51
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Wang S, Xu J, Li W, Sun S, Gao S, Hou Y. Magnetic Nanostructures: Rational Design and Fabrication Strategies toward Diverse Applications. Chem Rev 2022; 122:5411-5475. [PMID: 35014799 DOI: 10.1021/acs.chemrev.1c00370] [Citation(s) in RCA: 32] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
In recent years, the continuous development of magnetic nanostructures (MNSs) has tremendously promoted both fundamental scientific research and technological applications. Different from the bulk magnet, the systematic engineering on MNSs has brought a great breakthrough in some emerging fields such as the construction of MNSs, the magnetism exploration of multidimensional MNSs, and their potential translational applications. In this review, we give a detailed description of the synthetic strategies of MNSs based on the fundamental features and application potential of MNSs and discuss the recent progress of MNSs in the fields of nanomedicines, advanced nanobiotechnology, catalysis, and electromagnetic wave adsorption (EMWA), aiming to provide guidance for fabrication strategies of MNSs toward diverse applications.
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Affiliation(s)
- Shuren Wang
- Beijing Key Laboratory of Magnetoelectric Materials and Devices, School of Materials Science and Engineering, Beijing Innovation Centre for Engineering Science and Advanced Technology, Peking University, Beijing 100871, China
| | - Junjie Xu
- Beijing Key Laboratory of Magnetoelectric Materials and Devices, School of Materials Science and Engineering, Beijing Innovation Centre for Engineering Science and Advanced Technology, Peking University, Beijing 100871, China
| | - Wei Li
- Beijing Key Laboratory of Magnetoelectric Materials and Devices, School of Materials Science and Engineering, Beijing Innovation Centre for Engineering Science and Advanced Technology, Peking University, Beijing 100871, China
| | - Shengnan Sun
- Beijing Key Laboratory of Magnetoelectric Materials and Devices, School of Materials Science and Engineering, Beijing Innovation Centre for Engineering Science and Advanced Technology, Peking University, Beijing 100871, China
| | - Song Gao
- Beijing Key Laboratory of Magnetoelectric Materials and Devices, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China.,Institute of Spin-X Science and Technology, South China University of Technology, Guangzhou 511442, China
| | - Yanglong Hou
- Beijing Key Laboratory of Magnetoelectric Materials and Devices, School of Materials Science and Engineering, Beijing Innovation Centre for Engineering Science and Advanced Technology, Peking University, Beijing 100871, China
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52
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Uchida M, Sato S, Ishizuka H, Kurihara R, Nakajima T, Nakazawa Y, Ohno M, Kriener M, Miyake A, Ohishi K, Morikawa T, Bahramy MS, Arima TH, Tokunaga M, Nagaosa N, Kawasaki M. Above-ordering-temperature large anomalous Hall effect in a triangular-lattice magnetic semiconductor. SCIENCE ADVANCES 2021; 7:eabl5381. [PMID: 34936456 PMCID: PMC8694614 DOI: 10.1126/sciadv.abl5381] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Accepted: 11/03/2021] [Indexed: 06/14/2023]
Abstract
While anomalous Hall effect (AHE) has been extensively studied in the past, efforts for realizing large Hall response have been mainly limited within intrinsic mechanism. Lately, however, a theory of extrinsic mechanism has predicted that magnetic scattering by spin cluster can induce large AHE even above magnetic ordering temperature, particularly in magnetic semiconductors with low carrier density, strong exchange coupling, and finite spin chirality. Here, we find out a new magnetic semiconductor EuAs, where Eu2+ ions with large magnetic moments form distorted triangular lattice. In addition to colossal magnetoresistance, EuAs exhibits large AHE with an anomalous Hall angle of 0.13 at temperatures far above antiferromagnetic ordering. As also demonstrated by model calculations, observed AHE can be explained by the spin cluster scattering in a hopping regime. Our findings shed light on magnetic semiconductors hosting topological spin textures, developing a field targeting diluted carriers strongly coupled to noncoplanar spin structures.
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Affiliation(s)
- Masaki Uchida
- Department of Physics, Tokyo Institute of Technology, Tokyo 152-8550, Japan
- Department of Applied Physics and Quantum-Phase Electronics Center (QPEC), The University of Tokyo, Tokyo 113-8656, Japan
- PRESTO, Japan Science and Technology Agency (JST), Chiyoda-ku, Tokyo 102-0075, Japan
| | - Shin Sato
- Department of Applied Physics and Quantum-Phase Electronics Center (QPEC), The University of Tokyo, Tokyo 113-8656, Japan
| | - Hiroaki Ishizuka
- Department of Physics, Tokyo Institute of Technology, Tokyo 152-8550, Japan
| | - Ryosuke Kurihara
- Institute for Solid State Physics, The University of Tokyo, Kashiwa 277-8581, Japan
- RIKEN Center for Emergent Matter Science (CEMS), Wako 351-0198, Japan
| | - Taro Nakajima
- Institute for Solid State Physics, The University of Tokyo, Kashiwa 277-8581, Japan
| | - Yusuke Nakazawa
- Department of Applied Physics and Quantum-Phase Electronics Center (QPEC), The University of Tokyo, Tokyo 113-8656, Japan
| | - Mizuki Ohno
- Department of Physics, Tokyo Institute of Technology, Tokyo 152-8550, Japan
- Department of Applied Physics and Quantum-Phase Electronics Center (QPEC), The University of Tokyo, Tokyo 113-8656, Japan
| | - Markus Kriener
- RIKEN Center for Emergent Matter Science (CEMS), Wako 351-0198, Japan
| | - Atsushi Miyake
- Institute for Solid State Physics, The University of Tokyo, Kashiwa 277-8581, Japan
| | - Kazuki Ohishi
- Neutron Science and Technology Center, Comprehensive Research Organization for Science and Society (CROSS), Tokai 319-1106, Japan
| | - Toshiaki Morikawa
- Neutron Science and Technology Center, Comprehensive Research Organization for Science and Society (CROSS), Tokai 319-1106, Japan
| | - Mohammad Saeed Bahramy
- Department of Applied Physics and Quantum-Phase Electronics Center (QPEC), The University of Tokyo, Tokyo 113-8656, Japan
| | - Taka-hisa Arima
- RIKEN Center for Emergent Matter Science (CEMS), Wako 351-0198, Japan
- Department of Advanced Materials Science, University of Tokyo, Kashiwa 277-8561, Japan
| | - Masashi Tokunaga
- Institute for Solid State Physics, The University of Tokyo, Kashiwa 277-8581, Japan
- RIKEN Center for Emergent Matter Science (CEMS), Wako 351-0198, Japan
| | - Naoto Nagaosa
- Department of Applied Physics and Quantum-Phase Electronics Center (QPEC), The University of Tokyo, Tokyo 113-8656, Japan
- RIKEN Center for Emergent Matter Science (CEMS), Wako 351-0198, Japan
| | - Masashi Kawasaki
- Department of Applied Physics and Quantum-Phase Electronics Center (QPEC), The University of Tokyo, Tokyo 113-8656, Japan
- RIKEN Center for Emergent Matter Science (CEMS), Wako 351-0198, Japan
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53
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Belopolski I, Cochran TA, Liu X, Cheng ZJ, Yang XP, Guguchia Z, Tsirkin SS, Yin JX, Vir P, Thakur GS, Zhang SS, Zhang J, Kaznatcheev K, Cheng G, Chang G, Multer D, Shumiya N, Litskevich M, Vescovo E, Kim TK, Cacho C, Yao N, Felser C, Neupert T, Hasan MZ. Signatures of Weyl Fermion Annihilation in a Correlated Kagome Magnet. PHYSICAL REVIEW LETTERS 2021; 127:256403. [PMID: 35029418 DOI: 10.1103/physrevlett.127.256403] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Accepted: 11/12/2021] [Indexed: 06/14/2023]
Abstract
The manipulation of topological states in quantum matter is an essential pursuit of fundamental physics and next-generation quantum technology. Here we report the magnetic manipulation of Weyl fermions in the kagome spin-orbit semimetal Co_{3}Sn_{2}S_{2}, observed by high-resolution photoemission spectroscopy. We demonstrate the exchange collapse of spin-orbit-gapped ferromagnetic Weyl loops into paramagnetic Dirac loops under suppression of the magnetic order. We further observe that topological Fermi arcs disappear in the paramagnetic phase, suggesting the annihilation of exchange-split Weyl points. Our findings indicate that magnetic exchange collapse naturally drives Weyl fermion annihilation, opening new opportunities for engineering topology under correlated order parameters.
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Affiliation(s)
- Ilya Belopolski
- Laboratory for Topological Quantum Matter and Spectroscopy (B7), Department of Physics, Princeton University, Princeton, New Jersey 08544, USA
- RIKEN Center for Emergent Matter Science (CEMS), Wako, Saitama 351-0198, Japan
| | - Tyler A Cochran
- Laboratory for Topological Quantum Matter and Spectroscopy (B7), Department of Physics, Princeton University, Princeton, New Jersey 08544, USA
| | - Xiaoxiong Liu
- Department of Physics, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
| | - Zi-Jia Cheng
- Laboratory for Topological Quantum Matter and Spectroscopy (B7), Department of Physics, Princeton University, Princeton, New Jersey 08544, USA
| | - Xian P Yang
- Laboratory for Topological Quantum Matter and Spectroscopy (B7), Department of Physics, Princeton University, Princeton, New Jersey 08544, USA
| | - Zurab Guguchia
- Laboratory for Topological Quantum Matter and Spectroscopy (B7), Department of Physics, Princeton University, Princeton, New Jersey 08544, USA
- Laboratory for Muon Spin Spectroscopy, Paul Scherrer Institute, Villigen PSI, Switzerland
| | - Stepan S Tsirkin
- Department of Physics, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
| | - Jia-Xin Yin
- Laboratory for Topological Quantum Matter and Spectroscopy (B7), Department of Physics, Princeton University, Princeton, New Jersey 08544, USA
| | - Praveen Vir
- Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Straße 40, 01187 Dresden, Germany
| | - Gohil S Thakur
- Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Straße 40, 01187 Dresden, Germany
- Faculty of Chemistry and Food Chemistry, Technische Universitat, 01069 Dresden, Germany
| | - Songtian S Zhang
- Laboratory for Topological Quantum Matter and Spectroscopy (B7), Department of Physics, Princeton University, Princeton, New Jersey 08544, USA
| | - Junyi Zhang
- Department of Physics, Princeton University, Princeton, New Jersey 08544, USA
| | - Konstantine Kaznatcheev
- National Synchrotron Light Source II, Brookhaven National Laboratory, Upton, New York 11973, USA
| | - Guangming Cheng
- Princeton Institute for Science and Technology of Materials, Princeton University, Princeton, New Jersey 08544, USA
| | - Guoqing Chang
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, 637371 Singapore, Singapore
| | - Daniel Multer
- Laboratory for Topological Quantum Matter and Spectroscopy (B7), Department of Physics, Princeton University, Princeton, New Jersey 08544, USA
| | - Nana Shumiya
- Laboratory for Topological Quantum Matter and Spectroscopy (B7), Department of Physics, Princeton University, Princeton, New Jersey 08544, USA
| | - Maksim Litskevich
- Laboratory for Topological Quantum Matter and Spectroscopy (B7), Department of Physics, Princeton University, Princeton, New Jersey 08544, USA
| | - Elio Vescovo
- National Synchrotron Light Source II, Brookhaven National Laboratory, Upton, New York 11973, USA
| | - Timur K Kim
- Diamond Light Source, Didcot OX11 0DE, United Kingdom
| | - Cephise Cacho
- Diamond Light Source, Didcot OX11 0DE, United Kingdom
| | - Nan Yao
- Princeton Institute for Science and Technology of Materials, Princeton University, Princeton, New Jersey 08544, USA
| | - Claudia Felser
- Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Straße 40, 01187 Dresden, Germany
| | - Titus Neupert
- Department of Physics, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
| | - M Zahid Hasan
- Laboratory for Topological Quantum Matter and Spectroscopy (B7), Department of Physics, Princeton University, Princeton, New Jersey 08544, USA
- Princeton Institute for Science and Technology of Materials, Princeton University, Princeton, New Jersey 08544, USA
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
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54
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Singh S, Noky J, Bhattacharya S, Vir P, Sun Y, Kumar N, Felser C, Shekhar C. Anisotropic Nodal-Line-Derived Large Anomalous Hall Conductivity in ZrMnP and HfMnP. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2021; 33:e2104126. [PMID: 34510589 DOI: 10.1002/adma.202104126] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2021] [Revised: 07/02/2021] [Indexed: 06/13/2023]
Abstract
The nontrivial band structure of semimetals has attracted substantial research attention in condensed matter physics and materials science in recent years owing to its intriguing physical properties. Within this class, a group of nontrivial materials known as nodal-line semimetals is particularly important. Nodal-line semimetals exhibit the potential effects of electronic correlation in nonmagnetic materials, whereas they enhance the contribution of the Berry curvature in magnetic materials, resulting in high anomalous Hall conductivity (AHC). In this study, two ferromagnetic compounds, namely ZrMnP and HfMnP, are selected, wherein the abundance of mirror planes in the crystal structure ensures gapped nodal lines at the Fermi energy. These nodal lines result in one of the largest AHC values of 2840 Ω-1 cm-1 , with a high anomalous Hall angle of 13.6% in these compounds. First-principles calculations provide a clear and detailed understanding of nodal line-enhanced AHC. The finding suggests a guideline for searching large AHC compounds.
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Affiliation(s)
- Sukriti Singh
- Max Planck Institute for Chemical Physics of Solids, 01187, Dresden, Germany
| | - Jonathan Noky
- Max Planck Institute for Chemical Physics of Solids, 01187, Dresden, Germany
| | | | - Praveen Vir
- Max Planck Institute for Chemical Physics of Solids, 01187, Dresden, Germany
| | - Yan Sun
- Max Planck Institute for Chemical Physics of Solids, 01187, Dresden, Germany
| | - Nitesh Kumar
- Max Planck Institute for Chemical Physics of Solids, 01187, Dresden, Germany
| | - Claudia Felser
- Max Planck Institute for Chemical Physics of Solids, 01187, Dresden, Germany
| | - Chandra Shekhar
- Max Planck Institute for Chemical Physics of Solids, 01187, Dresden, Germany
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55
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Zhu W, Lin H, Yan F, Hu C, Wang Z, Zhao L, Deng Y, Kudrynskyi ZR, Zhou T, Kovalyuk ZD, Zheng Y, Patanè A, Žutić I, Li S, Zheng H, Wang K. Large Tunneling Magnetoresistance in van der Waals Ferromagnet/Semiconductor Heterojunctions. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2021; 33:e2104658. [PMID: 34642998 DOI: 10.1002/adma.202104658] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Revised: 09/01/2021] [Indexed: 06/13/2023]
Abstract
2D layered chalcogenide semiconductors have been proposed as a promising class of materials for low-dimensional electronic, optoelectronic, and spintronic devices. Here, all-2D van der Waals vertical spin-valve devices, that combine the 2D layered semiconductor InSe as a spacer with the 2D layered ferromagnetic metal Fe3 GeTe2 as spin injection and detection electrodes, are reported. Two distinct transport behaviors are observed: tunneling and metallic, which are assigned to the formation of a pinhole-free tunnel barrier at the Fe3 GeTe2 /InSe interface and pinholes in the InSe spacer layer, respectively. For the tunneling device, a large magnetoresistance (MR) of 41% is obtained under an applied bias current of 0.1 µA at 10 K, which is about three times larger than that of the metallic device. Moreover, the tunneling device exhibits a lower operating bias current but a more sensitive bias current dependence than the metallic device. The MR and spin polarization of both the metallic and tunneling devices decrease with increasing temperature, which can be fitted well by Bloch's law. These findings reveal the critical role of pinholes in the MR of all-2D van der Waals ferromagnet/semiconductor heterojunction devices.
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Affiliation(s)
- Wenkai Zhu
- State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing, 100083, China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Hailong Lin
- State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing, 100083, China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Faguang Yan
- State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing, 100083, China
| | - Ce Hu
- State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing, 100083, China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Ziao Wang
- State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing, 100083, China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Lixia Zhao
- State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing, 100083, China
- Tiangong University, Tianjin, 300387, China
| | - Yongcheng Deng
- State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing, 100083, China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Zakhar R Kudrynskyi
- School of Physics and Astronomy, University of Nottingham, Nottingham, NG7 2RD, UK
| | - Tong Zhou
- Department of Physics, University at Buffalo, State University of New York, Buffalo, NY, 14260, USA
| | - Zakhar D Kovalyuk
- Frantsevich Institute for Problems of Materials Science, The National Academy of Sciences of Ukraine, Chernivtsi Branch, Chernivtsi, 58001, Ukraine
| | - Yuanhui Zheng
- State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing, 100083, China
- Beijing Academy of Quantum Information Sciences, Beijing, 100193, China
| | - Amalia Patanè
- School of Physics and Astronomy, University of Nottingham, Nottingham, NG7 2RD, UK
| | - Igor Žutić
- Department of Physics, University at Buffalo, State University of New York, Buffalo, NY, 14260, USA
| | - Shushen Li
- State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing, 100083, China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Houzhi Zheng
- State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing, 100083, China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Kaiyou Wang
- State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing, 100083, China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing, 100049, China
- Beijing Academy of Quantum Information Sciences, Beijing, 100193, China
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56
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Sohn B, Lee E, Park SY, Kyung W, Hwang J, Denlinger JD, Kim M, Kim D, Kim B, Ryu H, Huh S, Oh JS, Jung JK, Oh D, Kim Y, Han M, Noh TW, Yang BJ, Kim C. Sign-tunable anomalous Hall effect induced by two-dimensional symmetry-protected nodal structures in ferromagnetic perovskite thin films. NATURE MATERIALS 2021; 20:1643-1649. [PMID: 34608283 DOI: 10.1038/s41563-021-01101-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Accepted: 08/11/2021] [Indexed: 06/13/2023]
Abstract
Magnetism and spin-orbit coupling are two quintessential ingredients underlying topological transport phenomena in itinerant ferromagnets. When spin-polarized bands support nodal points/lines with band degeneracy that can be lifted by spin-orbit coupling, the nodal structures become a source of Berry curvature, leading to a large anomalous Hall effect. However, two-dimensional systems can possess stable nodal structures only when proper crystalline symmetry exists. Here we show that two-dimensional spin-polarized band structures of perovskite oxides generally support symmetry-protected nodal lines and points that govern both the sign and the magnitude of the anomalous Hall effect. To demonstrate this, we performed angle-resolved photoemission studies of ultrathin films of SrRuO3, a representative metallic ferromagnet with spin-orbit coupling. We show that the sign-changing anomalous Hall effect upon variation in the film thickness, magnetization and chemical potential can be well explained by theoretical models. Our work may facilitate new switchable devices based on ferromagnetic ultrathin films.
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Affiliation(s)
- Byungmin Sohn
- Center for Correlated Electron Systems, Institute for Basic Science, Seoul, Korea
- Department of Physics and Astronomy, Seoul National University, Seoul, Korea
| | - Eunwoo Lee
- Center for Correlated Electron Systems, Institute for Basic Science, Seoul, Korea
- Department of Physics and Astronomy, Seoul National University, Seoul, Korea
- Center for Theoretical Physics, Seoul National University, Seoul, Korea
| | - Se Young Park
- Department of Physics and Origin of Matter and Evolution of Galaxies (OMEG) Institute, Soongsil University, Seoul, Korea.
| | - Wonshik Kyung
- Center for Correlated Electron Systems, Institute for Basic Science, Seoul, Korea
- Department of Physics and Astronomy, Seoul National University, Seoul, Korea
| | - Jinwoong Hwang
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | | | - Minsoo Kim
- Center for Correlated Electron Systems, Institute for Basic Science, Seoul, Korea
- Department of Physics and Astronomy, Seoul National University, Seoul, Korea
| | - Donghan Kim
- Center for Correlated Electron Systems, Institute for Basic Science, Seoul, Korea
- Department of Physics and Astronomy, Seoul National University, Seoul, Korea
| | - Bongju Kim
- Center for Correlated Electron Systems, Institute for Basic Science, Seoul, Korea
- Department of Physics and Astronomy, Seoul National University, Seoul, Korea
| | - Hanyoung Ryu
- Center for Correlated Electron Systems, Institute for Basic Science, Seoul, Korea
- Department of Physics and Astronomy, Seoul National University, Seoul, Korea
| | - Soonsang Huh
- Center for Correlated Electron Systems, Institute for Basic Science, Seoul, Korea
- Department of Physics and Astronomy, Seoul National University, Seoul, Korea
| | - Ji Seop Oh
- Center for Correlated Electron Systems, Institute for Basic Science, Seoul, Korea
- Department of Physics and Astronomy, Seoul National University, Seoul, Korea
| | - Jong Keun Jung
- Center for Correlated Electron Systems, Institute for Basic Science, Seoul, Korea
- Department of Physics and Astronomy, Seoul National University, Seoul, Korea
| | - Dongjin Oh
- Center for Correlated Electron Systems, Institute for Basic Science, Seoul, Korea
- Department of Physics and Astronomy, Seoul National University, Seoul, Korea
| | - Younsik Kim
- Center for Correlated Electron Systems, Institute for Basic Science, Seoul, Korea
- Department of Physics and Astronomy, Seoul National University, Seoul, Korea
| | - Moonsup Han
- Department of Physics, University of Seoul, Seoul, Korea
| | - Tae Won Noh
- Center for Correlated Electron Systems, Institute for Basic Science, Seoul, Korea
- Department of Physics and Astronomy, Seoul National University, Seoul, Korea
| | - Bohm-Jung Yang
- Center for Correlated Electron Systems, Institute for Basic Science, Seoul, Korea.
- Department of Physics and Astronomy, Seoul National University, Seoul, Korea.
- Center for Theoretical Physics, Seoul National University, Seoul, Korea.
| | - Changyoung Kim
- Center for Correlated Electron Systems, Institute for Basic Science, Seoul, Korea.
- Department of Physics and Astronomy, Seoul National University, Seoul, Korea.
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57
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Gaudet J, Yang HY, Baidya S, Lu B, Xu G, Zhao Y, Rodriguez-Rivera JA, Hoffmann CM, Graf DE, Torchinsky DH, Nikolić P, Vanderbilt D, Tafti F, Broholm CL. Weyl-mediated helical magnetism in NdAlSi. NATURE MATERIALS 2021; 20:1650-1656. [PMID: 34413490 DOI: 10.1038/s41563-021-01062-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Accepted: 06/23/2021] [Indexed: 06/13/2023]
Abstract
Emergent relativistic quasiparticles in Weyl semimetals are the source of exotic electronic properties such as surface Fermi arcs, the anomalous Hall effect and negative magnetoresistance, all observed in real materials. Whereas these phenomena highlight the effect of Weyl fermions on the electronic transport properties, less is known about what collective phenomena they may support. Here, we report a Weyl semimetal, NdAlSi, that offers an example. Using neutron diffraction, we found a long-wavelength helical magnetic order in NdAlSi, the periodicity of which is linked to the nesting vector between two topologically non-trivial Fermi pockets, which we characterize using density functional theory and quantum oscillation measurements. We further show the chiral transverse component of the spin structure is promoted by bond-oriented Dzyaloshinskii-Moriya interactions associated with Weyl exchange processes. Our work provides a rare example of Weyl fermions driving collective magnetism.
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Affiliation(s)
- Jonathan Gaudet
- Department of Physics and Astronomy and Institute for Quantum Matter, The Johns Hopkins University, Baltimore, MD, USA.
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, MD, USA.
- Department of Materials Science and Engineering, University of Maryland, College Park, MD, USA.
| | - Hung-Yu Yang
- Department of Physics, Boston College, Chestnut Hill, MA, USA
| | - Santu Baidya
- Department of Physics and Astronomy, Rutgers University, Piscataway, NJ, USA
| | - Baozhu Lu
- Department of Physics, Temple University, Philadelphia, PA, USA
| | - Guangyong Xu
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, MD, USA
| | - Yang Zhao
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, MD, USA
- Department of Materials Science and Engineering, University of Maryland, College Park, MD, USA
| | - Jose A Rodriguez-Rivera
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, MD, USA
- Department of Materials Science and Engineering, University of Maryland, College Park, MD, USA
| | | | - David E Graf
- National High Magnetic Field Laboratory, Tallahassee, FL, USA
| | | | - Predrag Nikolić
- Department of Physics and Astronomy and Institute for Quantum Matter, The Johns Hopkins University, Baltimore, MD, USA
- Department of Physics and Astronomy, George Mason University, Fairfax, VA, USA
| | - David Vanderbilt
- Department of Physics and Astronomy, Rutgers University, Piscataway, NJ, USA
| | - Fazel Tafti
- Department of Physics, Boston College, Chestnut Hill, MA, USA
| | - Collin L Broholm
- Department of Physics and Astronomy and Institute for Quantum Matter, The Johns Hopkins University, Baltimore, MD, USA
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, MD, USA
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58
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Seo J, De C, Ha H, Lee JE, Park S, Park J, Skourski Y, Choi ES, Kim B, Cho GY, Yeom HW, Cheong SW, Kim JH, Yang BJ, Kim K, Kim JS. Colossal angular magnetoresistance in ferrimagnetic nodal-line semiconductors. Nature 2021; 599:576-581. [PMID: 34819684 DOI: 10.1038/s41586-021-04028-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Accepted: 09/15/2021] [Indexed: 11/09/2022]
Abstract
Efficient magnetic control of electronic conduction is at the heart of spintronic functionality for memory and logic applications1,2. Magnets with topological band crossings serve as a good material platform for such control, because their topological band degeneracy can be readily tuned by spin configurations, dramatically modulating electronic conduction3-10. Here we propose that the topological nodal-line degeneracy of spin-polarized bands in magnetic semiconductors induces an extremely large angular response of magnetotransport. Taking a layered ferrimagnet, Mn3Si2Te6, and its derived compounds as a model system, we show that the topological band degeneracy, driven by chiral molecular orbital states, is lifted depending on spin orientation, which leads to a metal-insulator transition in the same ferrimagnetic phase. The resulting variation of angular magnetoresistance with rotating magnetization exceeds a trillion per cent per radian, which we call colossal angular magnetoresistance. Our findings demonstrate that magnetic nodal-line semiconductors are a promising platform for realizing extremely sensitive spin- and orbital-dependent functionalities.
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Affiliation(s)
- Junho Seo
- Center for Artificial Low Dimensional Electronic Systems, Institute for Basic Science (IBS), Pohang, Korea.,Department of Physics, Pohang University of Science and Technology (POSTECH), Pohang, Korea
| | - Chandan De
- Center for Artificial Low Dimensional Electronic Systems, Institute for Basic Science (IBS), Pohang, Korea.,Laboratory of Pohang Emergent Materials, Pohang Accelerator Laboratory, Pohang, Korea
| | - Hyunsoo Ha
- Department of Physics and Astronomy, Seoul National University, Seoul, Korea
| | - Ji Eun Lee
- Department of Physics, Yonsei University, Seoul, Korea
| | - Sungyu Park
- Center for Artificial Low Dimensional Electronic Systems, Institute for Basic Science (IBS), Pohang, Korea
| | - Joonbum Park
- Hochfeld-Magnetlabor Dresden (HLD-EMFL), Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany
| | - Yurii Skourski
- Hochfeld-Magnetlabor Dresden (HLD-EMFL), Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany
| | - Eun Sang Choi
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL, USA
| | - Bongjae Kim
- Department of Physics, Kunsan National University, Gunsan, Korea
| | - Gil Young Cho
- Center for Artificial Low Dimensional Electronic Systems, Institute for Basic Science (IBS), Pohang, Korea.,Department of Physics, Pohang University of Science and Technology (POSTECH), Pohang, Korea.,Asia Pacific Center for Theoretical Physics, Pohang, Korea
| | - Han Woong Yeom
- Center for Artificial Low Dimensional Electronic Systems, Institute for Basic Science (IBS), Pohang, Korea.,Department of Physics, Pohang University of Science and Technology (POSTECH), Pohang, Korea
| | - Sang-Wook Cheong
- Laboratory of Pohang Emergent Materials, Pohang Accelerator Laboratory, Pohang, Korea.,Rutgers Center for Emergent Materials and Department of Physics & Astronomy, Rutgers University, Piscataway, NJ, USA
| | - Jae Hoon Kim
- Department of Physics, Yonsei University, Seoul, Korea.
| | - Bohm-Jung Yang
- Department of Physics and Astronomy, Seoul National University, Seoul, Korea. .,Center for Correlated Electron Systems, Institute for Basic Science (IBS), Seoul, Korea. .,Center for Theoretical Physics (CTP), Seoul National University, Seoul, Korea.
| | - Kyoo Kim
- Korea Atomic Energy Research Institute (KAERI), Daejeon, Korea.
| | - Jun Sung Kim
- Center for Artificial Low Dimensional Electronic Systems, Institute for Basic Science (IBS), Pohang, Korea. .,Department of Physics, Pohang University of Science and Technology (POSTECH), Pohang, Korea.
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59
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Chang Y, Wang X, Na S, Zhang W. Computational Simulation of the Electronic State Transition in the Ternary Hexagonal Compound BaAgBi. Front Chem 2021; 9:796323. [PMID: 34858952 PMCID: PMC8631810 DOI: 10.3389/fchem.2021.796323] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2021] [Accepted: 10/26/2021] [Indexed: 11/23/2022] Open
Abstract
Topological properties in metals or semimetals have sparked tremendous scientific interest in quantum chemistry because of their exotic surface state behavior. The current research focus is still on discovering ideal topological metal material candidates. We propose a ternary compound with a hexagonal crystal structure, BaAgBi, which was discovered to exhibit two Weyl nodal ring states around the Fermi energy level without the spin-orbit coupling (SOC) effect using theoretical calculations. When the SOC effect is considered, the topological phases transform into two Dirac nodal line states, and their locations also shift from the Weyl nodal rings. The surface states of both the Weyl nodal ring and Dirac nodal lines were calculated on the (001) surface projection using a tight-binding Hamiltonian, and clear drumhead states were observed, with large spatial distribution areas and wide energy variation ranges. These topological features in BaAgBi can be very beneficial for experimental detection, inspiring further experimental investigation.
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Affiliation(s)
- Yu Chang
- Tonghua Normal University, Tonghua, China
| | - Xin Wang
- Wonkwang University, Iksan, South Korea
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60
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Batool J, Alay-E-Abbas SM, Johansson G, Zulfiqar W, Danish MA, Bilal M, Larsson JA, Amin N. Oxygen-vacancy-induced magnetism in anti-perovskite topological Dirac semimetal Ba 3SnO. Phys Chem Chem Phys 2021; 23:24878-24891. [PMID: 34724010 DOI: 10.1039/d1cp03989j] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The thermodynamic, structural, magnetic and electronic properties of the pristine and intrinsic vacancy-defect-containing topological Dirac semimetal Ba3SnO are studied using first-principles density functional theory calculations. The thermodynamic stability of Ba3SnO has been evaluated with reference to its competing binary phases Ba2Sn, BaSn and BaO. Subsequently, valid limits of the atomic chemical potentials derived from the thermodynamic stability were used for assessing the formation of Ba, Sn and O vacancy defects in Ba3SnO under different synthesis environments. Based on the calculated defect-formation energies, we find that the charge-neutral oxygen vacancies are the most favourable type of vacancy defect under most chemical environments. The calculated electronic properties of pristine Ba3SnO show that inclusion of spin-orbit coupling in exchange-correlation potentials computed using generalized gradient approximation yields a semimetallic band structure exhibiting twin Dirac cones along the Γ-X path of the Brillouin zone. The effect of spin-polarization and spin-orbit coupling on the physical properties of intrinsic vacancy defects containing Ba3SnO has been examined in detail. Using Bader charges, electron localization function (ELF), electronic density of states (DOS) and spin density, we show that the isolated oxygen vacancy is a magnetic defect in anti-perovskite Ba3SnO. Our results show that the origin of magnetism in Ba3SnO is the accumulation of unpaired charges at the oxygen vacancy sites, which couple strongly with the 5d states of the Ba atom. Owing to the metastability observed in earlier theoretically predicted magnetic topological semimetals, the present study reveals the important role of intrinsic vacancy defects in giving rise to magnetism and also provides opportunities for engineering the electronic structure of a Dirac semimetal.
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Affiliation(s)
- Javaria Batool
- Computational Materials Modeling Laboratory, Department of Physics, Government College University Faisalabad, 38040 Faisalabad, Pakistan. .,Department of Physics, Government College Women University Faisalabad, Faisalabad, Pakistan
| | - Syed Muhammad Alay-E-Abbas
- Computational Materials Modeling Laboratory, Department of Physics, Government College University Faisalabad, 38040 Faisalabad, Pakistan. .,Applied Physics, Division of Materials Science, Department of Engineering Sciences and Mathematics, Luleå University of Technology, 97187 Luleå, Sweden
| | - Gustav Johansson
- Applied Physics, Division of Materials Science, Department of Engineering Sciences and Mathematics, Luleå University of Technology, 97187 Luleå, Sweden
| | - Waqas Zulfiqar
- Computational Materials Modeling Laboratory, Department of Physics, Government College University Faisalabad, 38040 Faisalabad, Pakistan.
| | - Muhammad Arsam Danish
- Computational Materials Modeling Laboratory, Department of Physics, Government College University Faisalabad, 38040 Faisalabad, Pakistan.
| | - Muhammad Bilal
- Computational Materials Modeling Laboratory, Department of Physics, Government College University Faisalabad, 38040 Faisalabad, Pakistan.
| | - J Andreas Larsson
- Applied Physics, Division of Materials Science, Department of Engineering Sciences and Mathematics, Luleå University of Technology, 97187 Luleå, Sweden
| | - Nasir Amin
- Computational Materials Modeling Laboratory, Department of Physics, Government College University Faisalabad, 38040 Faisalabad, Pakistan.
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61
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Kim SJ, Choi D, Kim KW, Lee KY, Kim DH, Hong S, Suh J, Lee C, Kim SK, Park TE, Koo HC. Interface Engineering of Magnetic Anisotropy in van der Waals Ferromagnet-based Heterostructures. ACS NANO 2021; 15:16395-16403. [PMID: 34608798 DOI: 10.1021/acsnano.1c05790] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Interface engineering is an effective approach to tune the magnetic properties of van der Waals (vdW) magnets and their heterostructures. The prerequisites for the practical utilization of vdW magnets and heterostructures are a quantitative analysis of their magnetic anisotropy and the ability to modulate their interfacial properties, which have been challenging to achieve with conventional methods. Here we characterize the magnetic anisotropy of Fe3GeTe2 layers by employing the magnetometric technique based on anomalous Hall measurements and confirm its intrinsic nature. In addition, on the basis of the thickness dependences of the anisotropy field, we identify the interfacial and bulk contributions. Furthermore, we demonstrate that the interfacial anisotropy in Fe3GeTe2-based heterostructures is locally controlled by adjacent layers, leading to the realization of multiple magnetic behaviors in a single channel. This work proposes that the magnetometric technique is a useful platform for investigating the intrinsic properties of vdW magnets and that functional devices can be realized by local interface engineering.
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Affiliation(s)
- Sung Jong Kim
- KU-KIST Graduate School of Converging Science and Technology, Korea University, Seoul 02841, Korea
- Center for Spintronics, Korea Institute of Science and Technology, Seoul 02792, Korea
| | - Dongwon Choi
- Center for Spintronics, Korea Institute of Science and Technology, Seoul 02792, Korea
- Display and Nanosystem Laboratory, Department of Electrical Engineering, Korea University, Seoul 02841, Korea
| | - Kyoung-Whan Kim
- Center for Spintronics, Korea Institute of Science and Technology, Seoul 02792, Korea
| | - Ki-Young Lee
- Center for Spintronics, Korea Institute of Science and Technology, Seoul 02792, Korea
| | - Duck-Ho Kim
- Center for Spintronics, Korea Institute of Science and Technology, Seoul 02792, Korea
| | - Seokmin Hong
- Center for Spintronics, Korea Institute of Science and Technology, Seoul 02792, Korea
| | - Joonki Suh
- Department of Materials Science and Engineering, Ulsan National Institute of Science and Technology, Ulsan 44919, Korea
| | - Changgu Lee
- School of Mechanical Engineering, Sungkyunkwan University, Suwon 16419, Korea
| | - Se Kwon Kim
- Department of Physics, Korea Advanced Institute of Science and Technology, Daejeon 34141, Korea
| | - Tae-Eon Park
- Center for Spintronics, Korea Institute of Science and Technology, Seoul 02792, Korea
| | - Hyun Cheol Koo
- KU-KIST Graduate School of Converging Science and Technology, Korea University, Seoul 02841, Korea
- Center for Spintronics, Korea Institute of Science and Technology, Seoul 02792, Korea
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Prediction of unconventional magnetism in doped FeSb 2. Proc Natl Acad Sci U S A 2021; 118:2108924118. [PMID: 34649995 DOI: 10.1073/pnas.2108924118] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/02/2021] [Indexed: 11/18/2022] Open
Abstract
It is commonly believed that the energy bands of typical collinear antiferromagnets (AFs), which have zero net magnetization, are Kramers spin-degenerate. Kramers nondegeneracy is usually associated with a global time-reversal symmetry breaking (e.g., via ferromagnetism) or with a combination of spin-orbit interaction and broken spatial inversion symmetry. Recently, another type of spin splitting was demonstrated to emerge in some collinear magnets that are fully spin compensated by symmetry, nonrelativistic, and not even necessarily noncentrosymmetric. These materials feature nonzero spin density staggered in real space as seen in traditional AFs but also spin splitting in momentum space, generally seen only in ferromagnets. This results in a combination of materials characteristics typical of both ferromagnets and AFs. Here, we discuss this recently discovered class with application to a well-known semiconductor, FeSb2, and predict that with certain alloying, it becomes magnetic and metallic and features the aforementioned magnetic dualism. The calculated energy bands split antisymmetrically with respect to spin-degenerate nodal surfaces rather than nodal points, as in the case of spin-orbit splitting. The combination of a large (0.2-eV) spin splitting, compensated net magnetization with metallic ground state, and a specific magnetic easy axis generates a large anomalous Hall conductivity (∼150 S/cm) and a sizable magnetooptical Kerr effect, all deemed to be hallmarks of nonzero net magnetization. We identify a large contribution to the anomalous response originating from the spin-orbit interaction gapped anti-Kramers nodal surfaces, a mechanism distinct from the nodal lines and Weyl points in ferromagnets.
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Zhang P, Ouyang T, Li J, He C, Chen Y, Zhang C, Tang C, Zhong J. Tunable topologically nontrivial states in newly discovered graphyne allotropes: from Dirac nodal grid to Dirac nodal loop. NANOTECHNOLOGY 2021; 32:485705. [PMID: 34380128 DOI: 10.1088/1361-6528/ac1cbe] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/08/2021] [Accepted: 08/09/2021] [Indexed: 06/13/2023]
Abstract
By means of quotient-graph associated crystal prediction method, a new graphyne allotrope with unique Dirac nodal grid state is reported in this work. It is named as 191-E24Y24-1 according to its hexagonal lattice (with P6/mmm symmetry, No. 191) containing 24 sp2-hybridized carbon atoms and 24 sp-hybridized ones. The first-principles results show that the total energy of 191-E24Y24-1 is more favorable than that of recent synthesizedβ-graphdiyne and carbon ene-yne. It is also demonstrated to be dynamically, thermally, and mechanically stable. Interestingly, the 191-E24Y24-1 harbors intrinsic semimetal features showing intriguing hexagonal Dirac nodal grid state in the reciprocal space. Such unique electronic state is stable against small external tensile strains, and it is tunable under compression strains which will transform to new triangle Dirac nodal grid state. Moreover, a new metastable graphyne allotrope named 191-E12Y36-4 with Dirac nodal loop state is also observed in the process of stretching 191-E24Y24-1 with large tensile strains. The results presented in this work reveal two novel graphyne allotropes with exotic electronic properties. These discoveries are not only physical interesting, but also provide potential material candidates for carbon-based high performance electronic nanodevices.
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Affiliation(s)
- Pei Zhang
- Hunan Key Laboratory for Micro-Nano Energy Materials and Device, Xiangtan University, Xiangtan 411105, Hunan, People's Republic of China
- School of Physics and Optoelectronics, Xiangtan University, Xiangtan 411105, Hunan, People's Republic of China
| | - Tao Ouyang
- Hunan Key Laboratory for Micro-Nano Energy Materials and Device, Xiangtan University, Xiangtan 411105, Hunan, People's Republic of China
- School of Physics and Optoelectronics, Xiangtan University, Xiangtan 411105, Hunan, People's Republic of China
| | - Jin Li
- Hunan Key Laboratory for Micro-Nano Energy Materials and Device, Xiangtan University, Xiangtan 411105, Hunan, People's Republic of China
- School of Physics and Optoelectronics, Xiangtan University, Xiangtan 411105, Hunan, People's Republic of China
| | - Chaoyu He
- Hunan Key Laboratory for Micro-Nano Energy Materials and Device, Xiangtan University, Xiangtan 411105, Hunan, People's Republic of China
- School of Physics and Optoelectronics, Xiangtan University, Xiangtan 411105, Hunan, People's Republic of China
| | - Yuanping Chen
- Faculty of Science, Jiangsu University, Zhenjiang, 212013, Jiangsu, People's Republic of China
| | - Chunxiao Zhang
- Hunan Key Laboratory for Micro-Nano Energy Materials and Device, Xiangtan University, Xiangtan 411105, Hunan, People's Republic of China
- School of Physics and Optoelectronics, Xiangtan University, Xiangtan 411105, Hunan, People's Republic of China
| | - Chao Tang
- Hunan Key Laboratory for Micro-Nano Energy Materials and Device, Xiangtan University, Xiangtan 411105, Hunan, People's Republic of China
- School of Physics and Optoelectronics, Xiangtan University, Xiangtan 411105, Hunan, People's Republic of China
| | - Jianxin Zhong
- Hunan Key Laboratory for Micro-Nano Energy Materials and Device, Xiangtan University, Xiangtan 411105, Hunan, People's Republic of China
- School of Physics and Optoelectronics, Xiangtan University, Xiangtan 411105, Hunan, People's Republic of China
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64
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Kim D, Lee C, Jang BG, Kim K, Shim JH. Drastic change of magnetic anisotropy in Fe 3GeTe 2 and Fe 4GeTe 2 monolayers under electric field studied by density functional theory. Sci Rep 2021; 11:17567. [PMID: 34475450 PMCID: PMC8413389 DOI: 10.1038/s41598-021-96639-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Accepted: 08/02/2021] [Indexed: 11/09/2022] Open
Abstract
Magnetic anisotropy energy (MAE) is one of the most important properties in two-dimensional magnetism since the magnetization in two dimension is vulnerable to the spin rotational fluctuations. Using density functional theory calculation, we show that perpendicular electric field dramatically enhances the in-plane and out-of-plane magnetic anisotropies in Fe3GeTe2 and Fe4GeTe2 monolayers, respectively, allowing the change of easy axis in both systems. The changes of the MAE under the electric field are understood as the result of charge redistribution inside the layer, which is available due to the three-dimensional (3D) network of Fe atoms in the monolayers. As a result, we suggest that due to the unique structure of FenGeTe2 compounds composed by peculiar 3D networks of metal atoms, the MAE can be dramatically changed by the external perpendicular electric field.
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Affiliation(s)
- Dongwook Kim
- Department of Chemistry, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Korea
| | - Changhoon Lee
- Department of Chemistry, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Korea.,Max Planck POSTECH Center for Complex Phase of Materials, Pohang University of Science and Technology, Pohang, 37673, Korea
| | - Bo Gyu Jang
- Korea Institute for Advanced Study (KIAS), Seoul, 02455, Korea
| | - Kyoo Kim
- Korea Atomic Energy Research Institute (KAERI), Daejeon, 37673, Korea
| | - Ji Hoon Shim
- Department of Chemistry, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Korea. .,Department of Physics, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Korea. .,Division of Advanced Materials Science, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Korea.
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65
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Li D, Frauenheim T, He J. Robust Giant Magnetoresistance in 2D Van der Waals Molecular Magnetic Tunnel Junctions. ACS APPLIED MATERIALS & INTERFACES 2021; 13:36098-36105. [PMID: 34308645 DOI: 10.1021/acsami.1c10673] [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
The spin transport across a zero-dimensional (0D) single-molecule sandwiched by two-dimensional (2D) van der Waals (vdW) ferromagnetic electrodes may open vast opportunities to create novel mixed-dimensional spintronics devices. However, this remains unexplored yet. Inspired by the recent discovery of 2D intrinsic ferromagnets Fe3GeTe2, using first-principles spin transport calculations, we show that single-molecule junctions based on Fe3GeTe2 can yield perfect spin filtering and a significant magnetoresistance (MR) of up to ∼6075%. This remarkable MR is more than 2 orders of magnitude higher than the MR obtained for the corresponding junctions with conventional ferromagnetic metals (e.g., Ni, Fe, and Co). We demonstrate the results of two representative examples that are feasible in the experiments: (i) A benzene or (ii) bezenedithiol (BDT) connected either through a scanning tunneling microscope or break-junction setups. We find that the conductance of BDT junctions is more than 10 times larger than that of the benzene junction due to a much stronger hybridization effect at the molecule-metal interfaces. The key mechanism of the perfect spin filtering and large MR in single-molecule junctions is mainly determined by the intrinsic properties of Fe3GeTe2 electrodes, while the actual conductance is determined by the hybridization strength of the majority spin channel at the molecule-metal interfaces. It is also predicted that the perfect spin filtering and the remarkably huge MR are highly insensitive to structural variations, interface defects, and stacking orders of the electrodes. Our results provide important insights for expanding molecular spintronics platforms from conventional ferromagnetic metals to new 2D vdw magnets.
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Affiliation(s)
- Dongzhe Li
- Institute for Advanced Study, Chengdu University, Chengdu 610100, P. R. China
| | - Thomas Frauenheim
- Bremen Center for Computational Materials Science, University of Bremen, Am Fallturm 1, 2835 Bremen, Germany
| | - Junjie He
- Bremen Center for Computational Materials Science, University of Bremen, Am Fallturm 1, 2835 Bremen, Germany
- Department of Physical and Macromolecular Chemistry & Charles University Centre of Advanced Materials, Faculty of Science, Charles University in Prague, Hlavova 8, 128 43 Prague 2, Czech Republic
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66
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Zhao M, Chen BB, Xi Y, Zhao Y, Xu H, Zhang H, Cheng N, Feng H, Zhuang J, Pan F, Xu X, Hao W, Li W, Zhou S, Dou SX, Du Y. Kondo Holes in the Two-Dimensional Itinerant Ising Ferromagnet Fe 3GeTe 2. NANO LETTERS 2021; 21:6117-6123. [PMID: 34279960 DOI: 10.1021/acs.nanolett.1c01661] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Heavy Fermion (HF) states emerge in correlated quantum materials due to the intriguing interplay between localized magnetic moments and itinerant electrons but rarely appear in 3d-electron systems due to high itinerancy of d-electrons. Here, an anomalous enhancement of Kondo screening is observed at the Kondo hole of local Fe vacancies in Fe3GeTe2 which is a recently discovered 3d-HF system featuring Kondo lattice and two-dimensional itinerant ferromagnetism. An itinerant Kondo-Ising model is established to reproduce the experimental results and provides insight into the competition between Ising ferromagnetism and Kondo screening. Our work explains the microscopic origin of the d-electron HF states in Fe3GeTe2 and inspires future studies of the enriched quantum many-body effects with Kondo holes.
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Affiliation(s)
- Mengting Zhao
- BUAA-UOW Joint Research Centre and School of Physics, Beihang University, Beijing 100191, China
- Institute for Superconducting and Electronic Materials, Australian Institute for Innovative Materials, University of Wollongong, Wollongong, New South Wales 2500, Australia
| | - Bin-Bin Chen
- BUAA-UOW Joint Research Centre and School of Physics, Beihang University, Beijing 100191, China
| | - Yilian Xi
- BUAA-UOW Joint Research Centre and School of Physics, Beihang University, Beijing 100191, China
- Institute for Superconducting and Electronic Materials, Australian Institute for Innovative Materials, University of Wollongong, Wollongong, New South Wales 2500, Australia
| | - Yanyan Zhao
- Key Laboratory of Materials Modification by Laser, Ion and Electron Beams, Ministry of Education, Dalian University of Technology, Dalian 116024, China
| | - Hang Xu
- BUAA-UOW Joint Research Centre and School of Physics, Beihang University, Beijing 100191, China
| | - Hongrun Zhang
- BUAA-UOW Joint Research Centre and School of Physics, Beihang University, Beijing 100191, China
| | - Ningyan Cheng
- 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 Feng
- BUAA-UOW Joint Research Centre and School of Physics, Beihang University, Beijing 100191, China
- Institute for Superconducting and Electronic Materials, Australian Institute for Innovative Materials, University of Wollongong, Wollongong, New South Wales 2500, Australia
| | - Jincheng Zhuang
- BUAA-UOW Joint Research Centre and School of Physics, Beihang University, Beijing 100191, China
| | - Feng Pan
- Research Institute for Frontier Science, Beihang University, Beijing 100191, China
| | - Xun Xu
- BUAA-UOW Joint Research Centre and School of Physics, Beihang University, Beijing 100191, China
- Institute for Superconducting and Electronic Materials, Australian Institute for Innovative Materials, University of Wollongong, Wollongong, New South Wales 2500, Australia
| | - Weichang Hao
- BUAA-UOW Joint Research Centre and School of Physics, Beihang University, Beijing 100191, China
| | - Wei Li
- BUAA-UOW Joint Research Centre and School of Physics, Beihang University, Beijing 100191, China
- International Research Institute of Multidisciplinary Science, Beihang University, Beijing 100191, China
| | - Si Zhou
- Institute for Superconducting and Electronic Materials, Australian Institute for Innovative Materials, University of Wollongong, Wollongong, New South Wales 2500, Australia
- Key Laboratory of Materials Modification by Laser, Ion and Electron Beams, Ministry of Education, Dalian University of Technology, Dalian 116024, China
| | - Shi Xue Dou
- BUAA-UOW Joint Research Centre and School of Physics, Beihang University, Beijing 100191, China
- Institute for Superconducting and Electronic Materials, Australian Institute for Innovative Materials, University of Wollongong, Wollongong, New South Wales 2500, Australia
| | - Yi Du
- BUAA-UOW Joint Research Centre and School of Physics, Beihang University, Beijing 100191, China
- Institute for Superconducting and Electronic Materials, Australian Institute for Innovative Materials, University of Wollongong, Wollongong, New South Wales 2500, Australia
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67
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Yang L, Wu H, Zhang L, Zhang G, Li H, Jin W, Zhang W, Chang H. Tunable and Robust Near-Room-Temperature Intrinsic Ferromagnetism of a van der Waals Layered Cr-Doped 2H-MoTe 2 Semiconductor with an Out-of-Plane Anisotropy. ACS APPLIED MATERIALS & INTERFACES 2021; 13:31880-31890. [PMID: 34182752 DOI: 10.1021/acsami.1c07680] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
The intrinsically nonmagnetic feature of van der Waals (vdW) layered transition-metal dichalcogenide (TMDC) semiconductors limits the spintronic applications of these semiconductors. In this paper, we demonstrate a facile Te flux strategy to induce intrinsic ferromagnetism in the vdW layered 2H-MoTe2 semiconductor by magnetic chromium (Cr) doping. The Curie temperature (Tc) and saturation magnetization (Ms) can be well tuned by adjusting the Cr doping concentration. A notable Tc up to 275 K can be achieved for the vdW layered Cr-doped 2H-MoTe2 bulk crystals, which is much higher than that of recently reported van der Waals ferromagnetic semiconductors (Tc is mostly less than 70 K), in contrast to the diamagnetic feature of the pristine MoTe2. Meanwhile, the highest Ms of the vdW layered Cr-doped 2H-MoTe2 bulk crystals can reach 4.78 emu g-1, which is stronger than most values reported for magnetic-element-doped van der Waals materials. In addition, all of the as-grown semiconducting Cr-doped 2H-MoTe2 (Cr-2H-MoTe2) single crystals display a large magnetic anisotropy with an out-of-plane easy axis of magnetization. The observed ferromagnetism in the Cr-2H-MoTe2 has intrinsic characteristics, which can be mainly attributed to the spin polarization caused by Cr doping as confirmed by the density functional theory (DFT) calculations. Our approach offers an avenue to tune the ferromagnetism in the vdW layered semiconductor and explore its diverse spintronic and magnetoelectric applications.
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Affiliation(s)
- Li Yang
- Center for Joining and Electronic Packaging, State Key Laboratory of Material Processing and Die & Mold Technology, School of Materials Science and Engineering, Huazhong University of Science and Technology (HUST), Wuhan 430074, China
- Shenzhen R&D Center of Huazhong University of Science and Technology (HUST), Shenzhen 518000, China
- Institute for Quantum Science and Engineering, Huazhong University of Science and Technology (HUST), Wuhan 430074, China
| | - Hao Wu
- Center for Joining and Electronic Packaging, State Key Laboratory of Material Processing and Die & Mold Technology, School of Materials Science and Engineering, Huazhong University of Science and Technology (HUST), Wuhan 430074, China
- Shenzhen R&D Center of Huazhong University of Science and Technology (HUST), Shenzhen 518000, China
- Institute for Quantum Science and Engineering, Huazhong University of Science and Technology (HUST), Wuhan 430074, China
| | - Liang Zhang
- School of Science and Center for Materials Science and Engineering, Guangxi University of Science and Technology, Liuzhou 545026, China
| | - Gaojie Zhang
- Center for Joining and Electronic Packaging, State Key Laboratory of Material Processing and Die & Mold Technology, School of Materials Science and Engineering, Huazhong University of Science and Technology (HUST), Wuhan 430074, China
- Shenzhen R&D Center of Huazhong University of Science and Technology (HUST), Shenzhen 518000, China
- Institute for Quantum Science and Engineering, Huazhong University of Science and Technology (HUST), Wuhan 430074, China
| | - Hongda Li
- School of Science and Center for Materials Science and Engineering, Guangxi University of Science and Technology, Liuzhou 545026, China
| | - Wen Jin
- Center for Joining and Electronic Packaging, State Key Laboratory of Material Processing and Die & Mold Technology, School of Materials Science and Engineering, Huazhong University of Science and Technology (HUST), Wuhan 430074, China
- Shenzhen R&D Center of Huazhong University of Science and Technology (HUST), Shenzhen 518000, China
- Institute for Quantum Science and Engineering, Huazhong University of Science and Technology (HUST), Wuhan 430074, China
| | - Wenfeng Zhang
- Center for Joining and Electronic Packaging, State Key Laboratory of Material Processing and Die & Mold Technology, School of Materials Science and Engineering, Huazhong University of Science and Technology (HUST), Wuhan 430074, China
- Shenzhen R&D Center of Huazhong University of Science and Technology (HUST), Shenzhen 518000, China
- Institute for Quantum Science and Engineering, Huazhong University of Science and Technology (HUST), Wuhan 430074, China
| | - Haixin Chang
- Center for Joining and Electronic Packaging, State Key Laboratory of Material Processing and Die & Mold Technology, School of Materials Science and Engineering, Huazhong University of Science and Technology (HUST), Wuhan 430074, China
- Shenzhen R&D Center of Huazhong University of Science and Technology (HUST), Shenzhen 518000, China
- Institute for Quantum Science and Engineering, Huazhong University of Science and Technology (HUST), Wuhan 430074, China
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68
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Tan C, Xie WQ, Zheng G, Aloufi N, Albarakati S, Algarni M, Li J, Partridge J, Culcer D, Wang X, Yi JB, Tian M, Xiong Y, Zhao YJ, Wang L. Gate-Controlled Magnetic Phase Transition in a van der Waals Magnet Fe 5GeTe 2. NANO LETTERS 2021; 21:5599-5605. [PMID: 34152781 DOI: 10.1021/acs.nanolett.1c01108] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Magnetic van der Waals (vdW) materials are poised to enable all-electrical control of magnetism in the two-dimensional limit. However, tuning the magnetic ground state in vdW itinerant ferromagnets by voltage-induced charge doping remains a significant challenge, due to the extremely large carrier densities in these materials. Here, by cleaving the vdW itinerant ferromagnet Fe5GeTe2 (F5GT) into 5.4 nm (around two unit cells), we find that the ferromagnetism (FM) in F5GT can be substantially tuned by the thickness. Moreover, by utilizing a solid protonic gate, an electron doping concentration of above 1021 cm-3 has been exhibited in F5GT nanosheets. Such a high carrier accumulation exceeds that possible in widely used electric double-layer transistors (EDLTs) and surpasses the intrinsic carrier density of F5GT. Importantly, it is accompanied by a magnetic phase transition from FM to antiferromagnetism (AFM). The realization of an antiferromagnetic phase in nanosheet F5GT suggests the promise of applications in high-temperature antiferromagnetic vdW devices and heterostructures.
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Affiliation(s)
- Cheng Tan
- School of Science, RMIT University, Melbourne, Victoria 3001, Australia
| | - Wen-Qiang Xie
- Department of Physics, South China University of Technology, Guangzhou 510640, China
| | - Guolin Zheng
- School of Science, RMIT University, Melbourne, Victoria 3001, Australia
| | - Nuriyah Aloufi
- School of Science, RMIT University, Melbourne, Victoria 3001, Australia
| | - Sultan Albarakati
- School of Science, RMIT University, Melbourne, Victoria 3001, Australia
| | - Meri Algarni
- School of Science, RMIT University, Melbourne, Victoria 3001, Australia
| | - Junbo Li
- Anhui Province Key Laboratory of Condensed Matter Physics at Extreme Conditions, High Magnetic Field Laboratory, Chinese Academy of Sciences (CAS), Hefei 230031, Anhui, China
| | - James Partridge
- School of Science, RMIT University, Melbourne, Victoria 3001, Australia
| | - Dimitrie Culcer
- School of Physics and ARC Centre of Excellence in Future Low-Energy Electronics Technologies, UNSW Node, University of New South Wales, Sydney, New South Wales 2052, Australia
| | - Xiaolin Wang
- Institute for Superconducting & Electronic Materials, Australian Institute of Innovative Materials, University of Wollongong, Wollongong, New South Wales 2500, Australia
- ARC Centre for Future Low-Energy Electronics Technologies (FLEET), University of Wollongong, Wollongong, New South Wales 2500, Australia
| | - Jia Bao Yi
- Global Innovative Center for Advanced Nanomaterials, School of Engineering, University of Newcastle, Callaghan, New South Wales 2308, Australia
| | - Mingliang Tian
- Anhui Province Key Laboratory of Condensed Matter Physics at Extreme Conditions, High Magnetic Field Laboratory, Chinese Academy of Sciences (CAS), Hefei 230031, Anhui, China
- Department of Physics, School of Physics and Materials Science, Anhui University, Hefei 230601, Anhui, China
- Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
| | - Yimin Xiong
- Anhui Province Key Laboratory of Condensed Matter Physics at Extreme Conditions, High Magnetic Field Laboratory, Chinese Academy of Sciences (CAS), Hefei 230031, Anhui, China
| | - Yu-Jun Zhao
- Department of Physics, South China University of Technology, Guangzhou 510640, China
| | - Lan Wang
- School of Science, RMIT University, Melbourne, Victoria 3001, Australia
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69
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Unconventional Hall effect and its variation with Co-doping in van der Waals Fe 3GeTe 2. Sci Rep 2021; 11:14121. [PMID: 34238967 PMCID: PMC8266818 DOI: 10.1038/s41598-021-93402-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Accepted: 06/16/2021] [Indexed: 11/18/2022] Open
Abstract
Two-dimensional (2D) van der Waals (vdW) magnetic materials have attracted a lot of attention owing to the stabilization of long range magnetic order down to atomic dimensions, and the prospect of novel spintronic devices with unique functionalities. The clarification of the magnetoresistive properties and its correlation to the underlying magnetic configurations is essential for 2D vdW-based spintronic devices. Here, the effect of Co-doping on the magnetic and magnetotransport properties of Fe3GeTe2 have been investigated. Magnetotransport measurements reveal an unusual Hall effect behavior whose strength was considerably modified by Co-doping and attributed to arise from the underlying complicated spin textures. The present results provide a clue to tailoring of the underlying interactions necessary for the realization of a variety of unconventional spin textures for 2D vdW FM-based spintronics.
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70
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Liu S, Li Z, Yang K, Zhang E, Narayan A, Zhang X, Zhu J, Liu W, Liao Z, Kudo M, Toriyama T, Yang Y, Li Q, Ai L, Huang C, Sun J, Guo X, Bao W, Deng Q, Chen Y, Yin L, Shen J, Han X, Matsumura S, Zou J, Xu Y, Xu X, Wu H, Xiu F. Tuning 2D magnetism in Fe3+XGeTe2 films by element doping. Natl Sci Rev 2021; 9:nwab117. [PMID: 35822066 PMCID: PMC9270067 DOI: 10.1093/nsr/nwab117] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Revised: 02/24/2021] [Accepted: 06/10/2021] [Indexed: 11/23/2022] Open
Abstract
Two-dimensional (2D) ferromagnetic materials have been discovered with tunable magnetism and orbital-driven nodal-line features. Controlling the 2D magnetism in exfoliated nanoflakes via electric/magnetic fields enables a boosted Curie temperature (TC) or phase transitions. One of the challenges, however, is the realization of high TC 2D magnets that are tunable, robust and suitable for large scale fabrication. Here, we report molecular-beam epitaxy growth of wafer-scale Fe3+XGeTe2 films with TC above room temperature. By controlling the Fe composition in Fe3+XGeTe2, a continuously modulated TC in a broad range of 185–320 K has been achieved. This widely tunable TC is attributed to the doped interlayer Fe that provides a 40% enhancement around the optimal composition X = 2. We further fabricated magnetic tunneling junction device arrays that exhibit clear tunneling signals. Our results show an effective and reliable approach, i.e. element doping, to producing robust and tunable ferromagnetism beyond room temperature in a large-scale 2D Fe3+XGeTe2 fashion.
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Affiliation(s)
- Shanshan Liu
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433, China
- Institute for Nanoelectronic Devices and Quantum Computing, Fudan University, Shanghai 200433, China
| | - Zihan Li
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433, China
- Institute for Nanoelectronic Devices and Quantum Computing, Fudan University, Shanghai 200433, China
| | - Ke Yang
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433, China
- Laboratory for Computational Physical Sciences (MOE), Fudan University, Shanghai 200433, China
| | - Enze Zhang
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433, China
- Institute for Nanoelectronic Devices and Quantum Computing, Fudan University, Shanghai 200433, China
| | - Awadhesh Narayan
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore 560012, India
| | - Xiaoqian Zhang
- School of Electronic Science and Engineering, Nanjing University, Nanjing 210093, China
| | - Jiayi Zhu
- Department of Physics, University of Washington, Seattle, WA 98195-1560, USA
| | - Wenqing Liu
- Department of Electronic Engineering, Royal Holloway University of London, Egham TW20 0EX, UK
| | - Zhiming Liao
- Materials Engineering, The University of Queensland, Brisbane QLD 4072, Australia
- Beijing Key Lab of Microstructure and Property of Advanced Material, Institute of Microstructure and Properties of Advanced Materials, Beijing University of Technology, Beijing 100124, China
| | - Masaki Kudo
- The Ultramicroscopy Research Center, Kyushu University, Fukuoka 819-0395, Japan
| | - Takaaki Toriyama
- The Ultramicroscopy Research Center, Kyushu University, Fukuoka 819-0395, Japan
| | - Yunkun Yang
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433, China
- Institute for Nanoelectronic Devices and Quantum Computing, Fudan University, Shanghai 200433, China
| | - Qiang Li
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433, China
- Institute for Nanoelectronic Devices and Quantum Computing, Fudan University, Shanghai 200433, China
| | - Linfeng Ai
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433, China
- Institute for Nanoelectronic Devices and Quantum Computing, Fudan University, Shanghai 200433, China
| | - Ce Huang
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433, China
- Institute for Nanoelectronic Devices and Quantum Computing, Fudan University, Shanghai 200433, China
| | - Jiabao Sun
- Department of Electronic Engineering, Royal Holloway University of London, Egham TW20 0EX, UK
| | - Xiaojiao Guo
- State Key Laboratory of ASIC and System, School of Microelectronics, Fudan University, Shanghai 200433, China
| | - Wenzhong Bao
- State Key Laboratory of ASIC and System, School of Microelectronics, Fudan University, Shanghai 200433, China
| | - Qingsong Deng
- Beijing Key Lab of Microstructure and Property of Advanced Material, Institute of Microstructure and Properties of Advanced Materials, Beijing University of Technology, Beijing 100124, China
| | - Yanhui Chen
- Beijing Key Lab of Microstructure and Property of Advanced Material, Institute of Microstructure and Properties of Advanced Materials, Beijing University of Technology, Beijing 100124, China
| | - Lifeng Yin
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433, China
- Institute for Nanoelectronic Devices and Quantum Computing, Fudan University, Shanghai 200433, China
- Collaborative Innovation Center of Advanced Microstructures, Nanjing 210093, China
| | - Jian Shen
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433, China
- Institute for Nanoelectronic Devices and Quantum Computing, Fudan University, Shanghai 200433, China
- Collaborative Innovation Center of Advanced Microstructures, Nanjing 210093, China
| | - Xiaodong Han
- Beijing Key Lab of Microstructure and Property of Advanced Material, Institute of Microstructure and Properties of Advanced Materials, Beijing University of Technology, Beijing 100124, China
| | - Syo Matsumura
- The Ultramicroscopy Research Center, Kyushu University, Fukuoka 819-0395, Japan
- Department of Applied Quantum Physics and Nuclear Engineering, Kyushu University, Fukuoka 819-0395, Japan
| | - Jin Zou
- Materials Engineering, The University of Queensland, Brisbane QLD 4072, Australia
- Centre for Microscopy and Microanalysis, The University of Queensland, Brisbane QLD 4072, Australia
| | - Yongbing Xu
- School of Electronic Science and Engineering, Nanjing University, Nanjing 210093, China
| | - Xiaodong Xu
- Department of Physics, University of Washington, Seattle, WA 98195-1560, USA
| | - Hua Wu
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433, China
- Laboratory for Computational Physical Sciences (MOE), Fudan University, Shanghai 200433, China
- Collaborative Innovation Center of Advanced Microstructures, Nanjing 210093, China
| | - Faxian Xiu
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433, China
- Institute for Nanoelectronic Devices and Quantum Computing, Fudan University, Shanghai 200433, China
- Collaborative Innovation Center of Advanced Microstructures, Nanjing 210093, China
- Shanghai Research Center for Quantum Sciences, Shanghai 201315, China
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71
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Huang M, Wang S, Wang Z, Liu P, Xiang J, Feng C, Wang X, Zhang Z, Wen Z, Xu H, Yu G, Lu Y, Zhao W, Yang SA, Hou D, Xiang B. Colossal Anomalous Hall Effect in Ferromagnetic van der Waals CrTe 2. ACS NANO 2021; 15:9759-9763. [PMID: 33881844 DOI: 10.1021/acsnano.1c00488] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
van der Waals crystals exhibit excellent material performance when exfoliated to few-atomic-layer thickness. In contrast, the van der Waals thin films more than 10 nm thick are believed to show bulk properties, in which outstanding material performance is rarely found. Here we report the largest anomalous Hall conductivity observed so far in a 170 nm van der Waals ferromagnetic 1T-CrTe2 flake, which reaches 67,000 Ω-1 cm-1. Such a colossal anomalous Hall conductivity in 1T-CrTe2 is dominated by the extrinsic skew scattering process rather than the intrinsic Berry phase effect, as evidenced by the linear relation between the anomalous Hall conductivity and the longitudinal conductivity. Defying the dilemma of mutually exclusive large anomalous Hall angle and high electric conductivity for most ferromagnets, 1T-CrTe2 achieves both in a thin film sample. Considering the shared physics of the anomalous Hall effect and the spin Hall effect, our finding offers a guideline for searching large spin Hall materials of high conductivity which may overcome the bottleneck of overheating in spintronics devices.
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Affiliation(s)
- Meng Huang
- Hefei National Research Center for Physical Sciences at the Microscale, International Centre for Quantum Design of Functional Materials, Department of Materials Science & Engineering, CAS Key Lab of Materials for Energy Conversion, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Shanshan Wang
- School of Physics, Southeast University, Nanjing 211189, China
| | - Zhaohao Wang
- Fert Beijing Institute, BDBC, and School of Microelectronics, Beihang University, Beijing 100191, China
| | - Ping Liu
- Hefei National Research Center for Physical Sciences at the Microscale, International Centre for Quantum Design of Functional Materials, Department of Materials Science & Engineering, CAS Key Lab of Materials for Energy Conversion, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Junxiang Xiang
- Hefei National Research Center for Physical Sciences at the Microscale, International Centre for Quantum Design of Functional Materials, Department of Materials Science & Engineering, CAS Key Lab of Materials for Energy Conversion, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Chao Feng
- Hefei National Research Center for Physical Sciences at the Microscale, International Centre for Quantum Design of Functional Materials, Department of Materials Science & Engineering, CAS Key Lab of Materials for Energy Conversion, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Xiangqi Wang
- Department of Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Zengming Zhang
- The Centre for Physical Experiments, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Zhenchao Wen
- National Institute for Materials Science (NIMS), Tsukuba 304-0047, Japan
| | - Hongjun Xu
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing 100190, China
| | - Guoqiang Yu
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing 100190, China
| | - Yalin Lu
- Hefei National Research Center for Physical Sciences at the Microscale, International Centre for Quantum Design of Functional Materials, Department of Materials Science & Engineering, CAS Key Lab of Materials for Energy Conversion, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Weisheng Zhao
- Fert Beijing Institute, BDBC, and School of Microelectronics, Beihang University, Beijing 100191, China
| | - Shengyuan A Yang
- Research Laboratory for Quantum Materials, Singapore University of Technology and Design, Singapore 487372, Singapore
| | - Dazhi Hou
- Hefei National Research Center for Physical Sciences at the Microscale, International Centre for Quantum Design of Functional Materials, Department of Materials Science & Engineering, CAS Key Lab of Materials for Energy Conversion, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Bin Xiang
- Hefei National Research Center for Physical Sciences at the Microscale, International Centre for Quantum Design of Functional Materials, Department of Materials Science & Engineering, CAS Key Lab of Materials for Energy Conversion, University of Science and Technology of China, Hefei, Anhui 230026, China
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72
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Huang M, Gao L, Zhang Y, Lei X, Hu G, Xiang J, Zeng H, Fu X, Zhang Z, Chai G, Peng Y, Lu Y, Du H, Chen G, Zang J, Xiang B. Possible Topological Hall Effect above Room Temperature in Layered Cr 1.2Te 2 Ferromagnet. NANO LETTERS 2021; 21:4280-4286. [PMID: 33979154 DOI: 10.1021/acs.nanolett.1c00493] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Topological Hall effect (THE) has been used as a powerful tool to unlock spin chirality in novel magnetic materials. Recent focus has been widely paid to THE and possible chiral spin textures in two-dimensional (2D) layered magnetic materials. However, the room-temperature THE has been barely reported in 2D materials, which hinders its practical applications in 2D spintronics. In this paper, we report a possible THE signal featuring antisymmetric peaks in a wide temperature window up to 320 K in Cr1.2Te2, a new quasi-2D ferromagnetic material. The temperature, thickness, and magnetic field dependences of the THE lead to potential spin chirality origin that is associated with the spin canting under external magnetic fields. Our work holds promise for practical applications in future chiral spin-based vdW spintronic devices.
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Affiliation(s)
- Meng Huang
- Hefei National Laboratory for Physical Sciences at the Microscale, Department of Materials Science and Engineering, CAS Key Lab of Materials for Energy Conversion, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Lei Gao
- Key Laboratory of Magnetism and Magnetic Materials of the Ministry of Education, Lanzhou University, Lanzhou 730000, P.R. China
| | - Ying Zhang
- Hefei National Laboratory for Physical Sciences at the Microscale, Department of Materials Science and Engineering, CAS Key Lab of Materials for Energy Conversion, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Xunyong Lei
- Hefei National Laboratory for Physical Sciences at the Microscale, Department of Materials Science and Engineering, CAS Key Lab of Materials for Energy Conversion, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Guojing Hu
- Hefei National Laboratory for Physical Sciences at the Microscale, Department of Materials Science and Engineering, CAS Key Lab of Materials for Energy Conversion, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Junxiang Xiang
- Hefei National Laboratory for Physical Sciences at the Microscale, Department of Materials Science and Engineering, CAS Key Lab of Materials for Energy Conversion, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Hualing Zeng
- Hefei National Laboratory for Physical Sciences at the Microscale, Department of Materials Science and Engineering, CAS Key Lab of Materials for Energy Conversion, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Xuewen Fu
- School of Physics, Nankai University, Tianjin 300071 China
| | - Zengming Zhang
- The Center for Physical Experiments, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Guozhi Chai
- Key Laboratory of Magnetism and Magnetic Materials of the Ministry of Education, Lanzhou University, Lanzhou 730000, P.R. China
| | - Yong Peng
- Key Laboratory of Magnetism and Magnetic Materials of the Ministry of Education, Lanzhou University, Lanzhou 730000, P.R. China
| | - Yalin Lu
- Hefei National Laboratory for Physical Sciences at the Microscale, Department of Materials Science and Engineering, CAS Key Lab of Materials for Energy Conversion, University of Science and Technology of China, Hefei, Anhui 230026, China
- Anhui Laboratory of Advanced Photon Science and Technology, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Haifeng Du
- High Magnetic Field Laboratory, Chinese Academy of Science (CAS), Hefei, Anhui Province 230031, China
| | - Gong Chen
- Physics Department, Georgetown University, Washington, DC 20057, United States
| | - Jiadong Zang
- Department of Physics and Materials Science Program, University of New Hampshire, Durham, New Hampshire 03824, United States
| | - Bin Xiang
- Hefei National Laboratory for Physical Sciences at the Microscale, Department of Materials Science and Engineering, CAS Key Lab of Materials for Energy Conversion, University of Science and Technology of China, Hefei, Anhui 230026, China
- Anhui Laboratory of Advanced Photon Science and Technology, University of Science and Technology of China, Hefei, Anhui 230026, China
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73
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Li M, Wang Q, Wang G, Yuan Z, Song W, Lou R, Liu Z, Huang Y, Liu Z, Lei H, Yin Z, Wang S. Dirac cone, flat band and saddle point in kagome magnet YMn 6Sn 6. Nat Commun 2021; 12:3129. [PMID: 34035305 PMCID: PMC8149840 DOI: 10.1038/s41467-021-23536-8] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Accepted: 04/13/2021] [Indexed: 11/08/2022] Open
Abstract
Kagome-lattices of 3d-transition metals hosting Weyl/Dirac fermions and topological flat bands exhibit non-trivial topological characters and novel quantum phases, such as the anomalous Hall effect and fractional quantum Hall effect. With consideration of spin-orbit coupling and electron correlation, several instabilities could be induced. The typical characters of the electronic structure of a kagome lattice, i.e., the saddle point, Dirac-cone, and flat band, around the Fermi energy (EF) remain elusive in magnetic kagome materials. We present the experimental observation of the complete features in ferromagnetic kagome layers of YMn6Sn6 helically coupled along the c-axis, by using angle-resolved photoemission spectroscopy and band structure calculations. We demonstrate a Dirac dispersion near EF, which is predicted by spin-polarized theoretical calculations, carries an intrinsic Berry curvature and contributes to the anomalous Hall effect in transport measurements. In addition, a flat band and a saddle point with a high density of states near EF are observed. These multi-sets of kagome features are of orbital-selective origin and could cause multi-orbital magnetism. The Dirac fermion, flat band and saddle point in the vicinity of EF open an opportunity in manipulating the topological properties in magnetic materials.
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Affiliation(s)
- Man Li
- Department of Physics and Beijing Key Laboratory of Opto-Electronic Functional Materials & Micro-Nano Devices, Renmin University of China, Beijing, China
| | - Qi Wang
- Department of Physics and Beijing Key Laboratory of Opto-Electronic Functional Materials & Micro-Nano Devices, Renmin University of China, Beijing, China
| | - Guangwei Wang
- Department of Physics and Center for Advanced Quantum Studies, Beijing Normal University, Beijing, China
| | - Zhihong Yuan
- Department of Physics and Center for Advanced Quantum Studies, Beijing Normal University, Beijing, China
| | - Wenhua Song
- Department of Physics and Beijing Key Laboratory of Opto-Electronic Functional Materials & Micro-Nano Devices, Renmin University of China, Beijing, China
| | - Rui Lou
- School of Physical Science and Technology, Lanzhou University, Lanzhou, China
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai, China
- Collaborative Innovation Center of Advanced Microstructures, Nanjing, China
| | - Zhengtai Liu
- State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai, China
| | - Yaobo Huang
- Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai, China
| | - Zhonghao Liu
- State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai, China.
- College of Materials Science and Opto-Electronic Technology, University of Chinese Academy of Sciences, Beijing, China.
| | - Hechang Lei
- Department of Physics and Beijing Key Laboratory of Opto-Electronic Functional Materials & Micro-Nano Devices, Renmin University of China, Beijing, China.
| | - Zhiping Yin
- Department of Physics and Center for Advanced Quantum Studies, Beijing Normal University, Beijing, China.
| | - Shancai Wang
- Department of Physics and Beijing Key Laboratory of Opto-Electronic Functional Materials & Micro-Nano Devices, Renmin University of China, Beijing, China.
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74
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Seo J, An ES, Park T, Hwang SY, Kim GY, Song K, Noh WS, Kim JY, Choi GS, Choi M, Oh E, Watanabe K, Taniguchi T, Park JH, Jo YJ, Yeom HW, Choi SY, Shim JH, Kim JS. Tunable high-temperature itinerant antiferromagnetism in a van der Waals magnet. Nat Commun 2021; 12:2844. [PMID: 33990589 PMCID: PMC8121823 DOI: 10.1038/s41467-021-23122-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Accepted: 04/13/2021] [Indexed: 11/29/2022] Open
Abstract
Discovery of two dimensional (2D) magnets, showing intrinsic ferromagnetic (FM) or antiferromagnetic (AFM) orders, has accelerated development of novel 2D spintronics, in which all the key components are made of van der Waals (vdW) materials and their heterostructures. High-performing and energy-efficient spin functionalities have been proposed, often relying on current-driven manipulation and detection of the spin states. In this regard, metallic vdW magnets are expected to have several advantages over the widely-studied insulating counterparts, but have not been much explored due to the lack of suitable materials. Here, we report tunable itinerant ferro- and antiferromagnetism in Co-doped Fe4GeTe2 utilizing the vdW interlayer coupling, extremely sensitive to the material composition. This leads to high TN antiferromagnetism of TN ~ 226 K in a bulk and ~210 K in 8 nm-thick nanoflakes, together with tunable magnetic anisotropy. The resulting spin configurations and orientations are sensitively controlled by doping, magnetic field, and thickness, which are effectively read out by electrical conduction. These findings manifest strong merits of metallic vdW magnets as an active component of vdW spintronic applications. Metallic van der Waals magnets have considerable technological promise, due to their ability to be strongly coupled with electronic currents and integrated in two dimensional heterostructures. Here, Seo et al. demonstrate highly tunable itinerant antiferromagnetism in a van der Waals magnet.
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Affiliation(s)
- Junho Seo
- Center for Artificial Low Dimensional Electronic Systems, Institute for Basic Science (IBS), Pohang, Korea.,Department of Physics, Pohang University of Science and Technology (POSTECH), Pohang, Korea
| | - Eun Su An
- Center for Artificial Low Dimensional Electronic Systems, Institute for Basic Science (IBS), Pohang, Korea.,Department of Physics, Pohang University of Science and Technology (POSTECH), Pohang, Korea
| | - Taesu Park
- Department of Chemistry, Pohang University of Science and Technology (POSTECH), Pohang, Korea
| | - Soo-Yoon Hwang
- Department of Materials Science and Engineering, Pohang University of Science and Technology (POSTECH), Pohang, Korea
| | - Gi-Yeop Kim
- Department of Materials Science and Engineering, Pohang University of Science and Technology (POSTECH), Pohang, Korea
| | - Kyung Song
- Materials Modeling and Characterization Department, KIMS, Changwon, Korea
| | - Woo-Suk Noh
- MPPC-CPM, Max Planck POSTECH/Korea Research Initiative, Pohang, Korea
| | - J Y Kim
- Center for Artificial Low Dimensional Electronic Systems, Institute for Basic Science (IBS), Pohang, Korea
| | - Gyu Seung Choi
- Center for Artificial Low Dimensional Electronic Systems, Institute for Basic Science (IBS), Pohang, Korea.,Department of Physics, Pohang University of Science and Technology (POSTECH), Pohang, Korea
| | - Minhyuk Choi
- Center for Artificial Low Dimensional Electronic Systems, Institute for Basic Science (IBS), Pohang, Korea.,Department of Physics, Pohang University of Science and Technology (POSTECH), Pohang, Korea
| | - Eunseok Oh
- Center for Artificial Low Dimensional Electronic Systems, Institute for Basic Science (IBS), Pohang, Korea.,Department of Physics, Pohang University of Science and Technology (POSTECH), Pohang, Korea
| | - Kenji Watanabe
- Research Center for Functional Materials, National Institute for Materials Science, Tsukuba, Japan
| | - Takashi Taniguchi
- International Center for Materials Nanoarchitectonics, National Institute for Materials Science, Tsukuba, Japan
| | - J -H Park
- Department of Physics, Pohang University of Science and Technology (POSTECH), Pohang, Korea.,MPPC-CPM, Max Planck POSTECH/Korea Research Initiative, Pohang, Korea
| | - Youn Jung Jo
- Department of Physics, Kyungpook National University, Daegu, Korea
| | - Han Woong Yeom
- Center for Artificial Low Dimensional Electronic Systems, Institute for Basic Science (IBS), Pohang, Korea.,Department of Physics, Pohang University of Science and Technology (POSTECH), Pohang, Korea
| | - Si-Young Choi
- Department of Materials Science and Engineering, Pohang University of Science and Technology (POSTECH), Pohang, Korea.
| | - Ji Hoon Shim
- Department of Physics, Pohang University of Science and Technology (POSTECH), Pohang, Korea. .,Department of Chemistry, Pohang University of Science and Technology (POSTECH), Pohang, Korea.
| | - Jun Sung Kim
- Center for Artificial Low Dimensional Electronic Systems, Institute for Basic Science (IBS), Pohang, Korea. .,Department of Physics, Pohang University of Science and Technology (POSTECH), Pohang, Korea.
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75
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Guin SN, Xu Q, Kumar N, Kung HH, Dufresne S, Le C, Vir P, Michiardi M, Pedersen T, Gorovikov S, Zhdanovich S, Manna K, Auffermann G, Schnelle W, Gooth J, Shekhar C, Damascelli A, Sun Y, Felser C. 2D-Berry-Curvature-Driven Large Anomalous Hall Effect in Layered Topological Nodal-Line MnAlGe. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2021; 33:e2006301. [PMID: 33734505 DOI: 10.1002/adma.202006301] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Revised: 01/20/2021] [Indexed: 06/12/2023]
Abstract
Topological magnets comprising 2D magnetic layers with Curie temperatures (TC ) exceeding room temperature are key for dissipationless quantum transport devices. However, the identification of a material with 2D ferromagnetic planes that exhibits an out-of-plane-magnetization remains a challenge. This study reports a ferromagnetic, topological, nodal-line, and semimetal MnAlGe composed of square-net Mn layers that are separated by nonmagnetic Al-Ge spacers. The 2D ferromagnetic Mn layers exhibit an out-of-plane magnetization below TC ≈ 503 K. Density functional calculations demonstrate that 2D arrays of Mn atoms control the electrical, magnetic, and therefore topological properties in MnAlGe. The unique 2D distribution of the Berry curvature resembles the 2D Fermi surface of the bands that form the topological nodal line near the Fermi energy. A large anomalous Hall conductivity of ≈700 S cm-1 is obtained at 2 K and related to this nodal-line-induced 2D Berry curvature distribution. The high transition temperature, large anisotropic out-of-plane magnetism, and natural heterostructure-type atomic arrangements consisting of magnetic Mn and nonmagnetic Al/Ge elements render nodal-line MnAlGe one of the few, unique, and layered topological ferromagnets that have ever been observed.
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Affiliation(s)
- Satya N Guin
- Department of Solid State Chemistry, Max Planck Institute for Chemical Physics of Solids, Dresden, 01187, Germany
| | - Qiunan Xu
- Department of Solid State Chemistry, Max Planck Institute for Chemical Physics of Solids, Dresden, 01187, Germany
| | - Nitesh Kumar
- Department of Solid State Chemistry, Max Planck Institute for Chemical Physics of Solids, Dresden, 01187, Germany
| | - Hsiang-Hsi Kung
- Department of Solid State Chemistry, Max Planck Institute for Chemical Physics of Solids, Dresden, 01187, Germany
- Quantum Matter Institute, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada
- Department of Physics and Astronomy, University of British Columbia, Vancouver, BC, V6T 1Z1, Canada
| | - Sydney Dufresne
- Quantum Matter Institute, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada
- Department of Physics and Astronomy, University of British Columbia, Vancouver, BC, V6T 1Z1, Canada
| | - Congcong Le
- Department of Solid State Chemistry, Max Planck Institute for Chemical Physics of Solids, Dresden, 01187, Germany
| | - Praveen Vir
- Department of Solid State Chemistry, Max Planck Institute for Chemical Physics of Solids, Dresden, 01187, Germany
| | - Matteo Michiardi
- Department of Solid State Chemistry, Max Planck Institute for Chemical Physics of Solids, Dresden, 01187, Germany
- Quantum Matter Institute, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada
- Department of Physics and Astronomy, University of British Columbia, Vancouver, BC, V6T 1Z1, Canada
| | - Tor Pedersen
- Canadian Light Source, Inc., 44 Innovation Boulevard, Saskatoon, SK, S7N 2V3, Canada
| | - Sergey Gorovikov
- Canadian Light Source, Inc., 44 Innovation Boulevard, Saskatoon, SK, S7N 2V3, Canada
| | - Sergey Zhdanovich
- Quantum Matter Institute, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada
- Department of Physics and Astronomy, University of British Columbia, Vancouver, BC, V6T 1Z1, Canada
| | - Kaustuv Manna
- Department of Solid State Chemistry, Max Planck Institute for Chemical Physics of Solids, Dresden, 01187, Germany
| | - Gudrun Auffermann
- Department of Solid State Chemistry, Max Planck Institute for Chemical Physics of Solids, Dresden, 01187, Germany
| | - Walter Schnelle
- Department of Solid State Chemistry, Max Planck Institute for Chemical Physics of Solids, Dresden, 01187, Germany
| | - Johannes Gooth
- Department of Solid State Chemistry, Max Planck Institute for Chemical Physics of Solids, Dresden, 01187, Germany
| | - Chandra Shekhar
- Department of Solid State Chemistry, Max Planck Institute for Chemical Physics of Solids, Dresden, 01187, Germany
| | - Andrea Damascelli
- Quantum Matter Institute, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada
- Department of Physics and Astronomy, University of British Columbia, Vancouver, BC, V6T 1Z1, Canada
| | - Yan Sun
- Department of Solid State Chemistry, Max Planck Institute for Chemical Physics of Solids, Dresden, 01187, Germany
| | - Claudia Felser
- Department of Solid State Chemistry, Max Planck Institute for Chemical Physics of Solids, Dresden, 01187, Germany
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76
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He J, Li S, Bandyopadhyay A, Frauenheim T. Unravelling Photoinduced Interlayer Spin Transfer Dynamics in Two-Dimensional Nonmagnetic-Ferromagnetic van der Waals Heterostructures. NANO LETTERS 2021; 21:3237-3244. [PMID: 33749285 DOI: 10.1021/acs.nanolett.1c00520] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Although light is the fastest means to manipulate the interfacial spin injection and magnetic proximity related quantum properties of two-dimensional (2D) magnetic van der Waals (vdW) heterostructures, its potential remains mostly untapped. Here, inspired by the recent discovery of 2D ferromagnets Fe3GeTe2 (FGT), we applied the real-time density functional theory (rt-TDDFT) to study photoinduced interlayer spin transfer dynamics in 2D nonmagnetic-ferromagnetic (NM-FM) vdW heterostructures, including graphene-FGT, silicene-FGT, germanene-FGT, antimonene-FGT and h-BN-FGT interfaces. We observed that laser pulses induce significant large spin injection from FGT to nonmagnetic (NM) layers within a few femtoseconds. In addition, we identified an interfacial atom-mediated spin transfer pathway in heterostructures in which the photoexcited spin of Fe first transfers to intralayered Te atoms and then hops to interlayered NM layers. Interlayer hopping is approximately two times slower than intralayer spin transfer. Our results provide the microscopic understanding for optically control interlayer spin dynamics in 2D magnetic heterostructures.
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Affiliation(s)
- Junjie He
- Bremen Center for Computational Materials Science, University of Bremen, Am Fallturm 1, 2835, Bremen, Germany
- Department of Physical and Macromolecular Chemistry & Charles University Centre of Advanced Materials, Faculty of Science, Charles University in Prague, Hlavova 8, Prague 2, 128 43, Czech Republic
| | - Shuo Li
- Department of Physical and Macromolecular Chemistry & Charles University Centre of Advanced Materials, Faculty of Science, Charles University in Prague, Hlavova 8, Prague 2, 128 43, Czech Republic
| | - Arkamita Bandyopadhyay
- Bremen Center for Computational Materials Science, University of Bremen, Am Fallturm 1, 2835, Bremen, Germany
| | - Thomas Frauenheim
- Bremen Center for Computational Materials Science, University of Bremen, Am Fallturm 1, 2835, Bremen, Germany
- Beijing Computational Science Research Center (CSRC), Beijing 100193, China
- Shenzhen Computational Science and Applied Research (CSAR) Institute, Shenzhen 518110, China
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77
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Tiwari A, Chen F, Zhong S, Drueke E, Koo J, Kaczmarek A, Xiao C, Gao J, Luo X, Niu Q, Sun Y, Yan B, Zhao L, Tsen AW. Giant c-axis nonlinear anomalous Hall effect in T d-MoTe 2 and WTe 2. Nat Commun 2021; 12:2049. [PMID: 33824340 PMCID: PMC8024290 DOI: 10.1038/s41467-021-22343-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Accepted: 03/10/2021] [Indexed: 02/01/2023] Open
Abstract
While the anomalous Hall effect can manifest even without an external magnetic field, time reversal symmetry is nonetheless still broken by the internal magnetization of the sample. Recently, it has been shown that certain materials without an inversion center allow for a nonlinear type of anomalous Hall effect whilst retaining time reversal symmetry. The effect may arise from either Berry curvature or through various asymmetric scattering mechanisms. Here, we report the observation of an extremely large c-axis nonlinear anomalous Hall effect in the non-centrosymmetric Td phase of MoTe2 and WTe2 without intrinsic magnetic order. We find that the effect is dominated by skew-scattering at higher temperatures combined with another scattering process active at low temperatures. Application of higher bias yields an extremely large Hall ratio of E⊥/E|| = 2.47 and corresponding anomalous Hall conductivity of order 8 × 107 S/m.
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Affiliation(s)
- Archana Tiwari
- Institute for Quantum Computing, Department of Physics and Astronomy, and Department of Chemistry, University of Waterloo, Waterloo, ON, Canada
| | - Fangchu Chen
- Institute for Quantum Computing, Department of Physics and Astronomy, and Department of Chemistry, University of Waterloo, Waterloo, ON, Canada
| | - Shazhou Zhong
- Institute for Quantum Computing, Department of Physics and Astronomy, and Department of Chemistry, University of Waterloo, Waterloo, ON, Canada
| | - Elizabeth Drueke
- Department of Physics, University of Michigan, Ann Arbor, MI, USA
| | - Jahyun Koo
- Department of Condensed Matter Physics, Weizmann Institute of Science, Rehovot, Israel
| | - Austin Kaczmarek
- Department of Physics, University of Michigan, Ann Arbor, MI, USA
| | - Cong Xiao
- Department of Physics, The University of Texas at Austin, Austin, TX, USA
| | - Jingjing Gao
- Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei, China
| | - Xuan Luo
- Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei, China
| | - Qian Niu
- Department of Physics, The University of Texas at Austin, Austin, TX, USA
| | - Yuping Sun
- Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei, China
- Anhui Province Key Laboratory of Condensed Matter Physics at Extreme Conditions, High Magnetic Field Laboratory, Chinese Academy of Sciences, Hefei, China
- Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, China
| | - Binghai Yan
- Department of Condensed Matter Physics, Weizmann Institute of Science, Rehovot, Israel
| | - Liuyan Zhao
- Department of Physics, University of Michigan, Ann Arbor, MI, USA
| | - Adam W Tsen
- Institute for Quantum Computing, Department of Physics and Astronomy, and Department of Chemistry, University of Waterloo, Waterloo, ON, Canada.
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78
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Abstract
Skyrmion, a concept originally proposed in particle physics half a century ago, can now find the most fertile field for its applicability, that is, the magnetic skyrmion realized in helimagnetic materials. The spin swirling vortex-like texture of the magnetic skyrmion can define the particle nature by topology; that is, all the constituent spin moments within the two-dimensional sheet wrap the sphere just one time. Such a topological nature of the magnetic skyrmion can lead to extraordinary metastability via topological protection and the driven motion with low electric-current excitation, which may promise future application to spintronics. The skyrmions in the magnetic materials frequently show up as the crystal lattice form, e.g., hexagonal lattice, but sometimes as isolated or independent particles. These skyrmions in magnets were initially found in acentric magnets, such as chiral, polar, and bilayered magnets endowed with antisymmetric spin exchange interaction, while the skyrmion host materials have been explored in a broader family of compounds including centrosymmetric magnets. This review describes the materials science and materials chemistry of magnetic skyrmions using the classification scheme of the skyrmion forming microscopic mechanisms. The emergent phenomena and functions mediated by skyrmions are described, including the generation of emergent magnetic and electric field by statics and dynamics of skrymions and the inherent magnetoelectric effect. The other important magnetic topological defects in two or three dimensions, such as biskyrmions, antiskyrmions, merons, and hedgehogs, are also reviewed in light of their interplay with the skyrmions.
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Affiliation(s)
- Yoshinori Tokura
- Department of Applied Physics, 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
| | - Naoya Kanazawa
- Department of Applied Physics, University of Tokyo, Tokyo 113-8656, Japan
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79
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Kumar N, Guin SN, Manna K, Shekhar C, Felser C. Topological Quantum Materials from the Viewpoint of Chemistry. Chem Rev 2021; 121:2780-2815. [PMID: 33151662 PMCID: PMC7953380 DOI: 10.1021/acs.chemrev.0c00732] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Indexed: 11/29/2022]
Abstract
Topology, a mathematical concept, has recently become a popular and truly transdisciplinary topic encompassing condensed matter physics, solid state chemistry, and materials science. Since there is a direct connection between real space, namely atoms, valence electrons, bonds, and orbitals, and reciprocal space, namely bands and Fermi surfaces, via symmetry and topology, classifying topological materials within a single-particle picture is possible. Currently, most materials are classified as trivial insulators, semimetals, and metals or as topological insulators, Dirac and Weyl nodal-line semimetals, and topological metals. The key ingredients for topology are certain symmetries, the inert pair effect of the outer electrons leading to inversion of the conduction and valence bands, and spin-orbit coupling. This review presents the topological concepts related to solids from the viewpoint of a solid-state chemist, summarizes techniques for growing single crystals, and describes basic physical property measurement techniques to characterize topological materials beyond their structure and provide examples of such materials. Finally, a brief outlook on the impact of topology in other areas of chemistry is provided at the end of the article.
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Affiliation(s)
- Nitesh Kumar
- Max Planck Institute for
Chemical
Physics of Solids, 01187 Dresden, Germany
| | - Satya N. Guin
- Max Planck Institute for
Chemical
Physics of Solids, 01187 Dresden, Germany
| | - Kaustuv Manna
- Max Planck Institute for
Chemical
Physics of Solids, 01187 Dresden, Germany
| | - 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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80
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Gweon HK, Lee SY, Kwon HY, Jeong J, Chang HJ, Kim KW, Qiu ZQ, Ryu H, Jang C, Choi JW. Exchange Bias in Weakly Interlayer-Coupled van der Waals Magnet Fe 3GeTe 2. NANO LETTERS 2021; 21:1672-1678. [PMID: 33570963 DOI: 10.1021/acs.nanolett.0c04434] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
van der Waals (vdW) magnetic materials provide an ideal platform to study low-dimensional magnetism. However, observations of magnetic characteristics of these layered materials truly distinguishing them from conventional magnetic thin film systems have been mostly lacking. In an effort to investigate magnetic properties unique to vdW magnetic materials, we examine the exchange bias effect, a magnetic phenomenon emerging at the ferromagnetic-antiferromagnetic interface. Exchange bias is observed in the naturally oxidized vdW ferromagnet Fe3GeTe2, owing to an antiferromagnetic ordering in the surface oxide layer. Interestingly, the magnitude and thickness dependence of the effect is unlike those expected in typical thin-film systems. We propose a possible mechanism for this behavior, based on the weak interlayer magnetic coupling inherent to vdW magnets, demonstrating the distinct properties of these materials. Furthermore, the robust and sizable exchange bias for vdW magnets persisting up to relatively high temperatures presents a significant advance for realizing practical two-dimensional spintronics.
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Affiliation(s)
- Hyung Keun Gweon
- Center for Spintronics, Korea Institute of Science and Technology, Seoul 02792, Republic of Korea
| | - Sang Yeop Lee
- Center for Spintronics, Korea Institute of Science and Technology, Seoul 02792, Republic of Korea
| | - Hee Young Kwon
- Center for Spintronics, Korea Institute of Science and Technology, Seoul 02792, Republic of Korea
| | - Juyoung Jeong
- Advanced Analysis Center, Korea Institute of Science and Technology, Seoul 02792, Republic of Korea
| | - Hye Jung Chang
- Advanced Analysis Center, Korea Institute of Science and Technology, Seoul 02792, Republic of Korea
- Division of Nano & Information Technology, KIST school, University of Science and Technology, Seoul 02792, Republic of Korea
| | - Kyoung-Whan Kim
- Center for Spintronics, Korea Institute of Science and Technology, Seoul 02792, Republic of Korea
| | - Zi Qiang Qiu
- Department of Physics, University of California, Berkeley 94720, California, United States
| | - Hyejin Ryu
- Center for Spintronics, Korea Institute of Science and Technology, Seoul 02792, Republic of Korea
| | - Chaun Jang
- Center for Spintronics, Korea Institute of Science and Technology, Seoul 02792, Republic of Korea
| | - Jun Woo Choi
- Center for Spintronics, Korea Institute of Science and Technology, Seoul 02792, Republic of Korea
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81
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Yan P, Ouyang T, He C, Li J, Zhang C, Tang C, Zhong J. Newly discovered graphyne allotrope with rare and robust Dirac node loop. NANOSCALE 2021; 13:3564-3571. [PMID: 33522533 DOI: 10.1039/d0nr08397f] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Two-dimensional (2D) carbon allotropes with topologically nontrivial states are drawing considerable attention owing to their unique physical properties and great potential applications in the next generation of micro-nano devices. In contrast to the numerous Dirac points predicted in 2D carbon allotropes, systems featuring Dirac nodal lines (loops) are still quite rare. Here, by means of first-principles calculation, we report our newly discovered carbon monolayer 123-E8Y24-1 with robust Dirac nodal line states, which possesses a tetragonal lattice with P4/mmm symmetry and contains 8 sp2 carbon atoms (graphene: E8) and 24 sp carbon atoms (grapheyne: Y24) in the crystalline cell. This 2D material is as energetically stable as the recently experimentally synthesized β-graphdiyne, and it is further predicted to be dynamically, mechanically, and also thermodynamically stable. Owing to its intrinsic geometric characteristics, 123-E8Y24-1 also exhibits obvious Young's modulus anisotropy, with a sizable ratio between the maximum and minimum value of up to 5.8. Remarkably, 123-E8Y24-1 presents a semimetal nature and possesses Dirac nodal line states in the electronic band structure, and such behavior could be kept well under external strain between -10.0% and 8.0%. The electronic properties of 123-E8Y24-1 can be carefully confirmed by constructing a tight-binding (TB) model. The findings presented in this paper reveal a novel 2D Dirac nodal loop carbon sheet, providing a new candidate for carbon-based high-speed electronic devices.
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Affiliation(s)
- Pinglan Yan
- Hunan Key Laboratory for Micro-Nano Energy Materials and Device, Xiangtan University, Xiangtan 411105, Hunan, China. and School of Physics and Optoelectronics, Xiangtan University, Xiangtan 411105, Hunan, China
| | - Tao Ouyang
- Hunan Key Laboratory for Micro-Nano Energy Materials and Device, Xiangtan University, Xiangtan 411105, Hunan, China. and School of Physics and Optoelectronics, Xiangtan University, Xiangtan 411105, Hunan, China
| | - Chaoyu He
- Hunan Key Laboratory for Micro-Nano Energy Materials and Device, Xiangtan University, Xiangtan 411105, Hunan, China. and School of Physics and Optoelectronics, Xiangtan University, Xiangtan 411105, Hunan, China
| | - Jin Li
- Hunan Key Laboratory for Micro-Nano Energy Materials and Device, Xiangtan University, Xiangtan 411105, Hunan, China. and School of Physics and Optoelectronics, Xiangtan University, Xiangtan 411105, Hunan, China
| | - Chunxiao Zhang
- Hunan Key Laboratory for Micro-Nano Energy Materials and Device, Xiangtan University, Xiangtan 411105, Hunan, China. and School of Physics and Optoelectronics, Xiangtan University, Xiangtan 411105, Hunan, China
| | - Chao Tang
- Hunan Key Laboratory for Micro-Nano Energy Materials and Device, Xiangtan University, Xiangtan 411105, Hunan, China. and School of Physics and Optoelectronics, Xiangtan University, Xiangtan 411105, Hunan, China
| | - Jianxin Zhong
- Hunan Key Laboratory for Micro-Nano Energy Materials and Device, Xiangtan University, Xiangtan 411105, Hunan, China. and School of Physics and Optoelectronics, Xiangtan University, Xiangtan 411105, Hunan, China
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82
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Zhang K, Han S, Lee Y, Coak MJ, Kim J, Hwang I, Son S, Shin J, Lim M, Jo D, Kim K, Kim D, Lee HW, Park JG. Gigantic Current Control of Coercive Field and Magnetic Memory Based on Nanometer-Thin Ferromagnetic van der Waals Fe 3 GeTe 2. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2021; 33:e2004110. [PMID: 33283320 DOI: 10.1002/adma.202004110] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Revised: 09/25/2020] [Indexed: 06/12/2023]
Abstract
Controlling magnetic states by a small current is essential for the next-generation of energy-efficient spintronic devices. However, it invariably requires considerable energy to change a magnetic ground state of intrinsically quantum nature governed by fundamental Hamiltonian, once stabilized below a phase-transition temperature. Here, it is reported that, surprisingly, an in-plane current can tune the magnetic state of the nanometer-thin van der Waals ferromagnet Fe3 GeTe2 from a hard magnetic state to a soft magnetic state. It is a direct demonstration of the current-induced substantial reduction of the coercive field. This surprising finding is possible because the in-plane current produces a highly unusual type of gigantic spin-orbit torque for Fe3 GeTe2 . In addition, a working model of a new nonvolatile magnetic memory based on the principle of the discovery in Fe3 GeTe2 , controlled by a tiny current, is further demonstrated. The findings open up a new window of exciting opportunities for magnetic van der Waals materials with potentially huge impact on the future development of spintronic and magnetic memory.
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Affiliation(s)
- Kaixuan Zhang
- Center for Correlated Electron Systems, Institute for Basic Science, Seoul, 08826, South Korea
- Department of Physics and Astronomy, and Institute of Applied Physics, Seoul National University, Seoul, 08826, South Korea
- Center for Quantum Materials, Seoul National University, Seoul, 08826, South Korea
| | - Seungyun Han
- Department of Physics, Pohang University of Science and Technology, Pohang, 37673, South Korea
| | - Youjin Lee
- Center for Correlated Electron Systems, Institute for Basic Science, Seoul, 08826, South Korea
- Department of Physics and Astronomy, and Institute of Applied Physics, Seoul National University, Seoul, 08826, South Korea
- Center for Quantum Materials, Seoul National University, Seoul, 08826, South Korea
| | - Matthew J Coak
- Center for Correlated Electron Systems, Institute for Basic Science, Seoul, 08826, South Korea
- Department of Physics and Astronomy, and Institute of Applied Physics, Seoul National University, Seoul, 08826, South Korea
| | - Junghyun Kim
- Center for Correlated Electron Systems, Institute for Basic Science, Seoul, 08826, South Korea
- Department of Physics and Astronomy, and Institute of Applied Physics, Seoul National University, Seoul, 08826, South Korea
- Center for Quantum Materials, Seoul National University, Seoul, 08826, South Korea
| | - Inho Hwang
- Center for Correlated Electron Systems, Institute for Basic Science, Seoul, 08826, South Korea
- Department of Physics and Astronomy, and Institute of Applied Physics, Seoul National University, Seoul, 08826, South Korea
- Center for Quantum Materials, Seoul National University, Seoul, 08826, South Korea
| | - Suhan Son
- Center for Correlated Electron Systems, Institute for Basic Science, Seoul, 08826, South Korea
- Department of Physics and Astronomy, and Institute of Applied Physics, Seoul National University, Seoul, 08826, South Korea
- Center for Quantum Materials, Seoul National University, Seoul, 08826, South Korea
| | - Jeacheol Shin
- Department of Physics and Astronomy, and Institute of Applied Physics, Seoul National University, Seoul, 08826, South Korea
| | - Mijin Lim
- Department of Physics, Pohang University of Science and Technology, Pohang, 37673, South Korea
| | - Daegeun Jo
- Department of Physics, Pohang University of Science and Technology, Pohang, 37673, South Korea
| | - Kyoo Kim
- Korea Atomic Energy Research Institute, 111 Daedeok-daero, Daejeon, 34057, South Korea
| | - Dohun Kim
- Department of Physics and Astronomy, and Institute of Applied Physics, Seoul National University, Seoul, 08826, South Korea
| | - Hyun-Woo Lee
- Department of Physics, Pohang University of Science and Technology, Pohang, 37673, South Korea
- Asia Pacific Center for Theoretical Physics, 77 Cheongam-ro, Nam-gu, Pohang, 3773, South Korea
| | - Je-Geun Park
- Center for Correlated Electron Systems, Institute for Basic Science, Seoul, 08826, South Korea
- Department of Physics and Astronomy, and Institute of Applied Physics, Seoul National University, Seoul, 08826, South Korea
- Center for Quantum Materials, Seoul National University, Seoul, 08826, South Korea
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83
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Wang Y, Wang C, Liang SJ, Ma Z, Xu K, Liu X, Zhang L, Admasu AS, Cheong SW, Wang L, Chen M, Liu Z, Cheng B, Ji W, Miao F. Strain-Sensitive Magnetization Reversal of a van der Waals Magnet. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2020; 32:e2004533. [PMID: 32924236 DOI: 10.1002/adma.202004533] [Citation(s) in RCA: 49] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Revised: 08/08/2020] [Indexed: 06/11/2023]
Abstract
By virtue of the layered structure, van der Waals (vdW) magnets are sensitive to the lattice deformation controlled by the external strain, providing an ideal platform to explore the one-step magnetization reversal that is still conceptual in conventional magnets due to the limited strain-tuning range of the coercive field. In this study, a uniaxial tensile strain is applied to thin flakes of the vdW magnet Fe3 GeTe2 (FGT), and a dramatic increase of the coercive field (Hc ) by more than 150% with an applied strain of 0.32% is observed. Moreover, the change of the transition temperatures between the different magnetic phases under strain is investigated, and the phase diagram of FGT in the strain-temperature plane is obtained. Comparing the phase diagram with theoretical results, the strain-tunable magnetism is attributed to the sensitive change of magnetic anisotropy energy. Remarkably, strain allows an ultrasensitive magnetization reversal to be achieved, which may promote the development of novel straintronic device applications.
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Affiliation(s)
- Yu Wang
- National Laboratory of Solid State Microstructures, School of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, 210093, China
| | - Cong Wang
- Beijing Key Laboratory of Optoelectronic Functional Materials & Micro-Nano Devices, Department of Physics, Renmin University of China, Beijing, 100872, P. R. China
| | - Shi-Jun Liang
- National Laboratory of Solid State Microstructures, School of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, 210093, China
| | - Zecheng Ma
- National Laboratory of Solid State Microstructures, School of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, 210093, China
| | - Kang Xu
- National Laboratory of Solid State Microstructures, School of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, 210093, China
| | - Xiaowei Liu
- National Laboratory of Solid State Microstructures, School of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, 210093, China
| | - Lili Zhang
- National Laboratory of Solid State Microstructures, School of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, 210093, China
| | - Alemayehu S Admasu
- Center for Quantum Materials Synthesis, and Department of Physics and Astronomy, Rutgers, The State University of New Jersey, Piscataway, NJ, 08854, USA
| | - Sang-Wook Cheong
- Center for Quantum Materials Synthesis, and Department of Physics and Astronomy, Rutgers, The State University of New Jersey, Piscataway, NJ, 08854, USA
| | - Lizheng Wang
- National Laboratory of Solid State Microstructures, School of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, 210093, China
| | - Moyu Chen
- National Laboratory of Solid State Microstructures, School of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, 210093, China
| | - Zenglin Liu
- National Laboratory of Solid State Microstructures, School of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, 210093, China
| | - Bin Cheng
- National Laboratory of Solid State Microstructures, School of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, 210093, China
| | - Wei Ji
- Beijing Key Laboratory of Optoelectronic Functional Materials & Micro-Nano Devices, Department of Physics, Renmin University of China, Beijing, 100872, P. R. China
| | - Feng Miao
- National Laboratory of Solid State Microstructures, School of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, 210093, China
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84
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Hu G, Zhu Y, Xiang J, Yang TY, Huang M, Wang Z, Wang Z, Liu P, Zhang Y, Feng C, Hou D, Zhu W, Gu M, Hsu CH, Chuang FC, Lu Y, Xiang B, Chueh YL. Antisymmetric Magnetoresistance in a van der Waals Antiferromagnetic/Ferromagnetic Layered MnPS 3/Fe 3GeTe 2 Stacking Heterostructure. ACS NANO 2020; 14:12037-12044. [PMID: 32885948 DOI: 10.1021/acsnano.0c05252] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The presence of two-dimensional (2D) layer-stacking heterostructures that can efficiently tune the interface properties by stacking desirable materials provides a platform to investigate some physical phenomena, such as the proximity effect and magnetic exchange coupling. Here, we report the observation of antisymmetric magnetoresistance in a van der Waals (vdW) antiferromagnetic/ferromagnetic (AFM/FM) heterostructure of MnPS3/Fe3GeTe2 when the temperature is below the Neel temperature of MnPS3. Distinguished from two resistance states in conventional giant magnetoresistance, the magnetoresistance in the MnPS3/Fe3GeTe2 heterostructure exhibits three states, of high, intermediate, and low resistance. This antisymmetric magnetoresistance spike is determined by an unsynchronized magnetic switching between the AFM/FM interface layer and the bulk of Fe3GeTe2 during magnetization reversal. Our work highlights that the artificial vdW stacking structure holds potential to explore some physical phenomena and spintronic device applications.
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Affiliation(s)
- Guojing Hu
- Hefei National Research Center for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui 230026, China
- Department of Materials Science & Engineering, CAS Key Lab of Materials for Energy Conversion, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Yuanmin Zhu
- SUSTech Academy for Advanced Interdisciplinary Studies, Southern University of Science and Technology of China, Shenzhen, Guangdong 518055, China
- Department of Materials Science and Engineering, Southern University of Science and Technology of China, Shenzhen, Guangdong 518055, China
| | - Junxiang Xiang
- Hefei National Research Center for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui 230026, China
- Department of Materials Science & Engineering, CAS Key Lab of Materials for Energy Conversion, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Tzu-Yi Yang
- Department of Materials Science and Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan
- Frontier Research Center on Fundamental and Applied Sciences of Matters, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - Meng Huang
- Hefei National Research Center for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui 230026, China
- Department of Materials Science & Engineering, CAS Key Lab of Materials for Energy Conversion, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Zhe Wang
- Hefei National Research Center for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui 230026, China
- Department of Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Zhi Wang
- Hefei National Research Center for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui 230026, China
- Department of Materials Science & Engineering, CAS Key Lab of Materials for Energy Conversion, University of Science and Technology of China, Hefei, Anhui 230026, China
- Anhui Laboratory of Advanced Photon Science and Technology, University of Science and Technology of China, Hefei 230026, China
| | - Ping Liu
- Hefei National Research Center for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui 230026, China
- Department of Materials Science & Engineering, CAS Key Lab of Materials for Energy Conversion, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Ying Zhang
- Hefei National Research Center for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui 230026, China
- Department of Materials Science & Engineering, CAS Key Lab of Materials for Energy Conversion, University of Science and Technology of China, Hefei, Anhui 230026, China
- Anhui Laboratory of Advanced Photon Science and Technology, University of Science and Technology of China, Hefei 230026, China
| | - Chao Feng
- Hefei National Research Center for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui 230026, China
- Department of Materials Science & Engineering, CAS Key Lab of Materials for Energy Conversion, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Dazhi Hou
- Hefei National Research Center for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Wenguang Zhu
- Hefei National Research Center for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui 230026, China
- Department of Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Meng Gu
- Department of Materials Science and Engineering, Southern University of Science and Technology of China, Shenzhen, Guangdong 518055, China
| | - Chia-Hsiu Hsu
- Department of Physics, National Sun Yat-Sen University, Kaohsiung 80424, Taiwan
| | - Feng-Chuan Chuang
- Department of Physics, National Sun Yat-Sen University, Kaohsiung 80424, Taiwan
- Department of Physics, National Tsing Hua University, Hsinchu 30013, Taiwan
- Physics Division, National Center for Theoretical Sciences, Hsinchu 30013, Taiwan
| | - Yalin Lu
- Hefei National Research Center for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui 230026, China
- Department of Materials Science & Engineering, CAS Key Lab of Materials for Energy Conversion, University of Science and Technology of China, Hefei, Anhui 230026, China
- Anhui Laboratory of Advanced Photon Science and Technology, University of Science and Technology of China, Hefei 230026, China
| | - Bin Xiang
- Hefei National Research Center for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui 230026, China
- Department of Materials Science & Engineering, CAS Key Lab of Materials for Energy Conversion, University of Science and Technology of China, Hefei, Anhui 230026, China
- Anhui Laboratory of Advanced Photon Science and Technology, University of Science and Technology of China, Hefei 230026, China
| | - Yu-Lun Chueh
- Department of Materials Science and Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan
- Department of Physics, National Sun Yat-Sen University, Kaohsiung 80424, Taiwan
- Frontier Research Center on Fundamental and Applied Sciences of Matters, National Tsing Hua University, Hsinchu 30013, Taiwan
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85
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Li Z, Xia W, Su H, Yu Z, Fu Y, Chen L, Wang X, Yu N, Zou Z, Guo Y. Magnetic critical behavior of the van der Waals Fe 5GeTe 2 crystal with near room temperature ferromagnetism. Sci Rep 2020; 10:15345. [PMID: 32948794 PMCID: PMC7501290 DOI: 10.1038/s41598-020-72203-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Accepted: 08/27/2020] [Indexed: 12/03/2022] Open
Abstract
The van der Waals ferromagnet Fe5GeTe2 has a Curie temperature TC of about 270 K, which is tunable through controlling the Fe deficiency content and can even reach above room temperature. To achieve insights into its ferromagnetic exchange that gives the high TC, the critical behavior has been investigated by measuring the magnetization in Fe5GeTe2 crystal around the ferromagnetic ordering temperature. The analysis of the measured magnetization by using various techniques harmonically reached to a set of reliable critical exponents with TC = 273.7 K, β = 0.3457 ± 0.001, γ = 1.40617 ± 0.003, and δ = 5.021 ± 0.001. By comparing these critical exponents with those predicted by various models, it seems that the magnetic properties of Fe5GeTe2 could be interpreted by a three-dimensional magnetic exchange with the exchange distance decaying as J(r) ≈ r−4.916, close to that of a three-dimensional Heisenberg model with long-range magnetic coupling.
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Affiliation(s)
- Zhengxian Li
- School of Physical Science and Technology, ShanghaiTech University, Shanghai, 201210, China.,Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai, 201800, China.,University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Wei Xia
- School of Physical Science and Technology, ShanghaiTech University, Shanghai, 201210, China.,Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai, 201800, China.,University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Hao Su
- School of Physical Science and Technology, ShanghaiTech University, Shanghai, 201210, China.,Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai, 201800, China.,University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Zhenhai Yu
- School of Physical Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Yunpeng Fu
- School of Physical Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Leiming Chen
- School of Materials Science and Engineering, Henan Key Laboratory of Aeronautic Materials and Application Technology, Zhengzhou University of Aeronautics, Zhengzhou, 450046, Henan, China.
| | - Xia Wang
- School of Physical Science and Technology, ShanghaiTech University, Shanghai, 201210, China.,Analytical Instrumentation Center, School of Physical Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Na Yu
- School of Physical Science and Technology, ShanghaiTech University, Shanghai, 201210, China.,Analytical Instrumentation Center, School of Physical Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Zhiqiang Zou
- School of Physical Science and Technology, ShanghaiTech University, Shanghai, 201210, China.,Analytical Instrumentation Center, School of Physical Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Yanfeng Guo
- School of Physical Science and Technology, ShanghaiTech University, Shanghai, 201210, China.
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86
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Abstract
CeTe3 is a unique platform to investigate the itinerant magnetism in a van der Waals (vdW) coupled metal. Despite chemical pressure being a promising route to boost quantum fluctuation in this system, a systematic study on the chemical pressure effect on Ce3+(4f1) states is absent. Here, we report on the successful growth of a series of Se doped single crystals of CeTe3. We found a fluctuation driven exotic magnetic rotation from the usual easy-axis ordering to an unusual hard-axis ordering. Unlike in localized magnetic systems, near-critical magnetism can increase itinerancy hand-in-hand with enhancing fluctuation of magnetism. Thus, seemingly unstable hard-axis ordering emerges through kinetic energy gain, with the self-consistent observation of enhanced magnetic fluctuation (disorder). As far as we recognize, this order-by-disorder process in fermionic system is observed for the first time within vdW materials. Our finding opens a unique experimental platform for direct visualization of the rich quasiparticle Fermi surface deformation associated with the Fermionic order-by-disorder process. Also, the search for emergent exotic phases by further tuning of quantum fluctuation is suggested as a promising future challenge.
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87
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Shen J, Yao Q, Zeng Q, Sun H, Xi X, Wu G, Wang W, Shen B, Liu Q, Liu E. Local Disorder-Induced Elevation of Intrinsic Anomalous Hall Conductance in an Electron-Doped Magnetic Weyl Semimetal. PHYSICAL REVIEW LETTERS 2020; 125:086602. [PMID: 32909775 DOI: 10.1103/physrevlett.125.086602] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2020] [Revised: 05/14/2020] [Accepted: 07/10/2020] [Indexed: 06/11/2023]
Abstract
Topological materials are expected to show distinct transport signatures owing to their unique band-inversion characteristic and band-crossing points. However, the intentional modulation of such topological responses through experimentally feasible means has yet to be explored in depth. Here, an unusual elevation of the anomalous Hall effect (AHE) is obtained in electron (Ni)-doped magnetic Weyl semimetals Co_{3-x}Ni_{x}Sn_{2}S_{2}, showing peak values in the anomalous Hall-conductivity, Hall-angle, and Hall-factor at a relatively low doping level of x=0.11. The separation of intrinsic and extrinsic contributions using the TYJ scaling model indicates that such a significant enhancement is dominated by the intrinsic mechanism of the electronic Berry curvature. Theoretical calculations reveal that compared with the Fermi-level shifting from electron filling, a usually overlooked effect of doping, that is, local disorder, imposes a striking effect on broadening of the bands and narrowing of the inverted gap, thus resulting in an elevation of the integrated Berry curvature. Our results not only realize an enhancement of the AHE in a magnetic Weyl semimetal, but also provide a practical design principle for modulating the bands and transport properties in topological materials by exploiting the local disorder effect from doping.
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Affiliation(s)
- Jianlei Shen
- State Key Laboratory for Magnetism, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Qiushi Yao
- Shenzhen Institute for Quantum Science and Technology and Department of Physics, Southern University of Science and Technology, Shenzhen 518055, China
| | - Qingqi Zeng
- State Key Laboratory for Magnetism, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Hongyi Sun
- Shenzhen Institute for Quantum Science and Technology and Department of Physics, Southern University of Science and Technology, Shenzhen 518055, China
| | - Xuekui Xi
- State Key Laboratory for Magnetism, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Guangheng Wu
- State Key Laboratory for Magnetism, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Wenhong Wang
- State Key Laboratory for Magnetism, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, China
| | - Baogen Shen
- State Key Laboratory for Magnetism, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- Institute of Rare Earths, Chinese Academy of Sciences, Jiangxi 341000, China
| | - Qihang Liu
- Shenzhen Institute for Quantum Science and Technology and Department of Physics, Southern University of Science and Technology, Shenzhen 518055, China
- Guangdong Provincial Key Laboratory for Computational Science and Material Design, Southern University of Science and Technology, Shenzhen 518055, China
- Shenzhen Key Laboratory of for Advanced Quantum Functional Materials and Devices, Southern University of Science and Technology, Shenzhen 518055, China
| | - Enke Liu
- State Key Laboratory for Magnetism, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, China
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88
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Liu Z, Li M, Wang Q, Wang G, Wen C, Jiang K, Lu X, Yan S, Huang Y, Shen D, Yin JX, Wang Z, Yin Z, Lei H, Wang S. Orbital-selective Dirac fermions and extremely flat bands in frustrated kagome-lattice metal CoSn. Nat Commun 2020; 11:4002. [PMID: 32778641 PMCID: PMC7417585 DOI: 10.1038/s41467-020-17462-4] [Citation(s) in RCA: 57] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2020] [Accepted: 06/30/2020] [Indexed: 12/03/2022] Open
Abstract
Layered kagome-lattice 3d transition metals are emerging as an exciting platform to explore the frustrated lattice geometry and quantum topology. However, the typical kagome electronic bands, characterized by sets of the Dirac-like band capped by a phase-destructive flat band, have not been clearly observed, and their orbital physics are even less well investigated. Here, we present close-to-textbook kagome bands with orbital differentiation physics in CoSn, which can be well described by a minimal tight-binding model with single-orbital hopping in Co kagome lattice. The capping flat bands with bandwidth less than 0.2 eV run through the whole Brillouin zone, especially the bandwidth of the flat band of out-of-plane orbitals is less than 0.02 eV along Γ-M. The energy gap induced by spin-orbit interaction at the Dirac cone of out-of-plane orbitals is much smaller than that of in-plane orbitals, suggesting orbital-selective character of the Dirac fermions.
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Affiliation(s)
- Zhonghao Liu
- State Key Laboratory of Functional Materials for Informatics and Center for Excellence in Superconducting Electronics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai, 200050, China.
- College of Materials Science and Opto-Electronic Technology, University of Chinese Academy of Sciences, Beijing, 100049, China.
| | - Man Li
- Department of Physics and Beijing Key Laboratory of Opto-Electronic Functional Materials&Micro-Nano Devices, Renmin University of China, Beijing, 100872, China
- Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai, 201204, China
| | - Qi Wang
- Department of Physics and Beijing Key Laboratory of Opto-Electronic Functional Materials&Micro-Nano Devices, Renmin University of China, Beijing, 100872, China
| | - Guangwei Wang
- Department of Physics and Center for Advanced Quantum Studies, Beijing Normal University, Beijing, 100875, China
| | - Chenhaoping Wen
- School of Physical Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Kun Jiang
- Department of Physics, Boston College, Chestnut Hill, MA, 02467, USA
| | - Xiangle Lu
- State Key Laboratory of Functional Materials for Informatics and Center for Excellence in Superconducting Electronics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai, 200050, China
- College of Materials Science and Opto-Electronic Technology, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Shichao Yan
- School of Physical Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Yaobo Huang
- Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai, 201204, China
| | - Dawei Shen
- State Key Laboratory of Functional Materials for Informatics and Center for Excellence in Superconducting Electronics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai, 200050, China
- College of Materials Science and Opto-Electronic Technology, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Jia-Xin Yin
- Laboratory for Topological Quantum Matter and Advanced Spectroscopy (B7), Department of Physics, Princeton University, Princeton, NJ, 08544, USA
| | - Ziqiang Wang
- Department of Physics, Boston College, Chestnut Hill, MA, 02467, USA
| | - Zhiping Yin
- Department of Physics and Center for Advanced Quantum Studies, Beijing Normal University, Beijing, 100875, China.
| | - Hechang Lei
- Department of Physics and Beijing Key Laboratory of Opto-Electronic Functional Materials&Micro-Nano Devices, Renmin University of China, Beijing, 100872, China.
| | - Shancai Wang
- Department of Physics and Beijing Key Laboratory of Opto-Electronic Functional Materials&Micro-Nano Devices, Renmin University of China, Beijing, 100872, China.
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89
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Wu Y, Zhang S, Zhang J, Wang W, Zhu YL, Hu J, Yin G, Wong K, Fang C, Wan C, Han X, Shao Q, Taniguchi T, Watanabe K, Zang J, Mao Z, Zhang X, Wang KL. Néel-type skyrmion in WTe 2/Fe 3GeTe 2 van der Waals heterostructure. Nat Commun 2020; 11:3860. [PMID: 32737289 PMCID: PMC7395126 DOI: 10.1038/s41467-020-17566-x] [Citation(s) in RCA: 89] [Impact Index Per Article: 22.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Accepted: 07/05/2020] [Indexed: 11/09/2022] Open
Abstract
The promise of high-density and low-energy-consumption devices motivates the search for layered structures that stabilize chiral spin textures such as topologically protected skyrmions. At the same time, recently discovered long-range intrinsic magnetic orders in the two-dimensional van der Waals materials provide a new platform for the discovery of novel physics and effects. Here we demonstrate the Dzyaloshinskii-Moriya interaction and Néel-type skyrmions are induced at the WTe2/Fe3GeTe2 interface. Transport measurements show the topological Hall effect in this heterostructure for temperatures below 100 K. Furthermore, Lorentz transmission electron microscopy is used to directly image Néel-type skyrmion lattice and the stripe-like magnetic domain structures as well. The interfacial coupling induced Dzyaloshinskii-Moriya interaction is estimated to have a large energy of 1.0 mJ m-2. This work paves a path towards the skyrmionic devices based on van der Waals layered heterostructures.
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Affiliation(s)
- Yingying Wu
- Department of Electrical and Computer Engineering, University of California-Los Angeles, Los Angeles, CA, 90095, USA
| | - Senfu Zhang
- Physical Science and Engineering Division, King Abdullah University of Science and Technology, Thuwal, 23955-6900, Saudi Arabia
| | - Junwei Zhang
- Physical Science and Engineering Division, King Abdullah University of Science and Technology, Thuwal, 23955-6900, Saudi Arabia
| | - Wei Wang
- Key Laboratory of Flexible Electronics & Institute of Advanced Materials, Jiangsu National Synergetic Innovation Center for Advanced Materials, Nanjing Tech University, Nanjing, 211816, China
| | - Yang Lin Zhu
- Department of Physics, Pennsylvania State University, University Park, PA, 16802, USA
| | - Jin Hu
- Department of Physics, University of Arkansas, Fayetteville, AR, 72701, USA
| | - Gen Yin
- Department of Electrical and Computer Engineering, University of California-Los Angeles, Los Angeles, CA, 90095, USA
| | - Kin Wong
- Department of Electrical and Computer Engineering, University of California-Los Angeles, Los Angeles, CA, 90095, USA
| | - Chi Fang
- Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
| | - Caihua Wan
- Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
| | - Xiufeng Han
- Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
| | - Qiming Shao
- Department of Electrical and Computer Engineering, University of California-Los Angeles, Los Angeles, CA, 90095, USA
| | - Takashi Taniguchi
- National Institute for Materials Science, 1-1 Namiki, Tsukuba, 305-0044, Japan
| | - Kenji Watanabe
- National Institute for Materials Science, 1-1 Namiki, Tsukuba, 305-0044, Japan
| | - Jiadong Zang
- Department of Physics and Astronomy, University of New Hampshire, Durham, NH, 03824, USA
| | - Zhiqiang Mao
- Department of Physics, Pennsylvania State University, University Park, PA, 16802, USA
| | - Xixiang Zhang
- Physical Science and Engineering Division, King Abdullah University of Science and Technology, Thuwal, 23955-6900, Saudi Arabia
| | - Kang L Wang
- Department of Electrical and Computer Engineering, University of California-Los Angeles, Los Angeles, CA, 90095, USA.
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90
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Li P, Koo J, Ning W, Li J, Miao L, Min L, Zhu Y, Wang Y, Alem N, Liu CX, Mao Z, Yan B. Giant room temperature anomalous Hall effect and tunable topology in a ferromagnetic topological semimetal Co 2MnAl. Nat Commun 2020; 11:3476. [PMID: 32651362 PMCID: PMC7351740 DOI: 10.1038/s41467-020-17174-9] [Citation(s) in RCA: 63] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2019] [Accepted: 06/12/2020] [Indexed: 02/07/2023] Open
Abstract
Weyl semimetals exhibit unusual surface states and anomalous transport phenomena. It is hard to manipulate the band structure topology of specific Weyl materials. Topological transport phenomena usually appear at very low temperatures, which sets challenges for applications. In this work, we demonstrate the band topology modification via a weak magnetic field in a ferromagnetic Weyl semimetal candidate, Co2MnAl, at room temperature. We observe a tunable, giant anomalous Hall effect (AHE) induced by the transition involving Weyl points and nodal rings. The AHE conductivity is as large as that of a 3D quantum AHE, with the Hall angle (ΘH) reaching a record value ([Formula: see text]) at the room temperature among magnetic conductors. Furthermore, we propose a material recipe to generate large AHE by gaping nodal rings without requiring Weyl points. Our work reveals an intrinsically magnetic platform to explore the interplay between magnetic dynamics and topological physics for developing spintronic devices.
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Affiliation(s)
- Peigang Li
- Department of Physics and Engineering Physics, Tulane University, New Orleans, LA, 70118, USA
| | - Jahyun Koo
- Department of Condensed Matter Physics, Weizmann Institute of Science, Rehovot, 7610001, Israel
| | - Wei Ning
- Department of Physics, Pennsylvania State University, University Park, State College, PA, 16802, USA.
| | - Jinguo Li
- Superalloys Division, Institute of Metal Reseach, Chinese Academy of Sciences, 110016, Shenyang, China
| | - Leixin Miao
- Department of Materials Science and Engineering, Pennsylvania State University, University Park, State College, PA, 16802, USA
| | - Lujin Min
- Department of Physics, Pennsylvania State University, University Park, State College, PA, 16802, USA.,Department of Materials Science and Engineering, Pennsylvania State University, University Park, State College, PA, 16802, USA
| | - Yanglin Zhu
- Department of Physics and Engineering Physics, Tulane University, New Orleans, LA, 70118, USA.,Department of Physics, Pennsylvania State University, University Park, State College, PA, 16802, USA
| | - Yu Wang
- Department of Physics and Engineering Physics, Tulane University, New Orleans, LA, 70118, USA.,Department of Physics, Pennsylvania State University, University Park, State College, PA, 16802, USA
| | - Nasim Alem
- Department of Materials Science and Engineering, Pennsylvania State University, University Park, State College, PA, 16802, USA
| | - Chao-Xing Liu
- Department of Physics, Pennsylvania State University, University Park, State College, PA, 16802, USA
| | - Zhiqiang Mao
- Department of Physics and Engineering Physics, Tulane University, New Orleans, LA, 70118, USA. .,Department of Physics, Pennsylvania State University, University Park, State College, PA, 16802, USA.
| | - Binghai Yan
- Department of Condensed Matter Physics, Weizmann Institute of Science, Rehovot, 7610001, Israel.
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91
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Chen SZ, Li S, Chen Y, Duan W. Nodal Flexible-surface Semimetals: Case of Carbon Nanotube Networks. NANO LETTERS 2020; 20:5400-5407. [PMID: 32496795 DOI: 10.1021/acs.nanolett.0c01786] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Nodal surface-based topological semimetals (TSMs) are drawing attention due to their unique excitation and plasmon behaviors. However, only nodal flat-surface and nodal sphere TSMs are theoretically proposed due to strict symmetry requirements. Here, we propose that a series of surface-based topological phases can be realized in a tight-binding (TB) model with sublattice symmetry. These topological phases, named as nodal flexible-surface semimetals, include not only nodal surface and nodal sphere TSMs but also novel phases, like nodal tube, nodal crossbar, and nodal hourglass-like surface TSMs. According to the TB model, a family of carbon nanotube networks are then identified as nodal flexible-surface TSMs by first-principles calculations, and the topological phase transitions between these TSMs can be induced by strains. Moreover, the nodal flexible-surface TSMs with intrinsic high density of states at the Fermi level and special drumhead surface states are promising for studying high-temperature superconductors and strong correlation effects.
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Affiliation(s)
- Shi-Zhang Chen
- State Key Laboratory of Low Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084, China
| | - Siwen Li
- Faculty of Science, Jiangsu University, Zhenjiang 212013, Jiangsu, China
| | - Yuanping Chen
- Faculty of Science, Jiangsu University, Zhenjiang 212013, Jiangsu, China
| | - Wenhui Duan
- State Key Laboratory of Low Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084, China
- Collaborative Innovation Center of Quantum Matter, Tsinghua University, Beijing 100084, China
- Institute for Advanced Study, Tsinghua University, Beijing 100084, China
- Frontier Science Center for Quantum Information, Beijing 100084, China
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92
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Ke J, Yang M, Xia W, Zhu H, Liu C, Chen R, Dong C, Liu W, Shi M, Guo Y, Wang J. Magnetic and magneto-transport studies of two-dimensional ferromagnetic compound Fe 3GeTe 2. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2020; 32:405805. [PMID: 32526709 DOI: 10.1088/1361-648x/ab9bc9] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Accepted: 06/11/2020] [Indexed: 06/11/2023]
Abstract
We have systematically reported the magnetic and magneto-transport properties of two-dimensional itinerant ferromagnetic compound Fe3GeTe2at high magnetic fields of 58 T and demonstrated the correlation between its transport and magnetism. Anomalous two-steps magnetic ordering and antiferromagnetic-like transitions in zero field-cooling (ZFC) curves forH∥ab-plane are observed. Additionally, we find that intrinsic negative magnetoresistances in bulk Fe3GeTe2single crystal are mainly attributed to the suppression of spin-fluctuations in low magnetic fields. Complex evolutions of temperature dependent high field magnetoresistances are detected under different magnetic field and current configurations, which can be explained as a result of the competition between spin-fluctuations, the magnon-scatterings and classical cyclotronic effects.
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Affiliation(s)
- Jiezun Ke
- Wuhan National High Magnetic Field Center and School of Physics, Huazhong University of Science and Technology, 430074, Wuhan, People's Republic of China
| | - Ming Yang
- Wuhan National High Magnetic Field Center and School of Physics, Huazhong University of Science and Technology, 430074, Wuhan, People's Republic of China
| | - Wei Xia
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, People's Republic of China
- Chinese Academy of Sciences, Shanghai Institute of Optics and Fine Mechanics, Shanghai 201800, People's Republic of China
- University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
| | - Haipeng Zhu
- Wuhan National High Magnetic Field Center and School of Physics, Huazhong University of Science and Technology, 430074, Wuhan, People's Republic of China
| | - Congbin Liu
- Wuhan National High Magnetic Field Center and School of Physics, Huazhong University of Science and Technology, 430074, Wuhan, People's Republic of China
| | - Rui Chen
- Wuhan National High Magnetic Field Center and School of Physics, Huazhong University of Science and Technology, 430074, Wuhan, People's Republic of China
| | - Chao Dong
- Wuhan National High Magnetic Field Center and School of Physics, Huazhong University of Science and Technology, 430074, Wuhan, People's Republic of China
| | - Wanxin Liu
- Wuhan National High Magnetic Field Center and School of Physics, Huazhong University of Science and Technology, 430074, Wuhan, People's Republic of China
| | - Mengyi Shi
- Wuhan National High Magnetic Field Center and School of Physics, Huazhong University of Science and Technology, 430074, Wuhan, People's Republic of China
| | - Yanfeng Guo
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, People's Republic of China
| | - Junfeng Wang
- Wuhan National High Magnetic Field Center and School of Physics, Huazhong University of Science and Technology, 430074, Wuhan, People's Republic of China
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93
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Jang SW, Yoon H, Jeong MY, Ryee S, Kim HS, Han MJ. Origin of ferromagnetism and the effect of doping on Fe 3GeTe 2. NANOSCALE 2020; 12:13501-13506. [PMID: 32555905 DOI: 10.1039/c9nr10171c] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Recent experimental findings of two dimensional ferromagnetism in Fe3GeTe2, whose critical temperature can reach room temperature by gating, has attracted great research interest. Here we performed elaborate ab initio studies using density functional theory, dynamical mean-field theory and magnetic force response theory. In contrast to the conventional wisdom, it is unambiguously shown that Fe3GeTe2 is not ferromagnetic but is antiferromagnetic, carrying zero net moment in its stoichiometric phase. Fe defect and hole doping are the keys to make this material ferromagnetic as supported by previously disregarded experiments. Furthermore, we found that electron doping also induces the antiferro- to ferro-magnetic transition. It is crucial to understand the notable recent experiments on gate-controlled ferromagnetism. Our results not only reveal the origin of ferromagnetism of this material but also show how it can be manipulated with defects and doping.
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Affiliation(s)
- Seung Woo Jang
- Department of Physics, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea.
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94
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Tartaglia TA, Tang JN, Lado JL, Bahrami F, Abramchuk M, McCandless GT, Doyle MC, Burch KS, Ran Y, Chan JY, Tafti F. Accessing new magnetic regimes by tuning the ligand spin-orbit coupling in van der Waals magnets. SCIENCE ADVANCES 2020; 6:eabb9379. [PMID: 32832677 PMCID: PMC7439302 DOI: 10.1126/sciadv.abb9379] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Accepted: 06/04/2020] [Indexed: 05/30/2023]
Abstract
Van der Waals (VdW) materials have opened new directions in the study of low dimensional magnetism. A largely unexplored arena is the intrinsic tuning of VdW magnets toward new ground states. Chromium trihalides provided the first such example with a change of interlayer magnetic coupling emerging upon exfoliation. Here, we take a different approach to engineer previously unknown ground states, not by exfoliation, but by tuning the spin-orbit coupling (SOC) of the nonmagnetic ligand atoms (Cl, Br, I). We synthesize a three-halide series, CrCl3 - x - y Br x I y , and map their magnetic properties as a function of Cl, Br, and I content. The resulting triangular phase diagrams unveil a frustrated regime near CrCl3. First-principles calculations confirm that the frustration is driven by a competition between the chromium and halide SOCs. Furthermore, we reveal a field-induced change of interlayer coupling in the bulk of CrCl3 - x - y Br x I y crystals at the same field as in the exfoliation experiments.
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Affiliation(s)
| | - Joseph N. Tang
- Department of Physics, Boston College, Chestnut Hill, MA 02467, USA
| | - Jose L. Lado
- Department of Applied Physics, Aalto University, Espoo, Finland
| | - Faranak Bahrami
- Department of Physics, Boston College, Chestnut Hill, MA 02467, USA
| | - Mykola Abramchuk
- Department of Physics, Boston College, Chestnut Hill, MA 02467, USA
| | - Gregory T. McCandless
- Department of Chemistry and Biochemistry, University of Texas at Dallas, Richardson, TX 75080, USA
| | - Meaghan C. Doyle
- Department of Physics, Boston College, Chestnut Hill, MA 02467, USA
| | - Kenneth S. Burch
- Department of Physics, Boston College, Chestnut Hill, MA 02467, USA
| | - Ying Ran
- Department of Physics, Boston College, Chestnut Hill, MA 02467, USA
| | - Julia Y. Chan
- Department of Chemistry and Biochemistry, University of Texas at Dallas, Richardson, TX 75080, USA
| | - Fazel Tafti
- Department of Physics, Boston College, Chestnut Hill, MA 02467, USA
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95
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Šmejkal L, González-Hernández R, Jungwirth T, Sinova J. Crystal time-reversal symmetry breaking and spontaneous Hall effect in collinear antiferromagnets. SCIENCE ADVANCES 2020; 6:eaaz8809. [PMID: 32548264 PMCID: PMC7274798 DOI: 10.1126/sciadv.aaz8809] [Citation(s) in RCA: 72] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Accepted: 04/09/2020] [Indexed: 05/14/2023]
Abstract
Electrons, commonly moving along the applied electric field, acquire in certain magnets a dissipationless transverse velocity. This spontaneous Hall effect, found more than a century ago, has been understood in terms of the time-reversal symmetry breaking by the internal spin structure of a ferromagnetic, noncolinear antiferromagnetic, or skyrmionic form. Here, we identify previously overlooked robust Hall effect mechanism arising from collinear antiferromagnetism combined with nonmagnetic atoms at noncentrosymmetric positions. We predict a large magnitude of this crystal Hall effect in a room temperature collinear antiferromagnet RuO2 and catalog, based on symmetry rules, extensive families of material candidates. We show that the crystal Hall effect is accompanied by the possibility to control its sign by the crystal chirality. We illustrate that accounting for the full magnetization density distribution instead of the simplified spin structure sheds new light on symmetry breaking phenomena in magnets and opens an alternative avenue toward low-dissipation nanoelectronics.
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Affiliation(s)
- Libor Šmejkal
- Institut für Physik, Johannes Gutenberg Universität Mainz, 55128 Mainz, Germany
- Institute of Physics, Czech Academy of Sciences, Cukrovarnická 10, 162 00 Praha 6, Czech Republic
- Faculty of Mathematics and Physics, Charles University, Ke Karlovu 3, 121 16 Prague 2, Czech Republic
- Corresponding author.
| | - Rafael González-Hernández
- Institut für Physik, Johannes Gutenberg Universität Mainz, 55128 Mainz, Germany
- Grupo de Investigación en Física Aplicada, Departamento de Física, Universidad del Norte, Barranquilla, Colombia
| | - T. Jungwirth
- Institute of Physics, Czech Academy of Sciences, Cukrovarnická 10, 162 00 Praha 6, Czech Republic
- School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, UK
| | - J. Sinova
- Institut für Physik, Johannes Gutenberg Universität Mainz, 55128 Mainz, Germany
- Institute of Physics, Czech Academy of Sciences, Cukrovarnická 10, 162 00 Praha 6, Czech Republic
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96
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Srivastava PK, Hassan Y, Ahn H, Kang B, Jung SG, Gebredingle Y, Joe M, Abbas MS, Park T, Park JG, Lee KJ, Lee C. Exchange Bias Effect in Ferro-/Antiferromagnetic van der Waals Heterostructures. NANO LETTERS 2020; 20:3978-3985. [PMID: 32330042 DOI: 10.1021/acs.nanolett.0c01176] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The recent discovery of magnetic van der Waals (vdW) materials provides a platform to answer fundamental questions on the two-dimensional (2D) limit of magnetic phenomena and applications. An important question in magnetism is the ultimate limit of the antiferromagnetic layer thickness in ferromagnetic (FM)/antiferromagnetic (AFM) heterostructures to observe the exchange bias (EB) effect, of which origin has been subject to a long-standing debate. Here, we report that the EB effect is maintained down to the atomic bilayer of AFM in the FM (Fe3GeTe2)/AFM (CrPS4) vdW heterostructure, but it vanishes at the single-layer limit. Given that CrPS4 is of A-type AFM and, thus, the bilayer is the smallest unit to form an AFM, this result clearly demonstrates the 2D limit of EB; only one unit of AFM ordering is sufficient for a finite EB effect. Moreover, the semiconducting property of AFM CrPS4 allows us to electrically control the exchange bias, providing an energy-efficient knob for spintronic devices.
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Affiliation(s)
- Pawan Kumar Srivastava
- School of Mechanical Engineering, Sungkyunkwan University, Suwon 16419, Republic of Korea
| | - Yasir Hassan
- SKKU Advanced Institute of Nanotechnology (SAINT), Sungkyunkwan University, Suwon 16419, Republic of Korea
| | - Hyobin Ahn
- SKKU Advanced Institute of Nanotechnology (SAINT), Sungkyunkwan University, Suwon 16419, Republic of Korea
| | - Byunggil Kang
- SKKU Advanced Institute of Nanotechnology (SAINT), Sungkyunkwan University, Suwon 16419, Republic of Korea
| | - Soon-Gil Jung
- Center for Quantum Materials and Superconductivity (CQMS), Sungkyunkwan University, Suwon 16419, Republic of Korea
- Department of Physics, Sungkyunkwan University, Suwon 16419, Republic of Korea
| | - Yisehak Gebredingle
- SKKU Advanced Institute of Nanotechnology (SAINT), Sungkyunkwan University, Suwon 16419, Republic of Korea
| | - Minwoong Joe
- School of Mechanical Engineering, Sungkyunkwan University, Suwon 16419, Republic of Korea
| | | | - Tuson Park
- Center for Quantum Materials and Superconductivity (CQMS), Sungkyunkwan University, Suwon 16419, Republic of Korea
- Department of Physics, Sungkyunkwan University, Suwon 16419, Republic of Korea
| | - Je-Geun Park
- Center for Correlated Electron Systems, Institute for Basic Science, Seoul 08826, Republic of Korea
- Department of Physics and Astronomy, Seoul National University, Seoul 08826, Republic of Korea
| | - Kyung-Jin Lee
- Department of Materials Science and Engineering, Korea University, Seoul 02841, Republic of Korea
- KU-KIST Graduate School of Converging Science and Technology, Korea University, Seoul 02841, Republic of Korea
| | - Changgu Lee
- School of Mechanical Engineering, Sungkyunkwan University, Suwon 16419, Republic of Korea
- SKKU Advanced Institute of Nanotechnology (SAINT), Sungkyunkwan University, Suwon 16419, Republic of Korea
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97
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Kim J, Kim KW, Kim B, Kang CJ, Shin D, Lee SH, Min BC, Park N. Exploitable Magnetic Anisotropy of the Two-Dimensional Magnet CrI 3. NANO LETTERS 2020; 20:929-935. [PMID: 31885277 DOI: 10.1021/acs.nanolett.9b03815] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Magnetic anisotropy often plays a central role in various static and dynamic properties of magnetic materials. In particular, for two-dimensional (2D) van der Waals materials, as inferred from the Mermin-Wagner theorem, it is an essential prerequisite for stabilizing ferromagnetic order. In this work, we carry out first-principles calculations for a CrI3 monolayer and investigate how its magnetic anisotropy is interrelated to adjustable parameters governing the underlying electronic structure. We explore various routes for controlled manipulation of magnetic anisotropy: chemical adsorption, substitutional doping, optical excitation, and charge transfer through a heterostructure. In particular, the vertical stacking of CrI3 and graphene is noteworthy in regard to controlling magnetic anisotropy: the spin anisotropy axis is switchable between the out-of-plane and in-plane directions, which is accompanied by a variation in the anisotropy energy of up to 500%. Our results show the possibility that dynamic control of the anisotropy of the 2D magnet CrI3 may enable the development of an advanced spintronic device with enhanced energy efficiency and high operation speed.
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Affiliation(s)
- Jeongwoo Kim
- Department of Physics , Incheon National University , Incheon 22012 , Korea
| | - Kyoung-Whan Kim
- Center for Spintronics , Korea Institute of Science and Technology , Seoul 02792 , Korea
| | - Bumseop Kim
- Department of Physics , Ulsan National Institute of Science and Technology , UNIST-gil 50 , Ulsan 44919 , Korea
| | - Chang-Jong Kang
- Department of Physics and Astronomy , Rutgers University , Piscataway , New Jersey 08854 , United States
| | - Dongbin Shin
- Department of Physics , Ulsan National Institute of Science and Technology , UNIST-gil 50 , Ulsan 44919 , Korea
| | - Sang-Hoon Lee
- Korea Institute for Advanced Study , Seoul 02455 , Korea
| | - Byoung-Chul Min
- Center for Spintronics , Korea Institute of Science and Technology , Seoul 02792 , Korea
| | - Noejung Park
- Department of Physics , Ulsan National Institute of Science and Technology , UNIST-gil 50 , Ulsan 44919 , Korea
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98
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Ding B, Li Z, Xu G, Li H, Hou Z, Liu E, Xi X, Xu F, Yao Y, Wang W. Observation of Magnetic Skyrmion Bubbles in a van der Waals Ferromagnet Fe 3GeTe 2. NANO LETTERS 2020; 20:868-873. [PMID: 31869236 DOI: 10.1021/acs.nanolett.9b03453] [Citation(s) in RCA: 82] [Impact Index Per Article: 20.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Two-dimensional (2D) van der Waals (vdW) magnetic materials have recently been introduced as a new horizon in materials science, and they enable potential applications for next-generation spintronic devices. Here, in this communication, the observations of stable Bloch-type magnetic skyrmions in single crystals of 2D vdW Fe3GeTe2 (FGT) are reported by using in situ Lorentz transmission electron microscopy (TEM). We find the ground-state magnetic stripe domains in FGT transform into skyrmion bubbles when an external magnetic field is applied perpendicularly to the (001) thin plate with temperatures below the Curie temperature TC. Most interestingly, a hexagonal lattice of skyrmion bubbles is obtained via field-cooling manipulation with magnetic field applied along the [001] direction. Owing to their topological stability, the skyrmion bubble lattices are stable to large field-cooling tilted angles and further reproduced by utilizing the micromagnetic simulations. These observations directly demonstrate that the 2D vdW FGT possesses a rich variety of topological spin textures, being of great promise for future applications in the field of spintronics.
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Affiliation(s)
- Bei Ding
- Beijing National Laboratory for Condensed Matter Physics , Institute of Physics, Chinese Academy of Sciences , Beijing 100190 , China
- University of Chinese Academy of Sciences , Beijing 100049 , China
| | - Zefang Li
- Beijing National Laboratory for Condensed Matter Physics , Institute of Physics, Chinese Academy of Sciences , Beijing 100190 , China
- University of Chinese Academy of Sciences , Beijing 100049 , China
| | - Guizhou Xu
- School of Materials Science and Engineering , Nanjing University of Science and Technology , Nanjing 210094 , China
| | - Hang Li
- Beijing National Laboratory for Condensed Matter Physics , Institute of Physics, Chinese Academy of Sciences , Beijing 100190 , China
- University of Chinese Academy of Sciences , Beijing 100049 , China
| | - Zhipeng Hou
- South China Academy of Advanced Optoelectronics , South China Normal University , Guangzhou 510006 , China
| | - Enke Liu
- Beijing National Laboratory for Condensed Matter Physics , Institute of Physics, Chinese Academy of Sciences , Beijing 100190 , China
| | - Xuekui Xi
- Beijing National Laboratory for Condensed Matter Physics , Institute of Physics, Chinese Academy of Sciences , Beijing 100190 , China
| | - Feng Xu
- School of Materials Science and Engineering , Nanjing University of Science and Technology , Nanjing 210094 , China
| | - Yuan Yao
- Beijing National Laboratory for Condensed Matter Physics , Institute of Physics, Chinese Academy of Sciences , Beijing 100190 , China
| | - Wenhong Wang
- Beijing National Laboratory for Condensed Matter Physics , Institute of Physics, Chinese Academy of Sciences , Beijing 100190 , China
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99
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Puphal P, Pomjakushin V, Kanazawa N, Ukleev V, Gawryluk DJ, Ma J, Naamneh M, Plumb NC, Keller L, Cubitt R, Pomjakushina E, White JS. Topological Magnetic Phase in the Candidate Weyl Semimetal CeAlGe. PHYSICAL REVIEW LETTERS 2020; 124:017202. [PMID: 31976692 DOI: 10.1103/physrevlett.124.017202] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Revised: 11/01/2019] [Indexed: 06/10/2023]
Abstract
We report the discovery of topological magnetism in the candidate magnetic Weyl semimetal CeAlGe. Using neutron scattering we find this system to host several incommensurate, square-coordinated multi-k[over →] magnetic phases below T_{N}. The topological properties of a phase stable at intermediate magnetic fields parallel to the c axis are suggested by observation of a topological Hall effect. Our findings highlight CeAlGe as an exceptional system for exploiting the interplay between the nontrivial topologies of the magnetization in real space and Weyl nodes in momentum space.
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Affiliation(s)
- Pascal Puphal
- Laboratory for Multiscale Materials Experiments (LMX), Paul Scherrer Institute (PSI), CH-5232 Villigen, Switzerland
| | - Vladimir Pomjakushin
- Laboratory for Neutron Scattering and Imaging (LNS), Paul Scherrer Institute (PSI), CH-5232 Villigen, Switzerland
| | - Naoya Kanazawa
- Department of Applied Physics, University of Tokyo, Tokyo 113-8656, Japan
| | - Victor Ukleev
- Laboratory for Neutron Scattering and Imaging (LNS), Paul Scherrer Institute (PSI), CH-5232 Villigen, Switzerland
| | - Dariusz J Gawryluk
- Laboratory for Multiscale Materials Experiments (LMX), Paul Scherrer Institute (PSI), CH-5232 Villigen, Switzerland
| | - Junzhang Ma
- Swiss Light Source (SLS), Paul Scherrer Institute (PSI), CH-5232 Villigen PSI, Switzerland
| | - Muntaser Naamneh
- Swiss Light Source (SLS), Paul Scherrer Institute (PSI), CH-5232 Villigen PSI, Switzerland
| | - Nicholas C Plumb
- Swiss Light Source (SLS), Paul Scherrer Institute (PSI), CH-5232 Villigen PSI, Switzerland
| | - Lukas Keller
- Laboratory for Neutron Scattering and Imaging (LNS), Paul Scherrer Institute (PSI), CH-5232 Villigen, Switzerland
| | - Robert Cubitt
- Institut Laue-Langevin (ILL), 71 avenue des Martyrs, CS 20156, 38042 Grenoble cedex 9, France
| | - Ekaterina Pomjakushina
- Laboratory for Multiscale Materials Experiments (LMX), Paul Scherrer Institute (PSI), CH-5232 Villigen, Switzerland
| | - Jonathan S White
- Laboratory for Neutron Scattering and Imaging (LNS), Paul Scherrer Institute (PSI), CH-5232 Villigen, Switzerland
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100
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Geishendorf K, Vir P, Shekhar C, Felser C, Facio JI, van den Brink J, Nielsch K, Thomas A, Goennenwein STB. Signatures of the Magnetic Entropy in the Thermopower Signals in Nanoribbons of the Magnetic Weyl Semimetal Co 3Sn 2S 2. NANO LETTERS 2020; 20:300-305. [PMID: 31774686 DOI: 10.1021/acs.nanolett.9b03822] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Weyl semimetals exhibit interesting electronic properties due to their topological band structure. In particular, large anomalous Hall and anomalous Nernst signals are often reported, which allow for a detailed and quantitative study of subtle features. We pattern single crystals of the magnetic Weyl semimetal Co3Sn2S2 into nanoribbon devices using focused ion beam cutting and optical lithography. This approach enables a very precise study of the galvano- and thermomagnetic transport properties. Indeed, we found interesting features in the temperature dependency of the anomalous Hall and Nernst effects. We present an analysis of the data based on the Mott relation and identify in the Nernst response signatures of magnetic fluctuations enhancing the anomalous Nernst conductivity at the magnetic phase transition.
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Affiliation(s)
- Kevin Geishendorf
- Leibniz IFW Dresden , Helmholtzstr. 20 , G-01 069 Dresden , Germany
- Institute of Applied Physics , Technische Universität Dresden , 01062 Dresden , Germany
| | - Praveen Vir
- Max Planck Institute for Chemical Physics of Solids , 01187 Dresden , Germany
| | - 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
| | - Jorge I Facio
- Leibniz IFW Dresden , Helmholtzstr. 20 , G-01 069 Dresden , Germany
| | | | - Kornelius Nielsch
- Leibniz IFW Dresden , Helmholtzstr. 20 , G-01 069 Dresden , Germany
- Institute of Applied Physics , Technische Universität Dresden , 01062 Dresden , Germany
- Institute of Materials Science , Technische Universität Dresden , 01062 Dresden , Germany
| | - Andy Thomas
- Leibniz IFW Dresden , Helmholtzstr. 20 , G-01 069 Dresden , Germany
| | - Sebastian T B Goennenwein
- Institut für Festkörper- und Materialphysik , Technische Universität Dresden and Würzburg-Dresden Cluster of Excellence ct.qmat , 01062 Dresden , Germany
- Center for Transport and Devices of Emergent Materials , Technische Universität Dresden , 01062 Dresden , Germany
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