1
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Fang N, Wu C, Zhang Y, Li Z, Zhou Z. Perspectives: Light Control of Magnetism and Device Development. ACS NANO 2024; 18:8600-8625. [PMID: 38469753 DOI: 10.1021/acsnano.3c13002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/13/2024]
Abstract
Accurately controlling magnetic and spin states presents a significant challenge in spintronics, especially as demands for higher data storage density and increased processing speeds grow. Approaches such as light control are gradually supplanting traditional magnetic field methods. Traditionally, the modulation of magnetism was predominantly achieved through polarized light with the help of ultrafast light technologies. With the growing demand for energy efficiency and multifunctionality in spintronic devices, integrating photovoltaic materials into magnetoelectric systems has introduced more physical effects. This development suggests that sunlight will play an increasingly pivotal role in manipulating spin orientation in the future. This review introduces and concludes the influence of various light types on magnetism, exploring mechanisms such as magneto-optical (MO) effects, light-induced magnetic phase transitions, and spin photovoltaic effects. This review briefly summarizes recent advancements in the light control of magnetism, especially sunlight, and their potential applications, providing an optimistic perspective on future research directions in this area.
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Affiliation(s)
- Ning Fang
- School of Materials Science and Engineering, Changzhou University, Changzhou 213164, China
| | - Changqing Wu
- School of Environmental Science and Engineering, Jiangsu Key Laboratory of Advanced Catalytic Materials and Technology, School of Petrochemical Engineering, Changzhou University, Changzhou 213164, China
| | - Yuzhe Zhang
- School of Environmental Science and Engineering, Jiangsu Key Laboratory of Advanced Catalytic Materials and Technology, School of Petrochemical Engineering, Changzhou University, Changzhou 213164, China
| | - Zhongyu Li
- School of Environmental Science and Engineering, Jiangsu Key Laboratory of Advanced Catalytic Materials and Technology, School of Petrochemical Engineering, Changzhou University, Changzhou 213164, China
| | - Ziyao Zhou
- School of Materials Science and Engineering, Changzhou University, Changzhou 213164, China
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2
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Wang H, Wen Y, Zeng H, Xiong Z, Tu Y, Zhu H, Cheng R, Yin L, Jiang J, Zhai B, Liu C, Shan C, He J. 2D Ferroic Materials for Nonvolatile Memory Applications. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023:e2305044. [PMID: 37486859 DOI: 10.1002/adma.202305044] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2023] [Revised: 07/21/2023] [Indexed: 07/26/2023]
Abstract
The emerging nonvolatile memory technologies based on ferroic materials are promising for producing high-speed, low-power, and high-density memory in the field of integrated circuits. Long-range ferroic orders observed in 2D materials have triggered extensive research interest in 2D magnets, 2D ferroelectrics, 2D multiferroics, and their device applications. Devices based on 2D ferroic materials and heterostructures with an atomically smooth interface and ultrathin thickness have exhibited impressive properties and significant potential for developing advanced nonvolatile memory. In this context, a systematic review of emergent 2D ferroic materials is conducted here, emphasizing their recent research on nonvolatile memory applications, with a view to proposing brighter prospects for 2D magnetic materials, 2D ferroelectric materials, 2D multiferroic materials, and their relevant devices.
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Affiliation(s)
- Hao Wang
- Key Laboratory of Artificial Micro- and Nano-Structures of Ministry of Education and School of Physics and Technology, Wuhan University, Wuhan, 430072, China
| | - Yao Wen
- Key Laboratory of Artificial Micro- and Nano-Structures of Ministry of Education and School of Physics and Technology, Wuhan University, Wuhan, 430072, China
| | - Hui Zeng
- Key Laboratory of Artificial Micro- and Nano-Structures of Ministry of Education and School of Physics and Technology, Wuhan University, Wuhan, 430072, China
| | - Ziren Xiong
- Key Laboratory of Artificial Micro- and Nano-Structures of Ministry of Education and School of Physics and Technology, Wuhan University, Wuhan, 430072, China
| | - Yangyuan Tu
- Key Laboratory of Artificial Micro- and Nano-Structures of Ministry of Education and School of Physics and Technology, Wuhan University, Wuhan, 430072, China
| | - Hao Zhu
- Key Laboratory of Artificial Micro- and Nano-Structures of Ministry of Education and School of Physics and Technology, Wuhan University, Wuhan, 430072, China
| | - Ruiqing Cheng
- Key Laboratory of Artificial Micro- and Nano-Structures of Ministry of Education and School of Physics and Technology, Wuhan University, Wuhan, 430072, China
| | - Lei Yin
- Key Laboratory of Artificial Micro- and Nano-Structures of Ministry of Education and School of Physics and Technology, Wuhan University, Wuhan, 430072, China
| | - Jian Jiang
- Key Laboratory of Artificial Micro- and Nano-Structures of Ministry of Education and School of Physics and Technology, Wuhan University, Wuhan, 430072, China
| | - Baoxing Zhai
- Key Laboratory of Artificial Micro- and Nano-Structures of Ministry of Education and School of Physics and Technology, Wuhan University, Wuhan, 430072, China
| | - Chuansheng Liu
- Key Laboratory of Artificial Micro- and Nano-Structures of Ministry of Education and School of Physics and Technology, Wuhan University, Wuhan, 430072, China
| | - Chongxin Shan
- Henan Key Laboratory of Diamond Optoelectronic Materials and Devices, Key Laboratory of Material Physics, Ministry of Education, School of Physics, Zhengzhou University, Zhengzhou, 450052, China
| | - Jun He
- Key Laboratory of Artificial Micro- and Nano-Structures of Ministry of Education and School of Physics and Technology, Wuhan University, Wuhan, 430072, China
- Hubei Luojia Laboratory, Wuhan, 430079, China
- Wuhan Institute of Quantum Technology, Wuhan, 430206, China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing, 100190, China
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3
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Wang QH, Bedoya-Pinto A, Blei M, Dismukes AH, Hamo A, Jenkins S, Koperski M, Liu Y, Sun QC, Telford EJ, Kim HH, Augustin M, Vool U, Yin JX, Li LH, Falin A, Dean CR, Casanova F, Evans RFL, Chshiev M, Mishchenko A, Petrovic C, He R, Zhao L, Tsen AW, Gerardot BD, Brotons-Gisbert M, Guguchia Z, Roy X, Tongay S, Wang Z, Hasan MZ, Wrachtrup J, Yacoby A, Fert A, Parkin S, Novoselov KS, Dai P, Balicas L, Santos EJG. The Magnetic Genome of Two-Dimensional van der Waals Materials. ACS NANO 2022; 16:6960-7079. [PMID: 35442017 PMCID: PMC9134533 DOI: 10.1021/acsnano.1c09150] [Citation(s) in RCA: 70] [Impact Index Per Article: 35.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Accepted: 02/23/2022] [Indexed: 05/23/2023]
Abstract
Magnetism in two-dimensional (2D) van der Waals (vdW) materials has recently emerged as one of the most promising areas in condensed matter research, with many exciting emerging properties and significant potential for applications ranging from topological magnonics to low-power spintronics, quantum computing, and optical communications. In the brief time after their discovery, 2D magnets have blossomed into a rich area for investigation, where fundamental concepts in magnetism are challenged by the behavior of spins that can develop at the single layer limit. However, much effort is still needed in multiple fronts before 2D magnets can be routinely used for practical implementations. In this comprehensive review, prominent authors with expertise in complementary fields of 2D magnetism (i.e., synthesis, device engineering, magneto-optics, imaging, transport, mechanics, spin excitations, and theory and simulations) have joined together to provide a genome of current knowledge and a guideline for future developments in 2D magnetic materials research.
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Affiliation(s)
- Qing Hua Wang
- Materials
Science and Engineering, School for Engineering of Matter, Transport
and Energy, Arizona State University, Tempe, Arizona 85287, United States
| | - Amilcar Bedoya-Pinto
- NISE
Department, Max Planck Institute of Microstructure
Physics, 06120 Halle, Germany
- Instituto
de Ciencia Molecular (ICMol), Universitat
de València, 46980 Paterna, Spain
| | - Mark Blei
- Materials
Science and Engineering, School for Engineering of Matter, Transport
and Energy, Arizona State University, Tempe, Arizona 85287, United States
| | - Avalon H. Dismukes
- Department
of Chemistry, Columbia University, New York, New York 10027, United States
| | - Assaf Hamo
- Department
of Physics, Harvard University, Cambridge, Massachusetts 02138, United States
| | - Sarah Jenkins
- Twist
Group,
Faculty of Physics, University of Duisburg-Essen, Campus Duisburg, 47057 Duisburg, Germany
| | - Maciej Koperski
- Institute
for Functional Intelligent Materials, National
University of Singapore, 117544 Singapore
| | - Yu Liu
- Condensed
Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, New York 11973, United States
| | - Qi-Chao Sun
- Physikalisches
Institut, University of Stuttgart, 70569 Stuttgart, Germany
| | - Evan J. Telford
- Department
of Chemistry, Columbia University, New York, New York 10027, United States
- Department
of Physics, Columbia University, New York, New York 10027, United States
| | - Hyun Ho Kim
- School
of Materials Science and Engineering, Department of Energy Engineering
Convergence, Kumoh National Institute of
Technology, Gumi 39177, Korea
| | - Mathias Augustin
- Institute
for Condensed Matter Physics and Complex Systems, School of Physics
and Astronomy, The University of Edinburgh, Edinburgh, EH9 3FD, United Kingdom
- Donostia
International Physics Center (DIPC), 20018 Donostia-San Sebastián, Basque Country, Spain
| | - Uri Vool
- Department
of Physics, Harvard University, Cambridge, Massachusetts 02138, United States
- John Harvard
Distinguished Science Fellows Program, Harvard
University, Cambridge, Massachusetts 02138, United States
| | - Jia-Xin Yin
- Laboratory
for Topological Quantum Matter and Spectroscopy, Department of Physics, Princeton University, Princeton, New Jersey 08544, United States
| | - Lu Hua Li
- Institute
for Frontier Materials, Deakin University, Geelong Waurn Ponds Campus, Waurn Ponds, Victoria 3216, Australia
| | - Alexey Falin
- Institute
for Frontier Materials, Deakin University, Geelong Waurn Ponds Campus, Waurn Ponds, Victoria 3216, Australia
| | - Cory R. Dean
- Department
of Physics, Columbia University, New York, New York 10027, United States
| | - Fèlix Casanova
- CIC nanoGUNE
BRTA, 20018 Donostia - San Sebastián, Basque
Country, Spain
- IKERBASQUE,
Basque Foundation for Science, 48013 Bilbao, Basque Country, Spain
| | - Richard F. L. Evans
- Department
of Physics, University of York, Heslington, York YO10 5DD, United Kingdom
| | - Mairbek Chshiev
- Université
Grenoble Alpes, CEA, CNRS, Spintec, 38000 Grenoble, France
- Institut
Universitaire de France, 75231 Paris, France
| | - Artem Mishchenko
- Department
of Physics and Astronomy, University of
Manchester, Manchester, M13 9PL, United Kingdom
- National
Graphene Institute, University of Manchester, Manchester, M13 9PL, United Kingdom
| | - Cedomir Petrovic
- Condensed
Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, New York 11973, United States
| | - Rui He
- Department
of Electrical and Computer Engineering, Texas Tech University, 910 Boston Avenue, Lubbock, Texas 79409, United
States
| | - Liuyan Zhao
- Department
of Physics, University of Michigan, 450 Church Street, Ann Arbor, Michigan 48109, United States
| | - Adam W. Tsen
- Institute
for Quantum Computing and Department of Chemistry, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
| | - Brian D. Gerardot
- SUPA, Institute
of Photonics and Quantum Sciences, Heriot-Watt
University, Edinburgh EH14 4AS, United Kingdom
| | - Mauro Brotons-Gisbert
- SUPA, Institute
of Photonics and Quantum Sciences, Heriot-Watt
University, Edinburgh EH14 4AS, United Kingdom
| | - Zurab Guguchia
- Laboratory
for Muon Spin Spectroscopy, Paul Scherrer
Institute, CH-5232 Villigen PSI, Switzerland
| | - Xavier Roy
- Department
of Chemistry, Columbia University, New York, New York 10027, United States
| | - Sefaattin Tongay
- Materials
Science and Engineering, School for Engineering of Matter, Transport
and Energy, Arizona State University, Tempe, Arizona 85287, United States
| | - Ziwei Wang
- Department
of Physics and Astronomy, University of
Manchester, Manchester, M13 9PL, United Kingdom
- National
Graphene Institute, University of Manchester, Manchester, M13 9PL, United Kingdom
| | - M. Zahid Hasan
- Materials
Sciences Division, Lawrence Berkeley National
Laboratory, Berkeley, California 94720, United States
- Princeton
Institute for Science and Technology of Materials, Princeton University, Princeton, New Jersey 08544, United States
- National
High Magnetic Field Laboratory, Florida
State University, Tallahassee, Florida 32310, United States
| | - Joerg Wrachtrup
- Physikalisches
Institut, University of Stuttgart, 70569 Stuttgart, Germany
- Max Planck
Institute for Solid State Research, 70569 Stuttgart, Germany
| | - Amir Yacoby
- Department
of Physics, Harvard University, Cambridge, Massachusetts 02138, United States
- John A.
Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, United States
| | - Albert Fert
- Donostia
International Physics Center (DIPC), 20018 Donostia-San Sebastián, Basque Country, Spain
- Unité
Mixte de Physique, CNRS, Thales, Université Paris-Saclay, 91767 Palaiseau, France
- Department
of Materials Physics UPV/EHU, 20018 Donostia - San Sebastián, Basque Country, Spain
| | - Stuart Parkin
- NISE
Department, Max Planck Institute of Microstructure
Physics, 06120 Halle, Germany
| | - Kostya S. Novoselov
- Institute
for Functional Intelligent Materials, National
University of Singapore, 117544 Singapore
| | - Pengcheng Dai
- Department
of Physics and Astronomy, Rice University, Houston, Texas 77005, United States
| | - Luis Balicas
- National
High Magnetic Field Laboratory, Florida
State University, Tallahassee, Florida 32310, United States
- Department
of Physics, Florida State University, Tallahassee, Florida 32306, United States
| | - Elton J. G. Santos
- Institute
for Condensed Matter Physics and Complex Systems, School of Physics
and Astronomy, The University of Edinburgh, Edinburgh, EH9 3FD, United Kingdom
- Donostia
International Physics Center (DIPC), 20018 Donostia-San Sebastián, Basque Country, Spain
- Higgs Centre
for Theoretical Physics, The University
of Edinburgh, Edinburgh EH9 3FD, United Kingdom
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4
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Experimental demonstration of skyrmionic magnetic tunnel junction at room temperature. Sci Bull (Beijing) 2022; 67:691-699. [DOI: 10.1016/j.scib.2022.01.016] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Revised: 01/07/2022] [Accepted: 01/12/2022] [Indexed: 11/24/2022]
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5
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Song T, Anderson E, Tu MWY, Seyler K, Taniguchi T, Watanabe K, McGuire MA, Li X, Cao T, Xiao D, Yao W, Xu X. Spin photovoltaic effect in magnetic van der Waals heterostructures. SCIENCE ADVANCES 2021; 7:eabg8094. [PMID: 34516904 PMCID: PMC8442881 DOI: 10.1126/sciadv.abg8094] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Accepted: 07/13/2021] [Indexed: 06/13/2023]
Abstract
The development of van der Waals (vdW) crystals and their heterostructures has created a fascinating platform for exploring optoelectronic properties in the two-dimensional (2D) limit. With the recent discovery of 2D magnets, the control of the spin degree of freedom can be integrated to realize 2D spin-optoelectronics. Here, we report spin photovoltaic effects in vdW heterostructures of 2D magnet chromium triiodide (CrI3) sandwiched by graphene contacts. The photocurrent displays a distinct dependence on light helicity, which can be tuned by varying the magnetic states and photon energy. Circular polarization–resolved absorption measurements reveal that these observations originate from magnetic order–coupled and, thus, helicity-dependent charge-transfer excitons. The photocurrent displays multiple plateaus as the magnetic field is swept, associated with different CrI3 spin configurations. Giant photo-magnetocurrent is observed, which tends to infinity for a small applied bias. Our results pave the way to explore emergent photospintronics by engineering magnetic vdW heterostructures.
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Affiliation(s)
- Tiancheng Song
- Department of Physics, University of Washington, Seattle, WA 98195, USA
| | - Eric Anderson
- Department of Physics, University of Washington, Seattle, WA 98195, USA
| | | | - Kyle Seyler
- Department of Physics, University of Washington, Seattle, WA 98195, USA
| | - Takashi Taniguchi
- International Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
| | - Kenji Watanabe
- Research Center for Functional Materials, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
| | - Michael A. McGuire
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Xiaosong Li
- Department of Materials Science and Engineering, University of Washington, Seattle, WA 98195, USA
| | - Ting Cao
- Department of Materials Science and Engineering, University of Washington, Seattle, WA 98195, USA
| | - Di Xiao
- Department of Physics, Carnegie Mellon University, Pittsburgh, PA 15213, USA
| | - Wang Yao
- Department of Physics, University of Hong Kong, Hong Kong, China
| | - Xiaodong Xu
- Department of Physics, University of Washington, Seattle, WA 98195, USA
- Department of Materials Science and Engineering, University of Washington, Seattle, WA 98195, USA
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6
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Yao Y, Zhan X, Sendeku MG, Yu P, Dajan FT, Zhu C, Li N, Wang J, Wang F, Wang Z, He J. Recent progress on emergent two-dimensional magnets and heterostructures. NANOTECHNOLOGY 2021; 32:472001. [PMID: 34315143 DOI: 10.1088/1361-6528/ac17fd] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Accepted: 07/26/2021] [Indexed: 06/13/2023]
Abstract
Intrinsic two-dimensional (2D) magnetic materials own strong long-range magnetism while their characteristics of the ultrathin thickness and smooth surface provide an ideal platform for manipulating the magnetic properties at 2D limit. This makes them to be potential candidates in various spintronic applications compared to their corresponding bulk counterparts. The discovery of magnetic ordering in 2D CrI3and Gr2Ge2Te6nanostructures stimulated tremendous research interest in both experimental and theoretical studies on various intrinsic magnets at 2D limit. This review gives a comprehensive overview of the recent progress on the emergent 2D magnets and heterostructures. Firstly, several kinds of typical 2D magnetic materials discovered in the last few years and their fabrication methods are summarized in detail. Secondly, the current strategies for manipulating magnetic properties in 2D materials are further discussed. Then, the recent advances on the construction of representative van der Waals magnetic heterostructures and their respective performance are provided. With the hope of motivating the researchers in this area, we finally offered the challenges and outlook on 2D magnetism.
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Affiliation(s)
- Yuyu Yao
- CAS Center for Excellence in Nanoscience, CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, National Center for Nanoscience and Technology, Beijing 100190, People's Republic of China
- Sino-Danish College, University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
- Sino-Danish Center for Education, Beijing 100049, People's Republic of China
| | - Xueying Zhan
- CAS Center for Excellence in Nanoscience, CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, National Center for Nanoscience and Technology, Beijing 100190, People's Republic of China
| | - Marshet Getaye Sendeku
- CAS Center for Excellence in Nanoscience, CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, National Center for Nanoscience and Technology, Beijing 100190, People's Republic of China
| | - Peng Yu
- CAS Center for Excellence in Nanoscience, CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, National Center for Nanoscience and Technology, Beijing 100190, People's Republic of China
| | - Fekadu Tsegaye Dajan
- CAS Center for Excellence in Nanoscience, CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, National Center for Nanoscience and Technology, Beijing 100190, People's Republic of China
| | - Chuanchao Zhu
- Institute for Quantum Information & State Key Laboratory of High Performance Computing, National University of Defense Technology, Changsha 410073, People's Republic of China
| | - Ningning Li
- CAS Center for Excellence in Nanoscience, CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, National Center for Nanoscience and Technology, Beijing 100190, People's Republic of China
- Sino-Danish College, University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
- Sino-Danish Center for Education, Beijing 100049, People's Republic of China
| | - Junjun Wang
- CAS Center for Excellence in Nanoscience, CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, National Center for Nanoscience and Technology, Beijing 100190, People's Republic of China
| | - Feng Wang
- CAS Center for Excellence in Nanoscience, CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, National Center for Nanoscience and Technology, Beijing 100190, People's Republic of China
| | - Zhenxing Wang
- CAS Center for Excellence in Nanoscience, CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, National Center for Nanoscience and Technology, Beijing 100190, People's Republic of China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
| | - Jun He
- CAS Center for Excellence in Nanoscience, CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, National Center for Nanoscience and Technology, Beijing 100190, People's Republic of China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
- Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education, School of Physics and Technology, Wuhan University, Wuhan 430072, People's Republic of China
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7
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Li W, Zhu B, He Q, Borisevich AY, Yun C, Wu R, Lu P, Qi Z, Wang Q, Chen A, Wang H, Cavill SA, Zhang KHL, MacManus‐Driscoll JL. Interface Engineered Room-Temperature Ferromagnetic Insulating State in Ultrathin Manganite Films. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2020; 7:1901606. [PMID: 31921553 PMCID: PMC6947487 DOI: 10.1002/advs.201901606] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Revised: 10/23/2019] [Indexed: 06/10/2023]
Abstract
Ultrathin epitaxial films of ferromagnetic insulators (FMIs) with Curie temperatures near room temperature are critically needed for use in dissipationless quantum computation and spintronic devices. However, such materials are extremely rare. Here, a room-temperature FMI is achieved in ultrathin La0.9Ba0.1MnO3 films grown on SrTiO3 substrates via an interface proximity effect. Detailed scanning transmission electron microscopy images clearly demonstrate that MnO6 octahedral rotations in La0.9Ba0.1MnO3 close to the interface are strongly suppressed. As determined from in situ X-ray photoemission spectroscopy, O K-edge X-ray absorption spectroscopy, and density functional theory, the realization of the FMI state arises from a reduction of Mn eg bandwidth caused by the quenched MnO6 octahedral rotations. The emerging FMI state in La0.9Ba0.1MnO3 together with necessary coherent interface achieved with the perovskite substrate gives very high potential for future high performance electronic devices.
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Affiliation(s)
- Weiwei Li
- Department of Materials Science and MetallurgyUniversity of Cambridge27 Charles Babbage RoadCambridgeCB3 0FSUK
| | - Bonan Zhu
- Department of Materials Science and MetallurgyUniversity of Cambridge27 Charles Babbage RoadCambridgeCB3 0FSUK
| | - Qian He
- Cardiff Catalysis InstituteSchool of ChemistryCardiff UniversityMain Building, Park PlaceCardiffCF10 3ATUK
| | - Albina Y. Borisevich
- Center for Nanophase Materials SciencesOak Ridge National LaboratoryOak RidgeTN37831USA
| | - Chao Yun
- Department of Materials Science and MetallurgyUniversity of Cambridge27 Charles Babbage RoadCambridgeCB3 0FSUK
| | - Rui Wu
- Department of Materials Science and MetallurgyUniversity of Cambridge27 Charles Babbage RoadCambridgeCB3 0FSUK
| | - Ping Lu
- Sandia National LaboratoryAlbuquerqueNM87185USA
| | - Zhimin Qi
- School of Materials EngineeringPurdue UniversityWest LafayetteIN47907USA
| | - Qiang Wang
- Department of Physics and AstronomyWest Virginia UniversityMorgantownWV26506USA
| | - Aiping Chen
- Center for Integrated NanotechnologiesLos Alamos National LaboratoryLos AlamosNM87545USA
| | - Haiyan Wang
- School of Materials EngineeringPurdue UniversityWest LafayetteIN47907USA
| | - Stuart A. Cavill
- Department of PhysicsUniversity of YorkYorkYO10 5DDUK
- Diamond Light SourceDidcotOX11 0DEUK
| | - Kelvin H. L. Zhang
- State Key Laboratory of Physical Chemistry of Solid SurfacesCollege of Chemistry and Chemical EngineeringXiamen UniversityXiamen361005China
| | - Judith L. MacManus‐Driscoll
- Department of Materials Science and MetallurgyUniversity of Cambridge27 Charles Babbage RoadCambridgeCB3 0FSUK
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8
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Kim HH, Yang B, Tian S, Li C, Miao GX, Lei H, Tsen AW. Tailored Tunnel Magnetoresistance Response in Three Ultrathin Chromium Trihalides. NANO LETTERS 2019; 19:5739-5745. [PMID: 31305077 DOI: 10.1021/acs.nanolett.9b02357] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Materials that demonstrate large magnetoresistance have attracted significant interest for many decades. Extremely large tunnel magnetoresistance (TMR) has been reported by several groups across ultrathin CrI3 by exploiting the weak antiferromagnetic coupling between adjacent layers. Here, we report a comparative study of TMR in all three chromium trihalides (CrX3, X = Cl, Br, or I) in the two-dimensional limit. As the materials exhibit different transition temperatures and interlayer magnetic ordering in the ground state, tunneling measurements allow for an easy determination of the field-temperature phase diagram for the three systems. By changing sample thickness and biasing conditions, we then demonstrate how to maximize and further tailor the TMR response at different temperatures for each material. In particular, near the magnetic transition temperature, TMR is nonsaturating up to the highest fields measured for all three compounds owing to the large, field-induced exchange coupling.
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Affiliation(s)
- Hyun Ho Kim
- Institute for Quantum Computing, Department of Chemistry, Department of Physics and Astronomy, and Department of Electrical and Computer Engineering , University of Waterloo , Waterloo , Ontario N2L 3G1 , Canada
| | - Bowen Yang
- Institute for Quantum Computing, Department of Chemistry, Department of Physics and Astronomy, and Department of Electrical and Computer Engineering , University of Waterloo , Waterloo , Ontario N2L 3G1 , Canada
| | - Shangjie Tian
- Department of Physics and Beijing Key Laboratory of Optoelectronic Functional Materials & Micro-Nano Devices , Renmin University of China , Beijing 100872 , China
| | - Chenghe Li
- Department of Physics and Beijing Key Laboratory of Optoelectronic Functional Materials & Micro-Nano Devices , Renmin University of China , Beijing 100872 , China
| | - Guo-Xing Miao
- Institute for Quantum Computing, Department of Chemistry, Department of Physics and Astronomy, and Department of Electrical and Computer Engineering , University of Waterloo , Waterloo , Ontario N2L 3G1 , Canada
| | - Hechang Lei
- Department of Physics and Beijing Key Laboratory of Optoelectronic Functional Materials & Micro-Nano Devices , Renmin University of China , Beijing 100872 , China
| | - Adam W Tsen
- Institute for Quantum Computing, Department of Chemistry, Department of Physics and Astronomy, and Department of Electrical and Computer Engineering , University of Waterloo , Waterloo , Ontario N2L 3G1 , Canada
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9
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Li H, Ruan S, Zeng YJ. Intrinsic Van Der Waals Magnetic Materials from Bulk to the 2D Limit: New Frontiers of Spintronics. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2019; 31:e1900065. [PMID: 31069896 DOI: 10.1002/adma.201900065] [Citation(s) in RCA: 110] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2019] [Revised: 02/21/2019] [Indexed: 05/22/2023]
Abstract
2D van der Waals (vdW) magnets, which present intrinsic ferromagnetic/antiferromagnetic ground states at finite temperatures down to atomic-layer thicknesses, open a new horizon in materials science and enable the potential development of new spin-related applications. The layered structure of vdW magnets facilitates their atomic-layer cleavability and magnetic anisotropy, which counteracts spin fluctuations, thereby providing an ideal platform for theoretically and experimentally exploring magnetic phase transitions in the 2D limit. With reduced dimensions, the susceptibility of 2D magnets to a large variety of external stimuli also makes them more promising than their bulk counterpart in various device applications. Here, the current status of characterization and tuning of the magnetic properties of 2D vdW magnets, particularly the atomic-layer thickness, is presented. Various state-of-the-art optical and electrical techniques have been applied to reveal the magnetic states of 2D vdW magnets. Other emerging 2D vdW magnets and future perspectives on the stacking strategy are also given; it is believed that they will excite more intensive research and provide unprecedented opportunities in the field of spintronics.
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Affiliation(s)
- Hui Li
- College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen, 518060, P. R. China
- Center for Advanced Material Diagnostic Technology, Shenzhen Technology University, Shenzhen, 518118, P. R. China
| | - Shuangchen Ruan
- College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen, 518060, P. R. China
| | - Yu-Jia Zeng
- College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen, 518060, P. R. China
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10
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Cai X, Song T, Wilson NP, Clark G, He M, Zhang X, Taniguchi T, Watanabe K, Yao W, Xiao D, McGuire MA, Cobden DH, Xu X. Atomically Thin CrCl 3: An In-Plane Layered Antiferromagnetic Insulator. NANO LETTERS 2019; 19:3993-3998. [PMID: 31083954 DOI: 10.1021/acs.nanolett.9b01317] [Citation(s) in RCA: 92] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
The recent discovery of magnetism in atomically thin layers of van der Waals (vdW) crystals has created new opportunities for exploring magnetic phenomena in the two-dimensional (2D) limit. In most 2D magnets studied to date, the c-axis is an easy axis, so that at zero applied field the polarization of each layer is perpendicular to the plane. Here, we demonstrate that atomically thin CrCl3 is a layered antiferromagnetic insulator with an easy-plane normal to the c-axis, that is, the polarization is in the plane of each layer and has no preferred direction within it. Ligand-field photoluminescence at 870 nm is observed down to the monolayer limit, demonstrating its insulating properties. We investigate the in-plane magnetic order using tunneling magnetoresistance in graphene/CrCl3/graphene tunnel junctions, establishing that the interlayer coupling is antiferromagnetic down to the bilayer. From the temperature dependence of the magnetoresistance, we obtain an effective magnetic phase diagram for the bilayer. Our result shows that CrCl3 should be useful for studying the physics of 2D phase transitions and for making new kinds of vdW spintronic devices.
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Affiliation(s)
- Xinghan Cai
- Department of Physics , University of Washington , Seattle , Washington 98195 , United States
- National Key Laboratory of Science and Technology on Micro/Nano Fabrication, Department of Micro/Nano Electronics , Shanghai Jiao Tong University , Shanghai 200240 , China
| | - Tiancheng Song
- Department of Physics , University of Washington , Seattle , Washington 98195 , United States
| | - Nathan P Wilson
- Department of Physics , University of Washington , Seattle , Washington 98195 , United States
| | - Genevieve Clark
- Department of Materials Science and Engineering , University of Washington , Seattle , Washington 98195 , United States
| | - Minhao He
- Department of Physics , University of Washington , Seattle , Washington 98195 , United States
| | - Xiaoou Zhang
- Department of Physics , Carnegie Mellon University , Pittsburgh , Pennsylvania 15213 , United States
| | - Takashi Taniguchi
- National Institute for Materials Science , Tsukuba , Ibaraki 305-0044 , Japan
| | - Kenji Watanabe
- National Institute for Materials Science , Tsukuba , Ibaraki 305-0044 , Japan
| | - Wang Yao
- Department of Physics and Center of Theoretical and Computational Physics , University of Hong Kong , Hong Kong , China
| | - Di Xiao
- Department of Physics , Carnegie Mellon University , Pittsburgh , Pennsylvania 15213 , United States
| | - Michael A McGuire
- Materials Science and Technology Division , Oak Ridge National Laboratory , Oak Ridge , Tennessee 37831 , United States
| | - David H Cobden
- Department of Physics , University of Washington , Seattle , Washington 98195 , United States
| | - Xiaodong Xu
- Department of Physics , University of Washington , Seattle , Washington 98195 , United States
- Department of Materials Science and Engineering , University of Washington , Seattle , Washington 98195 , United States
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11
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Kim HH, Yang B, Li S, Jiang S, Jin C, Tao Z, Nichols G, Sfigakis F, Zhong S, Li C, Tian S, Cory DG, Miao GX, Shan J, Mak KF, Lei H, Sun K, Zhao L, Tsen AW. Evolution of interlayer and intralayer magnetism in three atomically thin chromium trihalides. Proc Natl Acad Sci U S A 2019; 116:11131-11136. [PMID: 31110023 PMCID: PMC6561243 DOI: 10.1073/pnas.1902100116] [Citation(s) in RCA: 93] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
We conduct a comprehensive study of three different magnetic semiconductors, CrI3, CrBr3, and CrCl3, by incorporating both few-layer and bilayer samples in van der Waals tunnel junctions. We find that the interlayer magnetic ordering, exchange gap, magnetic anisotropy, and magnon excitations evolve systematically with changing halogen atom. By fitting to a spin wave theory that accounts for nearest-neighbor exchange interactions, we are able to further determine a simple spin Hamiltonian describing all three systems. These results extend the 2D magnetism platform to Ising, Heisenberg, and XY spin classes in a single material family. Using magneto-optical measurements, we additionally demonstrate that ferromagnetism can be stabilized down to monolayer in more isotropic CrBr3, with transition temperature still close to that of the bulk.
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Affiliation(s)
- Hyun Ho Kim
- Institute for Quantum Computing, University of Waterloo, Waterloo, ON N2L 3G1, Canada
- Department of Chemistry, University of Waterloo, Waterloo, ON N2L 3G1, Canada
| | - Bowen Yang
- Institute for Quantum Computing, University of Waterloo, Waterloo, ON N2L 3G1, Canada
- Department of Physics and Astronomy, University of Waterloo, Waterloo, ON N2L 3G1, Canada
| | - Siwen Li
- Department of Physics, University of Michigan, Ann Arbor, MI 48109
| | - Shengwei Jiang
- School of Applied and Engineering Physics, Cornell University, Ithaca, NY 14853
- Department of Physics, Cornell University, Ithaca, NY 14853
- Kavli Institute at Cornell for Nanoscale Science, Cornell University, Ithaca, NY 14853
| | - Chenhao Jin
- School of Applied and Engineering Physics, Cornell University, Ithaca, NY 14853
- Department of Physics, Cornell University, Ithaca, NY 14853
- Kavli Institute at Cornell for Nanoscale Science, Cornell University, Ithaca, NY 14853
| | - Zui Tao
- School of Applied and Engineering Physics, Cornell University, Ithaca, NY 14853
- Department of Physics, Cornell University, Ithaca, NY 14853
- Kavli Institute at Cornell for Nanoscale Science, Cornell University, Ithaca, NY 14853
| | - George Nichols
- Institute for Quantum Computing, University of Waterloo, Waterloo, ON N2L 3G1, Canada
- Department of Physics and Astronomy, University of Waterloo, Waterloo, ON N2L 3G1, Canada
| | - Francois Sfigakis
- Institute for Quantum Computing, University of Waterloo, Waterloo, ON N2L 3G1, Canada
- Department of Chemistry, University of Waterloo, Waterloo, ON N2L 3G1, Canada
| | - Shazhou Zhong
- Institute for Quantum Computing, University of Waterloo, Waterloo, ON N2L 3G1, Canada
- Department of Physics and Astronomy, University of Waterloo, Waterloo, ON N2L 3G1, Canada
| | - Chenghe Li
- Department of Physics, Renmin University of China, 100872 Beijing, China
- Beijing Key Laboratory of Opto-electronic Functional Materials & Micro-Nano Devices, Renmin University of China, 100872 Beijing, China
| | - Shangjie Tian
- Department of Physics, Renmin University of China, 100872 Beijing, China
- Beijing Key Laboratory of Opto-electronic Functional Materials & Micro-Nano Devices, Renmin University of China, 100872 Beijing, China
| | - David G Cory
- Institute for Quantum Computing, University of Waterloo, Waterloo, ON N2L 3G1, Canada
- Department of Chemistry, University of Waterloo, Waterloo, ON N2L 3G1, Canada
| | - Guo-Xing Miao
- Institute for Quantum Computing, University of Waterloo, Waterloo, ON N2L 3G1, Canada
- Department of Electrical and Computer Engineering, University of Waterloo, Waterloo, ON N2L 3G1, Canada
| | - Jie Shan
- School of Applied and Engineering Physics, Cornell University, Ithaca, NY 14853
- Department of Physics, Cornell University, Ithaca, NY 14853
- Kavli Institute at Cornell for Nanoscale Science, Cornell University, Ithaca, NY 14853
| | - Kin Fai Mak
- School of Applied and Engineering Physics, Cornell University, Ithaca, NY 14853
- Department of Physics, Cornell University, Ithaca, NY 14853
- Kavli Institute at Cornell for Nanoscale Science, Cornell University, Ithaca, NY 14853
| | - Hechang Lei
- Department of Physics, Renmin University of China, 100872 Beijing, China
- Beijing Key Laboratory of Opto-electronic Functional Materials & Micro-Nano Devices, Renmin University of China, 100872 Beijing, China
| | - Kai Sun
- Department of Physics, University of Michigan, Ann Arbor, MI 48109
| | - Liuyan Zhao
- Department of Physics, University of Michigan, Ann Arbor, MI 48109
| | - Adam W Tsen
- Institute for Quantum Computing, University of Waterloo, Waterloo, ON N2L 3G1, Canada;
- Department of Chemistry, University of Waterloo, Waterloo, ON N2L 3G1, Canada
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12
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Gong C, Zhang X. Two-dimensional magnetic crystals and emergent heterostructure devices. Science 2019; 363:363/6428/eaav4450. [DOI: 10.1126/science.aav4450] [Citation(s) in RCA: 683] [Impact Index Per Article: 136.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Magnetism, originating from the moving charges and spin of elementary particles, has revolutionized important technologies such as data storage and biomedical imaging, and continues to bring forth new phenomena in emergent materials and reduced dimensions. The recently discovered two-dimensional (2D) magnetic van der Waals crystals provide ideal platforms for understanding 2D magnetism, the control of which has been fueling opportunities for atomically thin, flexible magneto-optic and magnetoelectric devices (such as magnetoresistive memories and spin field-effect transistors). The seamless integration of 2D magnets with dissimilar electronic and photonic materials opens up exciting possibilities for unprecedented properties and functionalities. We review the progress in this area and identify the possible directions for device applications, which may lead to advances in spintronics, sensors, and computing.
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13
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Song T, Tu MWY, Carnahan C, Cai X, Taniguchi T, Watanabe K, McGuire MA, Cobden DH, Xiao D, Yao W, Xu X. Voltage Control of a van der Waals Spin-Filter Magnetic Tunnel Junction. NANO LETTERS 2019; 19:915-920. [PMID: 30620202 DOI: 10.1021/acs.nanolett.8b04160] [Citation(s) in RCA: 52] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Atomically thin chromium triiodide (CrI3) has recently been identified as a layered antiferromagnetic insulator, in which adjacent ferromagnetic monolayers are antiferromagnetically coupled. This unusual magnetic structure naturally comprises a series of antialigned spin filters, which can be utilized to make spin-filter magnetic tunnel junctions with very large tunneling magnetoresistance (TMR). Here we report voltage control of TMR formed by four-layer CrI3 sandwiched by monolayer graphene contacts in a dual-gated structure. By varying the gate voltages at fixed magnetic field, the device can be switched reversibly between bistable magnetic states with the same net magnetization but drastically different resistance (by a factor of 10 or more). In addition, without switching the state, the TMR can be continuously modulated between 17,000% and 57,000%, due to the combination of spin-dependent tunnel barrier with changing carrier distributions in the graphene contacts. Our work demonstrates new kinds of magnetically moderated transistor action and opens up possibilities for voltage-controlled van der Waals spintronic devices.
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Affiliation(s)
- Tiancheng Song
- Department of Physics , University of Washington , Seattle , Washington 98195 , United States
| | - Matisse Wei-Yuan Tu
- Department of Physics and Center of Theoretical and Computational Physics , University of Hong Kong , Hong Kong , China
| | - Caitlin Carnahan
- Department of Physics , Carnegie Mellon University , Pittsburgh , Pennsylvania 15213 , United States
| | - Xinghan Cai
- Department of Physics , University of Washington , Seattle , Washington 98195 , United States
| | - Takashi Taniguchi
- National Institute for Materials Science , Tsukuba , Ibaraki 305-0044 , Japan
| | - Kenji Watanabe
- National Institute for Materials Science , Tsukuba , Ibaraki 305-0044 , Japan
| | - Michael A McGuire
- Materials Science and Technology Division , Oak Ridge National Laboratory , Oak Ridge , Tennessee 37831 , United States
| | - David H Cobden
- Department of Physics , University of Washington , Seattle , Washington 98195 , United States
| | - Di Xiao
- Department of Physics , Carnegie Mellon University , Pittsburgh , Pennsylvania 15213 , United States
| | - Wang Yao
- Department of Physics and Center of Theoretical and Computational Physics , University of Hong Kong , Hong Kong , China
| | - Xiaodong Xu
- Department of Physics , University of Washington , Seattle , Washington 98195 , United States
- Department of Materials Science and Engineering , University of Washington , Seattle , Washington 98195 , United States
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14
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Burch KS, Mandrus D, Park JG. Magnetism in two-dimensional van der Waals materials. Nature 2018; 563:47-52. [DOI: 10.1038/s41586-018-0631-z] [Citation(s) in RCA: 664] [Impact Index Per Article: 110.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2018] [Accepted: 08/20/2018] [Indexed: 11/09/2022]
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15
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Cardoso C, Soriano D, García-Martínez NA, Fernández-Rossier J. Van der Waals Spin Valves. PHYSICAL REVIEW LETTERS 2018; 121:067701. [PMID: 30141640 DOI: 10.1103/physrevlett.121.067701] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2018] [Indexed: 05/22/2023]
Abstract
We propose spin valves where a 2D nonmagnetic conductor is intercalated between two ferromagnetic insulating layers. In this setup, the relative orientation of the magnetizations of the insulating layers can have a strong impact on the in-plane conductivity of the 2D conductor. We first show this for a graphene bilayer, described with a tight-binding model, placed between two ferromagnetic insulators. In the antiparallel configuration, a band gap opens at the Dirac point, whereas in the parallel configuration, the graphene bilayer remains conducting. We then compute the electronic structure of graphene bilayer placed between two monolayers of the ferromagnetic insulator CrI_{3}, using density functional theory. Consistent with the model, we find that a gap opens at the Dirac point only in the antiparallel configuration.
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Affiliation(s)
- C Cardoso
- QuantaLab, International Iberian Nanotechnology Laboratory (INL), Avenida Mestre José Veiga, 4715-330 Braga, Portugal
| | - D Soriano
- QuantaLab, International Iberian Nanotechnology Laboratory (INL), Avenida Mestre José Veiga, 4715-330 Braga, Portugal
| | - N A García-Martínez
- QuantaLab, International Iberian Nanotechnology Laboratory (INL), Avenida Mestre José Veiga, 4715-330 Braga, Portugal
| | - J Fernández-Rossier
- QuantaLab, International Iberian Nanotechnology Laboratory (INL), Avenida Mestre José Veiga, 4715-330 Braga, Portugal
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16
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Kim HH, Yang B, Patel T, Sfigakis F, Li C, Tian S, Lei H, Tsen AW. One Million Percent Tunnel Magnetoresistance in a Magnetic van der Waals Heterostructure. NANO LETTERS 2018; 18:4885-4890. [PMID: 30001134 DOI: 10.1021/acs.nanolett.8b01552] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
We report the observation of a very large negative magnetoresistance effect in a van der Waals tunnel junction incorporating a thin magnetic semiconductor, CrI3, as the active layer. At constant voltage bias, current increases by nearly one million percent upon application of a 2 T field. The effect arises from a change between antiparallel to parallel alignment of spins across the different CrI3 layers. Our results elucidate the nature of the magnetic state in ultrathin CrI3 and present new opportunities for spintronics based on two-dimensional materials.
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Affiliation(s)
- Hyun Ho Kim
- Institute for Quantum Computing , University of Waterloo , Waterloo , Ontario N2L 3G1 , Canada
- Department of Chemistry , University of Waterloo , Waterloo , Ontario N2L 3G1 , Canada
| | - Bowen Yang
- Institute for Quantum Computing , University of Waterloo , Waterloo , Ontario N2L 3G1 , Canada
- Department of Physics and Astronomy , University of Waterloo , Waterloo , Ontario N2L 3G1 , Canada
| | - Tarun Patel
- Institute for Quantum Computing , University of Waterloo , Waterloo , Ontario N2L 3G1 , Canada
- Department of Physics and Astronomy , University of Waterloo , Waterloo , Ontario N2L 3G1 , Canada
| | - Francois Sfigakis
- Institute for Quantum Computing , University of Waterloo , Waterloo , Ontario N2L 3G1 , Canada
- Department of Chemistry , University of Waterloo , Waterloo , Ontario N2L 3G1 , Canada
| | - Chenghe Li
- Department of Physics and Beijing Key Laboratory of Optoelectronic Functional Materials & Micro-Nano Devices , Renmin University of China , Beijing 100872 , China
| | - Shangjie Tian
- Department of Physics and Beijing Key Laboratory of Optoelectronic Functional Materials & Micro-Nano Devices , Renmin University of China , Beijing 100872 , China
| | - Hechang Lei
- Department of Physics and Beijing Key Laboratory of Optoelectronic Functional Materials & Micro-Nano Devices , Renmin University of China , Beijing 100872 , China
| | - Adam W Tsen
- Institute for Quantum Computing , University of Waterloo , Waterloo , Ontario N2L 3G1 , Canada
- Department of Chemistry , University of Waterloo , Waterloo , Ontario N2L 3G1 , Canada
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17
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Wang Z, Gutiérrez-Lezama I, Ubrig N, Kroner M, Gibertini M, Taniguchi T, Watanabe K, Imamoğlu A, Giannini E, Morpurgo AF. Very large tunneling magnetoresistance in layered magnetic semiconductor CrI 3. Nat Commun 2018; 9:2516. [PMID: 29955066 PMCID: PMC6023911 DOI: 10.1038/s41467-018-04953-8] [Citation(s) in RCA: 201] [Impact Index Per Article: 33.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2018] [Accepted: 06/05/2018] [Indexed: 11/30/2022] Open
Abstract
Magnetic layered van der Waals crystals are an emerging class of materials giving access to new physical phenomena, as illustrated by the recent observation of 2D ferromagnetism in Cr2Ge2Te6 and CrI3. Of particular interest in semiconductors is the interplay between magnetism and transport, which has remained unexplored. Here we report magneto-transport measurements on exfoliated CrI3 crystals. We find that tunneling conduction in the direction perpendicular to the crystalline planes exhibits a magnetoresistance as large as 10,000%. The evolution of the magnetoresistance with magnetic field and temperature reveals that the phenomenon originates from multiple transitions to different magnetic states, whose possible microscopic nature is discussed on the basis of all existing experimental observations. This observed dependence of the conductance of a tunnel barrier on its magnetic state is a phenomenon that demonstrates the presence of a strong coupling between transport and magnetism in magnetic van der Waals semiconductors.
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Affiliation(s)
- Zhe Wang
- Department of Quantum Matter Physics, University of Geneva, 24 Quai Ernest Ansermet, CH-1211, Geneva, Switzerland.
- Group of Applied Physics, University of Geneva, 24 Quai Ernest Ansermet, CH-1211, Geneva, Switzerland.
| | - Ignacio Gutiérrez-Lezama
- Department of Quantum Matter Physics, University of Geneva, 24 Quai Ernest Ansermet, CH-1211, Geneva, Switzerland
- Group of Applied Physics, University of Geneva, 24 Quai Ernest Ansermet, CH-1211, Geneva, Switzerland
| | - Nicolas Ubrig
- Department of Quantum Matter Physics, University of Geneva, 24 Quai Ernest Ansermet, CH-1211, Geneva, Switzerland
- Group of Applied Physics, University of Geneva, 24 Quai Ernest Ansermet, CH-1211, Geneva, Switzerland
| | - Martin Kroner
- Institute of Quantum Electronics, ETH Zürich, CH-8093, Zürich, Switzerland
| | - Marco Gibertini
- Department of Quantum Matter Physics, University of Geneva, 24 Quai Ernest Ansermet, CH-1211, Geneva, Switzerland
- Group of Applied Physics, University of Geneva, 24 Quai Ernest Ansermet, CH-1211, Geneva, Switzerland
| | - 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
| | - Ataç Imamoğlu
- Institute of Quantum Electronics, ETH Zürich, CH-8093, Zürich, Switzerland
| | - Enrico Giannini
- Department of Quantum Matter Physics, University of Geneva, 24 Quai Ernest Ansermet, CH-1211, Geneva, Switzerland
| | - Alberto F Morpurgo
- Department of Quantum Matter Physics, University of Geneva, 24 Quai Ernest Ansermet, CH-1211, Geneva, Switzerland.
- Group of Applied Physics, University of Geneva, 24 Quai Ernest Ansermet, CH-1211, Geneva, Switzerland.
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18
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Klein DR, MacNeill D, Lado JL, Soriano D, Navarro-Moratalla E, Watanabe K, Taniguchi T, Manni S, Canfield P, Fernández-Rossier J, Jarillo-Herrero P. Probing magnetism in 2D van der Waals crystalline insulators via electron tunneling. Science 2018; 360:1218-1222. [DOI: 10.1126/science.aar3617] [Citation(s) in RCA: 508] [Impact Index Per Article: 84.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2017] [Accepted: 04/24/2018] [Indexed: 12/14/2022]
Abstract
Magnetic insulators are a key resource for next-generation spintronic and topological devices. The family of layered metal halides promises varied magnetic states, including ultrathin insulating multiferroics, spin liquids, and ferromagnets, but device-oriented characterization methods are needed to unlock their potential. Here, we report tunneling through the layered magnetic insulator CrI3 as a function of temperature and applied magnetic field. We electrically detect the magnetic ground state and interlayer coupling and observe a field-induced metamagnetic transition. The metamagnetic transition results in magnetoresistances of 95, 300, and 550% for bilayer, trilayer, and tetralayer CrI3 barriers, respectively. We further measure inelastic tunneling spectra for our junctions, unveiling a rich spectrum consistent with collective magnetic excitations (magnons) in CrI3.
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19
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Song T, Cai X, Tu MWY, Zhang X, Huang B, Wilson NP, Seyler KL, Zhu L, Taniguchi T, Watanabe K, McGuire MA, Cobden DH, Xiao D, Yao W, Xu X. Giant tunneling magnetoresistance in spin-filter van der Waals heterostructures. Science 2018; 360:1214-1218. [DOI: 10.1126/science.aar4851] [Citation(s) in RCA: 648] [Impact Index Per Article: 108.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2017] [Accepted: 04/24/2018] [Indexed: 01/19/2023]
Abstract
Magnetic multilayer devices that exploit magnetoresistance are the backbone of magnetic sensing and data storage technologies. Here, we report multiple-spin-filter magnetic tunnel junctions (sf-MTJs) based on van der Waals (vdW) heterostructures in which atomically thin chromium triiodide (CrI3) acts as a spin-filter tunnel barrier sandwiched between graphene contacts. We demonstrate tunneling magnetoresistance that is drastically enhanced with increasing CrI3 layer thickness, reaching a record 19,000% for magnetic multilayer structures using four-layer sf-MTJs at low temperatures. Using magnetic circular dichroism measurements, we attribute these effects to the intrinsic layer-by-layer antiferromagnetic ordering of the atomically thin CrI3. Our work reveals the possibility to push magnetic information storage to the atomically thin limit and highlights CrI3 as a superlative magnetic tunnel barrier for vdW heterostructure spintronic devices.
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20
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Zhou X, Zhang KHL, Xiong J, Park JH, Dickerson JH, He W. Size- and dimensionality-dependent optical, magnetic and magneto-optical properties of binary europium-based nanocrystals: EuX (X = O, S, Se, Te). NANOTECHNOLOGY 2016; 27:192001. [PMID: 27023644 DOI: 10.1088/0957-4484/27/19/192001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Europium chalcogenides (EuX, X = O, S, Se, Te), a class of prototypical Heisenberg magnetic semiconductors, exhibit intriguing properties in optics, magnetism, and magneto-optics at the nanoscale, and have broad application potential in optical/magnetic sensors, spintronics, optical isolators, etc. EuX nanocrystals (NCs) exhibit enhanced properties, such as high saturation magnetization, a strong magneto-optic effect (Faraday rotation), and high magneto resistance, which are all unanimously dependent on the NC's size, shape, and surface information. In this report, we give an overview of the fundamental properties of bulk EuX, and illustrate the quantum confinement effects on the optical, magnetic and magneto-optical properties of EuX nanostructures. We then focus on doping and self-assembly-two efficient methods that enhance magnetic properties by manipulating magnetic coupling in EuX nanostructures. In particular, we look towards future research on Eu(2+) NCs, which along with the overview provides an up-to-date platform for evaluating the fundamental properties and application potential of Eu-based semiconductors.
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Affiliation(s)
- Xingzhi Zhou
- School of Energy Science and Engineering, University of Electronic Science and Technology of China, Chengdu, Sichuan 611731, People's Republic of China
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21
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Interface Engineering to Create a Strong Spin Filter Contact to Silicon. Sci Rep 2016; 6:22912. [PMID: 26975515 PMCID: PMC4791633 DOI: 10.1038/srep22912] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2015] [Accepted: 02/24/2016] [Indexed: 11/08/2022] Open
Abstract
Integrating epitaxial and ferromagnetic Europium Oxide (EuO) directly on silicon is a perfect route to enrich silicon nanotechnology with spin filter functionality. To date, the inherent chemical reactivity between EuO and Si has prevented a heteroepitaxial integration without significant contaminations of the interface with Eu silicides and Si oxides. We present a solution to this long-standing problem by applying two complementary passivation techniques for the reactive EuO/Si interface: (i) an in situ hydrogen-Si (001) passivation and (ii) the application of oxygen-protective Eu monolayers-without using any additional buffer layers. By careful chemical depth profiling of the oxide-semiconductor interface via hard x-ray photoemission spectroscopy, we show how to systematically minimize both Eu silicide and Si oxide formation to the sub-monolayer regime-and how to ultimately interface-engineer chemically clean, heteroepitaxial and ferromagnetic EuO/Si (001) in order to create a strong spin filter contact to silicon.
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22
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Tang YH, Chu FC, Kioussis N. Dual Control of Giant Field-like Spin Torque in Spin Filter Tunnel Junctions. Sci Rep 2015; 5:11341. [PMID: 26095146 PMCID: PMC4476168 DOI: 10.1038/srep11341] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2015] [Accepted: 05/20/2015] [Indexed: 11/28/2022] Open
Abstract
We predict a giant field-like spin torque, , in spin-filter (SF) barrier tunnel junctions in sharp contrast to existing junctions based on nonmagnetic passive barriers. We demonstrate that has linear bias behavior, is independent of the SF thickness, and has odd parity with respect to the SF’s exchange splitting. Thus, it can be selectively controlled via external bias or external magnetic field which gives rise to sign reversal of via magnetic field switching. The underlying mechanism is the interlayer exchange coupling between the noncollinear magnetizations of the SF and free ferromagnetic electrode via the nonmagnetic insulating (I) spacer giving rise to giant spin-dependent reflection at the SF/I interface. These findings suggest that the proposed field-like-spin-torque MRAM may provide promising dual functionalities for both ‘reading’ and ‘writing’ processes which require lower critical current densities and faster writing and reading speeds.
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Affiliation(s)
- Y-H Tang
- Department of Physics, National Central University, Jung-Li 32001, Taiwan
| | - F-C Chu
- Department of Physics, National Central University, Jung-Li 32001, Taiwan
| | - Nicholas Kioussis
- Department of Physics, California State University, Northridge, CA 91330-8268, USA
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Boncher W, Dalafu H, Rosa N, Stoll S. Europium chalcogenide magnetic semiconductor nanostructures. Coord Chem Rev 2015. [DOI: 10.1016/j.ccr.2014.12.008] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Bruno FY, Grisolia MN, Visani C, Valencia S, Varela M, Abrudan R, Tornos J, Rivera-Calzada A, Ünal AA, Pennycook SJ, Sefrioui Z, Leon C, Villegas JE, Santamaria J, Barthélémy A, Bibes M. Insight into spin transport in oxide heterostructures from interface-resolved magnetic mapping. Nat Commun 2015; 6:6306. [PMID: 25686532 DOI: 10.1038/ncomms7306] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2014] [Accepted: 01/15/2015] [Indexed: 11/09/2022] Open
Abstract
At interfaces between complex oxides, electronic, orbital and magnetic reconstructions may produce states of matter absent from the materials involved, offering novel possibilities for electronic and spintronic devices. Here we show that magnetic reconstruction has a strong influence on the interfacial spin selectivity, a key parameter controlling spin transport in magnetic tunnel junctions. In epitaxial heterostructures combining layers of antiferromagnetic LaFeO(3) (LFO) and ferromagnetic La(0.7)Sr(0.3)MnO(3) (LSMO), we find that a net magnetic moment is induced in the first few unit planes of LFO near the interface with LSMO. Using X-ray photoemission electron microscopy, we show that the ferromagnetic domain structure of the manganite electrodes is imprinted into the antiferromagnetic tunnel barrier, endowing it with spin selectivity. Finally, we find that the spin arrangement resulting from coexisting ferromagnetic and antiferromagnetic interactions strongly influences the tunnel magnetoresistance of LSMO/LFO/LSMO junctions through competing spin-polarization and spin-filtering effects.
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Affiliation(s)
- F Y Bruno
- Unité Mixte de Physique CNRS/Thales, 1 Avenue A. Fresnel, 91767 Palaiseau, France and Université Paris-Sud, 91405 Orsay, France
| | - M N Grisolia
- Unité Mixte de Physique CNRS/Thales, 1 Avenue A. Fresnel, 91767 Palaiseau, France and Université Paris-Sud, 91405 Orsay, France
| | - C Visani
- Unité Mixte de Physique CNRS/Thales, 1 Avenue A. Fresnel, 91767 Palaiseau, France and Université Paris-Sud, 91405 Orsay, France
| | - S Valencia
- Helmholtz-Zentrum-Berlin für Materialen und Energie, Albert-Einstein-Strasse 15, 12489 Berlin, Germany
| | - M Varela
- 1] GFMC, Departamento Física Aplicada III, Universidad Complutense Madrid, 28040 Madrid, Spain [2] Laboratorio de Heteroestructuras con aplicación en Spintronica, Unidad Asociada CSIC/Universidad Complutense de Madrid, Sor Juana Inés de la Cruz, 3, 28049 Madrid, Spain [3] Materials Science &Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - R Abrudan
- 1] Helmholtz-Zentrum-Berlin für Materialen und Energie, Albert-Einstein-Strasse 15, 12489 Berlin, Germany [2] Institut für Experimentalphysik/Festkörperphysik, Ruhr-Universität Bochum, 44780 Bochum, Germany
| | - J Tornos
- 1] GFMC, Departamento Física Aplicada III, Universidad Complutense Madrid, 28040 Madrid, Spain [2] Laboratorio de Heteroestructuras con aplicación en Spintronica, Unidad Asociada CSIC/Universidad Complutense de Madrid, Sor Juana Inés de la Cruz, 3, 28049 Madrid, Spain
| | - A Rivera-Calzada
- 1] GFMC, Departamento Física Aplicada III, Universidad Complutense Madrid, 28040 Madrid, Spain [2] Laboratorio de Heteroestructuras con aplicación en Spintronica, Unidad Asociada CSIC/Universidad Complutense de Madrid, Sor Juana Inés de la Cruz, 3, 28049 Madrid, Spain
| | - A A Ünal
- Helmholtz-Zentrum-Berlin für Materialen und Energie, Albert-Einstein-Strasse 15, 12489 Berlin, Germany
| | - S J Pennycook
- Department of Materials Science and Engineering, The University of Tennessee, Knoxville, Tennessee 37996, USA
| | - Z Sefrioui
- 1] GFMC, Departamento Física Aplicada III, Universidad Complutense Madrid, 28040 Madrid, Spain [2] Laboratorio de Heteroestructuras con aplicación en Spintronica, Unidad Asociada CSIC/Universidad Complutense de Madrid, Sor Juana Inés de la Cruz, 3, 28049 Madrid, Spain
| | - C Leon
- 1] GFMC, Departamento Física Aplicada III, Universidad Complutense Madrid, 28040 Madrid, Spain [2] Laboratorio de Heteroestructuras con aplicación en Spintronica, Unidad Asociada CSIC/Universidad Complutense de Madrid, Sor Juana Inés de la Cruz, 3, 28049 Madrid, Spain
| | - J E Villegas
- Unité Mixte de Physique CNRS/Thales, 1 Avenue A. Fresnel, 91767 Palaiseau, France and Université Paris-Sud, 91405 Orsay, France
| | - J Santamaria
- 1] GFMC, Departamento Física Aplicada III, Universidad Complutense Madrid, 28040 Madrid, Spain [2] Laboratorio de Heteroestructuras con aplicación en Spintronica, Unidad Asociada CSIC/Universidad Complutense de Madrid, Sor Juana Inés de la Cruz, 3, 28049 Madrid, Spain
| | - A Barthélémy
- Unité Mixte de Physique CNRS/Thales, 1 Avenue A. Fresnel, 91767 Palaiseau, France and Université Paris-Sud, 91405 Orsay, France
| | - M Bibes
- Unité Mixte de Physique CNRS/Thales, 1 Avenue A. Fresnel, 91767 Palaiseau, France and Université Paris-Sud, 91405 Orsay, France
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Miao GX, Moodera JS. Spin manipulation with magnetic semiconductor barriers. Phys Chem Chem Phys 2015; 17:751-61. [DOI: 10.1039/c4cp04599h] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Magnetic semiconductors with unique spin-filtering property and the ability to create excessive internal magnetic fields can open myriads of new phenomena.
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Affiliation(s)
- Guo-Xing Miao
- Institute for Quantum
- Computing and Department of Electrical and Computer Engineering
- University of Waterloo
- Waterloo
- Canada
| | - Jagadeesh S. Moodera
- Francis Bitter Magnet Laboratory
- Massachusetts Institute of Technology
- Cambridge
- USA
- Department of Physics
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26
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Spin regulation in composite spin-filter barrier devices. Nat Commun 2014; 5:3682. [PMID: 24759596 DOI: 10.1038/ncomms4682] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2013] [Accepted: 03/18/2014] [Indexed: 11/09/2022] Open
Abstract
Magnetic insulators are known to provide large effective Zeeman fields that are confined at an interface, making them especially powerful in modifying adjacent one- or two-dimensional electronic structures. Utilizing this phenomenon and the other important property of magnetic insulators--spin filtering--here we report the generation and subsequent detection of a large interface field, as large as tens of tesla in EuS/Al/EuS heterostructures with metallic coulomb islands confined within a magnetic insulator barrier. The unique energy profile across this sandwich structure produces spin-assisted charge transfer across the device, generating a spontaneous spin current and voltage. These unique properties can be practical for controlling spin flows in electronic devices and for energy harvesting.
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Liu Y, Cuellar FA, Sefrioui Z, Freeland JW, Fitzsimmons MR, Leon C, Santamaria J, te Velthuis SGE. Emergent spin filter at the interface between ferromagnetic and insulating layered oxides. PHYSICAL REVIEW LETTERS 2013; 111:247203. [PMID: 24483696 DOI: 10.1103/physrevlett.111.247203] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2013] [Indexed: 06/03/2023]
Abstract
We report a strong effect of interface-induced magnetization on the transport properties of magnetic tunnel junctions consisting of ferromagnetic manganite La0.7Ca0.3MnO3 and insulating cuprate PrBa2Cu3O7. Contrary to the typically observed steady increase of the tunnel magnetoresistance with decreasing temperature, this system exhibits a sudden anomalous decrease at low temperatures. Interestingly, this anomalous behavior can be attributed to the competition between the positive spin polarization of the manganite contacts and the negative spin-filter effect from the interface-induced Cu magnetization.
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Affiliation(s)
- Yaohua Liu
- Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - F A Cuellar
- GFMC, Departamento de Fisica Aplicada III, Universidad Complutense de Madrid, Campus Moncloa, ES-28040 Madrid, Spain
| | - Z Sefrioui
- GFMC, Departamento de Fisica Aplicada III, Universidad Complutense de Madrid, Campus Moncloa, ES-28040 Madrid, Spain
| | - J W Freeland
- Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - M R Fitzsimmons
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - C Leon
- GFMC, Departamento de Fisica Aplicada III, Universidad Complutense de Madrid, Campus Moncloa, ES-28040 Madrid, Spain
| | - J Santamaria
- GFMC, Departamento de Fisica Aplicada III, Universidad Complutense de Madrid, Campus Moncloa, ES-28040 Madrid, Spain
| | - S G E te Velthuis
- Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439, USA
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28
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Pal A, Senapati K, Barber ZH, Blamire MG. Electric-field-dependent spin polarization in GdN spin filter tunnel junctions. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2013; 25:5581-5585. [PMID: 23893892 DOI: 10.1002/adma.201300636] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/06/2013] [Revised: 06/02/2013] [Indexed: 06/02/2023]
Abstract
Tunnel junctions incorporating GdN ferromagnetic semiconductor barriers show a spin polarization exceeding 90% and a high conductance. These devices show an unusual low-bias conductance peak arising from a strong bias-dependence of the spin polarization. This originates from a strong magneto-electric coupling within a double Schottky barrier formed with the NbN electrodes.
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Affiliation(s)
- Avradeep Pal
- Department of Materials Science and Metallurgy, University of Cambridge, Pembroke Street, Cambridge, CB2 3QZ, UK
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29
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Wei P, Katmis F, Assaf BA, Steinberg H, Jarillo-Herrero P, Heiman D, Moodera JS. Exchange-coupling-induced symmetry breaking in topological insulators. PHYSICAL REVIEW LETTERS 2013; 110:186807. [PMID: 23683236 DOI: 10.1103/physrevlett.110.186807] [Citation(s) in RCA: 90] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2012] [Indexed: 05/22/2023]
Abstract
An exchange gap in the Dirac surface states of a topological insulator (TI) is necessary for observing the predicted unique features such as the topological magnetoelectric effect as well as to confine Majorana fermions. We experimentally demonstrate proximity-induced ferromagnetism in a TI, combining a ferromagnetic insulator EuS layer with Bi(2)Se(3), without introducing defects. By magnetic and magnetotransport studies, including anomalous Hall effect and magnetoresistance measurements, we show the emergence of a ferromagnetic phase in TI, a step forward in unveiling their exotic properties.
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Affiliation(s)
- Peng Wei
- Francis Bitter Magnet Lab, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
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Harada T, Ohkubo I, Lippmaa M, Sakurai Y, Matsumoto Y, Muto S, Koinuma H, Oshima M. Spin-filter tunnel junction with matched fermi surfaces. PHYSICAL REVIEW LETTERS 2012; 109:076602. [PMID: 23006390 DOI: 10.1103/physrevlett.109.076602] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2012] [Indexed: 06/01/2023]
Abstract
Efficient injection of spin-polarized current into a semiconductor is a basic prerequisite for building semiconductor-based spintronic devices. Here, we use inelastic electron tunneling spectroscopy to show that the efficiency of spin-filter-type spin injectors is limited by spin scattering of the tunneling electrons. By matching the Fermi-surface shapes of the current injection source and target electrode material, spin injection efficiency can be significantly increased in epitaxial ferromagnetic insulator tunnel junctions. Our results demonstrate that not only structural but also Fermi-surface matching is important to suppress scattering processes in spintronic devices.
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Affiliation(s)
- T Harada
- Department of Applied Chemistry, The University of Tokyo, Hongo, Bunkyo-ku, Japan
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31
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Using Spatial Structure Analysis of Hyperspectral Imaging Data and Fourier Transformed Infrared Analysis to Determine Bioactivity of Surface Pesticide Treatment. REMOTE SENSING 2010. [DOI: 10.3390/rs2040908] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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32
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Kaminski B, Lafrentz M, Pisarev RV, Yakovlev DR, Pavlov VV, Lukoshkin VA, Henriques AB, Springholz G, Bauer G, Abramof E, Rappl PHO, Bayer M. Spin-induced optical second harmonic generation in the centrosymmetric magnetic semiconductors EuTe and EuSe. PHYSICAL REVIEW LETTERS 2009; 103:057203. [PMID: 19792530 DOI: 10.1103/physrevlett.103.057203] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2009] [Indexed: 05/28/2023]
Abstract
Spectroscopy of the centrosymmetric magnetic semiconductors EuTe and EuSe reveals spin-induced optical second harmonic generation (SHG) in the band gap vicinity at 2.1-2.4 eV. The magnetic field and temperature dependence demonstrates that the SHG arises from the bulk of the materials due to a novel type of nonlinear optical susceptibility caused by the magnetic dipole contribution combined with spontaneous or induced magnetization. This spin-induced susceptibility opens access to a wide class of centrosymmetric systems by harmonics generation spectroscopy.
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Affiliation(s)
- B Kaminski
- Experimentelle Physik 2, Technische Universität Dortmund, D-44221 Dortmund, Germany
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