1
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Xu S, Dai B, Jiang Y, Xiong D, Cheng H, Tai L, Tang M, Sun Y, He Y, Yang B, Peng Y, Wang KL, Zhao W. Universal scaling law for chiral antiferromagnetism. Nat Commun 2024; 15:3717. [PMID: 38697983 PMCID: PMC11066068 DOI: 10.1038/s41467-024-46325-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Accepted: 02/22/2024] [Indexed: 05/05/2024] Open
Abstract
The chiral antiferromagnetic (AFM) materials, which have been widely investigated due to their rich physics, such as non-zero Berry phase and topology, provide a platform for the development of antiferromagnetic spintronics. Here, we find two distinctive anomalous Hall effect (AHE) contributions in the chiral AFM Mn3Pt, originating from a time-reversal symmetry breaking induced intrinsic mechanism and a skew scattering induced topological AHE due to an out-of-plane spin canting with respect to the Kagome plane. We propose a universal AHE scaling law to explain the AHE resistivity (ρ A H ) in this chiral magnet, with both a scalar spin chirality (SSC)-induced skew scattering topological AHE term,a s k and non-collinear spin-texture induced intrinsic anomalous Hall term,b i n . We found thata s k andb i n can be effectively modulated by the interfacial electron scattering, exhibiting a linear relation with the inverse film thickness. Moreover, the scaling law can explain the anomalous Hall effect in various chiral magnets and has far-reaching implications for chiral-based spintronics devices.
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Affiliation(s)
- Shijie Xu
- National Key Laboratory of Spintronics, Hangzhou International Innovation Institute, Beihang University, 311115, Hangzhou, China
- Department of Electrical and Computer Engineering, University of California, Los Angeles, CA, 90095, USA
- Shanghai Key Laboratory of Special Artificial Microstructure, Pohl Institute of Solid State Physics and School of Physics Science and Engineering, Tongji University, Shanghai, 200092, China
- Fert Beijing Institute, School of Integrated Circuit Science and Engineering, Beihang University, Beijing, 100191, China
- Hefei Innovation Research Institute, Beihang University, Hefei, China
| | - Bingqian Dai
- Department of Electrical and Computer Engineering, University of California, Los Angeles, CA, 90095, USA
| | - Yuhao Jiang
- National Key Laboratory of Spintronics, Hangzhou International Innovation Institute, Beihang University, 311115, Hangzhou, China
- Shanghai Key Laboratory of Special Artificial Microstructure, Pohl Institute of Solid State Physics and School of Physics Science and Engineering, Tongji University, Shanghai, 200092, China
| | - Danrong Xiong
- National Key Laboratory of Spintronics, Hangzhou International Innovation Institute, Beihang University, 311115, Hangzhou, China
- Fert Beijing Institute, School of Integrated Circuit Science and Engineering, Beihang University, Beijing, 100191, China
| | - Houyi Cheng
- National Key Laboratory of Spintronics, Hangzhou International Innovation Institute, Beihang University, 311115, Hangzhou, China
- Fert Beijing Institute, School of Integrated Circuit Science and Engineering, Beihang University, Beijing, 100191, China
- Hefei Innovation Research Institute, Beihang University, Hefei, China
| | - Lixuan Tai
- Department of Electrical and Computer Engineering, University of California, Los Angeles, CA, 90095, USA
| | - Meng Tang
- Shanghai Key Laboratory of Special Artificial Microstructure, Pohl Institute of Solid State Physics and School of Physics Science and Engineering, Tongji University, Shanghai, 200092, China
| | - Yadong Sun
- Shanghai Key Laboratory of Special Artificial Microstructure, Pohl Institute of Solid State Physics and School of Physics Science and Engineering, Tongji University, Shanghai, 200092, China
| | - Yu He
- National Key Laboratory of Spintronics, Hangzhou International Innovation Institute, Beihang University, 311115, Hangzhou, China
- Fert Beijing Institute, School of Integrated Circuit Science and Engineering, Beihang University, Beijing, 100191, China
| | - Baolin Yang
- School of Materials and Energy, or Electron Microscopy Centre of Lanzhou University, Lanzhou University, Lanzhou, 730000, P. R. China
| | - Yong Peng
- School of Materials and Energy, or Electron Microscopy Centre of Lanzhou University, Lanzhou University, Lanzhou, 730000, P. R. China
| | - Kang L Wang
- Department of Electrical and Computer Engineering, University of California, Los Angeles, CA, 90095, USA
| | - Weisheng Zhao
- National Key Laboratory of Spintronics, Hangzhou International Innovation Institute, Beihang University, 311115, Hangzhou, China.
- Fert Beijing Institute, School of Integrated Circuit Science and Engineering, Beihang University, Beijing, 100191, China.
- Hefei Innovation Research Institute, Beihang University, Hefei, China.
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2
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Chen H, Liu L, Zhou X, Meng Z, Wang X, Duan Z, Zhao G, Yan H, Qin P, Liu Z. Emerging Antiferromagnets for Spintronics. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024; 36:e2310379. [PMID: 38183310 DOI: 10.1002/adma.202310379] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2023] [Revised: 12/18/2023] [Indexed: 01/08/2024]
Abstract
Antiferromagnets constitute promising contender materials for next-generation spintronic devices with superior stability, scalability, and dynamics. Nevertheless, the perception of well-established ferromagnetic spintronics underpinned by spontaneous magnetization seemed to indicate the inadequacy of antiferromagnets for spintronics-their compensated magnetization has been perceived to result in uncontrollable antiferromagnetic order and subtle magnetoelectronic responses. However, remarkable advancements have been achieved in antiferromagnetic spintronics in recent years, with consecutive unanticipated discoveries substantiating the feasibility of antiferromagnet-centered spintronic devices. It is emphasized that, distinct from ferromagnets, the richness in complex antiferromagnetic crystal structures is the unique and essential virtue of antiferromagnets that can open up their endless possibilities of novel phenomena and functionality for spintronics. In this Perspective, the recent progress in antiferromagnetic spintronics is reviewed, with a particular focus on that based on several kinds of antiferromagnets with special antiferromagnetic crystal structures. The latest developments in efficiently manipulating antiferromagnetic order, exploring novel antiferromagnetic physical responses, and demonstrating prototype antiferromagnetic spintronic devices are discussed. An outlook on future research directions is also provided. It is hoped that this Perspective can serve as guidance for readers who are interested in this field and encourage unprecedented studies on antiferromagnetic spintronic materials, phenomena, and devices.
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Affiliation(s)
- Hongyu Chen
- School of Materials Science and Engineering, Beihang University, Beijing, 100191, China
| | - Li Liu
- School of Materials Science and Engineering, Beihang University, Beijing, 100191, China
| | - Xiaorong Zhou
- School of Materials Science and Engineering, Beihang University, Beijing, 100191, China
| | - Ziang Meng
- School of Materials Science and Engineering, Beihang University, Beijing, 100191, China
| | - Xiaoning Wang
- School of Materials Science and Engineering, Beihang University, Beijing, 100191, China
| | - Zhiyuan Duan
- School of Materials Science and Engineering, Beihang University, Beijing, 100191, China
| | - Guojian Zhao
- School of Materials Science and Engineering, Beihang University, Beijing, 100191, China
| | - Han Yan
- School of Materials Science and Engineering, Beihang University, Beijing, 100191, China
| | - Peixin Qin
- School of Materials Science and Engineering, Beihang University, Beijing, 100191, China
| | - Zhiqi Liu
- School of Materials Science and Engineering, Beihang University, Beijing, 100191, China
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3
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Wu W, Shi Z, Ozerov M, Du Y, Wang Y, Ni XS, Meng X, Jiang X, Wang G, Hao C, Wang X, Zhang P, Pan C, Pan H, Sun Z, Yang R, Xu Y, Hou Y, Yan Z, Zhang C, Lu HZ, Chu J, Yuan X. The discovery of three-dimensional Van Hove singularity. Nat Commun 2024; 15:2313. [PMID: 38485978 PMCID: PMC10940667 DOI: 10.1038/s41467-024-46626-9] [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: 07/04/2023] [Accepted: 02/29/2024] [Indexed: 03/18/2024] Open
Abstract
Arising from the extreme/saddle point in electronic bands, Van Hove singularity (VHS) manifests divergent density of states (DOS) and induces various new states of matter such as unconventional superconductivity. VHS is believed to exist in one and two dimensions, but rarely found in three dimension (3D). Here, we report the discovery of 3D VHS in a topological magnet EuCd2As2 by magneto-infrared spectroscopy. External magnetic fields effectively control the exchange interaction in EuCd2As2, and shift 3D Weyl bands continuously, leading to the modification of Fermi velocity and energy dispersion. Above the critical field, the 3D VHS forms and is evidenced by the abrupt emergence of inter-band transitions, which can be quantitatively described by the minimal model of Weyl semimetals. Three additional optical transitions are further predicted theoretically and verified in magneto-near-infrared spectra. Our results pave the way to exploring VHS in 3D systems and uncovering the coordination between electronic correlation and the topological phase.
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Affiliation(s)
- Wenbin Wu
- State Key Laboratory of Precision Spectroscopy, East China Normal University, 200241, Shanghai, China
- Key Laboratory of Polar Materials and Devices, Ministry of Education, School of Physics and Electronic Science, East China Normal University, 200241, Shanghai, China
- Shanghai Center of Brain-Inspired Intelligent Materials and Devices, East China Normal University, 200241, Shanghai, China
| | - Zeping Shi
- State Key Laboratory of Precision Spectroscopy, East China Normal University, 200241, Shanghai, China
| | - Mykhaylo Ozerov
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL, 32310, USA
| | - Yuhan Du
- State Key Laboratory of Precision Spectroscopy, East China Normal University, 200241, Shanghai, China
| | - Yuxiang Wang
- State Key Laboratory of Surface Physics and Institute for Nanoelectronic Devices and Quantum Computing, Fudan University, 200433, Shanghai, China
| | - Xiao-Sheng Ni
- Guangdong Provincial Key Laboratory of Magnetoelectric Physics and Devices, School of Physics, Sun Yat-Sen University, 510275, Guangzhou, China
| | - Xianghao Meng
- State Key Laboratory of Precision Spectroscopy, East China Normal University, 200241, Shanghai, China
| | - Xiangyu Jiang
- State Key Laboratory of Precision Spectroscopy, East China Normal University, 200241, Shanghai, China
| | - Guangyi Wang
- State Key Laboratory of Precision Spectroscopy, East China Normal University, 200241, Shanghai, China
| | - Congming Hao
- State Key Laboratory of Precision Spectroscopy, East China Normal University, 200241, Shanghai, China
| | - Xinyi Wang
- State Key Laboratory of Precision Spectroscopy, East China Normal University, 200241, Shanghai, China
| | - Pengcheng Zhang
- State Key Laboratory of Precision Spectroscopy, East China Normal University, 200241, Shanghai, China
| | - Chunhui Pan
- Multifunctional Platform for Innovation Precision Machining Center, East China Normal University, 200241, Shanghai, China
| | - Haifeng Pan
- State Key Laboratory of Precision Spectroscopy, East China Normal University, 200241, Shanghai, China
| | - Zhenrong Sun
- State Key Laboratory of Precision Spectroscopy, East China Normal University, 200241, Shanghai, China
| | - Run Yang
- Key Laboratory of Quantum Materials and Devices of Ministry of Education, School of Physics, Southeast University, 211189, Nanjing, China
| | - Yang Xu
- Key Laboratory of Polar Materials and Devices, Ministry of Education, School of Physics and Electronic Science, East China Normal University, 200241, Shanghai, China
| | - Yusheng Hou
- Guangdong Provincial Key Laboratory of Magnetoelectric Physics and Devices, School of Physics, Sun Yat-Sen University, 510275, Guangzhou, China
| | - Zhongbo Yan
- Guangdong Provincial Key Laboratory of Magnetoelectric Physics and Devices, School of Physics, Sun Yat-Sen University, 510275, Guangzhou, China
| | - Cheng Zhang
- State Key Laboratory of Surface Physics and Institute for Nanoelectronic Devices and Quantum Computing, Fudan University, 200433, Shanghai, China
- Zhangjiang Fudan International Innovation Center, Fudan University, 201210, Shanghai, China
| | - Hai-Zhou Lu
- Shenzhen Institute for Quantum Science and Engineering and Department of Physics, Southern University of Science and Technology (SUSTech), 518055, Shenzhen, China
| | - Junhao Chu
- Key Laboratory of Polar Materials and Devices, Ministry of Education, School of Physics and Electronic Science, East China Normal University, 200241, Shanghai, China
- Institute of Optoelectronics, Fudan University, 200438, Shanghai, China
| | - Xiang Yuan
- State Key Laboratory of Precision Spectroscopy, East China Normal University, 200241, Shanghai, China.
- Key Laboratory of Polar Materials and Devices, Ministry of Education, School of Physics and Electronic Science, East China Normal University, 200241, Shanghai, China.
- Shanghai Center of Brain-Inspired Intelligent Materials and Devices, East China Normal University, 200241, Shanghai, China.
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4
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Ghosh S, Low A, Changdar S, Purwar S, Thirupathaiah S. Unusual multiple magnetic transitions and anomalous Hall effect observed in antiferromagnetic Weyl semimetal, Mn 2.94Ge (Ge-rich). JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2024; 36:215705. [PMID: 38364271 DOI: 10.1088/1361-648x/ad2a0b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2023] [Accepted: 02/16/2024] [Indexed: 02/18/2024]
Abstract
We report on the magnetic and Hall effect measurements of the magnetic Weyl semimetal, Mn2.94Ge (Ge-rich) single crystal. From the magnetic properties study, we identify unusual multiple magnetic transitions below the Ne'el temperature of 353 K, such as the spin-reorientation (TSR) and ferromagnetic-like transitions. Consistent with the magnetic properties, the Hall effect study shows unusual behavior around the spin-reorientation transition. Specifically, the anomalous Hall conductivity increases with increasing temperature, reaching a maximum atTSR, which then gradually decreases with increasing temperature. This observation is quite in contrast to the Mn3+δGe (Mn-rich) system, though both compositions share the same hexagonal crystal symmetry. This study unravels the sensitivity of magnetic and topological properties on the Mn 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
| | - Susmita Changdar
- Department of Condensed Matter and Materials Physics, S. N. Bose National Centre for Basic Sciences, Kolkata, West Bengal 700106, India
| | - Shubham Purwar
- 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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5
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Mazzola F, Brzezicki W, Mercaldo MT, Guarino A, Bigi C, Miwa JA, De Fazio D, Crepaldi A, Fujii J, Rossi G, Orgiani P, Chaluvadi SK, Chalil SP, Panaccione G, Jana A, Polewczyk V, Vobornik I, Kim C, Miletto-Granozio F, Fittipaldi R, Ortix C, Cuoco M, Vecchione A. Signatures of a surface spin-orbital chiral metal. Nature 2024; 626:752-758. [PMID: 38326617 PMCID: PMC10881390 DOI: 10.1038/s41586-024-07033-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Accepted: 01/05/2024] [Indexed: 02/09/2024]
Abstract
The relation between crystal symmetries, electron correlations and electronic structure steers the formation of a large array of unconventional phases of matter, including magneto-electric loop currents and chiral magnetism1-6. The detection of such hidden orders is an important goal in condensed-matter physics. However, until now, non-standard forms of magnetism with chiral electronic ordering have been difficult to detect experimentally7. Here we develop a theory for symmetry-broken chiral ground states and propose a methodology based on circularly polarized, spin-selective, angular-resolved photoelectron spectroscopy to study them. We use the archetypal quantum material Sr2RuO4 and reveal spectroscopic signatures that, despite being subtle, can be reconciled with the formation of spin-orbital chiral currents at the surface of the material8-10. As we shed light on these chiral regimes, our findings pave the way for a deeper understanding of ordering phenomena and unconventional magnetism.
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Affiliation(s)
- Federico Mazzola
- Department of Molecular Sciences and Nanosystems, Ca' Foscari University of Venice, Venice, Italy.
- Istituto Officina dei Materiali, Consiglio Nazionale delle Ricerche, Trieste, Italy.
| | - Wojciech Brzezicki
- Institute of Theoretical Physics, Jagiellonian University, Kraków, Poland
- International Centre for Interfacing Magnetism and Superconductivity with Topological Matter, Institute of Physics, Polish Academy of Sciences, Warsaw, Poland
| | | | - Anita Guarino
- Istituto SPIN, Consiglio Nazionale delle Ricerche, Fisciano, Italy
| | | | - Jill A Miwa
- Department of Physics and Astronomy, Interdisciplinary Nanoscience Center, Aarhus University, Aarhus, Denmark
| | - Domenico De Fazio
- Department of Molecular Sciences and Nanosystems, Ca' Foscari University of Venice, Venice, Italy
| | | | - Jun Fujii
- Istituto Officina dei Materiali, Consiglio Nazionale delle Ricerche, Trieste, Italy
| | - Giorgio Rossi
- Istituto Officina dei Materiali, Consiglio Nazionale delle Ricerche, Trieste, Italy
- Dipartimento di Fisica, Università degli Studi di Milano, Milan, Italy
| | - Pasquale Orgiani
- Istituto Officina dei Materiali, Consiglio Nazionale delle Ricerche, Trieste, Italy
| | | | | | - Giancarlo Panaccione
- Istituto Officina dei Materiali, Consiglio Nazionale delle Ricerche, Trieste, Italy
| | - Anupam Jana
- Istituto Officina dei Materiali, Consiglio Nazionale delle Ricerche, Trieste, Italy
| | - Vincent Polewczyk
- Istituto Officina dei Materiali, Consiglio Nazionale delle Ricerche, Trieste, Italy
| | - Ivana Vobornik
- Istituto Officina dei Materiali, Consiglio Nazionale delle Ricerche, Trieste, Italy
| | - Changyoung Kim
- Department of Physics and Astronomy, Seoul National University, Seoul, Korea
| | | | | | - Carmine Ortix
- Dipartimento di Fisica "E. R. Caianiello", Università di Salerno, Fisciano, Italy
| | - Mario Cuoco
- Istituto SPIN, Consiglio Nazionale delle Ricerche, Fisciano, Italy.
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6
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Guo X, Li X, Zhu Z, Behnia K. Onsager Reciprocal Relation between Anomalous Transverse Coefficients of an Anisotropic Antiferromagnet. PHYSICAL REVIEW LETTERS 2023; 131:246302. [PMID: 38181139 DOI: 10.1103/physrevlett.131.246302] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2023] [Revised: 10/23/2023] [Accepted: 11/21/2023] [Indexed: 01/07/2024]
Abstract
Whenever two irreversible processes occur simultaneously, time-reversal symmetry of microscopic dynamics gives rise, on a macroscopic level, to Onsager's reciprocal relations, which impose constraints on the number of independent components of any transport coefficient tensor. Here, we show that in the antiferromagnetic YbMnBi_{2}, which displays a strong temperature-dependent anisotropy, Onsager's reciprocal relations are strictly satisfied for anomalous electric (σ_{ij}^{A}) and anomalous thermoelectric (α_{ij}^{A}) conductivity tensors. In contradiction with what was recently reported by Pan et al. [Nat. Mater. 21, 203 (2022)NMAACR1476-112210.1038/s41563-021-01149-2], we find that σ_{ij}^{A}(H)=σ_{ji}^{A}(-H) and α_{ij}^{A}(H)=α_{ji}^{A}(-H). This equality holds in the whole temperature window irrespective of the relative weights of the intrinsic or extrinsic mechanisms. The α_{ij}^{A}/σ_{ij}^{A} ratio is close to k_{B}/e at room temperature but peaks to an unprecedented magnitude of 2.9k_{B}/e at ∼150 K, which may involve nondegenerate carriers of small Fermi surface pockets.
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Affiliation(s)
- Xiaodong Guo
- Wuhan National High Magnetic Field Center and School of Physics, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Xiaokang Li
- Wuhan National High Magnetic Field Center and School of Physics, Huazhong University of Science and Technology, Wuhan 430074, China
| | - 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 Etude des Matériaux (CNRS/UPMC), Ecole Supérieure de Physique et de Chimie Industrielles, 10 Rue Vauquelin, 75005 Paris, France
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7
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Skaggs CM, Ryu DC, Bhandari H, Xin Y, Kang CJ, Lapidus SH, Siegfried PE, Ghimire NJ, Tan X. IrGe 4: A Predicted Weyl-Metal with a Chiral Crystal Structure. Inorg Chem 2023; 62:19395-19403. [PMID: 37983308 DOI: 10.1021/acs.inorgchem.3c01528] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2023]
Abstract
Polycrystalline IrGe4 was synthesized by annealing elements at 800 °C for 240 h, and the composition was confirmed by energy-dispersive X-ray spectroscopy. IrGe4 adopts a chiral crystal structure (space group P3121) instead of a polar crystal structure (P31), which was corroborated by the convergent-beam electron diffraction and Rietveld refinements using synchrotron powder X-ray diffraction data. The crystal structure features layers of IrGe8 polyhedra along the b axis, and the layers are connected by edge- and corner-sharing. Each layer consists of corner-shared [Ir3Ge20] trimers, which are formed by three IrGe8 polyhedra connected by edge-sharing. Temperature-dependent resistivity indicates metallic behavior. The magnetoresistance increases with increasing applied magnetic field, and the nonsaturating magnetoresistance reaches 11.5% at 9 T and 10 K. The Hall resistivity suggests that holes are the majority carrier type, with a carrier concentration of 4.02 × 1021 cm-3 at 300 K. Electronic band structures calculated by density functional theory reveal a Weyl point with a chiral charge of +3 above the Fermi level.
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Affiliation(s)
- Callista M Skaggs
- Department of Chemistry and Biochemistry, George Mason University, Fairfax, Virginia 22030, United States
| | - Dong-Choon Ryu
- Department of Physics, Chungnam National University, Daejeon 34134, Republic of Korea
- Institute of Quantum Systems, Chungnam National University, Daejeon 34134, Republic of Korea
| | - Hari Bhandari
- Department of Physics and Astronomy, George Mason University, Fairfax, Virginia 22030, United States
- Quantum Science and Engineering Center, George Mason University, Fairfax, Virginia 22030, United States
| | - Yan Xin
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32310, United States
| | - Chang-Jong Kang
- Department of Physics, Chungnam National University, Daejeon 34134, Republic of Korea
- Institute of Quantum Systems, Chungnam National University, Daejeon 34134, Republic of Korea
| | - Saul H Lapidus
- Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, United States
| | - Peter E Siegfried
- Department of Physics and Astronomy, George Mason University, Fairfax, Virginia 22030, United States
- Quantum Science and Engineering Center, George Mason University, Fairfax, Virginia 22030, United States
| | - Nirmal J Ghimire
- Department of Physics and Astronomy and Stavropoulos Center for Complex Quantum Matter, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - Xiaoyan Tan
- Department of Chemistry and Biochemistry, George Mason University, Fairfax, Virginia 22030, United States
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8
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Wang R, Zhang J, Li T, Chen K, Li Z, Wu M, Ling L, Xi C, Hong K, Miao L, Yuan S, Chen T, Wang J. SdH Oscillations from the Dirac Surface State in the Fermi-Arc Antiferromagnet NdBi. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2023; 10:e2303978. [PMID: 37877606 PMCID: PMC10724392 DOI: 10.1002/advs.202303978] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2023] [Revised: 08/31/2023] [Indexed: 10/26/2023]
Abstract
The recent progress in CuMnAs and Mn3X (X = Sn, Ge, Pt) shows that antiferromagnets (AFMs) provide a promising platform for advanced spintronics device innovations. Most recently, a switchable Fermi-arc is discovered by the ARPES technique in antiferromagnet NdBi, but the knowledge about electron-transport property and the manipulability of the magnetic structure in NdBi is still vacant to date. In this study, SdH oscillations are successfully verified from the Dirac surface states (SSs) with 2-dimensionality and nonzero Berry phase. Particularly, it is observed that the spin-flop transition only appears when the external magnetical field is applied along [001] direction, and features obvious hysteresis for the first time in NdBi, which provides a powerful handle for adjusting the spin texture in NdBi. Crucially, the DFT shows the Dirac cone and the Fermi arc strongly depend on the high-order magnetic structure of NdBi and further reveals the orbital magnetic moment of Nd plays a crucial role in fostering the peculiar SSs, leading to unveil the mystery of the band-splitting effect and to manipulate the electronic transport, high-effectively, in the thin film works in NdBi. It is believed that this study provides important guidance for the development of new antiferromagnet-based spintronics devices based on cutting-edge rare-earth monopnictides.
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Affiliation(s)
- Ruoqi Wang
- Key Laboratory of Quantum Materials and Devices of Ministry of EducationSchool of PhysicsSoutheast UniversityNanjing211189China
| | - Junchao Zhang
- Key Laboratory of Quantum Materials and Devices of Ministry of EducationSchool of PhysicsSoutheast UniversityNanjing211189China
| | - Tian Li
- High Magnetic Field LaboratoryChinese Academy of SciencesHefei230031China
| | - Keming Chen
- Key Laboratory of Quantum Materials and Devices of Ministry of EducationSchool of PhysicsSoutheast UniversityNanjing211189China
| | - Zhengyu Li
- High Magnetic Field LaboratoryChinese Academy of SciencesHefei230031China
| | - Mingliang Wu
- Key Laboratory of Quantum Materials and Devices of Ministry of EducationSchool of PhysicsSoutheast UniversityNanjing211189China
| | - Langsheng Ling
- High Magnetic Field LaboratoryChinese Academy of SciencesHefei230031China
| | - Chuanying Xi
- High Magnetic Field LaboratoryChinese Academy of SciencesHefei230031China
| | - Kunquan Hong
- Key Laboratory of Quantum Materials and Devices of Ministry of EducationSchool of PhysicsSoutheast UniversityNanjing211189China
| | - Lin Miao
- Key Laboratory of Quantum Materials and Devices of Ministry of EducationSchool of PhysicsSoutheast UniversityNanjing211189China
| | - Shijun Yuan
- Key Laboratory of Quantum Materials and Devices of Ministry of EducationSchool of PhysicsSoutheast UniversityNanjing211189China
| | - Taishi Chen
- Key Laboratory of Quantum Materials and Devices of Ministry of EducationSchool of PhysicsSoutheast UniversityNanjing211189China
| | - Jinlan Wang
- Key Laboratory of Quantum Materials and Devices of Ministry of EducationSchool of PhysicsSoutheast UniversityNanjing211189China
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9
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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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10
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Tanaka H, Higo T, Uesugi R, Yamagata K, Nakanishi Y, Machinaga H, Nakatsuji S. Roll-to-Roll Printing of Anomalous Nernst Thermopile for Direct Sensing of Perpendicular Heat Flux. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2303416. [PMID: 37343181 DOI: 10.1002/adma.202303416] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2023] [Revised: 06/12/2023] [Indexed: 06/23/2023]
Abstract
The anomalous Nernst effect (ANE) converts heat flux perpendicular to the plane into electricity, in sharp contrast with the Seebeck effect (SE), enabling mass production, large area, and flexibility of their devices through ordinary thin-film fabrication techniques. Heat flux sensors, one of the most promising applications of ANE, are powerful devices for evaluating heat flow and can lead to energy savings through efficient thermal management. In reality, however, SE caused by the in-plane heat flux is always superimposed on the measurement signal, making it difficult to evaluate the perpendicular heat flux. Here, ANE-type heat flux sensors that selectively detect a perpendicular heat flux are fabricated by adjusting the net Seebeck coefficient in their thermopile circuit with mass-producible roll-to-roll sputtering methods. The direct sensing of perpendicular heat flux using ANE-based flexible thermopiles, as well as their simple fabrication process, paves the way for the practical application of thin-film thermoelectric devices.
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Affiliation(s)
- Hirokazu Tanaka
- Laboratory for Magnetic and Electronic Properties at Interface, The University of Tokyo, 7-3-1 Bunkyo-ku, Tokyo, 113-0033, Japan
- Core Technology Research Center, Nitto Denko Corporation, 1-1-2 Ibaraki, Osaka, 567-8680, Japan
| | - Tomoya Higo
- Laboratory for Magnetic and Electronic Properties at Interface, The University of Tokyo, 7-3-1 Bunkyo-ku, Tokyo, 113-0033, Japan
- Department of Physics, The University of Tokyo, 7-3-1 Bunkyo-ku, Tokyo, 113-0033, Japan
- Institute for Solid State Physics, The University of Tokyo, 5-1-5 Kashiwa, Chiba, 277-8581, Japan
| | - Ryota Uesugi
- Institute for Solid State Physics, The University of Tokyo, 5-1-5 Kashiwa, Chiba, 277-8581, Japan
| | - Kazuto Yamagata
- Laboratory for Magnetic and Electronic Properties at Interface, The University of Tokyo, 7-3-1 Bunkyo-ku, Tokyo, 113-0033, Japan
- Core Technology Research Center, Nitto Denko Corporation, 1-1-2 Ibaraki, Osaka, 567-8680, Japan
| | - Yosuke Nakanishi
- Laboratory for Magnetic and Electronic Properties at Interface, The University of Tokyo, 7-3-1 Bunkyo-ku, Tokyo, 113-0033, Japan
- Core Technology Research Center, Nitto Denko Corporation, 1-1-2 Ibaraki, Osaka, 567-8680, Japan
| | - Hironobu Machinaga
- Laboratory for Magnetic and Electronic Properties at Interface, The University of Tokyo, 7-3-1 Bunkyo-ku, Tokyo, 113-0033, Japan
- Core Technology Research Center, Nitto Denko Corporation, 1-1-2 Ibaraki, Osaka, 567-8680, Japan
| | - Satoru Nakatsuji
- Laboratory for Magnetic and Electronic Properties at Interface, The University of Tokyo, 7-3-1 Bunkyo-ku, Tokyo, 113-0033, Japan
- Department of Physics, The University of Tokyo, 7-3-1 Bunkyo-ku, Tokyo, 113-0033, Japan
- Institute for Solid State Physics, The University of Tokyo, 5-1-5 Kashiwa, Chiba, 277-8581, Japan
- Trans-scale Quantum Science Institute, The University of Tokyo, 7-3-1 Bunkyo-ku, Tokyo, 113-0033, Japan
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11
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Jeon KR, Hazra BK, Kim JK, Jeon JC, Han H, Meyerheim HL, Kontos T, Cottet A, Parkin SSP. Chiral antiferromagnetic Josephson junctions as spin-triplet supercurrent spin valves and d.c. SQUIDs. NATURE NANOTECHNOLOGY 2023; 18:747-753. [PMID: 36997754 PMCID: PMC10359187 DOI: 10.1038/s41565-023-01336-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Accepted: 01/31/2023] [Indexed: 06/19/2023]
Abstract
Spin-triplet supercurrent spin valves are of practical importance for the realization of superconducting spintronic logic circuits. In ferromagnetic Josephson junctions, the magnetic-field-controlled non-collinearity between the spin-mixer and spin-rotator magnetizations switches the spin-polarized triplet supercurrents on and off. Here we report an antiferromagnetic equivalent of such spin-triplet supercurrent spin valves in chiral antiferromagnetic Josephson junctions as well as a direct-current superconducting quantum interference device. We employ the topological chiral antiferromagnet Mn3Ge, in which the Berry curvature of the band structure produces fictitious magnetic fields, and the non-collinear atomic-scale spin arrangement accommodates triplet Cooper pairing over long distances (>150 nm). We theoretically verify the observed supercurrent spin-valve behaviours under a small magnetic field of <2 mT for current-biased junctions and the direct-current superconducting quantum interference device functionality. Our calculations reproduce the observed hysteretic field interference of the Josephson critical current and link these to the magnetic-field-modulated antiferromagnetic texture that alters the Berry curvature. Our work employs band topology to control the pairing amplitude of spin-triplet Cooper pairs in a single chiral antiferromagnet.
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Affiliation(s)
- Kun-Rok Jeon
- Max Planck Institute of Microstructure Physics, Halle (Saale), Germany.
- Department of Physics, Chung-Ang University (CAU), Seoul, Republic of Korea.
| | | | - Jae-Keun Kim
- Max Planck Institute of Microstructure Physics, Halle (Saale), Germany
| | - Jae-Chun Jeon
- Max Planck Institute of Microstructure Physics, Halle (Saale), Germany
| | - Hyeon Han
- Max Planck Institute of Microstructure Physics, Halle (Saale), Germany
| | | | - Takis Kontos
- Laboratoire de Physique de l'Ecole normale supérieure, ENS, Université PSL, CNRS, Sorbonne Université, Université de Paris, Paris, France
| | - Audrey Cottet
- Laboratoire de Physique de l'Ecole normale supérieure, ENS, Université PSL, CNRS, Sorbonne Université, Université de Paris, Paris, France.
| | - Stuart S P Parkin
- Max Planck Institute of Microstructure Physics, Halle (Saale), Germany.
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12
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Spin-flip-driven anomalous Hall effect and anisotropic magnetoresistance in a layered Ising antiferromagnet. Sci Rep 2023; 13:3391. [PMID: 36854958 PMCID: PMC9974960 DOI: 10.1038/s41598-023-30076-2] [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: 10/29/2022] [Accepted: 02/15/2023] [Indexed: 03/02/2023] Open
Abstract
The influence of magnetocrystalline anisotropy in antiferromagnets is evident in a spin flip or flop transition. Contrary to spin flops, a spin-flip transition has been scarcely presented due to its specific condition of relatively strong magnetocrystalline anisotropy and the role of spin-flips on anisotropic phenomena has not been investigated in detail. In this study, we present antiferromagnet-based functional properties on an itinerant Ising antiferromagnet Ca0.9Sr0.1Co2As2. In the presence of a rotating magnetic field, anomalous Hall conductivity and anisotropic magnetoresistance are demonstrated, the effects of which are maximized above the spin-flip transition. Moreover, a joint experimental and theoretical study is conducted to provide an efficient tool to identify various spin states, which can be useful in spin-processing functionalities.
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13
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Wang Y, Kajihara S, Matsuoka H, Saika BK, Yamagami K, Takeda Y, Wadati H, Ishizaka K, Iwasa Y, Nakano M. Layer-Number-Independent Two-Dimensional Ferromagnetism in Cr 3Te 4. NANO LETTERS 2022; 22:9964-9971. [PMID: 36516275 DOI: 10.1021/acs.nanolett.2c03532] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
In a conventional magnetic material, a long-range magnetic order develops in three dimensions, and reducing a layer number weakens its magnetism. Here we demonstrate anomalous layer-number-independent ferromagnetism down to the two-dimensional (2D) limit in a metastable phase of Cr3Te4. We fabricated Cr3Te4 thin films by molecular-beam epitaxy and found that Cr3Te4 could host two distinct ferromagnetic phases characterized with different Curie temperatures (TC). One is the bulk-like "high-TC phase" showing room-temperature ferromagnetism, which is consistent with previous studies. The other is the metastable "low-TC phase" with TC ≈ 160 K, which exhibits a layer-number-independent TC down to the 2D limit in marked contrast with the conventional high-TC phase, demonstrating a purely 2D nature of its ferromagnetism. Such significant differences between two distinct phases could be attributed to a small variation in the doping level, making this material attractive for future ultracompact spintronics applications with potential gate-tunable room-temperature 2D ferromagnetism.
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Affiliation(s)
- Yue Wang
- Quantum-Phase Electronics Center and Department of Applied Physics, The University of Tokyo, Tokyo 113-8656, Japan
| | - Shun Kajihara
- Quantum-Phase Electronics Center and Department of Applied Physics, The University of Tokyo, Tokyo 113-8656, Japan
| | - Hideki Matsuoka
- Quantum-Phase Electronics Center and Department of Applied Physics, The University of Tokyo, Tokyo 113-8656, Japan
- RIKEN Center for Emergent Matter Science (CEMS), Wako 351-0198, Japan
| | - Bruno Kenichi Saika
- Quantum-Phase Electronics Center and Department of Applied Physics, The University of Tokyo, Tokyo 113-8656, Japan
| | - Kohei Yamagami
- Okinawa Institute of Science and Technology Graduate University, Onna, Okinawa 904-0495, Japan
| | - Yukiharu Takeda
- Materials Sciences Research Center, Japan Atomic Energy Agency, Sayo-gun, Hyogo 679-5148, Japan
| | - Hiroki Wadati
- Graduate School of Material Science, University of Hyogo, Kobe, Hyogo 678-1297, Japan
| | - Kyoko Ishizaka
- Quantum-Phase Electronics Center and Department of Applied Physics, The University of Tokyo, Tokyo 113-8656, Japan
- RIKEN Center for Emergent Matter Science (CEMS), Wako 351-0198, Japan
| | - Yoshihiro Iwasa
- Quantum-Phase Electronics Center and Department of Applied Physics, The University of Tokyo, Tokyo 113-8656, Japan
- RIKEN Center for Emergent Matter Science (CEMS), Wako 351-0198, Japan
| | - Masaki Nakano
- Quantum-Phase Electronics Center and Department of Applied Physics, The University of Tokyo, Tokyo 113-8656, Japan
- RIKEN Center for Emergent Matter Science (CEMS), Wako 351-0198, Japan
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14
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Parfenov OE, Taldenkov AN, Averyanov DV, Sokolov IS, Kondratev OA, Borisov MM, Yakunin SN, Karateev IA, Tokmachev AM, Storchak VG. Layer-controlled evolution of electron state in the silicene intercalation compound SrSi 2. MATERIALS HORIZONS 2022; 9:2854-2862. [PMID: 36056695 DOI: 10.1039/d2mh00640e] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Silicene, a Si-based analogue of graphene, holds a high promise for electronics because of its exceptional properties but a high chemical reactivity makes it a very challenging material to work with. The silicene lattice can be stabilized by active metals to form stoichiometric compounds MSi2. Being candidate topological semimetals, these materials provide an opportunity to probe layer dependence of unconventional electronic structures. It is demonstrated here that in the silicene compound SrSi2, the number of monolayers controls the electronic state. A series of films ranging from bulk-like multilayers down to a single monolayer have been synthesized on silicon and characterized with a combination of techniques - from electron and X-ray diffraction to high-resolution electron microscopy. Transport measurements reveal evolution of the chiral anomaly in bulk SrSi2 to weak localization in ultrathin films down to 3 monolayers followed by 3D and 2D strong localization in 2 and 1 monolayers, respectively. The results outline the range of stability of the chiral state, important for practical applications, and shed light on the localization phenomena in the limit of a few monolayers.
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Affiliation(s)
- Oleg E Parfenov
- National Research Center "Kurchatov Institute", Kurchatov Sq. 1, Moscow 123182, Russia.
| | - Alexander N Taldenkov
- National Research Center "Kurchatov Institute", Kurchatov Sq. 1, Moscow 123182, Russia.
| | - Dmitry V Averyanov
- National Research Center "Kurchatov Institute", Kurchatov Sq. 1, Moscow 123182, Russia.
| | - Ivan S Sokolov
- National Research Center "Kurchatov Institute", Kurchatov Sq. 1, Moscow 123182, Russia.
| | - Oleg A Kondratev
- National Research Center "Kurchatov Institute", Kurchatov Sq. 1, Moscow 123182, Russia.
| | - Mikhail M Borisov
- National Research Center "Kurchatov Institute", Kurchatov Sq. 1, Moscow 123182, Russia.
| | - Sergey N Yakunin
- National Research Center "Kurchatov Institute", Kurchatov Sq. 1, Moscow 123182, Russia.
| | - Igor A Karateev
- National Research Center "Kurchatov Institute", Kurchatov Sq. 1, Moscow 123182, Russia.
| | - Andrey M Tokmachev
- National Research Center "Kurchatov Institute", Kurchatov Sq. 1, Moscow 123182, Russia.
| | - Vyacheslav G Storchak
- National Research Center "Kurchatov Institute", Kurchatov Sq. 1, Moscow 123182, Russia.
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15
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Song J, Oh T, Ko EK, Lee JH, Kim WJ, Zhu Y, Yang BJ, Li Y, Noh TW. Higher harmonics in planar Hall effect induced by cluster magnetic multipoles. Nat Commun 2022; 13:6501. [PMID: 36310175 PMCID: PMC9618580 DOI: 10.1038/s41467-022-34189-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Accepted: 10/13/2022] [Indexed: 11/11/2022] Open
Abstract
Antiferromagnetic (AFM) materials are attracting tremendous attention due to their spintronic applications and associated novel topological phenomena. However, detecting and identifying the spin configurations in AFM materials are quite challenging due to the absence of net magnetization. Herein, we report the practicality of utilizing the planar Hall effect (PHE) to detect and distinguish “cluster magnetic multipoles” in AFM Nd2Ir2O7 (NIO-227) fully strained films. By imposing compressive strain on the spin structure of NIO-227, we artificially induced cluster magnetic multipoles, namely dipoles and A2- and T1-octupoles. Importantly, under magnetic field rotation, each magnetic multipole exhibits distinctive harmonics of the PHE oscillation. Moreover, the planar Hall conductivity has a nonlinear magnetic field dependence, which can be attributed to the magnetic response of the cluster magnetic octupoles. Our work provides a strategy for identifying cluster magnetic multipoles in AFM systems and would promote octupole-based AFM spintronics. The lack of net magnetization in antiferromagnets makes them technologically promising, but it also makes detecting the spin orders challenging. Here, using electrical transport measurement, Song et al show how the planar Hall effect can detect different cluster magnetic multipoles in antiferromagnetic Nd2Ir2O7 film.
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16
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Lopez-Polin G, Aramberri H, Marques-Marchan J, Weintrub BI, Bolotin KI, Cerdá JI, Asenjo A. High-Power-Density Energy-Harvesting Devices Based on the Anomalous Nernst Effect of Co/Pt Magnetic Multilayers. ACS APPLIED ENERGY MATERIALS 2022; 5:11835-11843. [PMID: 36185812 PMCID: PMC9516660 DOI: 10.1021/acsaem.2c02422] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Accepted: 08/18/2022] [Indexed: 06/16/2023]
Abstract
The anomalous Nernst effect (ANE) is a thermomagnetic phenomenon with potential applications in thermal energy harvesting. While many recent works studied the approaches to increase the ANE coefficient of materials, relatively little effort was devoted to increasing the power supplied by the effect. Here, we demonstrate a nanofabricated device with record power density generated by the ANE. To accomplish this, we fabricate micrometer-sized devices in which the thermal gradient is 3 orders of magnitude higher than conventional macroscopic devices. In addition, we use Co/Pt multilayers, a system characterized by a high ANE thermopower (∼1 μV/K), low electrical resistivity, and perpendicular magnetic anisotropy. These innovations allow us to obtain power densities of around 13 ± 2 W/cm3. We believe that this design may find uses in harvesting wasted energy, e.g., in electronic devices.
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Affiliation(s)
| | - Hugo Aramberri
- Materials
Research and Technology Department, Luxembourg
Institute of Science and Technology (LIST), L-4362 Esch-sur-Alzette, Luxembourg
| | | | | | - Kirill I. Bolotin
- Department
of Physics, Freie Universität Berlin, 14195 Berlin, Germany
| | - Jorge I. Cerdá
- Instituto
de Ciencia de Materiales de Madrid (ICMM-CSIC), 28049 Madrid, Spain
| | - Agustina Asenjo
- Instituto
de Ciencia de Materiales de Madrid (ICMM-CSIC), 28049 Madrid, Spain
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17
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Chen T, Minami S, Sakai A, Wang Y, Feng Z, Nomoto T, Hirayama M, Ishii R, Koretsune T, Arita R, Nakatsuji S. Large anomalous Nernst effect and nodal plane in an iron-based kagome ferromagnet. SCIENCE ADVANCES 2022; 8:eabk1480. [PMID: 35030028 PMCID: PMC8759748 DOI: 10.1126/sciadv.abk1480] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Accepted: 11/22/2021] [Indexed: 05/22/2023]
Abstract
Anomalous Nernst effect (ANE), converting a heat flow to transverse electric voltage, originates from the Berry phase of electronic wave function near the Fermi energy EF. Thus, the ANE provides a sensitive probe to detect a topological state that produces large Berry curvature. In addition, a magnet that exhibits a large ANE using low-cost and safe elements will be useful to develop a novel energy harvesting technology. Here, we report our observation of a high ANE exceeding 3 microvolts per kelvin above room temperature in the kagome ferromagnet Fe3Sn with the Curie temperature of 760 kelvin. Our theoretical analysis clarifies that a “nodal plane” produces a flat hexagonal frame with strongly enhanced Berry curvature, resulting in the large ANE. Our discovery of the large ANE in Fe3Sn opens the path for the previously unexplored functionality of flat degenerate electronic states and for developing flexible film thermopile and heat current sensors.
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Affiliation(s)
- Taishi Chen
- Department of Physics, University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
- Institute for Solid State Physics, University of Tokyo, Kashiwa 277-8581, Japan
- School of Physics, Southeast University, Nanjing 211189, China
| | - Susumu Minami
- Department of Physics, University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Akito Sakai
- Department of Physics, University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
- Institute for Solid State Physics, University of Tokyo, Kashiwa 277-8581, Japan
- CREST, Japan Science and Technology Agency (JST), 4-1-8 Honcho Kawaguchi, Saitama 332-0012, Japan
| | - Yangming Wang
- Department of Physics, University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Zili Feng
- Department of Physics, University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
- Institute for Solid State Physics, University of Tokyo, Kashiwa 277-8581, Japan
| | - Takuya Nomoto
- Department of Applied Physics, University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
| | - Motoaki Hirayama
- Department of Applied Physics, University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
- RIKEN Center for Emergent Matter Science (CEMS), 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Rieko Ishii
- Institute for Solid State Physics, University of Tokyo, Kashiwa 277-8581, Japan
| | - Takashi Koretsune
- Department of Physics, Tohoku University, 6-3 Aza-Aoba, Aramaki, Aoba-ku, Sendai 980-8578, Japan
- Center for Science and Innovation in Spintronics (CSIS), Tohoku University, Miyagi, Japan
| | - Ryotaro Arita
- CREST, Japan Science and Technology Agency (JST), 4-1-8 Honcho Kawaguchi, Saitama 332-0012, Japan
- Department of Applied Physics, University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
- RIKEN Center for Emergent Matter Science (CEMS), 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Satoru Nakatsuji
- Department of Physics, University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
- Institute for Solid State Physics, University of Tokyo, Kashiwa 277-8581, Japan
- CREST, Japan Science and Technology Agency (JST), 4-1-8 Honcho Kawaguchi, Saitama 332-0012, Japan
- Trans-scale Quantum Science Institute, University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
- Institute for Quantum Matter and Department of Physics and Astronomy, Johns Hopkins University, Baltimore, MD 21218, USA
- Corresponding author.
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18
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Giant field-like torque by the out-of-plane magnetic spin Hall effect in a topological antiferromagnet. Nat Commun 2021; 12:6491. [PMID: 34795211 PMCID: PMC8602386 DOI: 10.1038/s41467-021-26453-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2021] [Accepted: 09/27/2021] [Indexed: 12/03/2022] Open
Abstract
Spin-orbit torques (SOT) enable efficient electrical control of the magnetic state of ferromagnets, ferrimagnets and antiferromagnets. However, the conventional SOT has severe limitation that only in-plane spins accumulate near the surface, whether interpreted as a spin Hall effect (SHE) or as an Edelstein effect. Such a SOT is not suitable for controlling perpendicular magnetization, which would be more beneficial for realizing low-power-consumption memory devices. Here we report the observation of a giant magnetic-field-like SOT in a topological antiferromagnet Mn3Sn, whose direction and size can be tuned by changing the order parameter direction of the antiferromagnet. To understand the magnetic SHE (MSHE)- and the conventional SHE-induced SOTs on an equal footing, we formulate them as interface spin-electric-field responses and analyzed using a macroscopic symmetry analysis and a complementary microscopic quantum kinetic theory. In this framework, the large out-of-plane spin accumulation due to the MSHE has an inter-band origin and is likely to be caused by the large momentum-dependent spin splitting in Mn3Sn. Our work demonstrates the unique potential of antiferromagnetic Weyl semimetals in overcoming the limitations of conventional SOTs and in realizing low-power spintronics devices with new functionalities. Conventional spin-orbit torque (SOT) enables electrical control of in-plane spins, not suitable for perpendicular magnetization. Here, the authors observe a large magnetic-field-like SOT due to a large out-of-plane spin accumulation in topological antiferromagnet Mn3Sn.
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19
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Lyalin I, Cheng S, Kawakami RK. Spin-Orbit Torque in Bilayers of Kagome Ferromagnet Fe 3Sn 2 and Pt. NANO LETTERS 2021; 21:6975-6982. [PMID: 34380320 DOI: 10.1021/acs.nanolett.1c02270] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Spin-orbit torque phenomena enable efficient manipulation of the magnetization in ferromagnet/heavy metal bilayer systems for prospective magnetic memory and logic applications. Kagome magnets are of particular interest for spin-orbit torque due to the interplay of magnetic order and the nontrivial band topology (e.g., flat bands and Dirac and Weyl points). Here we demonstrate spin-orbit torque and quantify its efficiency in a bilayer system of topological kagome ferromagnet Fe3Sn2 and platinum. We use two different techniques, one based on the quasistatic magneto-optic Kerr effect (MOKE) and another based on time-resolved MOKE, to quantify spin-orbit torque. Both techniques give a consistent value of the effective spin Hall angle of the Fe3Sn2/Pt system. Our work may lead to further advances in spintronics based on topological kagome magnets.
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Affiliation(s)
- Igor Lyalin
- Department of Physics, The Ohio State University, Columbus, Ohio 43210, United States
| | - Shuyu Cheng
- Department of Physics, The Ohio State University, Columbus, Ohio 43210, United States
| | - Roland K Kawakami
- Department of Physics, The Ohio State University, Columbus, Ohio 43210, United States
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20
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Abstract
This short review article provides the reader with a summary of the history of organic conductors. To retain a neutral and objective point of view regarding the history, background, novelty, and details of each research subject within this field, a thousand references have been cited with full titles and arranged in chronological order. Among the research conducted over ~70 years, topics from the last two decades are discussed in more detail than the rest. Unlike other papers in this issue, this review will help readers to understand the origin of each topic within the field of organic conductors and how they have evolved. Due to the advancements achieved over these 70 years, the field is nearing new horizons. As history is often a reflection of the future, this review is expected to show the future directions of this research field.
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