mass Spectrometry for State Market Regulation, Center for Advanced Measurement Science, National Institute of Metrology, Beijing 100029, China
- MOE Key Laboratory of Advanced Micro-Structured Materials, Shanghai 200092, China
- Shanghai Institute of Intelligent Science and Technology, Tongji University, Shanghai 200092, China
- Shanghai Frontiers Science Center of Digital Optics, Shanghai 200092, China
| | - Bo Wang
- State Key Laboratory of Advanced Optical Communication Systems and Networks, School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Xiang Fang
- Technology Innovation Center of Mass Spectrometry for State Market Regulation, Center for Advanced Measurement Science, National Institute of Metrology, Beijing 100029, China
| | - Din Ping Tsai
- Department of Electrical Engineering, City University of Hong Kong, Kowloon 999077, Hong Kong
| | - Weiming Zhu
- School of Optoelectronic Science and Engineering, University of Electronic Science and Technology of China, Chengdu 610054, China
| | - Qinghua Song
- Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China
| | - Xiao Deng
- Institute of Precision Optical Engineering, School of Physics Science and Engineering, Tongji University, Shanghai 200092, China
- MOE Key Laboratory of Advanced Micro-Structured Materials, Shanghai 200092, China
- Shanghai Institute of Intelligent Science and Technology, Tongji University, Shanghai 200092, China
- Shanghai Frontiers Science Center of Digital Optics, Shanghai 200092, China
| | - Tao He
- Institute of Precision Optical Engineering, School of Physics Science and Engineering, Tongji University, Shanghai 200092, China
- MOE Key Laboratory of Advanced Micro-Structured Materials, Shanghai 200092, China
- Shanghai Institute of Intelligent Science and Technology, Tongji University, Shanghai 200092, China
- Shanghai Frontiers Science Center of Digital Optics, Shanghai 200092, China
| | - Xiaoyun Gong
- Technology Innovation Center of Mass Spectrometry for State Market Regulation, Center for Advanced Measurement Science, National Institute of Metrology, Beijing 100029, China
| | - Hong Luo
- Institute of Precision Optical Engineering, School of Physics Science and Engineering, Tongji University, Shanghai 200092, China
- Technology Innovation Center of Mass Spectrometry for State Market Regulation, Center for Advanced Measurement Science, National Institute of Metrology, Beijing 100029, China
- MOE Key Laboratory of Advanced Micro-Structured Materials, Shanghai 200092, China
- Shanghai Institute of Intelligent Science and Technology, Tongji University, Shanghai 200092, China
- Shanghai Frontiers Science Center of Digital Optics, Shanghai 200092, China
| | - Zhanshan Wang
- Institute of Precision Optical Engineering, School of Physics Science and Engineering, Tongji University, Shanghai 200092, China
- MOE Key Laboratory of Advanced Micro-Structured Materials, Shanghai 200092, China
- Shanghai Institute of Intelligent Science and Technology, Tongji University, Shanghai 200092, China
- Shanghai Frontiers Science Center of Digital Optics, Shanghai 200092, China
| | - Xinhua Dai
- Technology Innovation Center of Mass Spectrometry for State Market Regulation, Center for Advanced Measurement Science, National Institute of Metrology, Beijing 100029, China
| | - Yuzhi Shi
- Institute of Precision Optical Engineering, School of Physics Science and Engineering, Tongji University, Shanghai 200092, China
- MOE Key Laboratory of Advanced Micro-Structured Materials, Shanghai 200092, China
- Shanghai Institute of Intelligent Science and Technology, Tongji University, Shanghai 200092, China
- Shanghai Frontiers Science Center of Digital Optics, Shanghai 200092, China
| | - Xinbin Cheng
- Institute of Precision Optical Engineering, School of Physics Science and Engineering, Tongji University, Shanghai 200092, China
- MOE Key Laboratory of Advanced Micro-Structured Materials, Shanghai 200092, China
- Shanghai Institute of Intelligent Science and Technology, Tongji University, Shanghai 200092, China
- Shanghai Frontiers Science Center of Digital Optics, Shanghai 200092, China
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19
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Zhang Y, Shi M, Wang W, Xu X, Tian M, Song D, Du H. Room-Temperature Zero-Field kπ-Skyrmions and Their Field-Driven Evolutions in Chiral Nanodisks. NANO LETTERS 2023; 23:10205-10212. [PMID: 37942916 DOI: 10.1021/acs.nanolett.3c02746] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2023]
Abstract
Target skyrmion, characterized by a central skyrmion surrounded by a series of concentric cylinder domains known as kπ-skyrmions (k ≥ 2), holds promise as a novel storage state in next-generation memories. However, target skyrmions comprising one or more concentric cylindrical domains have not been observed in chiral magnets, particularly at room temperature. In this study, we experimentally achieved kπ-skyrmions (k = 2, 3, and 4) with diameters of ∼220, 320, and 410 nm, respectively, and room-temperature stability under zero magnetic field by tightly confining these topological spin textures in β-Mn-type Co8Zn10Mn2 nanodisks. The magnetic configurations and their field-driven evolutions were simultaneously investigated by using in situ off-axis electron holography. In combination with numerical simulations, we further investigated the dependence of kmax on the nanodisk diameter. These findings highlight the potential of kπ-skyrmions as information carriers and offer insights into manipulation of kπ-skyrmions in the future.
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Affiliation(s)
- Yongsen Zhang
- University of Science and Technology of China, Hefei 230026, China
- Anhui Province Key Laboratory of Condensed Matter Physics at Extreme Conditions, High Magnetic Field Laboratory, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, Anhui 230031, China
| | - Meng Shi
- University of Science and Technology of China, Hefei 230026, China
- Anhui Province Key Laboratory of Condensed Matter Physics at Extreme Conditions, High Magnetic Field Laboratory, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, Anhui 230031, China
| | - Weiwei Wang
- Information Materials and Intelligent Sensing Laboratory of Anhui Province, Key Laboratory of Structure and Functional Regulation of Hybrid Materials of Ministry of Education, Institutes of Physical Science and Information Technology, Anhui University, Hefei 230601, China
| | - Xitong Xu
- Anhui Province Key Laboratory of Condensed Matter Physics at Extreme Conditions, High Magnetic Field Laboratory, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, Anhui 230031, China
| | - Mingliang Tian
- Anhui Province Key Laboratory of Condensed Matter Physics at Extreme Conditions, High Magnetic Field Laboratory, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, Anhui 230031, China
| | - Dongsheng Song
- Information Materials and Intelligent Sensing Laboratory of Anhui Province, Key Laboratory of Structure and Functional Regulation of Hybrid Materials of Ministry of Education, Institutes of Physical Science and Information Technology, Anhui University, Hefei 230601, China
| | - Haifeng Du
- Anhui Province Key Laboratory of Condensed Matter Physics at Extreme Conditions, High Magnetic Field Laboratory, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, Anhui 230031, China
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20
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Roy P, Zhang D, Mazza AR, Cucciniello N, Kunwar S, Zeng H, Chen A, Jia Q. Manipulating topological Hall-like signatures by interface engineering in epitaxial ruthenate/manganite heterostructures. NANOSCALE 2023; 15:17589-17598. [PMID: 37873761 DOI: 10.1039/d3nr02407e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2023]
Abstract
Topologically protected non-trivial spin textures (e.g. skyrmions) give rise to a novel phenomenon called the topological Hall effect (THE) and have promising implications in future energy-efficient nanoelectronic and spintronic devices. Here, we have studied the Hall effect in SrRuO3/La0.42Ca0.58MnO3 (SRO/LCMO) bilayers. Our investigation suggests that pure SRO has hard and soft magnetic characteristics but the anomalous Hall effect (AHE) in SRO is governed by the high coercivity phase. We have shown that the proximity effect of a soft magnetic LCMO on SRO plays a critical role in interfacial magnetic coupling and transport properties in SRO. Upon reducing the SRO thickness in the bilayer, the proximity effect becomes the dominant feature, enhancing the magnitude and temperature range of THE-like signatures. The THE-like features in bilayers can be explained by a diffusive Berry phase transition model in the presence of an emergent magnetic state due to interface coupling. This work provides an alternative understanding of THE-like signatures and their manipulation in SRO-based heterostructures, bilayers and superlattices.
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Affiliation(s)
- Pinku Roy
- Department of Materials Design and Innovation, University at Buffalo - The State University of New York, Buffalo, NY 14260, USA.
- Center for Integrated Nanotechnologies (CINT), Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
| | - Di Zhang
- Center for Integrated Nanotechnologies (CINT), Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
| | - Alessandro R Mazza
- Center for Integrated Nanotechnologies (CINT), Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
| | - Nicholas Cucciniello
- Department of Materials Design and Innovation, University at Buffalo - The State University of New York, Buffalo, NY 14260, USA.
- Center for Integrated Nanotechnologies (CINT), Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
| | - Sundar Kunwar
- Center for Integrated Nanotechnologies (CINT), Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
| | - Hao Zeng
- Department of Physics, University at Buffalo - The State University of New York, Buffalo, NY 14260, USA
| | - Aiping Chen
- Center for Integrated Nanotechnologies (CINT), Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
| | - Quanxi Jia
- Department of Materials Design and Innovation, University at Buffalo - The State University of New York, Buffalo, NY 14260, USA.
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21
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He B, Tomasello R, Luo X, Zhang R, Nie Z, Carpentieri M, Han X, Finocchio G, Yu G. All-Electrical 9-Bit Skyrmion-Based Racetrack Memory Designed with Laser Irradiation. NANO LETTERS 2023; 23:9482-9490. [PMID: 37818857 DOI: 10.1021/acs.nanolett.3c02978] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/13/2023]
Abstract
Racetrack memories with magnetic skyrmions have recently been proposed as a promising storage technology. To be appealing, several challenges must still be faced for the deterministic generation of skyrmions, their high-fidelity transfer, and accurate reading. Here, we realize the first proof-of-concept of a 9-bit skyrmion racetrack memory with all-electrical controllable functionalities implemented in the same device. The key ingredient is the generation of a tailored nonuniform distribution of magnetic anisotropy via laser irradiation in order to (i) create a well-defined skyrmion nucleation center, (ii) define the memory cells hosting the information coded as the presence/absence of skyrmions, and (iii) improve the signal-to-noise ratio of anomalous Hall resistance measurements. This work introduces a strategy to unify previous findings and predictions for the development of a generation of racetrack memories with robust control of skyrmion nucleation and position, as well as effective skyrmion electrical detection.
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Affiliation(s)
- Bin He
- 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
| | - Riccardo Tomasello
- Department of Electrical and Information Engineering, Politecnico of Bari, Bari 70125, Italy
| | - 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
| | - Ran Zhang
- 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
| | - Zhuyang Nie
- 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
| | - Mario Carpentieri
- Department of Electrical and Information Engineering, Politecnico of Bari, Bari 70125, Italy
| | - 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
| | - Giovanni Finocchio
- Department of Mathematical and Computer Sciences, Physical Sciences and Earth Sciences, University of Messina, Messina 98166, Italy
| | - 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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Pohl D, Lee Y, Kriegner D, Beckert S, Schneider S, Rellinghaus B, Thomas A. Probing magnetic properties at the nanoscale: in-situ Hall measurements in a TEM. Sci Rep 2023; 13:14871. [PMID: 37684274 PMCID: PMC10491587 DOI: 10.1038/s41598-023-41985-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Accepted: 09/04/2023] [Indexed: 09/10/2023] Open
Abstract
We report on advanced in-situ magneto-transport measurements in a transmission electron microscope. The approach allows for concurrent magnetic imaging and high resolution structural and chemical characterization of the same sample. Proof-of-principle in-situ Hall measurements on presumably undemanding nickel thin films supported by micromagnetic simulations reveal that in samples with non-trivial structures and/or compositions, detailed knowledge of the latter is indispensable for a thorough understanding and reliable interpretation of the magneto-transport data. The proposed in-situ approach is thus expected to contribute to a better understanding of the Hall signatures in more complex magnetic textures.
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Affiliation(s)
- Darius Pohl
- Dresden Center for Nanoanalysis (DCN), cfaed, TU Dresden, 01062, Dresden, Germany.
| | - Yejin Lee
- Leibniz Institute for Solid State and Materials Research, IFW Dresden, 01062, Dresden, Germany
| | - Dominik Kriegner
- Institute of Physics, Academy of Sciences of the Czech Republic, Cukrovarnická 10, 162 00, Praha 6, Czech Republic
- Institute of Solid State and Materials Physics, TU Dresden, 01062, Dresden, Germany
| | - Sebastian Beckert
- Institute of Solid State and Materials Physics, TU Dresden, 01062, Dresden, Germany
| | - Sebastian Schneider
- Dresden Center for Nanoanalysis (DCN), cfaed, TU Dresden, 01062, Dresden, Germany
| | - Bernd Rellinghaus
- Dresden Center for Nanoanalysis (DCN), cfaed, TU Dresden, 01062, Dresden, Germany.
| | - Andy Thomas
- Leibniz Institute for Solid State and Materials Research, IFW Dresden, 01062, Dresden, Germany.
- Institute of Solid State and Materials Physics, TU Dresden, 01062, Dresden, Germany.
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23
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Ghosh S, Low A, Ghorai S, Mandal K, Thirupathaiah S. Tuning of electrical, magnetic, and topological properties of magnetic Weyl semimetal Mn3+xGe by Fe doping. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2023; 35:485701. [PMID: 37604158 DOI: 10.1088/1361-648x/acf262] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2023] [Accepted: 08/21/2023] [Indexed: 08/23/2023]
Abstract
We report on the tuning of electrical, magnetic, and topological properties of the magnetic Weyl semimetal (Mn3+xGe) by Fe doping at the Mn site, Mn(3+x)-δFeδGe (δ= 0, 0.30, and 0.62). Fe doping significantly changes the electrical and magnetic properties of Mn3+xGe. The resistivity of the parent compound displays metallic behavior, the system withδ= 0.30 of Fe doping exhibits semiconducting or bad-metallic behavior, and the system withδ= 0.62 of Fe doping demonstrates a metal-insulator transition at around 100 K. Further, we observe that the Fe doping increases in-plane ferromagnetism, magnetocrystalline anisotropy, and induces a spin-glass state at low temperatures. Surprisingly, topological Hall state has been noticed at a Fe doping ofδ= 0.30 that is not found in the parent compound or withδ= 0.62 of Fe doping. In addition, spontaneous anomalous Hall effect observed in the parent system is significantly reduced with increasing Fe doping concentration.
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Affiliation(s)
- Susanta Ghosh
- Department of Condensed Matter and Materials Physics, S. N. Bose National Centre for Basic Sciences, Kolkata, West Bengal 700106, India
| | - Achintya Low
- Department of Condensed Matter and Materials Physics, S. N. Bose National Centre for Basic Sciences, Kolkata, West Bengal 700106, India
| | - Soumya Ghorai
- Department of Condensed Matter and Materials Physics, S. N. Bose National Centre for Basic Sciences, Kolkata, West Bengal 700106, India
| | - Kalyan Mandal
- Department of Condensed Matter and Materials Physics, S. N. Bose National Centre for Basic Sciences, Kolkata, West Bengal 700106, India
| | - Setti Thirupathaiah
- Department of Condensed Matter and Materials Physics, S. N. Bose National Centre for Basic Sciences, Kolkata, West Bengal 700106, India
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24
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Kato YD, Okamura Y, Hirschberger M, Tokura Y, Takahashi Y. Topological magneto-optical effect from skyrmion lattice. Nat Commun 2023; 14:5416. [PMID: 37669971 PMCID: PMC10480175 DOI: 10.1038/s41467-023-41203-y] [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: 04/05/2023] [Accepted: 08/23/2023] [Indexed: 09/07/2023] Open
Abstract
The magnetic skyrmion is a spin-swirling topological object characterized by its nontrivial winding number, holding potential for next-generation spintronic devices. While optical readout has become increasingly important towards the high integration and ultrafast operation of those devices, the optical response of skyrmions has remained elusive. Here, we show the magneto-optical Kerr effect (MOKE) induced by the skyrmion formation, i.e., topological MOKE, in Gd2PdSi3. The significantly enhanced optical rotation found in the skyrmion phase demonstrates the emergence of topological MOKE, exemplifying the light-skyrmion interaction arising from the emergent gauge field. This gauge field in momentum space causes a dramatic reconstruction of the electronic band structure, giving rise to magneto-optical activity ranging up to the sub-eV region. The present findings pave a way for photonic technology based on skyrmionics.
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Affiliation(s)
- Yoshihiro D Kato
- Department of Applied Physics and Quantum Phase Electronics Center, University of Tokyo, Tokyo, 113-8656, Japan
| | - Yoshihiro Okamura
- Department of Applied Physics and Quantum Phase Electronics Center, University of Tokyo, Tokyo, 113-8656, Japan.
| | - Max Hirschberger
- Department of Applied Physics and Quantum Phase Electronics Center, University of Tokyo, Tokyo, 113-8656, Japan
- RIKEN Center for Emergent Matter Science (CEMS), Wako, 351-0198, Japan
| | - Yoshinori Tokura
- Department of Applied Physics and Quantum Phase Electronics Center, University of Tokyo, Tokyo, 113-8656, Japan
- RIKEN Center for Emergent Matter Science (CEMS), Wako, 351-0198, Japan
- Tokyo College, University of Tokyo, Tokyo, 113-8656, Japan
| | - Youtarou Takahashi
- Department of Applied Physics and Quantum Phase Electronics Center, University of Tokyo, Tokyo, 113-8656, Japan.
- RIKEN Center for Emergent Matter Science (CEMS), Wako, 351-0198, Japan.
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25
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Bao H, Tian H, Li X, Ma X, Xu C, Yang Y, Wu D. Manipulating two-dimensional magnetic states via electric field and pressure. Phys Chem Chem Phys 2023; 25:22244-22249. [PMID: 37577831 DOI: 10.1039/d3cp02043f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/15/2023]
Abstract
Topological spin configurations have been an intriguing topic due to the exotic transport properties and promising applications in spintronic devices. The discovery of two-dimensional (2D) magnetic materials such as CrI3 provides new platforms for manipulating magnetic structures. Here, by first-principles calculations and Monte Carlo methods, we investigated the exchange interaction and magnetic states of 2D van der Waals ferromagnetic/ferroelectric heterostructure CrI3/In2Se3. By switching the polarization in the ferroelectric In2Se3 layer under an electric field and changing the interlayer distance between CrI3 and In2Se3 under pressure, four spin configurations, ferromagnetic states, topological domain wall skyrmions, topological bimerons, and stripe domains can be realized. These striking tunable magnetic states can be understood from the Dzyaloshinskii-Moriya interaction and single-ion anisotropy parameters being modified by switching the polarization and changing the interlayer distance. Our results of controllable topological/non-topological spin states broaden the spin phenomena and potential of spintronic applications in van der Waals heterostructures.
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Affiliation(s)
- Hengxing Bao
- National Laboratory of Solid State Microstructures, Nanjing University, Nanjing 210093, China
- Jiangsu Key Laboratory of Artificial Functional Materials, Department of Materials Science and Engineering, Nanjing University, Nanjing 210093, China.
| | - Hao Tian
- School of Physics and Electronic Engineering, Zhengzhou Normal University, Zhengzhou 450044, China.
| | - Xu Li
- National Laboratory of Solid State Microstructures, Nanjing University, Nanjing 210093, China
- Jiangsu Key Laboratory of Artificial Functional Materials, Department of Materials Science and Engineering, Nanjing University, Nanjing 210093, China.
| | - Xingyue Ma
- National Laboratory of Solid State Microstructures, Nanjing University, Nanjing 210093, China
- Jiangsu Key Laboratory of Artificial Functional Materials, Department of Materials Science and Engineering, Nanjing University, Nanjing 210093, China.
| | - Changsong Xu
- Key Laboratory of Computational Physical Sciences (Ministry of Education), Institute of Computational Physical Sciences, State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433, China
| | - Yurong Yang
- National Laboratory of Solid State Microstructures, Nanjing University, Nanjing 210093, China
- Jiangsu Key Laboratory of Artificial Functional Materials, Department of Materials Science and Engineering, Nanjing University, Nanjing 210093, China.
| | - Di Wu
- National Laboratory of Solid State Microstructures, Nanjing University, Nanjing 210093, China
- Jiangsu Key Laboratory of Artificial Functional Materials, Department of Materials Science and Engineering, Nanjing University, Nanjing 210093, China.
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26
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Okumura S, Kravchuk VP, Garst M. Instability of Magnetic Skyrmion Strings Induced by Longitudinal Spin Currents. PHYSICAL REVIEW LETTERS 2023; 131:066702. [PMID: 37625063 DOI: 10.1103/physrevlett.131.066702] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Revised: 06/13/2023] [Accepted: 07/11/2023] [Indexed: 08/27/2023]
Abstract
It is well established that spin-transfer torques exerted by in-plane spin currents give rise to a motion of magnetic skyrmions resulting in a skyrmion Hall effect. In films of finite thickness or in three-dimensional bulk samples the skyrmions extend in the third direction forming a string. We demonstrate that a spin current flowing longitudinally along the skyrmion string instead induces a Goldstone spin wave instability. Our analytical results are confirmed by micromagnetic simulations of both a single string as well as string lattices, suggesting that the instability eventually breaks the strings. A longitudinal current is thus able to melt the skyrmion string lattice via a nonequilibrium phase transition. For films of finite thickness or in the presence of disorder a threshold current will be required, and we estimate the latter assuming weak collective pinning.
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Affiliation(s)
- Shun Okumura
- Department of Applied Physics, the University of Tokyo, Tokyo 113-8656, Japan
| | - Volodymyr P Kravchuk
- Institut für Theoretische Festkörperphysik, Karlsruher Institut für Technologie, D-76131 Karlsruhe, Germany
- Bogolyubov Institute for Theoretical Physics of National Academy of Sciences of Ukraine, 03143 Kyiv, Ukraine
| | - Markus Garst
- Institut für Theoretische Festkörperphysik, Karlsruher Institut für Technologie, D-76131 Karlsruhe, Germany
- Institute for Quantum Materials and Technology, Karlsruhe Institute of Technology, D-76131 Karlsruhe, Germany
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27
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Roychowdhury S, Samanta K, Yanda P, Malaman B, Yao M, Schnelle W, Guilmeau E, Constantinou P, Chandra S, Borrmann H, Vergniory MG, Strocov V, Shekhar C, Felser C. Interplay between Magnetism and Topology: Large Topological Hall Effect in an Antiferromagnetic Topological Insulator, EuCuAs. J Am Chem Soc 2023. [PMID: 37267070 DOI: 10.1021/jacs.3c04249] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Magnetic interactions in combination with nontrivial band structures can give rise to several exotic physical properties such as a large anomalous Hall effect, the anomalous Nernst effect, and the topological Hall effect (THE). Antiferromagnetic (AFM) materials exhibit the THE due to the presence of nontrivial spin structures. EuCuAs crystallizes in a hexagonal structure with an AFM ground state (Néel temperature ∼ 16 K). In this work, we observe a large topological Hall resistivity of ∼7.4 μΩ-cm at 13 K which is significantly higher than the giant topological Hall effect of Gd2PdSi3 (∼3 μΩ-cm). Neutron diffraction experiments reveal that the spins form a transverse conical structure during the metamagnetic transition, resulting in the large THE. In addition, by controlling the magnetic ordering structure of EuCuAs with an external magnetic field, several fascinating topological states such as Dirac and Weyl semimetals have been revealed. These results suggest the possibility of spintronic devices based on antiferromagnets with tailored noncoplanar spin configurations.
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Affiliation(s)
| | - Kartik Samanta
- Max Planck Institute for Chemical Physics of Solids, 01187 Dresden, Germany
| | - Premakumar Yanda
- Max Planck Institute for Chemical Physics of Solids, 01187 Dresden, Germany
| | - Bernard Malaman
- Centre National de la Recherche Scientifique, Institut Jean Lamour, Université de Lorraine, Nancy 54011, France
| | - Mengyu Yao
- Max Planck Institute for Chemical Physics of Solids, 01187 Dresden, Germany
| | - Walter Schnelle
- Max Planck Institute for Chemical Physics of Solids, 01187 Dresden, Germany
| | - Emmanuel Guilmeau
- CRISMAT, CNRS, Normandie University, ENSICAEN, UNICAEN, 14000 Caen, France
| | | | - Sushmita Chandra
- Max Planck Institute for Chemical Physics of Solids, 01187 Dresden, Germany
| | - Horst Borrmann
- Max Planck Institute for Chemical Physics of Solids, 01187 Dresden, Germany
| | - Maia G Vergniory
- Max Planck Institute for Chemical Physics of Solids, 01187 Dresden, Germany
- Donostia International Physics Center, 20018 Donostia-San Sebastian, Spain
| | - Vladimir Strocov
- Swiss Light Source, Paul Scherrer Institute, CH-5232 Villigen-PSI, Switzerland
| | - Chandra Shekhar
- Max Planck Institute for Chemical Physics of Solids, 01187 Dresden, Germany
| | - Claudia Felser
- Max Planck Institute for Chemical Physics of Solids, 01187 Dresden, Germany
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28
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Yu X, Liu Y, Iakoubovskii KV, Nakajima K, Kanazawa N, Nagaosa N, Tokura Y. Realization and Current-Driven Dynamics of Fractional Hopfions and Their Ensembles in a Helimagnet FeGe. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2210646. [PMID: 36871172 DOI: 10.1002/adma.202210646] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Revised: 02/19/2023] [Indexed: 05/19/2023]
Abstract
3D topological spin textures-hopfions-are predicted in helimagnetic systems but are not experimentally confirmed thus far. By utilizing an external magnetic field and electric current in the present study, 3D topological spin textures are realized, including fractional hopfions with nonzero topological index, in a skyrmion-hosting helimagnet FeGe. Microsecond current pulses are employed to control the dynamics of the expansion and contraction of a bundle composed of a skyrmion and a fractional hopfion, as well as its current-driven Hall motion. This research approach has demonstrated the novel electromagnetic properties of fractional hopfions and their ensembles in helimagnetic systems.
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Affiliation(s)
- Xiuzhen Yu
- RIKEN Center for Emergent Matter Science (CEMS), Wako, 351-0198, Japan
| | - Yizhou Liu
- RIKEN Center for Emergent Matter Science (CEMS), Wako, 351-0198, Japan
| | | | - Kiyomi Nakajima
- RIKEN Center for Emergent Matter Science (CEMS), Wako, 351-0198, Japan
| | - Naoya Kanazawa
- Department of Applied Physics, University of Tokyo, Tokyo, 113-8656, Japan
| | - Naoto Nagaosa
- RIKEN Center for Emergent Matter Science (CEMS), Wako, 351-0198, Japan
- Department of Applied Physics, University of Tokyo, Tokyo, 113-8656, 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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29
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Kolincio KK, Hirschberger M, Masell J, Arima TH, Nagaosa N, Tokura Y. Kagome Lattice Promotes Chiral Spin Fluctuations. PHYSICAL REVIEW LETTERS 2023; 130:136701. [PMID: 37067304 DOI: 10.1103/physrevlett.130.136701] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Revised: 12/23/2022] [Accepted: 01/13/2023] [Indexed: 06/19/2023]
Abstract
Dynamical spin fluctuations in magnets can be endowed with a slight bent toward left- or right-handed chirality by Dzyaloshinskii-Moriya interactions. However, little is known about the crucial role of lattice geometry on these chiral spin fluctuations and on fluctuation-related transport anomalies driven by the quantum-mechanical (Berry) phase of conduction electrons. Via thermoelectric Nernst effect and electric Hall effect experiments, we detect chiral spin fluctuations in the paramagnetic regime of a kagome lattice magnet; these signals are largely absent in a comparable triangular lattice magnet. Supported by Monte Carlo calculations, we identify lattices with at least two dissimilar plaquettes as most promising for Berry phase phenomena driven by thermal fluctuations in paramagnets.
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Affiliation(s)
- Kamil K Kolincio
- RIKEN Center for Emergent Matter Science (CEMS), Wako, Saitama 351-0198, Japan
- Faculty of Applied Physics and Mathematics, Gdańsk University of Technology, Narutowicza 11/12, 80-233 Gdańsk, Poland
| | - Max Hirschberger
- RIKEN Center for Emergent Matter Science (CEMS), Wako, Saitama 351-0198, Japan
- Department of Applied Physics and Quantum-Phase Electronics Center (QPEC), The University of Tokyo, Bunkyo-ku, Tokyo 113-8656, Japan
| | - Jan Masell
- RIKEN Center for Emergent Matter Science (CEMS), Wako, Saitama 351-0198, Japan
- Institute of Theoretical Solid State Physics, Karlsruhe Institute of Technology (KIT), 76049 Karlsruhe, Germany
| | - Taka-Hisa Arima
- RIKEN Center for Emergent Matter Science (CEMS), Wako, Saitama 351-0198, Japan
- Department of Advanced Materials Science, The University of Tokyo, Kashiwa 277-8561, Japan
| | - Naoto Nagaosa
- RIKEN Center for Emergent Matter Science (CEMS), Wako, Saitama 351-0198, Japan
- Department of Applied Physics and Quantum-Phase Electronics Center (QPEC), The University of Tokyo, Bunkyo-ku, Tokyo 113-8656, Japan
| | - Yoshinori Tokura
- RIKEN Center for Emergent Matter Science (CEMS), Wako, Saitama 351-0198, Japan
- Department of Applied Physics and Quantum-Phase Electronics Center (QPEC), The University of Tokyo, Bunkyo-ku, Tokyo 113-8656, Japan
- Tokyo College, The University of Tokyo, Bunkyo-ku, Tokyo 113-8656, Japan
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30
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Magadeev EB, Vakhitov RM, Kanbekov RR. Two methods of forming flat magnetic structures in magnetic films with topological features. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2023; 35:215801. [PMID: 36913732 DOI: 10.1088/1361-648x/acc3ea] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Accepted: 03/13/2023] [Indexed: 06/18/2023]
Abstract
The paper investigates vortex-like structures observed in ferromagnetic films with strong uniaxial easy-plane anisotropy in the presence of topological features in them. Two approaches to the creation of such features are considered, namely, perforation of the sample and the inclusion of artificial defects in it, and a theorem on their equivalence is proved, according to which the structure of magnetic inhomogeneities arising in the film itself turns out to be the same for both approaches. In the second case, the properties of magnetic vortices formed on defects are also studied, and for cylindrical defects explicit analytical expressions for the energy and configuration of vortices are obtained, which are applicable in a wide range of values of material parameters.
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Affiliation(s)
- E B Magadeev
- Laboratory of Design of New Materials, Bashkir State University, 450076 Bashkortostan, Russia
| | - R M Vakhitov
- Laboratory of Design of New Materials, Bashkir State University, 450076 Bashkortostan, Russia
| | - R R Kanbekov
- Laboratory of Design of New Materials, Bashkir State University, 450076 Bashkortostan, Russia
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31
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Li X, Koo J, Zhu Z, Behnia K, Yan B. Field-linear anomalous Hall effect and Berry curvature induced by spin chirality in the kagome antiferromagnet Mn 3Sn. Nat Commun 2023; 14:1642. [PMID: 36964128 PMCID: PMC10039076 DOI: 10.1038/s41467-023-37076-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2022] [Accepted: 03/01/2023] [Indexed: 03/26/2023] Open
Abstract
During the past two decades, it has been established that a non-trivial electron wave-function topology generates an anomalous Hall effect (AHE), which shows itself as a Hall conductivity non-linear in magnetic field. Here, we report on an unprecedented case of field-linear AHE. In Mn3Sn, a kagome magnet, the out-of-plane Hall response, which shows an abrupt jump, was discovered to be a case of AHE. We find now that the in-plane Hall response, which is perfectly linear in magnetic field, is set by the Berry curvature of the wavefunction. The amplitude of the Hall response and its concomitant Nernst signal exceed by far what is expected in the semiclassical picture. We argue that magnetic field induces out-of-plane spin canting and thereafter gives rise to nontrivial spin chirality on the kagome lattice. In band structure, we find that the spin chirality modifies the topology by gapping out Weyl nodal lines unknown before, accounting for the AHE observed. Our work reveals intriguing unification of real-space Berry phase from spin chirality and momentum-space Berry curvature in a kagome material.
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Affiliation(s)
- Xiaokang Li
- Wuhan National High Magnetic Field Center and School of Physics, Huazhong University of Science and Technology, Wuhan, 430074, China.
| | - Jahyun Koo
- Department of Condensed Matter Physics, Weizmann Institute of Science, 7610001, Rehovot, Israel
| | - Zengwei Zhu
- Wuhan National High Magnetic Field Center and School of Physics, Huazhong University of Science and Technology, Wuhan, 430074, China.
| | - Kamran Behnia
- Laboratoire de Physique et d'Étude des Matériaux (ESPCI-CNRS-Sorbonne Université), PSL Research University, 75005, Paris, France
| | - Binghai Yan
- Department of Condensed Matter Physics, Weizmann Institute of Science, 7610001, Rehovot, Israel.
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32
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Shen J, Gao J, Yi C, Li M, Zhang S, Yang J, Wang B, Zhou M, Huang R, Wei H, Yang H, Shi Y, Xu X, Gao HJ, Shen B, Li G, Wang Z, Liu E. Magnetic-field modulation of topological electronic state and emergent magneto-transport in a magnetic Weyl semimetal. Innovation (N Y) 2023; 4:100399. [PMID: 36923023 PMCID: PMC10009535 DOI: 10.1016/j.xinn.2023.100399] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Accepted: 02/14/2023] [Indexed: 02/22/2023] Open
Abstract
The modulation of topological electronic state by an external magnetic field is highly desired for condensed-matter physics. Schemes to achieve this have been proposed theoretically, but few can be realized experimentally. Here, combining transverse transport, theoretical calculations, and scanning tunneling microscopy/spectroscopy (STM/S) investigations, we provide an observation that the topological electronic state, accompanied by an emergent magneto-transport phenomenon, was modulated by applying magnetic field through induced non-collinear magnetism in the magnetic Weyl semimetal EuB6. A giant unconventional anomalous Hall effect (UAHE) is found during the magnetization re-orientation from easy axes to hard ones in magnetic field, with a UAHE peak around the low field of 5 kOe. Under the reasonable spin-canting effect, the folding of the topological anti-crossing bands occurs, generating a strong Berry curvature that accounts for the observed UAHE. Field-dependent STM/S reveals a highly synchronous evolution of electronic density of states, with a dI/dV peak around the same field of 5 kOe, which provides evidence to the folded bands and excited UAHE by external magnetic fields. This finding elucidates the connection between the real-space non-collinear magnetism and the k-space topological electronic state and establishes a novel manner to engineer the magneto-transport behaviors of correlated electrons for future topological spintronics.
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Affiliation(s)
- Jianlei Shen
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.,Key Laboratory of Magnetic Molecules and Magnetic Information Materials of Ministry of Education & Research Institute of Materials Science, Shanxi Normal University, Taiyuan 030000, China
| | - Jiacheng Gao
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.,School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Changjiang Yi
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Meng Li
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.,School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Shen Zhang
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.,School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jinying Yang
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.,School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Binbin Wang
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Min Zhou
- Key Laboratory of Cryogenics, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | - Rongjin Huang
- Key Laboratory of Cryogenics, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | - Hongxiang Wei
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Haitao Yang
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Youguo Shi
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.,Songshan Lake Materials Laboratory, Dongguan 523808, China
| | - Xiaohong Xu
- Key Laboratory of Magnetic Molecules and Magnetic Information Materials of Ministry of Education & Research Institute of Materials Science, Shanxi Normal University, Taiyuan 030000, China
| | - Hong-Jun Gao
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.,Songshan Lake Materials Laboratory, Dongguan 523808, China
| | - Baogen Shen
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.,School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China.,Ningbo Institute of Materials Technology & Engineering, Chinese Academy of Sciences, Ningbo, Zhejiang 315201, China.,Ganjiang Innovation Academy, Chinese Academy of Sciences, Ganzhou, Jiangxi 341000, China
| | - Geng Li
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.,Songshan Lake Materials Laboratory, Dongguan 523808, China
| | - Zhijun Wang
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.,School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Enke Liu
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.,Songshan Lake Materials Laboratory, Dongguan 523808, China
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33
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Fujisawa Y, Pardo-Almanza M, Hsu CH, Mohamed A, Yamagami K, Krishnadas A, Chang G, Chuang FC, Khoo KH, Zang J, Soumyanarayanan A, Okada Y. Widely Tunable Berry Curvature in the Magnetic Semimetal Cr 1+ δ Te 2. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2207121. [PMID: 36642840 DOI: 10.1002/adma.202207121] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Revised: 11/17/2022] [Indexed: 06/17/2023]
Abstract
Magnetic semimetals have increasingly emerged as lucrative platforms hosting spin-based topological phenomena in real and momentum spaces. Cr1+ δ Te2 is a self-intercalated magnetic transition metal dichalcogenide (TMD), which exhibits topological magnetism and tunable electron filling. While recent studies have explored real-space Berry curvature effects, similar considerations of momentum-space Berry curvature are lacking. Here, the electronic structure and transport properties of epitaxial Cr1+ δ Te2 thin films are systematically investigated over a range of doping, δ (0.33 - 0.71). Spectroscopic experiments reveal the presence of a characteristic semi-metallic band region, which shows a rigid like energy shift with δ. Transport experiments show that the intrinsic component of the anomalous Hall effect (AHE) is sizable and undergoes a sign flip across δ. Finally, density functional theory calculations establish a link between the doping evolution of the band structure and AHE: the AHE sign flip is shown to emerge from the sign change of the Berry curvature, as the semi-metallic band region crosses the Fermi energy. These findings underscore the increasing relevance of momentum-space Berry curvature in magnetic TMDs and provide a unique platform for intertwining topological physics in real and momentum spaces.
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Affiliation(s)
- Yuita Fujisawa
- Quantum Materials Science Unit, Okinawa Institute of Science and Technology (OIST), Okinawa, 904-0495, Japan
| | - Markel Pardo-Almanza
- Quantum Materials Science Unit, Okinawa Institute of Science and Technology (OIST), Okinawa, 904-0495, Japan
| | - Chia-Hsiu Hsu
- Quantum Materials Science Unit, Okinawa Institute of Science and Technology (OIST), Okinawa, 904-0495, Japan
- Department of Physics, National Sun Yat-sen University, Kaohsiung, 80424, Taiwan
- Physics Division, National Center for Theoretical Sciences, Taipei, 10617, Taiwan
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore, 637371, Singapore
| | - Atwa Mohamed
- Quantum Materials Science Unit, Okinawa Institute of Science and Technology (OIST), Okinawa, 904-0495, Japan
| | - Kohei Yamagami
- Quantum Materials Science Unit, Okinawa Institute of Science and Technology (OIST), Okinawa, 904-0495, Japan
| | - Anjana Krishnadas
- Quantum Materials Science Unit, Okinawa Institute of Science and Technology (OIST), Okinawa, 904-0495, Japan
| | - Guoqing Chang
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore, 637371, Singapore
| | - Feng-Chuan Chuang
- Department of Physics, National Sun Yat-sen University, Kaohsiung, 80424, Taiwan
- Physics Division, National Center for Theoretical Sciences, Taipei, 10617, Taiwan
- Center for Theoretical and Computational Physics, National Sun Yat-sen University, Kaohsiung, 80424, Taiwan
| | - Khoong Hong Khoo
- Institute of High Performance Computing, Agency for Science Technology and Research, Singapore, 138632, Singapore
| | - Jiadong Zang
- Department of Physics and Astronomy, University of New Hampshire, Durham, NH 03824, USA
- Materials Science Program, University of New Hampshire, Durham, NH 03824, USA
| | - Anjan Soumyanarayanan
- Department of Physics, National University of Singapore, Singapore, 117551, Singapore
- Institute of Materials Research and Engineering, Agency for Science Technology and Research, Singapore, 138634, Singapore
| | - Yoshinori Okada
- Quantum Materials Science Unit, Okinawa Institute of Science and Technology (OIST), Okinawa, 904-0495, Japan
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34
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Paul N, Zhang Y, Fu L. Giant proximity exchange and flat Chern band in 2D magnet-semiconductor heterostructures. SCIENCE ADVANCES 2023; 9:eabn1401. [PMID: 36827369 DOI: 10.1126/sciadv.abn1401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Accepted: 01/24/2023] [Indexed: 06/18/2023]
Abstract
van der Waals (vdW) heterostructures formed by two-dimensional (2D) magnets and semiconductors have provided a fertile ground for fundamental science and spintronics. We present first-principles calculations finding a proximity exchange splitting of 14 meV (equivalent to an effective Zeeman field of 120 T) in the vdW magnet-semiconductor heterostructure MoS 2/CrBr 3, leading to a 2D spin-polarized half-metal with carrier densities ranging up to 1013 cm-2. We consequently explore the effect of large exchange coupling on the electronic band structure when the magnetic layer hosts chiral spin textures such as skyrmions. A flat Chern band is found at a "magic" value of magnetization [Formula: see text] for Schrödinger electrons, and it generally occurs for Dirac electrons. The magnetic proximity-induced anomalous Hall effect enables transport-based detection of chiral spin textures, and flat Chern bands provide an avenue for engineering various strongly correlated states.
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Affiliation(s)
- Nisarga Paul
- Department of Physics, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Yang Zhang
- Department of Physics, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Liang Fu
- Department of Physics, Massachusetts Institute of Technology, Cambridge, MA, USA
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35
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Dai B, Wu D, Razavi SA, Xu S, He H, Shu Q, Jackson M, Mahfouzi F, Huang H, Pan Q, Cheng Y, Qu T, Wang T, Tai L, Wong K, Kioussis N, Wang KL. Electric field manipulation of spin chirality and skyrmion dynamic. SCIENCE ADVANCES 2023; 9:eade6836. [PMID: 36791189 PMCID: PMC9931210 DOI: 10.1126/sciadv.ade6836] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Accepted: 01/12/2023] [Indexed: 06/18/2023]
Abstract
The Dzyaloshinskii-Moriya interaction (DMI) is an antisymmetric exchange interaction that stabilizes spin chirality. One scientific and technological challenge is understanding and controlling the interaction between spin chirality and electric field. In this study, we investigate an unconventional electric field effect on interfacial DMI, skyrmion helicity, and skyrmion dynamics in a system with broken inversion symmetry. We design heterostructures with a 3d-5d atomic orbital interface to demonstrate the gate bias control of the DMI energy and thus transform the DMI between opposite chiralities. Furthermore, we use this voltage-controlled DMI (VCDMI) to manipulate the skyrmion spin texture. As a result, a type of intermediate skyrmion with a unique helicity is created, and its motion can be controlled and made to go straight. Our work shows the effective control of spin chirality, skyrmion helicity, and skyrmion dynamics by VCDMI. It promotes the emerging field of voltage-controlled chiral interactions and voltage-controlled skyrmionics.
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Affiliation(s)
- Bingqian Dai
- Departments of Electrical and Computer Engineering, Physics and Astronomy, and Material Science and Engineering, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Di Wu
- Departments of Electrical and Computer Engineering, Physics and Astronomy, and Material Science and Engineering, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Seyed Armin Razavi
- Departments of Electrical and Computer Engineering, Physics and Astronomy, and Material Science and Engineering, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Shijie Xu
- Departments of Electrical and Computer Engineering, Physics and Astronomy, and Material Science and Engineering, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Haoran He
- Departments of Electrical and Computer Engineering, Physics and Astronomy, and Material Science and Engineering, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Qingyuan Shu
- Departments of Electrical and Computer Engineering, Physics and Astronomy, and Material Science and Engineering, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Malcolm Jackson
- Departments of Electrical and Computer Engineering, Physics and Astronomy, and Material Science and Engineering, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Farzad Mahfouzi
- Department of Physics and Astronomy, California State University, Northridge, Los Angeles, CA 91330-8268, USA
| | - Hanshen Huang
- Departments of Electrical and Computer Engineering, Physics and Astronomy, and Material Science and Engineering, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Quanjun Pan
- Departments of Electrical and Computer Engineering, Physics and Astronomy, and Material Science and Engineering, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Yang Cheng
- Departments of Electrical and Computer Engineering, Physics and Astronomy, and Material Science and Engineering, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Tao Qu
- Departments of Electrical and Computer Engineering, Physics and Astronomy, and Material Science and Engineering, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Tianyi Wang
- Departments of Electrical and Computer Engineering, Physics and Astronomy, and Material Science and Engineering, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Lixuan Tai
- Departments of Electrical and Computer Engineering, Physics and Astronomy, and Material Science and Engineering, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Kin Wong
- Departments of Electrical and Computer Engineering, Physics and Astronomy, and Material Science and Engineering, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Nicholas Kioussis
- Department of Physics and Astronomy, California State University, Northridge, Los Angeles, CA 91330-8268, USA
| | - Kang L. Wang
- Departments of Electrical and Computer Engineering, Physics and Astronomy, and Material Science and Engineering, University of California, Los Angeles, Los Angeles, CA 90095, USA
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36
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Zuo S, Qiao K, Zhang Y, Zhao T, Jiang C, Shen B. Spontaneous Biskyrmion Lattice in a Centrosymmetric Rhombohedral Rare-Earth Magnet with Easy-Plane Anisotropy. NANO LETTERS 2023; 23:550-557. [PMID: 36633430 DOI: 10.1021/acs.nanolett.2c04001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Magnetic skyrmion and its derivatives have demonstrated fascinating topological behaviors with potential applications in future spintronic devices. Despite the recent progress, the spontaneous skyrmion lattice and successive topological transition in the magnets with easy-plane magnetic anisotropy are still elusive especially at room temperature. Here, in a centrosymmetric rhombohedral Nd2Co17 magnet with easy-plane magnetic anisotropy, spontaneous biskyrmions are observed over a wide temperature range across room temperature, and then evolve into enclosed in-plane domains with nanometric size due to the enhancement of the planar magnetic anisotropy. The spontaneous generation of the biskyrmion lattice and its evolution along different crystal orientations demonstrate the crucial role of intrinsic bi-anisotropy and demagnetization effects. This discovery provides a fundamental insight into the nature of topological magnetic textures in easy-plane anisotropy materials and suggests an arena to explore the topological states in rare-earth magnets as well as their applications in spintronics.
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Affiliation(s)
- Shulan Zuo
- School of Materials Science and Engineering, Beihang University, Beijing100191, P. R. China
| | - Kaiming Qiao
- School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing100083, P. R. China
| | - Ying Zhang
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing100190, P. R. China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong523808, P. R. China
| | - Tongyun Zhao
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing100190, P. R. China
| | - Chengbao Jiang
- School of Materials Science and Engineering, Beihang University, Beijing100191, P. R. China
| | - Baogen Shen
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing100190, P. R. China
- Ningbo Institute of Materials Technology & Engineering, Chinese Academy of Sciences, Ningbo, Zhejiang315201, P. R. China
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37
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Hall Effect Anisotropy in the Paramagnetic Phase of Ho 0.8Lu 0.2B 12 Induced by Dynamic Charge Stripes. Molecules 2023; 28:molecules28020676. [PMID: 36677734 PMCID: PMC9863903 DOI: 10.3390/molecules28020676] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Revised: 12/22/2022] [Accepted: 12/31/2022] [Indexed: 01/11/2023] Open
Abstract
A detailed study of charge transport in the paramagnetic phase of the cage-cluster dodecaboride Ho0.8Lu0.2B12 with an instability both of the fcc lattice (cooperative Jahn−Teller effect) and the electronic structure (dynamic charge stripes) was carried out at temperatures 1.9−300 K in magnetic fields up to 80 kOe. Four mono-domain single crystals of Ho0.8Lu0.2B12 samples with different crystal axis orientation were investigated in order to establish the singularities of Hall effect, which develop due to (i) the electronic phase separation (stripes) and (ii) formation of the disordered cage-glass state below T*~60 K. It was demonstrated that a considerable intrinsic anisotropic positive component ρanxy appears at low temperatures in addition to the ordinary negative Hall resistivity contribution in magnetic fields above 40 kOe applied along the [001] and [110] axes. A relation between anomalous components of the resistivity tensor ρanxy~ρanxx1.7 was found for H||[001] below T*~60 K, and a power law ρanxy~ρanxx0.83 for the orientation H||[110] at temperatures T < TS~15 K. It is argued that below characteristic temperature TS~15 K the anomalous odd ρanxy(T) and even ρanxx(T) parts of the resistivity tensor may be interpreted in terms of formation of long chains in the filamentary structure of fluctuating charges (stripes). We assume that these ρanxy(H||[001]) and ρanxy(H||[110]) components represent the intrinsic (Berry phase contribution) and extrinsic (skew scattering) mechanism, respectively. Apart from them, an additional ferromagnetic contribution to both isotropic and anisotropic components in the Hall signal was registered and attributed to the effect of magnetic polarization of 5d states (ferromagnetic nano-domains) in the conduction band of Ho0.8Lu0.2B12.
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38
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Zhang C, Liu C, Zhang J, Yuan Y, Wen Y, Li Y, Zheng D, Zhang Q, Hou Z, Yin G, Liu K, Peng Y, Zhang XX. Room-Temperature Magnetic Skyrmions and Large Topological Hall Effect in Chromium Telluride Engineered by Self-Intercalation. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2205967. [PMID: 36245330 DOI: 10.1002/adma.202205967] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Revised: 10/06/2022] [Indexed: 06/16/2023]
Abstract
Room-temperature magnetic skyrmion materials exhibiting robust topological Hall effect (THE) are crucial for novel nano-spintronic devices. However, such skyrmion-hosting materials are rare in nature. In this study, a self-intercalated transition metal dichalcogenide Cr1+ x Te2 with a layered crystal structure that hosts room-temperature skyrmions and exhibits large THE is reported. By tuning the self-intercalate concentration, a monotonic control of Curie temperature from 169 to 333 K and a magnetic anisotropy transition from out-of-plane to the in-plane configuration are achieved. Based on the intercalation engineering, room-temperature skyrmions are successfully created in Cr1.53 Te2 with a Curie temperature of 295 K and a relatively weak perpendicular magnetic anisotropy. Remarkably, a skyrmion-induced topological Hall resistivity as large as ≈106 nΩ cm is observed at 290 K. Moreover, a sign reversal of THE is also found at low temperatures, which can be ascribed to other topological spin textures having an opposite topological charge to that of the skyrmions. Therefore, chromium telluride can be a new paradigm of the skyrmion material family with promising prospects for future device applications.
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Affiliation(s)
- Chenhui Zhang
- Physical Science and Engineering Division (PSE), King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Saudi Arabia
| | - Chen Liu
- Physical Science and Engineering Division (PSE), King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Saudi Arabia
| | - Junwei Zhang
- School of Materials and Energy and Electron Microscopy Centre of Lanzhou University, Lanzhou University, Lanzhou, 730000, China
| | - Youyou Yuan
- Core Labs, King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Saudi Arabia
| | - Yan Wen
- Physical Science and Engineering Division (PSE), King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Saudi Arabia
| | - Yan Li
- Physical Science and Engineering Division (PSE), King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Saudi Arabia
| | - Dongxing Zheng
- Physical Science and Engineering Division (PSE), King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Saudi Arabia
| | - Qiang Zhang
- Core Technology Platforms, New York University Abu Dhabi, Abu Dhabi, 129188, United Arab Emirates
| | - Zhipeng Hou
- Guangdong Provincial Key Laboratory of Optical Information Materials and Technology & Institute for Advanced Materials, South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou, 510006, China
- National Center for International Research on Green Optoelectronics, South China Normal University, Guangzhou, 510006, China
| | - Gen Yin
- Physics Department, Georgetown University, Washington, DC, 20057, USA
| | - Kai Liu
- Physics Department, Georgetown University, Washington, DC, 20057, USA
| | - Yong Peng
- School of Materials and Energy and Electron Microscopy Centre of Lanzhou University, Lanzhou University, Lanzhou, 730000, China
| | - Xi-Xiang Zhang
- Physical Science and Engineering Division (PSE), King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Saudi Arabia
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39
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Liu Y, Watanabe H, Nagaosa N. Emergent Magnetomultipoles and Nonlinear Responses of a Magnetic Hopfion. PHYSICAL REVIEW LETTERS 2022; 129:267201. [PMID: 36608193 DOI: 10.1103/physrevlett.129.267201] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Revised: 10/13/2022] [Accepted: 12/06/2022] [Indexed: 06/17/2023]
Abstract
The three-dimensional emergent magnetic field B^{e} of a magnetic hopfion gives rise to emergent magnetomultipoles in a similar manner to the multipoles of classical electromagnetic field. Here, we show that the nonlinear responses of a hopfion are characterized by its emergent magnetic toroidal moment T_{z}^{e}=1/2∫(r×B^{e})_{z}dV and emergent magnetic octupole component Γ^{e}=∫[(x^{2}+y^{2})B_{z}^{e}-xzB_{x}^{e}-yzB_{y}^{e}]dV. The hopfion exhibits nonreciprocal dynamics (nonlinear hopfion Hall effect) under an ac driving current applied along (perpendicular to) the direction of T_{z}^{e}. The sign of nonreciprocity and nonlinear Hall angle is determined by the polarity and chirality of hopfion. The nonlinear electrical transport induced by a magnetic hopfion is also discussed. This Letter reveals the vital roles of emergent magnetomultipoles in nonlinear hopfion dynamics and could stimulate further investigations on the dynamical responses of topological spin textures induced by emergent electromagnetic multipoles.
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Affiliation(s)
- Yizhou Liu
- RIKEN Center for Emergent Matter Science (CEMS), Wako, Saitama 351-0198, Japan
| | - Hikaru Watanabe
- RIKEN Center for Emergent Matter Science (CEMS), Wako, Saitama 351-0198, Japan
| | - Naoto Nagaosa
- RIKEN Center for Emergent Matter Science (CEMS), Wako, Saitama 351-0198, Japan
- Department of Applied Physics, University of Tokyo, Tokyo 113-8656, Japan
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40
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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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41
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Du Q, Hu Z, Han MG, Camino F, Zhu Y, Petrovic C. Topological Hall Effect Anisotropy in Kagome Bilayer Metal Fe_{3}Sn_{2}. PHYSICAL REVIEW LETTERS 2022; 129:236601. [PMID: 36563198 DOI: 10.1103/physrevlett.129.236601] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Revised: 07/07/2022] [Accepted: 10/28/2022] [Indexed: 06/17/2023]
Abstract
Kagome lattice materials have attracted growing interest for their topological properties and flatbands in electronic structure. We present a comprehensive study on the anisotropy and out-of-plane electric transport in Fe_{3}Sn_{2}, a metal with bilayer of Fe kagome planes and with massive Dirac fermions that features high-temperature noncollinear magnetic structure and magnetic skyrmions. For the electrical current path along the c axis, in micron-size crystals, we found a large topological Hall effect over a wide temperature range down to spin-glass state. Twofold and fourfold angular magnetoresistance are observed for different magnetic phases, reflecting the competition of magnetic interactions and magnetic anisotropy in kagome lattice that preserve robust topological Hall effect for inter-kagome bilayer currents. This provides new insight into the anisotropy in Fe_{3}Sn_{2}, of interest in skyrmionic-bubble application-related micron-size devices.
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Affiliation(s)
- Qianheng Du
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, New York 11973, USA
- Department of Materials Science and Chemical Engineering, Stony Brook University, Stony Brook, New York 11790, USA
| | - Zhixiang Hu
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, New York 11973, USA
- Department of Materials Science and Chemical Engineering, Stony Brook University, Stony Brook, New York 11790, USA
| | - Myung-Geun Han
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, New York 11973, USA
| | - Fernando Camino
- Center for Functional Nanomaterials, Brookhaven National Laboratory, Upton, New York 11973, USA
| | - Yimei Zhu
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, New York 11973, USA
| | - C Petrovic
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, New York 11973, USA
- Department of Materials Science and Chemical Engineering, Stony Brook University, Stony Brook, New York 11790, USA
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42
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Verma N, Addison Z, Randeria M. Unified theory of the anomalous and topological Hall effects with phase-space Berry curvatures. SCIENCE ADVANCES 2022; 8:eabq2765. [PMID: 36351017 PMCID: PMC9645717 DOI: 10.1126/sciadv.abq2765] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Accepted: 09/19/2022] [Indexed: 06/16/2023]
Abstract
Spontaneously broken time-reversal symmetry in magnetic materials leads to a Hall response, with a nonzero voltage transverse to an applied current, even in the absence of external magnetic fields. It is common to analyze the Hall resistivity of chiral magnets as the sum of two terms: an anomalous Hall effect arising from spin-orbit coupling and a topological Hall signal coming from skyrmions, which are topologically nontrivial spin textures. The theoretical justification for such a decomposition has long remained an open problem. Using a controlled semiclassical approach that includes all phase-space Berry curvatures, we show that the solution of the Boltzmann equation leads to a Hall resistivity that is just the sum of an anomalous term arising from momentum-space curvature and a topological term related to the real-space curvature. We also present numerically exact results from a Kubo formalism that complement the semiclassical approach.
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43
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Criado JC, Schenk S, Spannowsky M, Hatton PD, Turnbull LA. Simulating anti-skyrmions on a lattice. Sci Rep 2022; 12:19179. [DOI: 10.1038/s41598-022-22043-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2022] [Accepted: 10/07/2022] [Indexed: 11/11/2022] Open
Abstract
AbstractMagnetic skyrmions are meta-stable spin structures that naturally emerge in magnetic materials. While a vast amount of effort has gone into the study of their properties, their counterpart of opposite topological charge, the anti-skyrmion, has not received as much attention. We aim to close this gap by deploying Monte Carlo simulations of spin-lattice systems in order to investigate which interactions support anti-skyrmions, as well as skyrmions of Bloch and Néel type. We find that the combination of ferromagnetic exchange and Dzyaloshinskii–Moriya (DM) interactions is able to stabilize each of the three types, depending on the specific structure of the DM interactions. Considering a three-dimensional spin lattice model, we provide a finite-temperature phase diagram featuring a stable anti-skyrmion lattice phase for a large range of temperatures. In addition, we also shed light on the creation and annihilation processes of these anti-skyrmion tubes and study the effects of the DM interaction strength on their typical size.
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44
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Yang S, Ju TS, Kim C, Kim HJ, An K, Moon KW, Park S, Hwang C. Magnetic Field Magnitudes Needed for Skyrmion Generation in a General Perpendicularly Magnetized Film. NANO LETTERS 2022; 22:8430-8436. [PMID: 36282733 PMCID: PMC9650724 DOI: 10.1021/acs.nanolett.2c02268] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/06/2022] [Revised: 10/08/2022] [Indexed: 06/16/2023]
Abstract
Due to its topological protection, the magnetic skyrmion has been intensively studied for both fundamental aspects and spintronics applications. However, despite recent advancements in skyrmion research, the deterministic creation of isolated skyrmions in a generic perpendicularly magnetized film is still one of the most essential and challenging techniques. Here, we present a method to create magnetic skyrmions in typical perpendicular magnetic anisotropy (PMA) films by applying a magnetic field pulse and a method to determine the magnitude of the required external magnetic fields. Furthermore, to demonstrate the usefulness of this result for future skyrmion research, we also experimentally study the PMA dependence on the minimum size of skyrmions. Although field-driven skyrmion generation is unsuitable for device application, this result can provide an easier approach for obtaining isolated skyrmions, making skyrmion-based research more accessible.
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Affiliation(s)
- Seungmo Yang
- Quantum
Spin Team, Korea Research Institute of Standards
and Science, Daejeon34113, Republic of Korea
| | - Tae-Seong Ju
- Quantum
Spin Team, Korea Research Institute of Standards
and Science, Daejeon34113, Republic of Korea
- Department
of Physics, Pusan National University, Busan46241, Republic of Korea
| | - Changsoo Kim
- Quantum
Spin Team, Korea Research Institute of Standards
and Science, Daejeon34113, Republic of Korea
| | - Hyun-Joong Kim
- Quantum
Spin Team, Korea Research Institute of Standards
and Science, Daejeon34113, Republic of Korea
| | - Kyongmo An
- Quantum
Spin Team, Korea Research Institute of Standards
and Science, Daejeon34113, Republic of Korea
| | - Kyoung-Woong Moon
- Quantum
Spin Team, Korea Research Institute of Standards
and Science, Daejeon34113, Republic of Korea
| | - Sungkyun Park
- Department
of Physics, Pusan National University, Busan46241, Republic of Korea
| | - Chanyong Hwang
- Quantum
Spin Team, Korea Research Institute of Standards
and Science, Daejeon34113, Republic of Korea
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45
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Liu K, Kang C, Tian J, Song Y, She L, Liu X, Zhang W. Canonical Spin Glass and the Anomalous Hall Effect in a Centrosymmetric Ferrimagnet. J Phys Chem Lett 2022; 13:10048-10055. [PMID: 36264631 DOI: 10.1021/acs.jpclett.2c02646] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Centrosymmetric ferro/ferrimagnets provide an ideal arena for fundamental research due to their fascinating magnetic and structural characters. In this work, the Co0.8MnSn compound with a single hexagonal phase was successfully synthesized, and the magnetic phase transition and magnetic and electronic properties have been systematically investigated. Interestingly, Arrott plots and normalized magnetic entropy changes derived from the isothermal magnetizing curves may imply the first-order nature of the magnetic ordering transition around TC ∼ 121 K. The AC susceptibility analysis and detailed nonequilibrium dynamical studies (including magnetic aging, rejuvenation, and memory effects) reveal the canonical spin-glass state of Co0.8MnSn at lower temperature. Further, negative magnetoresistance and the anomalous Hall effect dominated by a commonly intrinsic term are obtained. Moreover, the field-dependent AC susceptibility data indicated that complicated and nontrivial magnetic spin textures should exist in the compound. These studies may open up further research opportunities in exploring emergent physical phenomena and potential applications in centrosymmetric magnets.
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Affiliation(s)
- Kai Liu
- Henan Key Lab of Photovoltaic Materials and Center for Topological Functional Materials, Henan University, Kaifeng475004, China
| | - Chaoyang Kang
- Henan Key Lab of Photovoltaic Materials and Center for Topological Functional Materials, Henan University, Kaifeng475004, China
| | - Jianjun Tian
- Henan Key Lab of Photovoltaic Materials and Center for Topological Functional Materials, Henan University, Kaifeng475004, China
| | - Yeheng Song
- Henan Key Lab of Photovoltaic Materials and Center for Topological Functional Materials, Henan University, Kaifeng475004, China
| | - Limin She
- Henan Key Lab of Photovoltaic Materials and Center for Topological Functional Materials, Henan University, Kaifeng475004, China
| | - Xiansheng Liu
- Henan Key Lab of Photovoltaic Materials and Center for Topological Functional Materials, Henan University, Kaifeng475004, China
| | - Weifeng Zhang
- Henan Key Lab of Photovoltaic Materials and Center for Topological Functional Materials, Henan University, Kaifeng475004, China
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46
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Tai L, Dai B, Li J, Huang H, Chong SK, Wong KL, Zhang H, Zhang P, Deng P, Eckberg C, Qiu G, He H, Wu D, Xu S, Davydov A, Wu R, Wang KL. Distinguishing the Two-Component Anomalous Hall Effect from the Topological Hall Effect. ACS NANO 2022; 16:17336-17346. [PMID: 36126321 DOI: 10.1021/acsnano.2c08155] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
In transport, the topological Hall effect (THE) presents itself as nonmonotonic features (or humps and dips) in the Hall signal and is widely interpreted as a sign of chiral spin textures, like magnetic skyrmions. However, when the anomalous Hall effect (AHE) is also present, the coexistence of two AHEs could give rise to similar artifacts, making it difficult to distinguish between genuine THE with AHE and two-component AHE. Here, we confirm genuine THE with AHE by means of transport and magneto-optical Kerr effect (MOKE) microscopy, in which magnetic skyrmions are directly observed, and find that genuine THE occurs in the transition region of the AHE. In sharp contrast, the artifact "THE" or two-component AHE occurs well beyond the saturation of the "AHE component" (under the false assumption of THE + AHE). Furthermore, we distinguish artifact "THE" from genuine THE by three methods: (1) minor loops, (2) temperature dependence, and (3) gate dependence. Minor loops of genuine THE with AHE are always within the full loop, while minor loops of the artifact "THE" may reveal a single loop that cannot fit into the "AHE component". In addition, the temperature or gate dependence of the artifact "THE" may also be accompanied by a polarity change of the "AHE component", as the nonmonotonic features vanish, while the temperature dependence of genuine THE with AHE reveals no such change. Our work may help future researchers to exercise caution and use these methods for careful examination in order to ascertain the genuine THE.
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Affiliation(s)
- Lixuan Tai
- Department of Electrical and Computer Engineering, University of California, Los Angeles, California 90095, United States
| | - Bingqian Dai
- Department of Electrical and Computer Engineering, University of California, Los Angeles, California 90095, United States
| | - Jie Li
- Department of Physics and Astronomy, University of California, Irvine, California 92697, United States
| | - Hanshen Huang
- Department of Electrical and Computer Engineering, University of California, Los Angeles, California 90095, United States
| | - Su Kong Chong
- Department of Electrical and Computer Engineering, University of California, Los Angeles, California 90095, United States
| | - Kin L Wong
- Department of Electrical and Computer Engineering, University of California, Los Angeles, California 90095, United States
| | - Huairuo Zhang
- Theiss Research, Inc., La Jolla, California 92037, United States
- Materials Science and Engineering Division, National Institute of Standards and Technology (NIST), Gaithersburg, Maryland 20899, United States
| | - Peng Zhang
- Department of Electrical and Computer Engineering, University of California, Los Angeles, California 90095, United States
| | - Peng Deng
- Department of Electrical and Computer Engineering, University of California, Los Angeles, California 90095, United States
| | - Christopher Eckberg
- Department of Electrical and Computer Engineering, University of California, Los Angeles, California 90095, United States
- Fibertek, Inc., Herndon, Virginia 20171, United States
- US Army Research Laboratory, Adelphi, Maryland 20783, United States
- US Army Research Laboratory, Playa Vista, California 90094, United States
| | - Gang Qiu
- Department of Electrical and Computer Engineering, University of California, Los Angeles, California 90095, United States
| | - Haoran He
- Department of Electrical and Computer Engineering, University of California, Los Angeles, California 90095, United States
| | - Di Wu
- Department of Electrical and Computer Engineering, University of California, Los Angeles, California 90095, United States
| | - Shijie Xu
- Department of Electrical and Computer Engineering, University of California, Los Angeles, California 90095, United States
- Shanghai Key Laboratory of Special Artificial Microstructure and Pohl Institute of Solid State Physics and School of Physics Science and Engineering, Tongji University, Shanghai 200092, China
| | - Albert Davydov
- Materials Science and Engineering Division, National Institute of Standards and Technology (NIST), Gaithersburg, Maryland 20899, United States
| | - Ruqian Wu
- Department of Physics and Astronomy, University of California, Irvine, California 92697, United States
| | - Kang L Wang
- Department of Electrical and Computer Engineering, University of California, Los Angeles, California 90095, United States
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47
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Qin G, Zhang R, Yang C, Lv X, Pei K, Yang L, Liu X, Zhang X, Che R. Magnetic-Field-Assisted Diffusion Motion of Magnetic Skyrmions. ACS NANO 2022; 16:15927-15934. [PMID: 36166823 DOI: 10.1021/acsnano.2c03046] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Studies of the diffusion dynamics of magnetic skyrmions have generated widespread interest in both fundamental physics and spintronics applications. Here we report the magnetic-field-assisted diffusion motion of skyrmions in a microstructured chiral FeGe magnet. We demonstrate the enhancement of diffusion motion of magnetic skyrmions that is manipulated and driven by an oscillatory magnetic field. Further, the directed diffusion of skyrmions is observed when an in-plane field was introduced to break the symmetry of the system. Finally, we demonstrate the application of a magnetic field can induce an arrangements transition of skyrmions assemble in microstructure, that is, from a stiff hexagonal lattice to a weak interactional isotropic state. By using a step-ascended magnetic field we finished the observation of a particle-like diffusive motion for magnetic skyrmions that transport from high-concentration regions to low-concentration regions and the diffusion flux is proportional to the concentration gradient followed Fick's law.
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Affiliation(s)
- Gang Qin
- Laboratory of Advanced Materials, Shanghai Key Lab of Molecular Catalysis and Innovative Materials, Department of Materials Science, Fudan University, Shanghai 200438, P. R. China
| | - Ruixuan Zhang
- Laboratory of Advanced Materials, Shanghai Key Lab of Molecular Catalysis and Innovative Materials, Department of Materials Science, Fudan University, Shanghai 200438, P. R. China
| | - Chendi Yang
- Laboratory of Advanced Materials, Shanghai Key Lab of Molecular Catalysis and Innovative Materials, Department of Materials Science, Fudan University, Shanghai 200438, P. R. China
| | - Xiaowei Lv
- Laboratory of Advanced Materials, Shanghai Key Lab of Molecular Catalysis and Innovative Materials, Department of Materials Science, Fudan University, Shanghai 200438, P. R. China
| | - Ke Pei
- Laboratory of Advanced Materials, Shanghai Key Lab of Molecular Catalysis and Innovative Materials, Department of Materials Science, Fudan University, Shanghai 200438, P. R. China
| | - Liting Yang
- Laboratory of Advanced Materials, Shanghai Key Lab of Molecular Catalysis and Innovative Materials, Department of Materials Science, Fudan University, Shanghai 200438, P. R. China
| | - Xianhu Liu
- Laboratory of Advanced Materials, Shanghai Key Lab of Molecular Catalysis and Innovative Materials, Department of Materials Science, Fudan University, Shanghai 200438, P. R. China
| | - Xuefeng Zhang
- Laboratory of Advanced Materials, Shanghai Key Lab of Molecular Catalysis and Innovative Materials, Department of Materials Science, Fudan University, Shanghai 200438, P. R. China
| | - Renchao Che
- Laboratory of Advanced Materials, Shanghai Key Lab of Molecular Catalysis and Innovative Materials, Department of Materials Science, Fudan University, Shanghai 200438, P. R. China
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48
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Roychowdhury S, Ochs AM, Guin SN, Samanta K, Noky J, Shekhar C, Vergniory MG, Goldberger JE, Felser C. Large Room Temperature Anomalous Transverse Thermoelectric Effect in Kagome Antiferromagnet YMn 6 Sn 6. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2022; 34:e2201350. [PMID: 35980946 DOI: 10.1002/adma.202201350] [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: 02/10/2022] [Revised: 08/03/2022] [Indexed: 06/15/2023]
Abstract
Kagome magnets possess several novel nontrivial topological features owing to the strong correlation between topology and magnetism that extends to their applications in the field of thermoelectricity. Conventional thermoelectric (TE) devices use the Seebeck effect to convert heat into electrical energy. In contrast, transverse thermoelectric devices based on the Nernst effect are attracting recent attention due to their unique transverse geometry, which uses a single material to eliminate the need for a multitude of electrical connections compared to conventional TE devices. Here, a large anomalous transverse thermoelectric effect of ≈2 µV K-1 at room temperature in a kagome antiferromagnet YMn6 Sn6 single crystal is obtained. The obtained value is larger than that of state-of-the-art canted antiferromagnetic (AFM) materials and comparable with ferromagnetic systems. The large anomalous Nernst effect (ANE) can be attributed to the net Berry curvature near the Fermi level. Furthermore, the ANE of the AFM YMn6 Sn6 exceeds the magnetization scaling relationship of conventional ferromagnets. The results clearly illustrate that AFM material YMn6 Sn6 is an ideal topological material for room-temperature transverse thermoelectric applications.
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Affiliation(s)
| | | | - Satya N Guin
- Department of Chemistry, Birla Institute of Technology and Science, Pilani - Hyderabad Campus, Hyderabad, 500078, India
| | - Kartik Samanta
- Max Planck Institute for Chemical Physics of Solids, 01187, Dresden, Germany
| | - Jonathan Noky
- Max Planck Institute for Chemical Physics of Solids, 01187, Dresden, Germany
| | - Chandra Shekhar
- Max Planck Institute for Chemical Physics of Solids, 01187, Dresden, Germany
| | - Maia G Vergniory
- Donostia International Physics Center, Donostia-San Sebastian, 20018, Spain
| | | | - Claudia Felser
- Max Planck Institute for Chemical Physics of Solids, 01187, Dresden, Germany
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49
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Paradezhenko GV, Pervishko AA, Swain N, Sengupta P, Yudin D. Spin-hedgehog-derived electromagnetic effects in itinerant magnets. Phys Chem Chem Phys 2022; 24:24317-24322. [PMID: 36173187 DOI: 10.1039/d2cp03486g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
In itinerant magnets, the indirect exchange coupling of Ruderman-Kittel-Kasuya-Yosida type is known to stabilize incommensurate spin spirals, whereas an account of higher order spin interactions favors the formation of a noncoplanar magnetic texture. This is manifested by the finite Berry phase the conduction electrons accumulate when their spins follow this texture, leading thus to the topological Hall effect. We herein utilize the effective spin model with bilinear-biquadratic exchange interactions for studying the formation of the magnetic hedgehog lattice, that represents a periodic array of magnetic anti- and monopoles and has been recently observed in the B20-type compounds, in a three-dimensional itinerant magnet. As opposed to widely used Monte Carlo simulations, we employ a neural-network-based approach for exploring the ground state spin configuration in a noncentrosymmetric crystal structure. Further, we address the topological Hall conductivity, associated with nonzero scalar spin chirality, in the itinerant magnet due to the coupling to the spin hedgehog lattice, and provide the evidence of a magneto-optic Kerr effect.
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Affiliation(s)
- G V Paradezhenko
- Skolkovo Institute of Science and Technology, Moscow 121205, Russia.
| | - A A Pervishko
- Skolkovo Institute of Science and Technology, Moscow 121205, Russia.
| | - N Swain
- MajuLab, CNRS-UCA-SU-NUS-NTU International Joint Research Unit IRL, 3654, Singapore.,Centre for Quantum Technologies, National University of Singapore, 117543, Singapore
| | - P Sengupta
- School of Physical and Mathematical Sciences, Nanyang Technological University, 637371, Singapore
| | - D Yudin
- Skolkovo Institute of Science and Technology, Moscow 121205, Russia.
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50
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Liu J, Ding B, Liang J, Li X, Yao Y, Wang W. Magnetic Skyrmionic Bubbles at Room Temperature and Sign Reversal of the Topological Hall Effect in a Layered Ferromagnet Cr 0.87Te. ACS NANO 2022; 16:13911-13918. [PMID: 36000915 DOI: 10.1021/acsnano.2c02928] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
The search for materials that exhibit topologically protected spin configurations, such as magnetic skyrmions, continues to be fueled by the promise of outstanding candidate components for spin-based applications. In this study, in situ Lorentz transmission electron microscopy directly images Bloch-type magnetic skyrmionic bubbles in a layered ferromagnet Cr0.87Te single crystal. Owing to the competition between a magnetic dipole interaction and uniaxial easy axis anisotropy, nanoscale magnetic bubbles with random chirality can be observed in a wide temperature range covering room temperature when the external magnetic field is applied along the out-of-plane direction. Moreover, high-density and stable skyrmionic bubbles are successfully realized at zero magnetic field by appropriate field-cooling manipulation. Additionally, a sign reversal of the Hall effect and the derived topological Hall effect is observed and discussed. As quasi-two-dimensional materials, the binary chromium tellurides hosting magnetic skyrmions could have many applications in low-dimensional skyrmion-based spintronic devices in an ambient atmosphere.
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Affiliation(s)
- Jun Liu
- Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Bei Ding
- Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Jinjing Liang
- Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xue Li
- Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yuan Yao
- Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
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