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Yang H, Martín-García B, Kimák J, Schmoranzerová E, Dolan E, Chi Z, Gobbi M, Němec P, Hueso LE, Casanova F. Twist-angle-tunable spin texture in WSe 2/graphene van der Waals heterostructures. NATURE MATERIALS 2024:10.1038/s41563-024-01985-y. [PMID: 39191981 DOI: 10.1038/s41563-024-01985-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2023] [Accepted: 07/30/2024] [Indexed: 08/29/2024]
Abstract
Twist engineering has emerged as a powerful approach for modulating electronic properties in van der Waals heterostructures. While theoretical works have predicted the modulation of spin texture in graphene-based heterostructures by twist angle, experimental studies are lacking. Here, by performing spin precession experiments, we demonstrate tunability of the spin texture and associated spin-charge interconversion with twist angle in WSe2/graphene heterostructures. For specific twist angles, we detect a spin component radial with the electron's momentum, in addition to the standard orthogonal component. Our results show that the helicity of the spin texture can be reversed by twist angle, highlighting the critical role of the twist angle in the spin-orbit properties of WSe2/graphene heterostructures and paving the way for the development of spin-twistronic devices.
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Affiliation(s)
- Haozhe Yang
- CIC nanoGUNE BRTA, Donostia-San Sebastian, Spain.
- Fert Beijing Institute, MIIT Key Laboratory of Spintronics, School of Integrated Circuit Science and Engineering, Beihang University, Beijing, China.
| | - Beatriz Martín-García
- CIC nanoGUNE BRTA, Donostia-San Sebastian, Spain
- IKERBASQUE, Basque Foundation for Science, Bilbao, Spain
| | - Jozef Kimák
- Faculty of Mathematics and Physics, Charles University, Prague, Czech Republic
| | - Eva Schmoranzerová
- Faculty of Mathematics and Physics, Charles University, Prague, Czech Republic
| | - Eoin Dolan
- CIC nanoGUNE BRTA, Donostia-San Sebastian, Spain
| | - Zhendong Chi
- CIC nanoGUNE BRTA, Donostia-San Sebastian, Spain
| | - Marco Gobbi
- IKERBASQUE, Basque Foundation for Science, Bilbao, Spain
- Centro de Física de Materiales and Materials Physics Center, Donostia-San Sebastian, Spain
| | - Petr Němec
- Faculty of Mathematics and Physics, Charles University, Prague, Czech Republic
| | - Luis E Hueso
- CIC nanoGUNE BRTA, Donostia-San Sebastian, Spain
- IKERBASQUE, Basque Foundation for Science, Bilbao, Spain
| | - Fèlix Casanova
- CIC nanoGUNE BRTA, Donostia-San Sebastian, Spain.
- IKERBASQUE, Basque Foundation for Science, Bilbao, Spain.
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2
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Muñiz Cano B, Gudín A, Sánchez-Barriga J, Clark O, Anadón A, Díez JM, Olleros-Rodríguez P, Ajejas F, Arnay I, Jugovac M, Rault J, Le Fèvre P, Bertran F, Mazhjoo D, Bihlmayer G, Rader O, Blügel S, Miranda R, Camarero J, Valbuena MA, Perna P. Rashba-like Spin Textures in Graphene Promoted by Ferromagnet-Mediated Electronic Hybridization with a Heavy Metal. ACS NANO 2024; 18:15716-15728. [PMID: 38847339 DOI: 10.1021/acsnano.4c02154] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/19/2024]
Abstract
Epitaxial graphene/ferromagnetic metal (Gr/FM) heterostructures deposited onto heavy metals have been proposed for the realization of spintronic devices because of their perpendicular magnetic anisotropy and sizable Dzyaloshinskii-Moriya interaction (DMI), allowing for both enhanced thermal stability and stabilization of chiral spin textures. However, establishing routes toward this goal requires the fundamental understanding of the microscopic origin of their unusual properties. Here, we elucidate the nature of the induced spin-orbit coupling (SOC) at Gr/Co interfaces on Ir. Through spin- and angle-resolved photoemission spectroscopy along with density functional theory, we show that the interaction of the heavy metals with the Gr layer via hybridization with the FM is the source of strong SOC in the Gr layer. Furthermore, our studies on ultrathin Co films underneath Gr reveal an energy splitting of ∼100 meV for in-plane and negligible for out-of-plane spin polarized Gr π-bands, consistent with a Rashba-SOC at the Gr/Co interface, which is either the fingerprint or the origin of the DMI. This mechanism vanishes at large Co thicknesses, where neither in-plane nor out-of-plane spin-orbit splitting is observed, indicating that Gr π-states are electronically decoupled from the heavy metal. The present findings are important for future applications of Gr-based heterostructures in spintronic devices.
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Affiliation(s)
- Beatriz Muñiz Cano
- IMDEA Nanoscience, C/Faraday 9, Campus de Cantoblanco, 28049 Madrid, Spain
| | - Adrián Gudín
- IMDEA Nanoscience, C/Faraday 9, Campus de Cantoblanco, 28049 Madrid, Spain
- Departamento de Física de la Materia Condensada, Instituto Nicolás Cabrera and Condensed Matter Physics Center (IFIMAC), Universidad Autónoma de Madrid, Campus de Cantoblanco, 28049 Madrid, Spain
| | - Jaime Sánchez-Barriga
- IMDEA Nanoscience, C/Faraday 9, Campus de Cantoblanco, 28049 Madrid, Spain
- Helmholtz-Zentrum Berlin für Materialien und Energie, Albert-Einstein-Street 15, 12489 Berlin, Germany
| | - Oliver Clark
- Helmholtz-Zentrum Berlin für Materialien und Energie, Albert-Einstein-Street 15, 12489 Berlin, Germany
| | - Alberto Anadón
- IMDEA Nanoscience, C/Faraday 9, Campus de Cantoblanco, 28049 Madrid, Spain
| | - Jose Manuel Díez
- IMDEA Nanoscience, C/Faraday 9, Campus de Cantoblanco, 28049 Madrid, Spain
- Departamento de Física de la Materia Condensada, Instituto Nicolás Cabrera and Condensed Matter Physics Center (IFIMAC), Universidad Autónoma de Madrid, Campus de Cantoblanco, 28049 Madrid, Spain
| | | | - Fernando Ajejas
- IMDEA Nanoscience, C/Faraday 9, Campus de Cantoblanco, 28049 Madrid, Spain
| | - Iciar Arnay
- IMDEA Nanoscience, C/Faraday 9, Campus de Cantoblanco, 28049 Madrid, Spain
| | - Matteo Jugovac
- Elettra Sincrotrone Trieste, Strada Statale 14 km 163.5, 34149 Trieste, Italy
| | - Julien Rault
- Synchrotron SOLEIL, Saint-Aubin, 91192 Gif-sur-Yvette, France
| | | | | | - Donya Mazhjoo
- Peter Grünberg Institute and Institute for Advanced Simulation, Forschungszentrum Jülich, D-52425 Jülich, Germany
| | - Gustav Bihlmayer
- Peter Grünberg Institute and Institute for Advanced Simulation, Forschungszentrum Jülich, D-52425 Jülich, Germany
| | - Oliver Rader
- Helmholtz-Zentrum Berlin für Materialien und Energie, Albert-Einstein-Street 15, 12489 Berlin, Germany
| | - Stefan Blügel
- Peter Grünberg Institute and Institute for Advanced Simulation, Forschungszentrum Jülich, D-52425 Jülich, Germany
| | - Rodolfo Miranda
- IMDEA Nanoscience, C/Faraday 9, Campus de Cantoblanco, 28049 Madrid, Spain
- Departamento de Física de la Materia Condensada, Instituto Nicolás Cabrera and Condensed Matter Physics Center (IFIMAC), Universidad Autónoma de Madrid, Campus de Cantoblanco, 28049 Madrid, Spain
| | - Julio Camarero
- IMDEA Nanoscience, C/Faraday 9, Campus de Cantoblanco, 28049 Madrid, Spain
- Departamento de Física de la Materia Condensada, Instituto Nicolás Cabrera and Condensed Matter Physics Center (IFIMAC), Universidad Autónoma de Madrid, Campus de Cantoblanco, 28049 Madrid, Spain
| | | | - Paolo Perna
- IMDEA Nanoscience, C/Faraday 9, Campus de Cantoblanco, 28049 Madrid, Spain
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3
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Luo Z, Yu Z, Lu X, Niu W, Yu Y, Yao Y, Tian F, Tan CL, Sun H, Gao L, Qin W, Xu Y, Zhao Q, Song XX. Van der Waals Magnetic Electrode Transfer for Two-Dimensional Spintronic Devices. NANO LETTERS 2024; 24:6183-6191. [PMID: 38728596 DOI: 10.1021/acs.nanolett.4c01885] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2024]
Abstract
Two-dimensional (2D) materials are promising candidates for spintronic applications. Maintaining their atomically smooth interfaces during integration of ferromagnetic (FM) electrodes is crucial since conventional metal deposition tends to induce defects at the interfaces. Meanwhile, the difficulties in picking up FM metals with strong adhesion and in achieving conductance match between FM electrodes and spin transport channels make it challenging to fabricate high-quality 2D spintronic devices using metal transfer techniques. Here, we report a solvent-free magnetic electrode transfer technique that employs a graphene layer to assist in the transfer of FM metals. It also serves as part of the FM electrode after transfer for optimizing spin injection, which enables the realization of spin valves with excellent performance based on various 2D materials. In addition to two-terminal devices, we demonstrate that the technique is applicable for four-terminal spin valves with nonlocal geometry. Our results provide a promising future of realizing 2D spintronic applications using the developed magnetic electrode transfer technique.
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Affiliation(s)
- Zhongzhong Luo
- College of Electronic and Optical Engineering & College of Flexible Electronics (Future Technology), State Key Laboratory of Organic Electronics and Information Displays, Nanjing University of Posts and Telecommunications, Nanjing 210023, China
- Guangdong Greater Bay Area Institute of Integrated Circuit and System, Guangzhou 510535, China
| | - Zhihao Yu
- Guangdong Greater Bay Area Institute of Integrated Circuit and System, Guangzhou 510535, China
- College of Integrated Circuit Science and Engineering, Nanjing University of Posts and Telecommunications, Nanjing 210023, China
| | - Xiangqian Lu
- School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, China
| | - Wei Niu
- School of Science, Nanjing University of Posts and Telecommunications, Nanjing 210023, China
| | - Yao Yu
- College of Integrated Circuit Science and Engineering, Nanjing University of Posts and Telecommunications, Nanjing 210023, China
| | - Yu Yao
- Institute of Advanced Materials, Nanjing University of Posts and Telecommunications, Nanjing 210023, China
| | - Fuguo Tian
- Institute of Advanced Materials, Nanjing University of Posts and Telecommunications, Nanjing 210023, China
| | - Chee Leong Tan
- College of Integrated Circuit Science and Engineering, Nanjing University of Posts and Telecommunications, Nanjing 210023, China
| | - Huabin Sun
- Guangdong Greater Bay Area Institute of Integrated Circuit and System, Guangzhou 510535, China
- College of Integrated Circuit Science and Engineering, Nanjing University of Posts and Telecommunications, Nanjing 210023, China
| | - Li Gao
- School of Science, Nanjing University of Posts and Telecommunications, Nanjing 210023, China
- Institute of Advanced Materials, Nanjing University of Posts and Telecommunications, Nanjing 210023, China
| | - Wei Qin
- School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, China
| | - Yong Xu
- Guangdong Greater Bay Area Institute of Integrated Circuit and System, Guangzhou 510535, China
- College of Integrated Circuit Science and Engineering, Nanjing University of Posts and Telecommunications, Nanjing 210023, China
| | - Qiang Zhao
- College of Electronic and Optical Engineering & College of Flexible Electronics (Future Technology), State Key Laboratory of Organic Electronics and Information Displays, Nanjing University of Posts and Telecommunications, Nanjing 210023, China
- Institute of Advanced Materials, Nanjing University of Posts and Telecommunications, Nanjing 210023, China
| | - Xiang-Xiang Song
- CAS Key Laboratory of Quantum Information, University of Science and Technology of China, Hefei 230026, China
- Suzhou Institute for Advanced Research, University of Science and Technology of China Suzhou 215123, China
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4
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Su S, Zhao J, Ly TH. Scanning Probe Microscopies for Characterizations of 2D Materials. SMALL METHODS 2024:e2400211. [PMID: 38766949 DOI: 10.1002/smtd.202400211] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2024] [Revised: 04/12/2024] [Indexed: 05/22/2024]
Abstract
2D materials are intriguing due to their remarkably thin and flat structure. This unique configuration allows the majority of their constituent atoms to be accessible on the surface, facilitating easier electron tunneling while generating weak surface forces. To decipher the subtle signals inherent in these materials, the application of techniques that offer atomic resolution (horizontal) and sub-Angstrom (z-height vertical) sensitivity is crucial. Scanning probe microscopy (SPM) emerges as the quintessential tool in this regard, owing to its atomic-level spatial precision, ability to detect unitary charges, responsiveness to pico-newton-scale forces, and capability to discern pico-ampere currents. Furthermore, the versatility of SPM to operate under varying environmental conditions, such as different temperatures and in the presence of various gases or liquids, opens up the possibility of studying the stability and reactivity of 2D materials in situ. The characteristic flatness, surface accessibility, ultra-thinness, and weak signal strengths of 2D materials align perfectly with the capabilities of SPM technologies, enabling researchers to uncover the nuanced behaviors and properties of these advanced materials at the nanoscale and even the atomic scale.
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Affiliation(s)
- Shaoqiang Su
- Department of Chemistry and Center of Super-Diamond & Advanced Films (COSDAF), City University of Hong Kong, Kowloon, 999077, China
| | - Jiong Zhao
- Department of Applied Physics, The Hong Kong Polytechnic University, Kowloon, Hong Kong, 999077, P. R. China
- The Hong Kong Polytechnic University Shenzhen Research Institute, Shenzhen, 518057, China
| | - Thuc Hue Ly
- Department of Chemistry and Center of Super-Diamond & Advanced Films (COSDAF), City University of Hong Kong, Kowloon, 999077, China
- Department of Chemistry and State Key Laboratory of Marine Pollution, City University of Hong Kong, Hong Kong, 999077, China
- City University of Hong Kong Shenzhen Research Institute, Shenzhen, 518057, China
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5
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Guo L, Hu S, Gu X, Zhang R, Wang K, Yan W, Sun X. Emerging Spintronic Materials and Functionalities. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024; 36:e2301854. [PMID: 37309258 DOI: 10.1002/adma.202301854] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Revised: 06/01/2023] [Indexed: 06/14/2023]
Abstract
The explosive growth of the information era has put forward urgent requirements for ultrahigh-speed and extremely efficient computations. In direct contrary to charge-based computations, spintronics aims to use spins as information carriers for data storage, transmission, and decoding, to help fully realize electronic device miniaturization and high integration for next-generation computing technologies. Currently, many novel spintronic materials have been developed with unique properties and multifunctionalities, including organic semiconductors (OSCs), organic-inorganic hybrid perovskites (OIHPs), and 2D materials (2DMs). These materials are useful to fulfill the demand for developing diverse and advanced spintronic devices. Herein, these promising materials are systematically reviewed for advanced spintronic applications. Due to the distinct chemical and physical structures of OSCs, OIHPs, and 2DMs, their spintronic properties (spin transport and spin manipulation) are discussed separately. In addition, some multifunctionalities due to photoelectric and chiral-induced spin selectivity (CISS) are overviewed, including the spin-filter effect, spin-photovoltaics, spin-light emitting devices, and spin-transistor functions. Subsequently, challenges and future perspectives of using these multifunctional materials for the development of advanced spintronics are presented.
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Affiliation(s)
- Lidan Guo
- Key Laboratory of Nanosystem and Hierarchical Fabrication, National Center for Nanoscience and Technology, Beijing, 100190, P. R. China
| | - Shunhua Hu
- Key Laboratory of Nanosystem and Hierarchical Fabrication, National Center for Nanoscience and Technology, Beijing, 100190, P. R. China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing, 100049, P. R. China
| | - Xianrong Gu
- Key Laboratory of Nanosystem and Hierarchical Fabrication, National Center for Nanoscience and Technology, Beijing, 100190, P. R. China
| | - Rui Zhang
- Key Laboratory of Nanosystem and Hierarchical Fabrication, National Center for Nanoscience and Technology, Beijing, 100190, P. R. China
| | - Kai Wang
- Key Laboratory of Luminescence and Optical Information, Ministry of Education, School of Physical Science and Engineering, Institute of Optoelectronics Technology, Beijing Jiaotong University, Beijing, 100044, P. R. China
| | - Wenjing Yan
- School of Physics and Astronomy, University of Nottingham, University Park, Nottingham, NG9 2RD, UK
| | - Xiangnan Sun
- Key Laboratory of Nanosystem and Hierarchical Fabrication, National Center for Nanoscience and Technology, Beijing, 100190, P. R. China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing, 100049, P. R. China
- School of Material Science and Engineering, Zhengzhou University, Zhengzhou, 450001, P. R. China
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6
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Narayan J, Bezborah K. Recent advances in the functionalization, substitutional doping and applications of graphene/graphene composite nanomaterials. RSC Adv 2024; 14:13413-13444. [PMID: 38660531 PMCID: PMC11041312 DOI: 10.1039/d3ra07072g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2023] [Accepted: 04/01/2024] [Indexed: 04/26/2024] Open
Abstract
Recently, graphene and graphene-based nanomaterials have emerged as advanced carbon functional materials with specialized unique electronic, optical, mechanical, and chemical properties. These properties have made graphene an exceptional material for a wide range of promising applications in biological and non-biological fields. The present review illustrates the structural modifications of pristine graphene resulting in a wide variety of derivatives. The significance of substitutional doping with alkali-metals, alkaline earth metals, and III-VII group elements apart from the transition metals of the periodic table is discussed. The paper reviews various chemical and physical preparation routes of graphene, its derivatives and graphene-based nanocomposites at room and elevated temperatures in various solvents. The difficulty in dispersing it in water and organic solvents make it essential to functionalize graphene and its derivatives. Recent trends and advances are discussed at length. Controlled reduction reactions in the presence of various dopants leading to nanocomposites along with suitable surfactants essential to enhance its potential applications in the semiconductor industry and biological fields are discussed in detail.
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Affiliation(s)
- Jyoti Narayan
- Synthetic Nanochemistry Laboratory, Department of Basic Sciences & Social Sciences, (Chemistry Division) School of Technology, North Eastern Hill University Shillong 793022 Meghalaya India
| | - Kangkana Bezborah
- Synthetic Nanochemistry Laboratory, Department of Basic Sciences & Social Sciences, (Chemistry Division) School of Technology, North Eastern Hill University Shillong 793022 Meghalaya India
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7
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Xu J, Ping Y. Ab Initio Predictions of Spin Relaxation, Dephasing, and Diffusion in Solids. J Chem Theory Comput 2024; 20:492-512. [PMID: 38157422 DOI: 10.1021/acs.jctc.3c00598] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2024]
Abstract
Spin relaxation, dephasing, and diffusion are at the heart of spin-based information technology. Accurate theoretical approaches to simulate spin lifetimes (τs), determining how fast the spin polarization and phase information will be lost, are important to the understanding of the underlying mechanism of these spin processes, and invaluable in searching for promising candidates of spintronic materials. Recently, we develop a first-principles real-time density-matrix (FPDM) approach to simulate spin dynamics for general solid-state systems. Through the complete first-principles descriptions of light-matter interaction and scattering processes including electron-phonon, electron-impurity, and electron-electron scatterings with self-consistent spin-orbit coupling, as well as ab initio Landé g-factor, our method can predict τs at various conditions as a function of carrier density and temperature, under electric and magnetic fields. By employing this method, we successfully reproduce experimental results of disparate materials and identify the key factors affecting spin relaxation, dephasing, and diffusion in different materials. Specifically, we predict that germanene has long τs (∼100 ns at 50 K), a giant spin lifetime anisotropy, and spin-valley locking effect under electric fields, making it advantageous for spin-valleytronic applications. Based on our theoretical derivations and ab initio simulations, we propose a new useful electronic quantity, named spin-flip angle θ↑↓, for the understanding of spin relaxation through intervalley spin-flip scattering processes. Our method can be further applied to other emerging materials and extended to simulate exciton spin dynamics and steady-state photocurrents due to photogalvanic effect.
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Affiliation(s)
- Junqing Xu
- Department of Physics, Hefei University of Technology, Hefei 230031, Anhui China
- Department of Chemistry and Biochemistry, University of California, Santa Cruz, California 95064, United States
| | - Yuan Ping
- Department of Materials Science and Engineering, University of Wisconsin─Madison, Madison, Wisconsin 53706, United States
- Department of Physics, University of California, Santa Cruz, California 95064, United States
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8
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Liu X, Wang H, Chen Z, Zhu W, Li Z, Hu W, Xiao H, Zeng XC. Enhanced Direct Exchange Interaction and Hybridization by Single-Atom Linkers for High Curie Temperature and Superior Visible-Light Harvesting in Cr 3(CN 3) 2. NANO LETTERS 2024; 24:35-42. [PMID: 38117034 DOI: 10.1021/acs.nanolett.3c03044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2023]
Abstract
Designing two-dimensional (2D) ferromagnetic (FM) semiconductors with elevated Curie temperature, high carrier mobility, and strong light harvesting is challenging but crucial to the development of spintronics with multifunctionalities. Herein, we show first-principles computation evidence of the 2D metal-organic framework Kagome ferromagnet Cr3(CN3)2. Monolayer Cr3(CN3)2 is predicted to be an FM semiconductor with a record-high Curie temperature of 943 K owing to the use of a single-atom linker (N), which results in strong direct d-p exchange interaction and hybridization between dyz/xz and pz of Cr and N, as well as excellent matching characteristics in energy and symmetry. The single-atom linker structural feature also leads to notable band dispersion and a relatively high carrier mobility of 420 cm2 V-1 s-1. Moreover, under the in-plane strain, 2D Cr3(CN3)2 can be tuned to possess a strong visible-light-harvesting functionality. These novel properties render monolayer Cr3(CN3)2 a distinct 2D ferromagnet with high potential for the development of multifunctional spintronics.
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Affiliation(s)
- Xiaofeng Liu
- School of Physics, Hefei University of Technology, Hefei 230009, People's Republic of China
| | - Haidi Wang
- School of Physics, Hefei University of Technology, Hefei 230009, People's Republic of China
| | - Zhao Chen
- School of Physics, Hefei University of Technology, Hefei 230009, People's Republic of China
| | - Weiduo Zhu
- School of Physics, Hefei University of Technology, Hefei 230009, People's Republic of China
| | - Zhongjun Li
- School of Physics, Hefei University of Technology, Hefei 230009, People's Republic of China
- State Key Laboratory of Quantum Optics and Quantum Optics Devices, Shanxi University, Taiyuan 030006, People's Republic of China
| | - Wei Hu
- Hefei National Research Center for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei 230026, People's Republic of China
| | - Haixiao Xiao
- School of Physics, Hefei University of Technology, Hefei 230009, People's Republic of China
| | - Xiao Cheng Zeng
- Department of Materials Science & Engineering, City University of Hong Kong, Hong Kong 999077, People's Republic of China
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9
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Koinuma Y, Hasegawa S, Sakai M. Long-distance spin communication via ambipolar conductor with electron-hole spin exchange interaction. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2024; 36:135806. [PMID: 38118178 DOI: 10.1088/1361-648x/ad17a5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Accepted: 12/20/2023] [Indexed: 12/22/2023]
Abstract
Spin accumulation in a nonmagnetic (N) metal embedded between two ferromagnetic metals is still crucial in current spintronics because long-distance spin communication via the N metal can make all-spin logic (ASL) devices feasible. Graphene is almost the only N-region material suitable for ASL devices because its low intrinsic spin-orbit coupling results in a spin diffusion length,ℓN, of over 30µm at room temperature, but long-distance spin communication beyondℓNremains difficult. The present study proposes a way to remove the restriction caused byℓN. In our proposal, an ambipolar conductor, in which electron and hole contribute to electronic conduction and interact with each other, is used for the N-region in a double-heterojunction magnetic structure. When the electron-hole interaction is accompanied by spin exchange, long-distance spin communication characteristic is predicted. Approximately 70 types of ambipolar conductors, including elemental metals and metal alloys, are available. Hence, this material variation may open a new spintronics field, ambipolar spintronics, which may realize operation mechanisms that cannot be achieved using conventional single-band metals. Finally, we present a comprehensive argument on the interface-mediated coupling mechanism between spins and charges, which is the basis of the generation of the spin-coupled interface voltage.
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Affiliation(s)
- Yukihiro Koinuma
- Division of Material Science, Graduate School of Science and Engineering, Saitama University, Saitama 338-8570, Japan
| | | | - Masamichi Sakai
- Division of Material Science, Graduate School of Science and Engineering, Saitama University, Saitama 338-8570, Japan
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10
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Zeng X, Ye G, Yang F, Ye Q, Zhang L, Ma B, Liu Y, Xie M, Liu Y, Wang X, Hao Y, Han G. Tunable asymmetric magnetoresistance in an Fe 3GeTe 2/graphite/Fe 3GeTe 2 lateral spin valve. NANOSCALE 2023. [PMID: 38018435 DOI: 10.1039/d3nr04069k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2023]
Abstract
van der Waals (vdW) ferromagnetic heterojunctions, characterized by an ultraclean device interface and the absence of lattice matching, have emerged as indispensable and efficient building blocks for future spintronic devices. In this study, we present a seldom observed antisymmetric magnetoresistance (MR) behavior with three distinctive resistance states in a lateral van der Waals (vdW) structure comprising Fe3GeTe2 (FGT)/graphite/FGT. In contrast to traditional spin valves governed by the magnetization configurations of ferromagnetic electrodes (FEs), this distinct feature can be attributed to the interaction between FGT and the FGT/graphite interface, which is primarily influenced by the internal spin-momentum locking effect. Furthermore, modulation of the MR behavior is accomplished by employing the coupling between antiferromagnetic and ferromagnetic materials to adjust the coercive fields of two FEs subsequent to the in situ growth of an FGT oxide layer on FGT. This study elucidates the device physics and mechanism of property modulation in lateral spin valves and holds the potential for advancing the development of gate-tunable spintronic devices and next-generation integrated circuits.
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Affiliation(s)
- Xiangyu Zeng
- Hangzhou Institute of Technology, Xidian University, Hangzhou, 311200, China.
- State Key Discipline Laboratory of Wide Band Gap Semiconductor Technology, School of Microelectronics, Xidian University, Xi'an 710071, China
| | - Ge Ye
- Center for correlated matter and Department of Physics, Zhejiang University, Hangzhou, 310027, China
| | - Fazhi Yang
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Qikai Ye
- College of Information Science and Electronic Engineering, Zhejiang University, Hangzhou, 310027, China.
| | - Liang Zhang
- Research Center for Humanoid Sensing and Perception, Zhejiang Lab, Hangzhou, 311100, China
| | - Boyang Ma
- College of Information Science and Electronic Engineering, Zhejiang University, Hangzhou, 310027, China.
| | - Yulu Liu
- College of Information Science and Electronic Engineering, Zhejiang University, Hangzhou, 310027, China.
| | - Mengwei Xie
- Center for correlated matter and Department of Physics, Zhejiang University, Hangzhou, 310027, China
| | - Yan Liu
- Hangzhou Institute of Technology, Xidian University, Hangzhou, 311200, China.
- State Key Discipline Laboratory of Wide Band Gap Semiconductor Technology, School of Microelectronics, Xidian University, Xi'an 710071, China
| | - Xiaozhi Wang
- College of Information Science and Electronic Engineering, Zhejiang University, Hangzhou, 310027, China.
| | - Yue Hao
- Hangzhou Institute of Technology, Xidian University, Hangzhou, 311200, China.
- State Key Discipline Laboratory of Wide Band Gap Semiconductor Technology, School of Microelectronics, Xidian University, Xi'an 710071, China
| | - Genquan Han
- Hangzhou Institute of Technology, Xidian University, Hangzhou, 311200, China.
- State Key Discipline Laboratory of Wide Band Gap Semiconductor Technology, School of Microelectronics, Xidian University, Xi'an 710071, China
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11
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Liu X, Li H, Zhang W, Yang Z, Li D, Liu M, Jin K, Wang L, Yu G. Magnetoresistance in Organic Spin Valves Based on Acid-Exfoliated 2D Covalent Organic Frameworks Thin Films. Angew Chem Int Ed Engl 2023; 62:e202308921. [PMID: 37668952 DOI: 10.1002/anie.202308921] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2023] [Revised: 08/22/2023] [Accepted: 09/05/2023] [Indexed: 09/06/2023]
Abstract
Covalent organic frameworks (COFs), as a burgeoning class of crystalline porous materials, have made significant progress in their application to optoelectronic devices such as field-effect transistors, memristors, and photodetectors. However, the insoluble features of microcrystalline two-dimensional (2D) COF powders limit development of their thin film devices. Additionally, the exploration of spin transport properties in this category of π-conjugated skeleton materials remains vacant thus far. Herein, an imine-linked 2D Py-Np COF nanocrystalline powder was synthesized by Schiff base condensation of 4,4',4'',4'''-(pyrene-1,3,6,8-tetrayl)tetraaniline and naphthalene-2,6-dicarbaldehyde. Then, we prepared a large-scale free-standing Py-Np COF film via a top-down strategy of chemically assisted acid exfoliation. Moreover, high-quality COF films acted as active layers were transferred onto ferromagnetic La0.67 Sr0.33 MnO3 (LSMO) electrodes for the first attempt to fabricate organic spin valves (OSVs) based on 2D COF materials. This COF-based OSV device with a configuration of LSMO/Py-Np COF/Co/Au demonstrated a remarkable magnetoresistance (MR) value up to -26.5 % at 30 K. Meanwhile, the MR behavior of the COF-based OSVs exhibited a highly temperature dependence and operational stability. This work highlights the enormous application prospects of 2D COFs in organic spintronics and provides a promising approach for developing electronic and spintronic devices based on acid-exfoliated COF thin films.
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Affiliation(s)
- Xitong Liu
- Beijing National Laboratory for Molecular Sciences, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, P. R. China
- School of Chemical Sciences, University of Chinese Academy of Sciences, Beijing, 100049, P. R. China
| | - Hao Li
- Beijing National Laboratory for Molecular Sciences, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, P. R. China
- School of Materials Science and Engineering, University of Science and Technology, Beijing, 100083, P. R. China
| | - Weifeng Zhang
- Beijing National Laboratory for Molecular Sciences, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, P. R. China
- School of Chemical Sciences, University of Chinese Academy of Sciences, Beijing, 100049, P. R. China
| | - Zhen Yang
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, P. R. China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, 100049, P. R. China
| | - Dong Li
- Beijing National Laboratory for Molecular Sciences, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, P. R. China
- School of Chemical Sciences, University of Chinese Academy of Sciences, Beijing, 100049, P. R. China
| | - Mengya Liu
- Beijing National Laboratory for Molecular Sciences, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, P. R. China
- School of Materials Science and Engineering, University of Science and Technology, Beijing, 100083, P. R. China
| | - Kuijuan Jin
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, P. R. China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, 100049, P. R. China
- Songshan Lake Materials Laboratory Dongguan, Guangdong, 523808, P. R. China
| | - Liping Wang
- School of Materials Science and Engineering, University of Science and Technology, Beijing, 100083, P. R. China
| | - Gui Yu
- Beijing National Laboratory for Molecular Sciences, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, P. R. China
- School of Chemical Sciences, University of Chinese Academy of Sciences, Beijing, 100049, P. R. China
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12
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Kedves M, Szentpéteri B, Márffy A, Tóvári E, Papadopoulos N, Rout PK, Watanabe K, Taniguchi T, Goswami S, Csonka S, Makk P. Stabilizing the Inverted Phase of a WSe 2/BLG/WSe 2 Heterostructure via Hydrostatic Pressure. NANO LETTERS 2023; 23:9508-9514. [PMID: 37844301 PMCID: PMC10603803 DOI: 10.1021/acs.nanolett.3c03029] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2023] [Revised: 10/06/2023] [Indexed: 10/18/2023]
Abstract
Bilayer graphene (BLG) was recently shown to host a band-inverted phase with unconventional topology emerging from the Ising-type spin-orbit interaction (SOI) induced by the proximity of transition metal dichalcogenides with large intrinsic SOI. Here, we report the stabilization of this band-inverted phase in BLG symmetrically encapsulated in tungsten diselenide (WSe2) via hydrostatic pressure. Our observations from low temperature transport measurements are consistent with a single particle model with induced Ising SOI of opposite sign on the two graphene layers. To confirm the strengthening of the inverted phase, we present thermal activation measurements and show that the SOI-induced band gap increases by more than 100% due to the applied pressure. Finally, the investigation of Landau level spectra reveals the dependence of the level-crossings on the applied magnetic field, which further confirms the enhancement of SOI with pressure.
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Affiliation(s)
- Máté Kedves
- Department
of Physics, Institute of Physics, Budapest
University of Technology and Economics, Műegyetem rkp. 3, Budapest H-1111, Hungary
- MTA-BME
Correlated van der Waals Structures Momentum Research Group, Műegyetem rkp. 3, Budapest H-1111, Hungary
| | - Bálint Szentpéteri
- Department
of Physics, Institute of Physics, Budapest
University of Technology and Economics, Műegyetem rkp. 3, Budapest H-1111, Hungary
- MTA-BME
Correlated van der Waals Structures Momentum Research Group, Műegyetem rkp. 3, Budapest H-1111, Hungary
| | - Albin Márffy
- MTA-BME
Correlated van der Waals Structures Momentum Research Group, Műegyetem rkp. 3, Budapest H-1111, Hungary
- MTA-BME
Superconducting Nanoelectronics Momentum Research Group, Műegyetem rkp. 3, H-1111 Budapest, Hungary
| | - Endre Tóvári
- Department
of Physics, Institute of Physics, Budapest
University of Technology and Economics, Műegyetem rkp. 3, Budapest H-1111, Hungary
- MTA-BME
Correlated van der Waals Structures Momentum Research Group, Műegyetem rkp. 3, Budapest H-1111, Hungary
| | - Nikos Papadopoulos
- QuTech
and Kavli Institute of Nanoscience, Delft
University of Technology, Delft 2600 GA, The Netherlands
| | - Prasanna K. Rout
- QuTech
and Kavli Institute of Nanoscience, Delft
University of Technology, Delft 2600 GA, The Netherlands
| | - Kenji Watanabe
- Research
Center for Functional Materials, National
Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
| | - Takashi Taniguchi
- International
Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
| | - Srijit Goswami
- QuTech
and Kavli Institute of Nanoscience, Delft
University of Technology, Delft 2600 GA, The Netherlands
| | - Szabolcs Csonka
- Department
of Physics, Institute of Physics, Budapest
University of Technology and Economics, Műegyetem rkp. 3, Budapest H-1111, Hungary
- MTA-BME
Superconducting Nanoelectronics Momentum Research Group, Műegyetem rkp. 3, H-1111 Budapest, Hungary
| | - Péter Makk
- Department
of Physics, Institute of Physics, Budapest
University of Technology and Economics, Műegyetem rkp. 3, Budapest H-1111, Hungary
- MTA-BME
Correlated van der Waals Structures Momentum Research Group, Műegyetem rkp. 3, Budapest H-1111, Hungary
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13
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Ghising P, Biswas C, Lee YH. Graphene Spin Valves for Spin Logic Devices. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2209137. [PMID: 36618004 DOI: 10.1002/adma.202209137] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2022] [Revised: 11/23/2022] [Indexed: 06/09/2023]
Abstract
An alternative to charge-based electronics identifies the spin degree of freedom for information communication and processing. The long spin-diffusion length in graphene at room temperature demonstrates its ability for highly scalable spintronics. The development of the graphene spin valve (SV) has inspired spin devices in graphene including spin field-effect transistors and spin majority logic gates. A comprehensive picture of spin transport in graphene SVs is required for further development of spin logic. This review examines the advances in graphene SVs and their role in the development of spin logic devices. Different transport and scattering mechanisms in charge and spin are discussed. Furthermore, the on/off switching energy between graphene SVs and charge-based FETs is compared to highlight their prospects for low-power devices. The challenges and perspectives that need to be addressed for the future development of spin logic devices are then outlined.
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Affiliation(s)
- Pramod Ghising
- Center for Integrated Nanostructure Physics, Institute for Basic Science (IBS), Sungkyunkwan University (SKKU), Suwon, 16419, Republic of Korea
| | - Chandan Biswas
- Center for Integrated Nanostructure Physics, Institute for Basic Science (IBS), Sungkyunkwan University (SKKU), Suwon, 16419, Republic of Korea
| | - Young Hee Lee
- Center for Integrated Nanostructure Physics, Institute for Basic Science (IBS), Sungkyunkwan University (SKKU), Suwon, 16419, Republic of Korea
- Department of Energy Science, Department of Physics, Sungkyunkwan University, Suwon, 16419, Republic of Korea
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14
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Lau CS, Das S, Verzhbitskiy IA, Huang D, Zhang Y, Talha-Dean T, Fu W, Venkatakrishnarao D, Johnson Goh KE. Dielectrics for Two-Dimensional Transition-Metal Dichalcogenide Applications. ACS NANO 2023. [PMID: 37257134 DOI: 10.1021/acsnano.3c03455] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Despite over a decade of intense research efforts, the full potential of two-dimensional transition-metal dichalcogenides continues to be limited by major challenges. The lack of compatible and scalable dielectric materials and integration techniques restrict device performances and their commercial applications. Conventional dielectric integration techniques for bulk semiconductors are difficult to adapt for atomically thin two-dimensional materials. This review provides a brief introduction into various common and emerging dielectric synthesis and integration techniques and discusses their applicability for 2D transition metal dichalcogenides. Dielectric integration for various applications is reviewed in subsequent sections including nanoelectronics, optoelectronics, flexible electronics, valleytronics, biosensing, quantum information processing, and quantum sensing. For each application, we introduce basic device working principles, discuss the specific dielectric requirements, review current progress, present key challenges, and offer insights into future prospects and opportunities.
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Affiliation(s)
- Chit Siong Lau
- Institute of Materials Research and Engineering (IMRE), Agency for Science, Technology and Research (A*STAR), 2 Fusionopolis Way, Innovis #08-03, Singapore 138634, Republic of Singapore
| | - Sarthak Das
- Institute of Materials Research and Engineering (IMRE), Agency for Science, Technology and Research (A*STAR), 2 Fusionopolis Way, Innovis #08-03, Singapore 138634, Republic of Singapore
| | - Ivan A Verzhbitskiy
- Institute of Materials Research and Engineering (IMRE), Agency for Science, Technology and Research (A*STAR), 2 Fusionopolis Way, Innovis #08-03, Singapore 138634, Republic of Singapore
| | - Ding Huang
- Institute of Materials Research and Engineering (IMRE), Agency for Science, Technology and Research (A*STAR), 2 Fusionopolis Way, Innovis #08-03, Singapore 138634, Republic of Singapore
| | - Yiyu Zhang
- Institute of Materials Research and Engineering (IMRE), Agency for Science, Technology and Research (A*STAR), 2 Fusionopolis Way, Innovis #08-03, Singapore 138634, Republic of Singapore
| | - Teymour Talha-Dean
- Institute of Materials Research and Engineering (IMRE), Agency for Science, Technology and Research (A*STAR), 2 Fusionopolis Way, Innovis #08-03, Singapore 138634, Republic of Singapore
- Department of Physics and Astronomy, Queen Mary University of London, London E1 4NS, United Kingdom
| | - Wei Fu
- Institute of Materials Research and Engineering (IMRE), Agency for Science, Technology and Research (A*STAR), 2 Fusionopolis Way, Innovis #08-03, Singapore 138634, Republic of Singapore
| | - Dasari Venkatakrishnarao
- Institute of Materials Research and Engineering (IMRE), Agency for Science, Technology and Research (A*STAR), 2 Fusionopolis Way, Innovis #08-03, Singapore 138634, Republic of Singapore
| | - Kuan Eng Johnson Goh
- Institute of Materials Research and Engineering (IMRE), Agency for Science, Technology and Research (A*STAR), 2 Fusionopolis Way, Innovis #08-03, Singapore 138634, Republic of Singapore
- Department of Physics, National University of Singapore, 2 Science Drive 3, 117551, Singapore
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, 50 Nanyang Avenue 639798, Singapore
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15
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Márkus BG, Gmitra M, Dóra B, Csősz G, Fehér T, Szirmai P, Náfrádi B, Zólyomi V, Forró L, Fabian J, Simon F. Ultralong 100 ns spin relaxation time in graphite at room temperature. Nat Commun 2023; 14:2831. [PMID: 37198155 DOI: 10.1038/s41467-023-38288-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Accepted: 04/24/2023] [Indexed: 05/19/2023] Open
Abstract
Graphite has been intensively studied, yet its electron spins dynamics remains an unresolved problem even 70 years after the first experiments. The central quantities, the longitudinal (T1) and transverse (T2) relaxation times were postulated to be equal, mirroring standard metals, but T1 has never been measured for graphite. Here, based on a detailed band structure calculation including spin-orbit coupling, we predict an unexpected behavior of the relaxation times. We find, based on saturation ESR measurements, that T1 is markedly different from T2. Spins injected with perpendicular polarization with respect to the graphene plane have an extraordinarily long lifetime of 100 ns at room temperature. This is ten times more than in the best graphene samples. The spin diffusion length across graphite planes is thus expected to be ultralong, on the scale of ~ 70 μm, suggesting that thin films of graphite - or multilayer AB graphene stacks - can be excellent platforms for spintronics applications compatible with 2D van der Waals technologies. Finally, we provide a qualitative account of the observed spin relaxation based on the anisotropic spin admixture of the Bloch states in graphite obtained from density functional theory calculations.
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Affiliation(s)
- B G Márkus
- Stavropoulos Center for Complex Quantum Matter, Department of Physics and Astronomy, University of Notre Dame, Notre Dame, IN, 46556, USA
- Institute for Solid State Physics and Optics, Wigner Research Centre for Physics, Budapest, H-1525, Hungary
- Department of Physics, Institute of Physics, Budapest University of Technology and Economics, Műegyetem rkp. 3., H-1111, Budapest, Hungary
| | - M Gmitra
- Institute of Physics, Pavol Jozef Šafárik University in Košice, Park Angelinum 9, 040 01, Košice, Slovakia
- Institute of Experimental Physics, Slovak Academy of Sciences, Watsonova 47, 04001, Košice, Slovakia
| | - B Dóra
- Department of Theoretical Physics, Institute of Physics and MTA-BME Lendület Topology and Correlation Research Group Budapest University of Technology and Economics, Műegyetem rkp. 3., H-1111, Budapest, Hungary
| | - G Csősz
- Department of Physics, Institute of Physics, Budapest University of Technology and Economics, Műegyetem rkp. 3., H-1111, Budapest, Hungary
| | - T Fehér
- Department of Physics, Institute of Physics, Budapest University of Technology and Economics, Műegyetem rkp. 3., H-1111, Budapest, Hungary
| | - P Szirmai
- Laboratory of Physics of Complex Matter, École Polytechnique Fédérale de Lausanne, Lausanne, CH-1015, Switzerland
| | - B Náfrádi
- Laboratory of Physics of Complex Matter, École Polytechnique Fédérale de Lausanne, Lausanne, CH-1015, Switzerland
| | - V Zólyomi
- STFC Hartree Centre, Daresbury Laboratory, Daresbury, Warrington WA4 4AD, UK
| | - L Forró
- Stavropoulos Center for Complex Quantum Matter, Department of Physics and Astronomy, University of Notre Dame, Notre Dame, IN, 46556, USA
- Laboratory of Physics of Complex Matter, École Polytechnique Fédérale de Lausanne, Lausanne, CH-1015, Switzerland
| | - J Fabian
- Department of Physics, University of Regensburg, 93040, Regensburg, Germany.
| | - F Simon
- Institute for Solid State Physics and Optics, Wigner Research Centre for Physics, Budapest, H-1525, Hungary.
- Department of Physics, Institute of Physics and ELKH-BME Condensed Matter Research Group Budapest University of Technology and Economics, Műegyetem rkp. 3., H-1111, Budapest, Hungary.
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16
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Lee J, Kwon J, Lee E, Park J, Cha S, Watanabe K, Taniguchi T, Jo MH, Choi H. Spinful hinge states in the higher-order topological insulators WTe 2. Nat Commun 2023; 14:1801. [PMID: 37002230 PMCID: PMC10066182 DOI: 10.1038/s41467-023-37482-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Accepted: 03/20/2023] [Indexed: 04/03/2023] Open
Abstract
Higher-order topological insulators are recently discovered quantum materials exhibiting distinct topological phases with the generalized bulk-boundary correspondence. Td-WTe2 is a promising candidate to reveal topological hinge excitation in an atomically thin regime. However, with initial theories and experiments focusing on localized one-dimensional conductance only, no experimental reports exist on how the spin orientations are distributed over the helical hinges-this is critical, yet one missing puzzle. Here, we employ the magneto-optic Kerr effect to visualize the spinful characteristics of the hinge states in a few-layer Td-WTe2. By examining the spin polarization of electrons injected from WTe2 to graphene under external electric and magnetic fields, we conclude that WTe2 hosts a spinful and helical topological hinge state protected by the time-reversal symmetry. Our experiment provides a fertile diagnosis to investigate the topologically protected gapless hinge states, and may call for new theoretical studies to extend the previous spinless model.
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Affiliation(s)
- Jekwan Lee
- Department of Physics and Astronomy, Seoul National University, Seoul, 08826, Korea
- Institute of Applied Physics, Seoul National University, Seoul, 08826, Korea
| | - Jaehyeon Kwon
- Department of Physics and Astronomy, Seoul National University, Seoul, 08826, Korea
- Institute of Applied Physics, Seoul National University, Seoul, 08826, Korea
| | - Eunho Lee
- Department of Physics and Astronomy, Seoul National University, Seoul, 08826, Korea
- Institute of Applied Physics, Seoul National University, Seoul, 08826, Korea
| | - Jiwon Park
- Department of Physics and Astronomy, Seoul National University, Seoul, 08826, Korea
- Institute of Applied Physics, Seoul National University, Seoul, 08826, Korea
| | - Soonyoung Cha
- Center for Epitaxial van der Waals Quantum Solids, Institute for Basic Science, Pohang, 37673, Korea
- Department of Materials Science and Engineering, Pohang University of Science and Technoloagy, Pohang, 37673, Korea
| | - Kenji Watanabe
- Advanced Materials Laboratory, National Institute for Materials Science, 1-1 Namiki, Tsukuba, 305-0044, Japan
| | - Takashi Taniguchi
- Advanced Materials Laboratory, National Institute for Materials Science, 1-1 Namiki, Tsukuba, 305-0044, Japan
| | - Moon-Ho Jo
- Center for Epitaxial van der Waals Quantum Solids, Institute for Basic Science, Pohang, 37673, Korea
- Department of Materials Science and Engineering, Pohang University of Science and Technoloagy, Pohang, 37673, Korea
| | - Hyunyong Choi
- Department of Physics and Astronomy, Seoul National University, Seoul, 08826, Korea.
- Institute of Applied Physics, Seoul National University, Seoul, 08826, Korea.
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17
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He X, Zhang C, Zheng D, Li P, Xiao JQ, Zhang X. Nonlocal Spin Valves Based on Graphene/Fe 3GeTe 2 van der Waals Heterostructures. ACS APPLIED MATERIALS & INTERFACES 2023; 15:9649-9655. [PMID: 36753695 PMCID: PMC9951179 DOI: 10.1021/acsami.2c21918] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Accepted: 01/25/2023] [Indexed: 06/18/2023]
Abstract
With recent advances in two-dimensional (2D) ferromagnets with enhanced Curie temperatures, it is possible to develop all-2D spintronic devices with high-quality interfaces using 2D ferromagnets. In this study, we have successfully fabricated nonlocal spin valves with Fe3GeTe2 (FGT) as the spin source and detector and multilayer graphene as the spin transport channel. The nonlocal spin transport signal was found to strongly depend on temperature and disappear at a temperature below the Curie temperature of the FGT flakes, which stemmed from the temperature-dependent ferromagnetism of FGT. The spin injection efficiency was estimated to be about 1%, close to that of conventional nonlocal spin valves with transparent contacts between ferromagnetic electrodes and the graphene channel. In addition, the spin transport signal was found to depend on the direction of the magnetic field and the magnitude of the current, which was due to the strong perpendicular magnetic anisotropy of FGT and the thermal effect, respectively. Our results provide opportunities to extend the applications of van der Waals heterostructures in spintronic devices.
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Affiliation(s)
- Xin He
- Physical
Science and Engineering Division, King Abdullah
University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia
| | - Chenhui Zhang
- Physical
Science and Engineering Division, King Abdullah
University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia
| | - Dongxing Zheng
- Physical
Science and Engineering Division, King Abdullah
University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia
| | - Peng Li
- State
Key Laboratory of Electronic Thin Film and Integrated Devices, University of Electronic Science and Technology of
China, Chengdu 610054, China
| | - John Q. Xiao
- Department
of Physics and Astronomy, University of
Delaware, Newark, Delaware 19716, United States
| | - Xixiang Zhang
- Physical
Science and Engineering Division, King Abdullah
University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia
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18
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Ren L, Lombez L, Robert C, Beret D, Lagarde D, Urbaszek B, Renucci P, Taniguchi T, Watanabe K, Crooker SA, Marie X. Optical Detection of Long Electron Spin Transport Lengths in a Monolayer Semiconductor. PHYSICAL REVIEW LETTERS 2022; 129:027402. [PMID: 35867459 DOI: 10.1103/physrevlett.129.027402] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Accepted: 05/18/2022] [Indexed: 06/15/2023]
Abstract
Using a spatially resolved optical pump-probe experiment, we measure the lateral transport of spin-valley polarized electrons over very long distances (tens of micrometers) in a single WSe_{2} monolayer. By locally pumping the Fermi sea of 2D electrons to a high degree of spin-valley polarization (up to 75%) using circularly polarized light, the lateral diffusion of the electron polarization can be mapped out via the photoluminescence induced by a spatially separated and linearly polarized probe laser. Up to 25% spin-valley polarization is observed at pump-probe separations up to 20 μm. Characteristic spin-valley diffusion lengths of 18±3 μm are revealed at low temperatures. The dependence on temperature, pump helicity, pump intensity, and electron density highlight the key roles played by spin relaxation time and pumping efficiency on polarized electron transport in monolayer semiconductors possessing spin-valley locking.
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Affiliation(s)
- L Ren
- Université de Toulouse, INSA-CNRS-UPS, LPCNO, 135 Av. Rangueil, 31077 Toulouse, France
| | - L Lombez
- Université de Toulouse, INSA-CNRS-UPS, LPCNO, 135 Av. Rangueil, 31077 Toulouse, France
| | - C Robert
- Université de Toulouse, INSA-CNRS-UPS, LPCNO, 135 Av. Rangueil, 31077 Toulouse, France
| | - D Beret
- Université de Toulouse, INSA-CNRS-UPS, LPCNO, 135 Av. Rangueil, 31077 Toulouse, France
| | - D Lagarde
- Université de Toulouse, INSA-CNRS-UPS, LPCNO, 135 Av. Rangueil, 31077 Toulouse, France
| | - B Urbaszek
- Université de Toulouse, INSA-CNRS-UPS, LPCNO, 135 Av. Rangueil, 31077 Toulouse, France
| | - P Renucci
- Université de Toulouse, INSA-CNRS-UPS, LPCNO, 135 Av. Rangueil, 31077 Toulouse, France
| | - T Taniguchi
- International Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-00044, Japan
| | - K Watanabe
- Research Center for Functional Materials, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-00044, Japan
| | - S A Crooker
- National High Magnetic Field Laboratory, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - X Marie
- Université de Toulouse, INSA-CNRS-UPS, LPCNO, 135 Av. Rangueil, 31077 Toulouse, France
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19
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Bisswanger T, Winter Z, Schmidt A, Volmer F, Watanabe K, Taniguchi T, Stampfer C, Beschoten B. CVD Bilayer Graphene Spin Valves with 26 μm Spin Diffusion Length at Room Temperature. NANO LETTERS 2022; 22:4949-4955. [PMID: 35649273 DOI: 10.1021/acs.nanolett.2c01119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
We present inverted spin-valve devices fabricated from chemical vapor deposition (CVD)-grown bilayer graphene (BLG) that show more than a doubling in device performance at room temperature compared to state-of-the-art bilayer graphene spin valves. This is made possible by a polydimethylsiloxane droplet-assisted full-dry transfer technique that compensates for previous process drawbacks in device fabrication. Gate dependent Hanle measurements reveal spin lifetimes of up to 5.8 ns and a spin diffusion length of up to 26 μm at room temperature combined with a charge carrier mobility of about 24 000 cm2(V s)-1 for the best device. Our results demonstrate that CVD-grown BLG shows equally good room temperature spin transport properties as both CVD-grown single-layer graphene and even exfoliated single-layer graphene.
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Affiliation(s)
- Timo Bisswanger
- 2nd Institute of Physics and JARA-FIT, RWTH Aachen University, 52074 Aachen, Germany
| | - Zachary Winter
- 2nd Institute of Physics and JARA-FIT, RWTH Aachen University, 52074 Aachen, Germany
| | - Anne Schmidt
- 2nd Institute of Physics and JARA-FIT, RWTH Aachen University, 52074 Aachen, Germany
| | - Frank Volmer
- 2nd Institute of Physics and JARA-FIT, RWTH Aachen University, 52074 Aachen, Germany
| | - Kenji Watanabe
- Research Center for Functional Materials, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
| | - Takashi Taniguchi
- International Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
| | - Christoph Stampfer
- 2nd Institute of Physics and JARA-FIT, RWTH Aachen University, 52074 Aachen, Germany
- Peter Grünberg Institute (PGI-9) Forschungszentrum Jülich, 52425 Jülich, Germany
| | - Bernd Beschoten
- 2nd Institute of Physics and JARA-FIT, RWTH Aachen University, 52074 Aachen, Germany
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20
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Pal A, Zhang S, Chavan T, Agashiwala K, Yeh CH, Cao W, Banerjee K. Quantum-Engineered Devices Based on 2D Materials for Next-Generation Information Processing and Storage. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2022:e2109894. [PMID: 35468661 DOI: 10.1002/adma.202109894] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2021] [Revised: 04/11/2022] [Indexed: 06/14/2023]
Abstract
As an approximation to the quantum state of solids, the band theory, developed nearly seven decades ago, fostered the advance of modern integrated solid-state electronics, one of the most successful technologies in the history of human civilization. Nonetheless, their rapidly growing energy consumption and accompanied environmental issues call for more energy-efficient electronics and optoelectronics, which necessitate the exploration of more advanced quantum mechanical effects, such as band-to-band tunneling, spin-orbit coupling, spin-valley locking, and quantum entanglement. The emerging 2D layered materials, featured by their exotic electrical, magnetic, optical, and structural properties, provide a revolutionary low-dimensional and manufacture-friendly platform (and many more opportunities) to implement these quantum-engineered devices, compared to the traditional electronic materials system. Here, the progress in quantum-engineered devices is reviewed and the opportunities/challenges of exploiting 2D materials are analyzed to highlight their unique quantum properties that enable novel energy-efficient devices, and useful insights to quantum device engineers and 2D-material scientists are provided.
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Affiliation(s)
- Arnab Pal
- ECE Department, University of California, Santa Barbara, Santa Barbara, CA, 93106, USA
| | - Shuo Zhang
- ECE Department, University of California, Santa Barbara, Santa Barbara, CA, 93106, USA
- College of ISEE, Zhejiang University, Hangzhou, 310027, China
| | - Tanmay Chavan
- ECE Department, University of California, Santa Barbara, Santa Barbara, CA, 93106, USA
| | - Kunjesh Agashiwala
- ECE Department, University of California, Santa Barbara, Santa Barbara, CA, 93106, USA
| | - Chao-Hui Yeh
- ECE Department, University of California, Santa Barbara, Santa Barbara, CA, 93106, USA
| | - Wei Cao
- ECE Department, University of California, Santa Barbara, Santa Barbara, CA, 93106, USA
| | - Kaustav Banerjee
- ECE Department, University of California, Santa Barbara, Santa Barbara, CA, 93106, USA
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21
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He K, Barut B, Yin S, Randle MD, Dixit R, Arabchigavkani N, Nathawat J, Mahmood A, Echtenkamp W, Binek C, Dowben PA, Bird JP. Graphene on Chromia: A System for Beyond-Room-Temperature Spintronics. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2022; 34:e2105023. [PMID: 34986269 DOI: 10.1002/adma.202105023] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 12/23/2021] [Indexed: 06/14/2023]
Abstract
Evidence of robust spin-dependent transport in monolayer graphene, deposited on the (0001) surface of the antiferromagnetic (AFM)/magneto-electric oxide chromia (Cr2 O3 ), is provided. Measurements performed in the non-local spin-Hall geometry reveal a robust signal that is present at zero external magnetic field and which is significantly larger than any possible ohmic contribution. The spin-related signal persists well beyond the Néel temperature (≈307 K) that defines the transition between the AFM and paramagnetic states, remaining visible at the highest studied temperature of close to 450 K. This robust character is consistent with prior theoretical studies of the graphene/Cr2 O3 system, predicting that the lifting of sub-lattice symmetry in the graphene shall induce an effective spin-orbit term of ≈40 meV. Overall, the results indicate that graphene-on-chromia heterostructures are a highly promising framework for the implementation of spintronic devices, capable of operation well beyond room temperature.
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Affiliation(s)
- Keke He
- Department of Electrical Engineering, University at Buffalo, The State University of New York, Buffalo, New York, 14260, USA
| | - Bilal Barut
- Department of Electrical Engineering, University at Buffalo, The State University of New York, Buffalo, New York, 14260, USA
| | - Shenchu Yin
- Department of Electrical Engineering, University at Buffalo, The State University of New York, Buffalo, New York, 14260, USA
| | - Michael D Randle
- Department of Electrical Engineering, University at Buffalo, The State University of New York, Buffalo, New York, 14260, USA
| | - Ripudaman Dixit
- Department of Electrical Engineering, University at Buffalo, The State University of New York, Buffalo, New York, 14260, USA
| | - Nargess Arabchigavkani
- Department of Electrical Engineering, University at Buffalo, The State University of New York, Buffalo, New York, 14260, USA
| | - Jubin Nathawat
- Department of Electrical Engineering, University at Buffalo, The State University of New York, Buffalo, New York, 14260, USA
| | - Ather Mahmood
- Department of Physics and Astronomy, Theodore Jorgensen Hall, University of Nebraska Lincoln, Lincoln, Nebraska, 68588-0299, USA
| | - Will Echtenkamp
- Department of Physics and Astronomy, Theodore Jorgensen Hall, University of Nebraska Lincoln, Lincoln, Nebraska, 68588-0299, USA
| | - Christian Binek
- Department of Physics and Astronomy, Theodore Jorgensen Hall, University of Nebraska Lincoln, Lincoln, Nebraska, 68588-0299, USA
| | - Peter A Dowben
- Department of Physics and Astronomy, Theodore Jorgensen Hall, University of Nebraska Lincoln, Lincoln, Nebraska, 68588-0299, USA
| | - Jonathan P Bird
- Department of Electrical Engineering, University at Buffalo, The State University of New York, Buffalo, New York, 14260, USA
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22
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Spin-orbit coupling in buckled monolayer nitrogene. Sci Rep 2022; 12:3201. [PMID: 35217687 PMCID: PMC8881460 DOI: 10.1038/s41598-022-07215-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Accepted: 02/07/2022] [Indexed: 11/25/2022] Open
Abstract
Buckled monolayer nitrogene has been recently predicted to be stable above the room temperature. The low atomic number of nitrogen atom suggests, that spin–orbit coupling in nitrogene is weak, similar to graphene or silicene. We employ first principles calculations and perform a systematic study of the intrinsic and extrinsic spin–orbit coupling in this material. We calculate the spin mixing parameter \documentclass[12pt]{minimal}
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\begin{document}$$\Omega$$\end{document}Ω is also anisotropic, in particular for the conduction electrons.
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23
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Yu S, Tang J, Wang Y, Xu F, Li X, Wang X. Recent advances in two-dimensional ferromagnetism: strain-, doping-, structural- and electric field-engineering toward spintronic applications. SCIENCE AND TECHNOLOGY OF ADVANCED MATERIALS 2022; 23:140-160. [PMID: 35185390 PMCID: PMC8856075 DOI: 10.1080/14686996.2022.2030652] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2021] [Revised: 01/03/2022] [Accepted: 01/09/2022] [Indexed: 05/27/2023]
Abstract
Since the first report on truly two-dimensional (2D) magnetic materials in 2017, a wide variety of merging 2D magnetic materials with unusual physical characteristics have been discovered and thus provide an effective platform for exploring the associated novel 2D spintronic devices, which have been made significant progress in both theoretical and experimental studies. Herein, we make a comprehensive review on the recent scientific endeavors and advances on the various engineering strategies on 2D ferromagnets, such as strain-, doping-, structural- and electric field-engineering, toward practical spintronic applications, including spin tunneling junctions, spin field-effect transistors and spin logic gate, etc. In the last, we discuss on current challenges and future opportunities in this field, which may provide useful guidelines for scientists who are exploring the fundamental physical properties and practical spintronic devices of low-dimensional magnets.
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Affiliation(s)
- Sheng Yu
- Institute of Information Technology, Shenzhen Institute of Information Technology, Shenzhen, China
- Institute for Advanced Study, Shenzhen University, Shenzhen, China
| | - Junyu Tang
- Department of Physics and Astronomy, University of California, Riverside, CA, USA
| | - Yu Wang
- Institute for Advanced Study, Shenzhen University, Shenzhen, China
| | - Feixiang Xu
- Institute for Advanced Study, Shenzhen University, Shenzhen, China
| | - Xiaoguang Li
- Institute for Advanced Study, Shenzhen University, Shenzhen, China
| | - Xinzhong Wang
- Institute of Information Technology, Shenzhen Institute of Information Technology, Shenzhen, China
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24
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Guarochico-Moreira V, Sambricio JL, Omari K, Anderson CR, Bandurin DA, Toscano-Figueroa JC, Natera-Cordero N, Watanabe K, Taniguchi T, Grigorieva IV, Vera-Marun IJ. Tunable Spin Injection in High-Quality Graphene with One-Dimensional Contacts. NANO LETTERS 2022; 22:935-941. [PMID: 35089714 PMCID: PMC9098166 DOI: 10.1021/acs.nanolett.1c03625] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Revised: 01/20/2022] [Indexed: 06/09/2023]
Abstract
Spintronics involves the development of low-dimensional electronic systems with potential use in quantum-based computation. In graphene, there has been significant progress in improving spin transport characteristics by encapsulation and reducing impurities, but the influence of standard two-dimensional (2D) tunnel contacts, via pinholes and doping of the graphene channel, remains difficult to eliminate. Here, we report the observation of spin injection and tunable spin signal in fully encapsulated graphene, enabled by van der Waals heterostructures with one-dimensional (1D) contacts. This architecture prevents significant doping from the contacts, enabling high-quality graphene channels, currently with mobilities up to 130 000 cm2 V-1 s-1 and spin diffusion lengths approaching 20 μm. The nanoscale-wide 1D contacts allow spin injection both at room and at low temperature, with the latter exhibiting efficiency comparable with 2D tunnel contacts. At low temperature, the spin signals can be enhanced by as much as an order of magnitude by electrostatic gating, adding new functionality.
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Affiliation(s)
- Victor
H. Guarochico-Moreira
- Department
of Physics and Astronomy, University of
Manchester, Manchester M13 9PL, U.K.
- Facultad
de Ciencias Naturales y Matemáticas, Escuela Superior Politécnica del Litoral, ESPOL, Campus Gustavo Galindo, Km. 30.5
Vía Perimetral, P.O. Box 09-01-5863, 090902 Guayaquil, Ecuador
| | - Jose L. Sambricio
- Department
of Physics and Astronomy, University of
Manchester, Manchester M13 9PL, U.K.
| | - Khalid Omari
- Department
of Physics and Astronomy, University of
Manchester, Manchester M13 9PL, U.K.
| | | | - Denis A. Bandurin
- Department
of Physics and Astronomy, University of
Manchester, Manchester M13 9PL, U.K.
| | - Jesus C. Toscano-Figueroa
- Department
of Physics and Astronomy, University of
Manchester, Manchester M13 9PL, U.K.
- Consejo
Nacional de Ciencia y Tecnología (CONACyT), Av. Insurgentes Sur 1582, Col. Crédito Constructor, Alcaldía Benito Juarez, C.P. 03940, Ciudad de México, México
| | - Noel Natera-Cordero
- Department
of Physics and Astronomy, University of
Manchester, Manchester M13 9PL, U.K.
- Consejo
Nacional de Ciencia y Tecnología (CONACyT), Av. Insurgentes Sur 1582, Col. Crédito Constructor, Alcaldía Benito Juarez, C.P. 03940, Ciudad de México, México
| | - Kenji Watanabe
- National
Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
| | - Takashi Taniguchi
- National
Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
| | - Irina V. Grigorieva
- Department
of Physics and Astronomy, University of
Manchester, Manchester M13 9PL, U.K.
| | - Ivan J. Vera-Marun
- Department
of Physics and Astronomy, University of
Manchester, Manchester M13 9PL, U.K.
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25
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Tretyakov EV, Ovcharenko VI, Terent'ev AO, Krylov IB, Magdesieva TV, Mazhukin DG, Gritsan NP. Conjugated nitroxide radicals. RUSSIAN CHEMICAL REVIEWS 2022. [DOI: 10.1070/rcr5025] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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26
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Chen X, Zheng S, Wang XP, Wang HY. Ultrafast dynamics of spin relaxation in monolayer WSe2 and WSe2/graphene heterojunction. Phys Chem Chem Phys 2022; 24:16538-16544. [DOI: 10.1039/d2cp02105f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Excitonic devices based on two-dimensional (2D) transition metal dichalcogenides (TMDCs) can combine spintronics with valleytronics due to its special energy band structure. In this work, we studied the generation and...
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27
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Xu J, Takenaka H, Habib A, Sundararaman R, Ping Y. Giant Spin Lifetime Anisotropy and Spin-Valley Locking in Silicene and Germanene from First-Principles Density-Matrix Dynamics. NANO LETTERS 2021; 21:9594-9600. [PMID: 34767368 DOI: 10.1021/acs.nanolett.1c03345] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Through first-principles real-time density-matrix (FPDM) dynamics simulations, we investigated spin relaxation due to electron-phonon and electron-impurity scatterings with spin-orbit coupling (SOC) in two-dimensional Dirac materials silicene and germanene at finite temperatures. We discussed the applicability of conventional descriptions of spin relaxation mechanisms by Elliott-Yafet (EY) and D'yakonov-Perel' (DP) compared to the FPDM method, which is determined by a complex interplay of intrinsic SOC, external fields, and scattering strength. For example, the electric field dependence of the spin lifetime by FPDM is close to the DP mechanism for silicene at room temperature but similar to the EY mechanism for germanene. Because of its stronger SOC strength and buckled structure in contrast to graphene, germanene has a giant spin lifetime anisotropy and spin-valley locking effect under nonzero Ez and low temperatures. More importantly, germanene has a long spin lifetime (∼100 ns at 50 K) and an ultrahigh carrier mobility, making it advantageous for spin-valleytronic applications.
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Affiliation(s)
- Junqing Xu
- Department of Chemistry and Biochemistry, University of California, Santa Cruz, California 95064, United States
| | - Hiroyuki Takenaka
- Department of Chemistry and Biochemistry, University of California, Santa Cruz, California 95064, United States
| | - Adela Habib
- Department of Physics, Applied Physics and Astronomy, Rensselaer Polytechnic Institute, 110 Eighth Street, Troy, New York 12180, United States
- Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87544, United States
| | - Ravishankar Sundararaman
- Department of Materials Science and Engineering, Rensselaer Polytechnic Institute, 110 Eighth Street, Troy, New York 12180, United States
| | - Yuan Ping
- Department of Chemistry and Biochemistry, University of California, Santa Cruz, California 95064, United States
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28
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Juma IG, Kim G, Jariwala D, Behura SK. Direct growth of hexagonal boron nitride on non-metallic substrates and its heterostructures with graphene. iScience 2021; 24:103374. [PMID: 34816107 PMCID: PMC8593561 DOI: 10.1016/j.isci.2021.103374] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Hexagonal boron nitride (h-BN) and its heterostructures with graphene are widely investigated van der Waals (vdW) quantum materials for electronics, photonics, sensing, and energy storage/transduction. However, their metal catalyst-based growth and transfer-based heterostructure assembly approaches present impediments to obtaining high-quality and wafer-scale quantum material. Here, we have presented our perspective on the synthetic strategies that involve direct nucleation of h-BN on various dielectric substrates and its heterostructures with graphene. Mechanistic understanding of direct growth of h-BN via bottom-up approaches such as (a) the chemical-interaction guided nucleation on silicon-based dielectrics, (b) surface nitridation and N+ sputtering of h-BN target on sapphire, and (c) epitaxial growth of h-BN on sapphire, among others, are reviewed. Several design methodologies are presented for the direct growth of vertical and lateral vdW heterostructures of h-BN and graphene. These complex 2D heterostructures exhibit various physical phenomena and could potentially have a range of practical applications.
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Affiliation(s)
- Isaac G. Juma
- Department of Chemistry and Physics, University of Arkansas at Pine Bluff, 1200 N. University Drive, Pine Bluff, AR 71601, USA
- Department of Mathematics and Computer Science, University of Arkansas at Pine Bluff, 1200 N. University Drive, Pine Bluff, AR 71601, USA
| | - Gwangwoo Kim
- Department of Electrical and Systems Engineering, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Deep Jariwala
- Department of Electrical and Systems Engineering, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Sanjay K. Behura
- Department of Chemistry and Physics, University of Arkansas at Pine Bluff, 1200 N. University Drive, Pine Bluff, AR 71601, USA
- Department of Mathematics and Computer Science, University of Arkansas at Pine Bluff, 1200 N. University Drive, Pine Bluff, AR 71601, USA
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29
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Wu R, Hu Y, Li P, Peng J, Hu J, Yang M, Chen D, Guo Y, Zhang Q, Xie X, Dai J, Qiu W, Wang G, Pan M. Controlled Epitaxial Growth and Atomically Sharp Interface of Graphene/Ferromagnetic Heterostructure via Ambient Pressure Chemical Vapor Deposition. NANOMATERIALS (BASEL, SWITZERLAND) 2021; 11:3112. [PMID: 34835878 PMCID: PMC8620976 DOI: 10.3390/nano11113112] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/04/2021] [Revised: 11/12/2021] [Accepted: 11/13/2021] [Indexed: 11/25/2022]
Abstract
The strong spin filtering effect can be produced by C-Ni atomic orbital hybridization in lattice-matched graphene/Ni (111) heterostructures, which provides an ideal platform to improve the tunnel magnetoresistance (TMR) of magnetic tunnel junctions (MTJs). However, large-area, high-quality graphene/ferromagnetic epitaxial interfaces are mainly limited by the single-crystal size of the Ni (111) substrate and well-oriented graphene domains. In this work, based on the preparation of a 2-inch single-crystal Ni (111) film on an Al2O3 (0001) wafer, we successfully achieve the production of a full-coverage, high-quality graphene monolayer on a Ni (111) substrate with an atomically sharp interface via ambient pressure chemical vapor deposition (APCVD). The high crystallinity and strong coupling of the well-oriented epitaxial graphene/Ni (111) interface are systematically investigated and carefully demonstrated. Through the analysis of the growth model, it is shown that the oriented growth induced by the Ni (111) crystal, the optimized graphene nucleation and the subsurface carbon density jointly contribute to the resulting high-quality graphene/Ni (111) heterostructure. Our work provides a convenient approach for the controllable fabrication of a large-area homogeneous graphene/ferromagnetic interface, which would benefit interface engineering of graphene-based MTJs and future chip-level 2D spintronic applications.
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Affiliation(s)
- Ruinan Wu
- College of Intelligence Science and Technology, National University of Defense Technology, Changsha 410073, China; (R.W.); (Y.H.); (P.L.); (J.P.); (J.H.); (D.C.); (Y.G.); (Q.Z.)
| | - Yueguo Hu
- College of Intelligence Science and Technology, National University of Defense Technology, Changsha 410073, China; (R.W.); (Y.H.); (P.L.); (J.P.); (J.H.); (D.C.); (Y.G.); (Q.Z.)
| | - Peisen Li
- College of Intelligence Science and Technology, National University of Defense Technology, Changsha 410073, China; (R.W.); (Y.H.); (P.L.); (J.P.); (J.H.); (D.C.); (Y.G.); (Q.Z.)
| | - Junping Peng
- College of Intelligence Science and Technology, National University of Defense Technology, Changsha 410073, China; (R.W.); (Y.H.); (P.L.); (J.P.); (J.H.); (D.C.); (Y.G.); (Q.Z.)
| | - Jiafei Hu
- College of Intelligence Science and Technology, National University of Defense Technology, Changsha 410073, China; (R.W.); (Y.H.); (P.L.); (J.P.); (J.H.); (D.C.); (Y.G.); (Q.Z.)
| | - Ming Yang
- Department of Physics, College of Liberal Arts and Sciences, National University of Defense Technology, Changsha 410073, China; (M.Y.); (J.D.)
| | - Dixiang Chen
- College of Intelligence Science and Technology, National University of Defense Technology, Changsha 410073, China; (R.W.); (Y.H.); (P.L.); (J.P.); (J.H.); (D.C.); (Y.G.); (Q.Z.)
| | - Yanrui Guo
- College of Intelligence Science and Technology, National University of Defense Technology, Changsha 410073, China; (R.W.); (Y.H.); (P.L.); (J.P.); (J.H.); (D.C.); (Y.G.); (Q.Z.)
| | - Qi Zhang
- College of Intelligence Science and Technology, National University of Defense Technology, Changsha 410073, China; (R.W.); (Y.H.); (P.L.); (J.P.); (J.H.); (D.C.); (Y.G.); (Q.Z.)
| | - Xiangnan Xie
- State Key Laboratory of High Performance Computing, College of Computer Science and Technology, National University of Defense Technology, Changsha 410073, China;
| | - Jiayu Dai
- Department of Physics, College of Liberal Arts and Sciences, National University of Defense Technology, Changsha 410073, China; (M.Y.); (J.D.)
| | - Weicheng Qiu
- College of Intelligence Science and Technology, National University of Defense Technology, Changsha 410073, China; (R.W.); (Y.H.); (P.L.); (J.P.); (J.H.); (D.C.); (Y.G.); (Q.Z.)
| | - Guang Wang
- Department of Physics, College of Liberal Arts and Sciences, National University of Defense Technology, Changsha 410073, China; (M.Y.); (J.D.)
- State Key Laboratory of Low-Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084, China
| | - Mengchun Pan
- College of Intelligence Science and Technology, National University of Defense Technology, Changsha 410073, China; (R.W.); (Y.H.); (P.L.); (J.P.); (J.H.); (D.C.); (Y.G.); (Q.Z.)
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30
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Sierra JF, Fabian J, Kawakami RK, Roche S, Valenzuela SO. Van der Waals heterostructures for spintronics and opto-spintronics. NATURE NANOTECHNOLOGY 2021; 16:856-868. [PMID: 34282312 DOI: 10.1038/s41565-021-00936-x] [Citation(s) in RCA: 116] [Impact Index Per Article: 38.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2020] [Accepted: 06/03/2021] [Indexed: 06/13/2023]
Abstract
The large variety of 2D materials and their co-integration in van der Waals heterostructures enable innovative device engineering. In addition, their atomically thin nature promotes the design of artificial materials by proximity effects that originate from short-range interactions. Such a designer approach is particularly compelling for spintronics, which typically harnesses functionalities from thin layers of magnetic and non-magnetic materials and the interfaces between them. Here we provide an overview of recent progress in 2D spintronics and opto-spintronics using van der Waals heterostructures. After an introduction to the forefront of spin transport research, we highlight the unique spin-related phenomena arising from spin-orbit and magnetic proximity effects. We further describe the ability to create multifunctional hybrid heterostructures based on van der Waals materials, combining spin, valley and excitonic degrees of freedom. We end with an outlook on perspectives and challenges for the design and production of ultracompact all-2D spin devices and their potential applications in conventional and quantum technologies.
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Affiliation(s)
- Juan F Sierra
- Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and The Barcelona Institute of Science and Technology (BIST), Barcelona, Spain.
| | - Jaroslav Fabian
- Institute for Theoretical Physics, University of Regensburg, Regensburg, Germany
| | | | - Stephan Roche
- Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and The Barcelona Institute of Science and Technology (BIST), Barcelona, Spain
- Institució Catalana de Recerca i Estudis Avançats (ICREA), Barcelona, Spain
| | - Sergio O Valenzuela
- Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and The Barcelona Institute of Science and Technology (BIST), Barcelona, Spain.
- Institució Catalana de Recerca i Estudis Avançats (ICREA), Barcelona, Spain.
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31
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Chen Z, Li G, Wang H, Tang Q, Li Z. Substantial and stable magnetoresistance and spin conductance in phosphorene-based spintronic devices with Co electrodes. Phys Chem Chem Phys 2021; 23:10573-10579. [PMID: 33903865 DOI: 10.1039/d1cp00070e] [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
Designing devices with excellent spin-polarized properties has been a challenge in physics and materials science. In this work, we report a theoretical investigation of the spin injection and spin-polarized transport properties of monolayer and bilayer phosphorene devices with Co electrodes. Based on the analysis of transmission coefficients, spin-polarized current, magnetoresistance (MR) (or tunnel MR) ratio and spin injection efficiency (SIE), both devices show superior spin-polarized transport properties. As phosphorene in the device is changed from monolayer to bilayer, the charge carrier type can be tuned from n-type to p-type. For the monolayer phosphorene device, the tunnel MR ratio reaches about 210% and the SIE is about 80.7% at zero bias. Notably, the SIE and tunnel MR ratio maintain almost constant values against bias voltage and gate voltage, which makes it suitable for magnetic sensors. As for the bilayer phosphorene device, it not only exhibits a considerable tunnel MR ratio, but also shows significantly enhanced conductance, beneficial to the sensitivity of spintronic devices. Further analysis shows that the improvement of conductance is attributed to the low barrier height between the bilayer phosphorene channel and Co electrodes. According to our results, the studied phosphorene devices with Co electrodes demonstrate superior spin injection and transport properties. We believe that these theoretical findings will be a strong asset for future experimental works in spintronics.
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Affiliation(s)
- Zhao Chen
- School of Electronic Science and Applied Physics, Hefei University of Technology, Hefei, Anhui 230009, China.
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32
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Stephen GM, Hanbicki AT, Schumann T, Robinson JT, Goyal M, Stemmer S, Friedman AL. Room-Temperature Spin Transport in Cd 3As 2. ACS NANO 2021; 15:5459-5466. [PMID: 33705102 DOI: 10.1021/acsnano.1c00154] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
As the need for ever greater transistor density increases, the commensurate decrease in device size approaches the atomic limit, leading to increased energy loss and leakage currents, reducing energy efficiencies. Alternative state variables, such as electronic spin rather than electronic charge, have the potential to enable more energy-efficient and higher performance devices. These spintronic devices require materials capable of efficiently harnessing the electron spin. Here we show robust spin transport in Cd3As2 films up to room temperature. We demonstrate a nonlocal spin valve switch from this material, as well as inverse spin Hall effect measurements yielding spin Hall angles as high as θSH = 1.5 and spin diffusion lengths of 10-40 μm. Long spin-coherence lengths with efficient charge-to-spin conversion rates and coherent spin transport up to room temperature, as we show here in Cd3As2, are enabling steps toward realizing actual spintronic devices.
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Affiliation(s)
- Gregory M Stephen
- Laboratory for Physical Sciences, 8050 Greenmead Drive, College Park, Maryland 20740, United States
| | - Aubrey T Hanbicki
- Laboratory for Physical Sciences, 8050 Greenmead Drive, College Park, Maryland 20740, United States
| | - Timo Schumann
- Materials Department, University of California, Santa Barbara, California 93106-5050, United States
| | - Jeremy T Robinson
- Electronics Science and Technology Division, Naval Research Laboratory, 4555 Overlook Avenue, S.W., Washington, D.C. 20375, United States
| | - Manik Goyal
- Materials Department, University of California, Santa Barbara, California 93106-5050, United States
| | - Susanne Stemmer
- Materials Department, University of California, Santa Barbara, California 93106-5050, United States
| | - Adam L Friedman
- Laboratory for Physical Sciences, 8050 Greenmead Drive, College Park, Maryland 20740, United States
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33
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Hassanzadeh P. The capabilities of nanoelectronic 2-D materials for bio-inspired computing and drug delivery indicate their significance in modern drug design. Life Sci 2021; 279:119272. [PMID: 33631171 DOI: 10.1016/j.lfs.2021.119272] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2020] [Revised: 02/10/2021] [Accepted: 02/19/2021] [Indexed: 12/13/2022]
Abstract
Remarkable advancements in the computational techniques and nanoelectronics have attracted considerable interests for development of highly-sophisticated materials (Ms) including the theranostics with optimal characteristics and innovative delivery systems. Analyzing the huge amounts of multivariate data and solving the newly-emerged complicated problems including the healthcare-related ones have created increasing demands for improving the computational speed and minimizing the consumption of energy. Shifting towards the non-von Neumann approaches enables performing specific computational tasks and optimizing the processing of signals. Besides usefulness for neuromorphic computing and increasing the efficiency of computation energy, 2-D electronic Ms are capable of optical sensing with ultra-fast and ultra-sensitive responses, mimicking the neurons, detection of pathogens or biomolecules, and prediction of the progression of diseases, assessment of the pharmacokinetics/pharmacodynamics of therapeutic candidates, mimicking the dynamics of the release of neurotransmitters or fluxes of ions that might provide a deeper knowledge about the computations and information flow in the brain, and development of more effective treatment protocols with improved outcomes. 2-D Ms appear as the major components of the next-generation electronically-enabled devices for highly-advanced computations, bio-imaging, diagnostics, tissue engineering, and designing smart systems for site-specific delivery of therapeutics that might result in the reduced adverse effects of drugs and improved patient compliance. This manuscript highlights the significance of 2-D Ms in the neuromorphic computing, optimizing the energy efficiency of the multi-step computations, providing novel architectures or multi-functional systems, improved performance of a variety of devices and bio-inspired functionalities, and delivery of theranostics.
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Affiliation(s)
- Parichehr Hassanzadeh
- Nanotechnology Research Center, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran 13169-43551, Iran.
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34
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Chu J, Wang Y, Wang X, Hu K, Rao G, Gong C, Wu C, Hong H, Wang X, Liu K, Gao C, Xiong J. 2D Polarized Materials: Ferromagnetic, Ferrovalley, Ferroelectric Materials, and Related Heterostructures. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2021; 33:e2004469. [PMID: 33325574 DOI: 10.1002/adma.202004469] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Revised: 07/21/2020] [Indexed: 06/12/2023]
Abstract
The emergence of 2D polarized materials, including ferromagnetic, ferrovalley, and ferroelectric materials, has demonstrated unique quantum behaviors at atomic scales. These polarization behaviors are tightly bonded to the new degrees of freedom (DOFs) for next generation information storage and processing, which have been dramatically developed in the past few years. Here, the basic 2D polarized materials system and related devices' application in spintronics, valleytronics, and electronics are reviewed. Specifically, the underlying physical mechanism accompanied with symmetry broken theory and the modulation process through heterostructure engineering are highlighted. These summarized works focusing on the 2D polarization would continue to enrich the cognition of 2D quantum system and promising practical applications.
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Affiliation(s)
- Junwei Chu
- State Key Laboratory of Electronic Thin Film and Integrated Devices, University of Electronic Science and Technology of China, Chengdu, 610054, China
| | - Yang Wang
- State Key Laboratory of Electronic Thin Film and Integrated Devices, University of Electronic Science and Technology of China, Chengdu, 610054, China
| | - Xuepeng Wang
- State Key Laboratory of Electronic Thin Film and Integrated Devices, University of Electronic Science and Technology of China, Chengdu, 610054, China
| | - Kai Hu
- State Key Laboratory of Electronic Thin Film and Integrated Devices, University of Electronic Science and Technology of China, Chengdu, 610054, China
| | - Gaofeng Rao
- State Key Laboratory of Electronic Thin Film and Integrated Devices, University of Electronic Science and Technology of China, Chengdu, 610054, China
| | - Chuanhui Gong
- State Key Laboratory of Electronic Thin Film and Integrated Devices, University of Electronic Science and Technology of China, Chengdu, 610054, China
| | - Chunchun Wu
- State Key Laboratory of Electronic Thin Film and Integrated Devices, University of Electronic Science and Technology of China, Chengdu, 610054, China
| | - Hao Hong
- State Key Laboratory for Mesoscopic Physics, Collaborative Innovation Center of Quantum Matter, School of Physics, Peking University, Beijing, 100871, China
| | - Xianfu Wang
- State Key Laboratory of Electronic Thin Film and Integrated Devices, University of Electronic Science and Technology of China, Chengdu, 610054, China
| | - Kaihui Liu
- State Key Laboratory for Mesoscopic Physics, Collaborative Innovation Center of Quantum Matter, School of Physics, Peking University, Beijing, 100871, China
| | - Chunlei Gao
- State Key Laboratory of Surface Physics, Key Laboratory of Micro and Nano Photonic Structures (MOE), Department of Physics, and Institute for Nanoelectronic Devices and Quantum Computing, Fudan University, Shanghai, 200433, China
| | - Jie Xiong
- State Key Laboratory of Electronic Thin Film and Integrated Devices, University of Electronic Science and Technology of China, Chengdu, 610054, China
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35
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Hu G, Xiang B. Recent Advances in Two-Dimensional Spintronics. NANOSCALE RESEARCH LETTERS 2020; 15:226. [PMID: 33296058 PMCID: PMC7726086 DOI: 10.1186/s11671-020-03458-y] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Accepted: 11/29/2020] [Indexed: 05/06/2023]
Abstract
Spintronics is the most promising technology to develop alternative multi-functional, high-speed, low-energy electronic devices. Due to their unusual physical characteristics, emerging two-dimensional (2D) materials provide a new platform for exploring novel spintronic devices. Recently, 2D spintronics has made great progress in both theoretical and experimental researches. Here, the progress of 2D spintronics has been reviewed. In the last, the current challenges and future opportunities have been pointed out in this field.
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Affiliation(s)
- Guojing Hu
- Department of Materials Science and Engineering, CAS Key Lab of Materials for Energy Conversion, Hefei National Research Center for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, 230026 Anhui China
- Anhui Laboratory of Advanced Photon Science and Technology, University of Science and Technology of China, Hefei, 230026 China
| | - Bin Xiang
- Department of Materials Science and Engineering, CAS Key Lab of Materials for Energy Conversion, Hefei National Research Center for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, 230026 Anhui China
- Anhui Laboratory of Advanced Photon Science and Technology, University of Science and Technology of China, Hefei, 230026 China
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36
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Sukhanova EV, Kvashnin DG, Popov ZI. Induced spin polarization in graphene via interactions with halogen doped MoS 2 and MoSe 2 monolayers by DFT calculations. NANOSCALE 2020; 12:23248-23258. [PMID: 33206100 DOI: 10.1039/d0nr06287a] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Magnetic halogen doped MoX2 (X = S and Se) monolayers influenced the electronic structure of graphene through a proximity effect. This process was observed using state-of-the-art calculations. It was found that the substitution of a single chalcogen atom with a halogen atom (F, Cl, Br, and I) results in n-type doping of MoX2. An additional electron from the dopant is localized on binding orbitals with the nearest Mo atoms and leads to the formation of magnetism in the dichalcogenide layer. Detailed analysis of halogen doped MoX2/graphene heterostructures demonstrated the induction of spin polarization in graphene near the Fermi energy. Significant spin polarization near the Fermi energy and n-type doping were observed in the graphene layer of MoSe2/graphene heterostructures with MoSe2 doped with iodine. At the same time, fluorine-doped MoSe2 does not cause n-doping in graphene, while spin polarization still takes place. The possibility for the detection of the arrangement of the halogen impurities at the MoX2 basal plane even with the graphene layer deposited on top was demonstrated through STM measurements which will be undoubtedly useful for the fabrication of electronic schemes and elements based on the proposed heterostructures for their further application in nanoelectronics and spintronics.
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Affiliation(s)
- Ekaterina V Sukhanova
- Moscow Institute of Physics and Technology (State University), 9 Institutskiy per., Dolgoprudny, Moscow Region, 141701, Russian Federation.
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37
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Panda J, Ramu M, Karis O, Sarkar T, Kamalakar MV. Ultimate Spin Currents in Commercial Chemical Vapor Deposited Graphene. ACS NANO 2020; 14:12771-12780. [PMID: 32945650 PMCID: PMC7596785 DOI: 10.1021/acsnano.0c03376] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Accepted: 09/18/2020] [Indexed: 06/01/2023]
Abstract
Establishing ultimate spin current efficiency in graphene over industry-standard substrates can facilitate research and development exploration of spin current functions and spin sensing. At the same time, it can resolve core issues in spin relaxation physics while addressing the skepticism of graphene's practicality for planar spintronic applications. In this work, we reveal an exceptionally long spin communication capability of 45 μm and highest to date spin diffusion length of 13.6 μm in graphene on SiO2/Si at room temperature. Employing commercial chemical vapor deposited (CVD) graphene, we show how contact-induced surface charge transfer doping and device doping contributions, as well as spin relaxation, can be quenched in extremely long spin channels and thereby enable unexpectedly long spin diffusion lengths in polycrystalline CVD graphene. Extensive experiments show enhanced spin transport and precession in multiple longest channels (36 and 45 μm) that reveal the highest spin lifetime of ∼2.5-3.5 ns in graphene over SiO2/Si, even under ambient conditions. Such performance, made possible due to our devices approaching the intrinsic spin-orbit coupling of ∼20 μeV in graphene, reveals the role of the D'yakonov-Perel' spin relaxation mechanism in graphene channels as well as contact regions. Our record demonstration, fresh device engineering, and spin relaxation insights unlock the ultimate spin current capabilities of graphene on SiO2/Si, while the robust high performance of commercial CVD graphene can proliferate research and development of innovative spin sensors and spin computing circuits.
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Affiliation(s)
- J. Panda
- Department
of Physics and Astronomy, Uppsala University, Box 516, SE-751 20 Uppsala, Sweden
| | - M. Ramu
- Department
of Materials Science and Engineering, Uppsala
University, Box 35, SE-751 03 Uppsala, Sweden
| | - Olof Karis
- Department
of Physics and Astronomy, Uppsala University, Box 516, SE-751 20 Uppsala, Sweden
| | - Tapati Sarkar
- Department
of Materials Science and Engineering, Uppsala
University, Box 35, SE-751 03 Uppsala, Sweden
| | - M. Venkata Kamalakar
- Department
of Physics and Astronomy, Uppsala University, Box 516, SE-751 20 Uppsala, Sweden
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38
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Kochan D, Barth M, Costa A, Richter K, Fabian J. Spin Relaxation in s-Wave Superconductors in the Presence of Resonant Spin-Flip Scatterers. PHYSICAL REVIEW LETTERS 2020; 125:087001. [PMID: 32909806 DOI: 10.1103/physrevlett.125.087001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Revised: 05/22/2020] [Accepted: 07/22/2020] [Indexed: 06/11/2023]
Abstract
Employing analytical methods and quantum transport simulations we investigate the relaxation of quasiparticle spins in graphene proximitized by an s-wave superconductor in the presence of resonant magnetic and spin-orbit active impurities. Off resonance, the relaxation increases with decreasing temperature when electrons scatter off magnetic impurities-the Hebel-Slichter effect-and decreases when impurities have spin-orbit coupling. This distinct temperature dependence (not present in the normal state) uniquely discriminates between the two scattering mechanisms. However, we show that the Hebel-Slichter picture breaks down at resonances. The emergence of Yu-Shiba-Rusinov bound states within the superconducting gap redistributes the spectral weight away from magnetic resonances. The result is opposite to the Hebel-Slichter expectation: the spin relaxation decreases with decreasing temperature. Our findings hold for generic s-wave superconductors with resonant magnetic impurities, but also, as we show, for resonant magnetic Josephson junctions.
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Affiliation(s)
- Denis Kochan
- Institute for Theoretical Physics, University of Regensburg, 93040 Regensburg, Germany
| | - Michael Barth
- Institute for Theoretical Physics, University of Regensburg, 93040 Regensburg, Germany
| | - Andreas Costa
- Institute for Theoretical Physics, University of Regensburg, 93040 Regensburg, Germany
| | - Klaus Richter
- Institute for Theoretical Physics, University of Regensburg, 93040 Regensburg, Germany
| | - Jaroslav Fabian
- Institute for Theoretical Physics, University of Regensburg, 93040 Regensburg, Germany
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39
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Bonnet R, Martin P, Suffit S, Lafarge P, Lherbier A, Charlier JC, Della Rocca ML, Barraud C. Giant spin signals in chemically functionalized multiwall carbon nanotubes. SCIENCE ADVANCES 2020; 6:eaba5494. [PMID: 32789172 PMCID: PMC7399653 DOI: 10.1126/sciadv.aba5494] [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: 12/12/2019] [Accepted: 06/17/2020] [Indexed: 06/11/2023]
Abstract
Transporting quantum information such as the spin information over micrometric or even millimetric distances is a strong requirement for the next-generation electronic circuits such as low-voltage spin-logic devices. This crucial step of transportation remains delicate in nontopologically protected systems because of the volatile nature of spin states. Here, a beneficial combination of different phenomena is used to approach this sought-after milestone for the beyond-Complementary Metal Oxide Semiconductor (CMOS) technology roadmap. First, a strongly spin-polarized charge current is injected using highly spin-polarized hybridized states emerging at the complex ferromagnetic metal/molecule interfaces. Second, the spin information is brought toward the conducting inner shells of a multiwall carbon nanotube used as a confined nanoguide benefiting from both weak spin-orbit and hyperfine interactions. The spin information is finally electrically converted because of a strong magnetoresistive effect. The experimental results are also supported by calculations qualitatively revealing exceptional spin transport properties of this system.
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Affiliation(s)
- Roméo Bonnet
- Université de Paris, Laboratoire Matériaux et Phénomènes Quantiques, CNRS, UMR 7162, 75013 Paris, France
| | - Pascal Martin
- Université de Paris, ITODYS, CNRS, UMR 7086, 75013 Paris, France
| | - Stéphan Suffit
- Université de Paris, Laboratoire Matériaux et Phénomènes Quantiques, CNRS, UMR 7162, 75013 Paris, France
| | - Philippe Lafarge
- Université de Paris, Laboratoire Matériaux et Phénomènes Quantiques, CNRS, UMR 7162, 75013 Paris, France
| | - Aurélien Lherbier
- Institute of Condensed Matter and Nanosciences (IMCN), Université catholique de Louvain (UCLouvain), B-1348 Louvain-la-Neuve, Belgium
| | - Jean-Christophe Charlier
- Institute of Condensed Matter and Nanosciences (IMCN), Université catholique de Louvain (UCLouvain), B-1348 Louvain-la-Neuve, Belgium
| | - Maria Luisa Della Rocca
- Université de Paris, Laboratoire Matériaux et Phénomènes Quantiques, CNRS, UMR 7162, 75013 Paris, France
| | - Clément Barraud
- Université de Paris, Laboratoire Matériaux et Phénomènes Quantiques, CNRS, UMR 7162, 75013 Paris, France
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40
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Ten YA, Troshkova NM, Tretyakov EV. From spin-labelled fused polyaromatic compounds to magnetically active graphene nanostructures. RUSSIAN CHEMICAL REVIEWS 2020. [DOI: 10.1070/rcr4923] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Molecular design of magnetically active graphene nanoscale structures is an emerging field of research. The key goal of this research is to produce graphene nanoribbons and graphene quantum dots with specified electronic, optical and magnetic properties. The review considers methods for the synthesis of spin-labelled polycyclic aromatic hydrocarbons, which are homologous precursors of graphene nanostructures, and discusses the advances and prospects of the design of magnetically active graphene materials.
The bibliography includes 134 references.
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41
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Márkus BG, Szirmai P, Edelthalhammer KF, Eckerlein P, Hirsch A, Hauke F, Nemes NM, Chacón-Torres JC, Náfrádi B, Forró L, Pichler T, Simon F. Ultralong Spin Lifetime in Light Alkali Atom Doped Graphene. ACS NANO 2020; 14:7492-7501. [PMID: 32484657 PMCID: PMC7315639 DOI: 10.1021/acsnano.0c03191] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
Today's great challenges of energy and informational technologies are addressed with a singular compound, Li- and Na-doped few-layer graphene. All that is impossible for graphite (homogeneous and high-level Na doping) and unstable for single-layer graphene works very well for this structure. The transformation of the Raman G line to a Fano line shape and the emergence of strong, metallic-like electron spin resonance (ESR) modes attest the high level of graphene doping in liquid ammonia for both kinds of alkali atoms. The spin-relaxation time in our materials, deduced from the ESR line width, is 6-8 ns, which is comparable to the longest values found in spin-transport experiments on ultrahigh-mobility graphene flakes. This could qualify our material as a promising candidate in spintronics devices. On the other hand, the successful sodium doping, this being a highly abundant metal, could be an encouraging alternative to lithium batteries.
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Affiliation(s)
- B. G. Márkus
- Department
of Physics, Budapest University of Technology
and Economics and MTA-BME Lendület Spintronics Research Group
(PROSPIN), PO Box 91, H-1521 Budapest, Hungary
- Laboratory
of Physics of Complex Matter, École
Polytechnique Fédérale de Lausanne, Lausanne CH-1015, Switzerland
| | - P. Szirmai
- Laboratory
of Physics of Complex Matter, École
Polytechnique Fédérale de Lausanne, Lausanne CH-1015, Switzerland
| | - K. F. Edelthalhammer
- Department
of Chemistry and Pharmacy and Institute of Advanced Materials and
Processes (ZMP), University of Erlangen-Nürnberg, Nikolaus-Fiebiger-Strasse 10, 91058 Erlangen, Germany
| | - P. Eckerlein
- Department
of Chemistry and Pharmacy and Institute of Advanced Materials and
Processes (ZMP), University of Erlangen-Nürnberg, Nikolaus-Fiebiger-Strasse 10, 91058 Erlangen, Germany
| | - A. Hirsch
- Department
of Chemistry and Pharmacy and Institute of Advanced Materials and
Processes (ZMP), University of Erlangen-Nürnberg, Nikolaus-Fiebiger-Strasse 10, 91058 Erlangen, Germany
| | - F. Hauke
- Department
of Chemistry and Pharmacy and Institute of Advanced Materials and
Processes (ZMP), University of Erlangen-Nürnberg, Nikolaus-Fiebiger-Strasse 10, 91058 Erlangen, Germany
| | - N. M. Nemes
- GFMC,
Unidad Asociada ICMM-CSIC “Laboratorio de Heteroestructuras
con Aplicacion en Espintronica”, Departamento de Fisica de Materiales Universidad Complutense de Madrid, 28040 Madrid, Spain
| | - Julio C. Chacón-Torres
- Yachay
Tech University, School of Physical Sciences and Nanotechnology, 100119,
Urcuquí, Ecuador and Universidad UTE, Facultad de Ciencias,
Ingeniería y Construcción, 170147 Quito, Ecuador
| | - B. Náfrádi
- Laboratory
of Physics of Complex Matter, École
Polytechnique Fédérale de Lausanne, Lausanne CH-1015, Switzerland
| | - L. Forró
- Laboratory
of Physics of Complex Matter, École
Polytechnique Fédérale de Lausanne, Lausanne CH-1015, Switzerland
| | - T. Pichler
- Faculty
of Physics, University of Vienna, Strudlhofgasse 4, Vienna, A-1090, Austria
| | - F. Simon
- Department
of Physics, Budapest University of Technology
and Economics and MTA-BME Lendület Spintronics Research Group
(PROSPIN), PO Box 91, H-1521 Budapest, Hungary
- Laboratory
of Physics of Complex Matter, École
Polytechnique Fédérale de Lausanne, Lausanne CH-1015, Switzerland
- E-mail:
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42
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Vila M, Garcia JH, Cummings AW, Power SR, Groth CW, Waintal X, Roche S. Nonlocal Spin Dynamics in the Crossover from Diffusive to Ballistic Transport. PHYSICAL REVIEW LETTERS 2020; 124:196602. [PMID: 32469541 DOI: 10.1103/physrevlett.124.196602] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Accepted: 04/27/2020] [Indexed: 06/11/2023]
Abstract
Improved fabrication techniques have enabled the possibility of ballistic transport and unprecedented spin manipulation in ultraclean graphene devices. Spin transport in graphene is typically probed in a nonlocal spin valve and is analyzed using spin diffusion theory, but this theory is not necessarily applicable when charge transport becomes ballistic or when the spin diffusion length is exceptionally long. Here, we study these regimes by performing quantum simulations of graphene nonlocal spin valves. We find that conventional spin diffusion theory fails to capture the crossover to the ballistic regime as well as the limit of long spin diffusion length. We show that the latter can be described by an extension of the current theoretical framework. Finally, by covering the whole range of spin dynamics, our study opens a new perspective to predict and scrutinize spin transport in graphene and other two-dimensional material-based ultraclean devices.
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Affiliation(s)
- Marc Vila
- Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and BIST, Campus UAB, Bellaterra, 08193 Barcelona, Spain
- Department of Physics, Universitat Autònoma de Barcelona, Campus UAB, Bellaterra, 08193 Barcelona, Spain
| | - Jose H Garcia
- Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and BIST, Campus UAB, Bellaterra, 08193 Barcelona, Spain
| | - Aron W Cummings
- Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and BIST, Campus UAB, Bellaterra, 08193 Barcelona, Spain
| | - Stephen R Power
- Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and BIST, Campus UAB, Bellaterra, 08193 Barcelona, Spain
- Universitat Autònoma de Barcelona, Campus UAB, Bellaterra, 08193 Barcelona, Spain
- School of Physics, Trinity College Dublin, Dublin 2, Ireland
| | - Christoph W Groth
- Université Grenoble Alpes, CEA, IRIG-PHELIQS, 38000 Grenoble, France
| | - Xavier Waintal
- Université Grenoble Alpes, CEA, IRIG-PHELIQS, 38000 Grenoble, France
| | - Stephan Roche
- Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and BIST, Campus UAB, Bellaterra, 08193 Barcelona, Spain
- ICREA-Institució Catalana de Recerca i Estudis Avançats, 08010 Barcelona, Spain
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43
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Liu Y, Zeng C, Zhong J, Ding J, Wang ZM, Liu Z. Spintronics in Two-Dimensional Materials. NANO-MICRO LETTERS 2020; 12:93. [PMID: 34138100 PMCID: PMC7770708 DOI: 10.1007/s40820-020-00424-2] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Accepted: 03/18/2020] [Indexed: 05/30/2023]
Abstract
Spintronics, exploiting the spin degree of electrons as the information vector, is an attractive field for implementing the beyond Complemetary metal-oxide-semiconductor (CMOS) devices. Recently, two-dimensional (2D) materials have been drawing tremendous attention in spintronics owing to their distinctive spin-dependent properties, such as the ultra-long spin relaxation time of graphene and the spin-valley locking of transition metal dichalcogenides. Moreover, the related heterostructures provide an unprecedented probability of combining the different characteristics via proximity effect, which could remedy the limitation of individual 2D materials. Hence, the proximity engineering has been growing extremely fast and has made significant achievements in the spin injection and manipulation. Nevertheless, there are still challenges toward practical application; for example, the mechanism of spin relaxation in 2D materials is unclear, and the high-efficiency spin gating is not yet achieved. In this review, we focus on 2D materials and related heterostructures to systematically summarize the progress of the spin injection, transport, manipulation, and application for information storage and processing. We also highlight the current challenges and future perspectives on the studies of spintronic devices based on 2D materials.
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Affiliation(s)
- Yanping Liu
- School of Physics and Electronics, Hunan Key Laboratory for Super-Microstructure and Ultrafast Process, Central South University, 932 South Lushan Road, Changsha, 410083, Hunan, People's Republic of China.
- Shenzhen Research Institute of Central South University, A510a, Virtual University Building, Southern District, High-Tech Industrial Park, Yuehai Street, Nanshan District, Shenzhen, People's Republic of China.
- State Key Laboratory of High-Performance Complex Manufacturing, Central South University, 932 South Lushan Road, Changsha, 410083, Hunan, People's Republic of China.
| | - Cheng Zeng
- School of Physics and Electronics, Hunan Key Laboratory for Super-Microstructure and Ultrafast Process, Central South University, 932 South Lushan Road, Changsha, 410083, Hunan, People's Republic of China
| | - Jiahong Zhong
- School of Physics and Electronics, Hunan Key Laboratory for Super-Microstructure and Ultrafast Process, Central South University, 932 South Lushan Road, Changsha, 410083, Hunan, People's Republic of China
| | - Junnan Ding
- School of Physics and Electronics, Hunan Key Laboratory for Super-Microstructure and Ultrafast Process, Central South University, 932 South Lushan Road, Changsha, 410083, Hunan, People's Republic of China
| | - Zhiming M Wang
- Institute of Fundamental and Frontier Sciences, University of Electronic Science and Technology of China, Chengdu, 610054, People's Republic of China.
| | - Zongwen Liu
- School of Chemical and Biomolecular Engineering, The University of Sydney, Sydney, NSW, 2006, Australia.
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44
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Lu Q, Yin S, Gao T, Qin W, Xie S, Qu F, Saxena A. Spin Transport Based on Exchange Coupling in Doped Organic Polymers. J Phys Chem Lett 2020; 11:1087-1092. [PMID: 31957440 DOI: 10.1021/acs.jpclett.9b03703] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
We develop a spin diffusion theory based on the exchange mechanism among polarons to understand the organic pure spin current. It is demonstrated that the exchange coupling is strong enough to induce spin transport within the organic layer with impurity concentrations higher than 1018 cm-3. By calculating the inverse spin Hall voltage in an organic spin device, we predict that the voltage depends nonmonotonically on the impurity concentration of the organic material. By tuning the doping concentration, one can achieve a maximum inverse spin Hall voltage. Our results not only explain some recent experimental data but also inspire further experimental investigation on pure spin current in organic devices with variable impurity doping.
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Affiliation(s)
- Qiuxia Lu
- School of Physics, State Key Laboratory of Crystal Materials , Shandong University , Jinan 250100 , China
| | - Sun Yin
- School of Physics, State Key Laboratory of Crystal Materials , Shandong University , Jinan 250100 , China
| | - Teng Gao
- School of Physics, State Key Laboratory of Crystal Materials , Shandong University , Jinan 250100 , China
| | - Wei Qin
- School of Physics, State Key Laboratory of Crystal Materials , Shandong University , Jinan 250100 , China
| | - Shijie Xie
- School of Physics, State Key Laboratory of Crystal Materials , Shandong University , Jinan 250100 , China
| | - Fanyao Qu
- Instituto de F́ısica , Universidade de Braśılia , Braśılia DF 70919-970 , Brazil
| | - Avadh Saxena
- Theoretical Division , Los Alamos National Laboratory , Los Alamos , New Mexico 87545 , United States
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45
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Li S, Larionov KV, Popov ZI, Watanabe T, Amemiya K, Entani S, Avramov PV, Sakuraba Y, Naramoto H, Sorokin PB, Sakai S. Graphene/Half-Metallic Heusler Alloy: A Novel Heterostructure toward High-Performance Graphene Spintronic Devices. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2020; 32:e1905734. [PMID: 31793057 DOI: 10.1002/adma.201905734] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Revised: 10/04/2019] [Indexed: 06/10/2023]
Abstract
Graphene-based vertical spin valves (SVs) are expected to offer a large magnetoresistance effect without impairing the electrical conductivity, which can pave the way for the next generation of high-speed and low-power-consumption storage and memory technologies. However, the graphene-based vertical SV has failed to prove its competence due to the lack of a graphene/ferromagnet heterostructure, which can provide highly efficient spin transport. Herein, the synthesis and spin-dependent electronic properties of a novel heterostructure consisting of single-layer graphene (SLG) and a half-metallic Co2 Fe(Ge0.5 Ga0.5 ) (CFGG) Heusler alloy ferromagnet are reported. The growth of high-quality SLG with complete coverage by ultrahigh-vacuum chemical vapor deposition on a magnetron-sputtered single-crystalline CFGG thin film is demonstrated. The quasi-free-standing nature of SLG and robust magnetism of CFGG at the SLG/CFGG interface are revealed through depth-resolved X-ray magnetic circular dichroism spectroscopy. Density functional theory (DFT) calculation results indicate that the inherent electronic properties of SLG and CFGG such as the linear Dirac band and half-metallic band structure are preserved in the vicinity of the interface. These exciting findings suggest that the SLG/CFGG heterostructure possesses distinctive advantages over other reported graphene/ferromagnet heterostructures, for realizing effective transport of highly spin-polarized electrons in graphene-based vertical SV and other advanced spintronic devices.
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Affiliation(s)
- Songtian Li
- Quantum Beam Science Directorate, National Institutes for Quantum and Radiological Science and Technology QST, 1233 Watanuki, Takasaki, 370-1292, Japan
- Advanced Study Laboratory, National Institutes for Quantum and Radiological Science and Technology QST, 4-9-1 Anagawa, Inage, Chiba, 263-8555, Japan
- Faculty of Pure and Applied Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, 305-8577, Japan
- Technological Institute for Superhard and Novel Carbon Materials, 7a Centralnaya Street, Troitsk, Moscow, 108840, Russian Federation
| | - Konstantin V Larionov
- Laboratory of Inorganic Nanomaterials, National University of Science and Technology MISiS, 4 Leninskiy prospect, Moscow, 119049, Russian Federation
- Moscow Institute of Physics and Technology, 9 Institutskii per, Dolgoprudny, Moscow Region, 141700, Russian Federation
| | - Zakhar I Popov
- Laboratory of Inorganic Nanomaterials, National University of Science and Technology MISiS, 4 Leninskiy prospect, Moscow, 119049, Russian Federation
- Emanuel Institute of Biochemical Physics RAS, 4 Kosygina st, Moscow, 119334, Russian Federation
| | - Takahiro Watanabe
- Quantum Beam Science Directorate, National Institutes for Quantum and Radiological Science and Technology QST, 1233 Watanuki, Takasaki, 370-1292, Japan
- Photon Factory, Institute of Materials Structure Science, High Energy Accelerator Research Organization KEK, 1-1 Oho, Tsukuba, 305-0801, Japan
| | - Kenta Amemiya
- Photon Factory, Institute of Materials Structure Science, High Energy Accelerator Research Organization KEK, 1-1 Oho, Tsukuba, 305-0801, Japan
| | - Shiro Entani
- Quantum Beam Science Directorate, National Institutes for Quantum and Radiological Science and Technology QST, 1233 Watanuki, Takasaki, 370-1292, Japan
- Advanced Study Laboratory, National Institutes for Quantum and Radiological Science and Technology QST, 4-9-1 Anagawa, Inage, Chiba, 263-8555, Japan
| | - Pavel V Avramov
- Department of Chemistry, College of Natural Sciences, Kyungpook National University, Daegu, 702-701, Republic of Korea
| | - Yuya Sakuraba
- Research Center for Magnetic and Spintronic Materials, National Institute for Materials Science NIMS, 1-2-1 Sengen, Tsukuba, 305-0047, Japan
| | - Hiroshi Naramoto
- Quantum Beam Science Directorate, National Institutes for Quantum and Radiological Science and Technology QST, 1233 Watanuki, Takasaki, 370-1292, Japan
| | - Pavel B Sorokin
- Quantum Beam Science Directorate, National Institutes for Quantum and Radiological Science and Technology QST, 1233 Watanuki, Takasaki, 370-1292, Japan
- Advanced Study Laboratory, National Institutes for Quantum and Radiological Science and Technology QST, 4-9-1 Anagawa, Inage, Chiba, 263-8555, Japan
- Laboratory of Inorganic Nanomaterials, National University of Science and Technology MISiS, 4 Leninskiy prospect, Moscow, 119049, Russian Federation
- Moscow Institute of Physics and Technology, 9 Institutskii per, Dolgoprudny, Moscow Region, 141700, Russian Federation
| | - Seiji Sakai
- Quantum Beam Science Directorate, National Institutes for Quantum and Radiological Science and Technology QST, 1233 Watanuki, Takasaki, 370-1292, Japan
- Advanced Study Laboratory, National Institutes for Quantum and Radiological Science and Technology QST, 4-9-1 Anagawa, Inage, Chiba, 263-8555, Japan
- Laboratory of Inorganic Nanomaterials, National University of Science and Technology MISiS, 4 Leninskiy prospect, Moscow, 119049, Russian Federation
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46
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Behera SK, Deb P. Spin-transfer-torque mediated quantum magnetotransport in MoS2/phosphorene vdW heterostructure based MTJs. Phys Chem Chem Phys 2020; 22:19139-19146. [DOI: 10.1039/d0cp00836b] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Spin-transfer-torque mediated quantum magnetotransport behaviour can be realized via magnetization density switching in 2D van der Waals heterostructures for device applications.
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Affiliation(s)
- Sushant Kumar Behera
- Advanced Functional Material Laboratory (AFML)
- Department of Physics
- Tezpur University (Central University)
- Tezpur-784028
- India
| | - Pritam Deb
- Advanced Functional Material Laboratory (AFML)
- Department of Physics
- Tezpur University (Central University)
- Tezpur-784028
- India
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47
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Seo J, Kim DY, An ES, Kim K, Kim GY, Hwang SY, Kim DW, Jang BG, Kim H, Eom G, Seo SY, Stania R, Muntwiler M, Lee J, Watanabe K, Taniguchi T, Jo YJ, Lee J, Min BI, Jo MH, Yeom HW, Choi SY, Shim JH, Kim JS. Nearly room temperature ferromagnetism in a magnetic metal-rich van der Waals metal. SCIENCE ADVANCES 2020; 6:eaay8912. [PMID: 32010775 PMCID: PMC6968938 DOI: 10.1126/sciadv.aay8912] [Citation(s) in RCA: 72] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2019] [Accepted: 11/12/2019] [Indexed: 05/30/2023]
Abstract
In spintronics, two-dimensional van der Waals crystals constitute a most promising material class for long-distance spin transport or effective spin manipulation at room temperature. To realize all-vdW-material-based spintronic devices, however, vdW materials with itinerant ferromagnetism at room temperature are needed for spin current generation and thereby serve as an effective spin source. We report theoretical design and experimental realization of a iron-based vdW material, Fe4GeTe2, showing a nearly room temperature ferromagnetic order, together with a large magnetization and high conductivity. These properties are well retained even in cleaved crystals down to seven layers, with notable improvement in perpendicular magnetic anisotropy. Our findings highlight Fe4GeTe2 and its nanometer-thick crystals as a promising candidate for spin source operation at nearly room temperature and hold promise to further increase T c in vdW ferromagnets by theory-guided material discovery.
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Affiliation(s)
- Junho Seo
- Center for Artificial Low Dimensional Electronic Systems, Institute for Basic Science (IBS), Pohang 37673, Korea
- Department of Physics, Pohang University of Science and Technology, Pohang 37673, Korea
| | - Duck Young Kim
- Center for High Pressure Science and Technology Advanced Research, Shanghai, China
| | - Eun Su An
- Center for Artificial Low Dimensional Electronic Systems, Institute for Basic Science (IBS), Pohang 37673, Korea
- Department of Physics, Pohang University of Science and Technology, Pohang 37673, Korea
| | - Kyoo Kim
- Max Planck POSTECH/Hsinchu Center for Complex Phase Materials, Pohang University of Science and Technology, Pohang, Korea
| | - Gi-Yeop Kim
- Department of Materials Science and Engineering, Pohang University of Science and Technology, Pohang 37673, Korea
| | - Soo-Yoon Hwang
- Department of Materials Science and Engineering, Pohang University of Science and Technology, Pohang 37673, Korea
| | - Dong Wook Kim
- Department of Chemistry, Pohang University of Science and Technology, Pohang 37673, Korea
| | - Bo Gyu Jang
- Department of Chemistry, Pohang University of Science and Technology, Pohang 37673, Korea
| | - Heejung Kim
- Max Planck POSTECH/Hsinchu Center for Complex Phase Materials, Pohang University of Science and Technology, Pohang, Korea
| | - Gyeongsik Eom
- Department of Physics, Ajou University, Suwon 16499, Korea
| | - Seung Young Seo
- Center for Artificial Low Dimensional Electronic Systems, Institute for Basic Science (IBS), Pohang 37673, Korea
- Department of Materials Science and Engineering, Pohang University of Science and Technology, Pohang 37673, Korea
| | - Roland Stania
- Center for Artificial Low Dimensional Electronic Systems, Institute for Basic Science (IBS), Pohang 37673, Korea
| | | | - Jinwon Lee
- Center for Artificial Low Dimensional Electronic Systems, Institute for Basic Science (IBS), Pohang 37673, Korea
- Department of Physics, Pohang University of Science and Technology, Pohang 37673, Korea
| | - Kenji Watanabe
- National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
| | - Takashi Taniguchi
- National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
| | - Youn Jung Jo
- Department of Physics, Kyungpook National University, Daegu 41566, Korea
| | - Jieun Lee
- Department of Physics, Ajou University, Suwon 16499, Korea
| | - Byung Il Min
- Department of Physics, Pohang University of Science and Technology, Pohang 37673, Korea
| | - Moon Ho Jo
- Center for Artificial Low Dimensional Electronic Systems, Institute for Basic Science (IBS), Pohang 37673, Korea
- Department of Materials Science and Engineering, Pohang University of Science and Technology, Pohang 37673, Korea
| | - Han Woong Yeom
- Center for Artificial Low Dimensional Electronic Systems, Institute for Basic Science (IBS), Pohang 37673, Korea
- Department of Physics, Pohang University of Science and Technology, Pohang 37673, Korea
| | - Si-Young Choi
- Department of Materials Science and Engineering, Pohang University of Science and Technology, Pohang 37673, Korea
| | - Ji Hoon Shim
- Department of Chemistry, Pohang University of Science and Technology, Pohang 37673, Korea
| | - Jun Sung Kim
- Center for Artificial Low Dimensional Electronic Systems, Institute for Basic Science (IBS), Pohang 37673, Korea
- Department of Physics, Pohang University of Science and Technology, Pohang 37673, Korea
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48
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Safeer CK, Ontoso N, Ingla-Aynés J, Herling F, Pham VT, Kurzmann A, Ensslin K, Chuvilin A, Robredo I, Vergniory MG, de Juan F, Hueso LE, Calvo MR, Casanova F. Large Multidirectional Spin-to-Charge Conversion in Low-Symmetry Semimetal MoTe 2 at Room Temperature. NANO LETTERS 2019; 19:8758-8766. [PMID: 31661967 DOI: 10.1021/acs.nanolett.9b03485] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
Efficient and versatile spin-to-charge current conversion is crucial for the development of spintronic applications, which strongly rely on the ability to electrically generate and detect spin currents. In this context, the spin Hall effect has been widely studied in heavy metals with strong spin-orbit coupling. While the high crystal symmetry in these materials limits the conversion to the orthogonal configuration, unusual configurations are expected in low-symmetry transition-metal dichalcogenide semimetals, which could add flexibility to the electrical injection and detection of pure spin currents. Here, we report the observation of spin-to-charge conversion in MoTe2 flakes, which are stacked in graphene lateral spin valves. We detect two distinct contributions arising from the conversion of two different spin orientations. In addition to the conventional conversion where the spin polarization is orthogonal to the charge current, we also detect a conversion where the spin polarization and the charge current are parallel. Both contributions, which could arise either from bulk spin Hall effect or surface Edelstein effect, show large efficiencies comparable to the best spin Hall metals and topological insulators. Our finding enables the simultaneous conversion of spin currents with any in-plane spin polarization in one single experimental configuration.
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Affiliation(s)
- C K Safeer
- CIC nanoGUNE , 20018 Donostia-San Sebastian , Basque Country , Spain
| | - Nerea Ontoso
- CIC nanoGUNE , 20018 Donostia-San Sebastian , Basque Country , Spain
| | - Josep Ingla-Aynés
- CIC nanoGUNE , 20018 Donostia-San Sebastian , Basque Country , Spain
| | - Franz Herling
- CIC nanoGUNE , 20018 Donostia-San Sebastian , Basque Country , Spain
| | - Van Tuong Pham
- CIC nanoGUNE , 20018 Donostia-San Sebastian , Basque Country , Spain
| | - Annika Kurzmann
- Solid State Physics Laboratory , ETH Zurich , 8093 Zurich , Switzerland
| | - Klaus Ensslin
- Solid State Physics Laboratory , ETH Zurich , 8093 Zurich , Switzerland
| | - Andrey Chuvilin
- CIC nanoGUNE , 20018 Donostia-San Sebastian , Basque Country , Spain
- IKERBASQUE, Basque Foundation for Science , 48013 Bilbao , Basque Country , Spain
| | - Iñigo Robredo
- Donostia International Physics Center (DIPC) , 20018 Donostia-San Sebastian , Basque Country , Spain
- Department of Condensed Matter Physics , University of the Basque Country (UPV/EHU) , 48080 Bilbao , Basque Country , Spain
| | - Maia G Vergniory
- IKERBASQUE, Basque Foundation for Science , 48013 Bilbao , Basque Country , Spain
- Donostia International Physics Center (DIPC) , 20018 Donostia-San Sebastian , Basque Country , Spain
| | - Fernando de Juan
- IKERBASQUE, Basque Foundation for Science , 48013 Bilbao , Basque Country , Spain
- Donostia International Physics Center (DIPC) , 20018 Donostia-San Sebastian , Basque Country , Spain
| | - Luis E Hueso
- CIC nanoGUNE , 20018 Donostia-San Sebastian , Basque Country , Spain
- IKERBASQUE, Basque Foundation for Science , 48013 Bilbao , Basque Country , Spain
| | - M Reyes Calvo
- CIC nanoGUNE , 20018 Donostia-San Sebastian , Basque Country , Spain
- IKERBASQUE, Basque Foundation for Science , 48013 Bilbao , Basque Country , Spain
- Departamento de Física Aplicada , Universidad de Alicante , 03690 Alicante , Spain
| | - Fèlix Casanova
- CIC nanoGUNE , 20018 Donostia-San Sebastian , Basque Country , Spain
- IKERBASQUE, Basque Foundation for Science , 48013 Bilbao , Basque Country , Spain
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49
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Cummings AW, Dubois SMM, Charlier JC, Roche S. Universal Spin Diffusion Length in Polycrystalline Graphene. NANO LETTERS 2019; 19:7418-7426. [PMID: 31532994 DOI: 10.1021/acs.nanolett.9b03112] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Graphene grown by chemical vapor deposition (CVD) is the most promising material for industrial-scale applications based on graphene monolayers. It also holds promise for spintronics; despite being polycrystalline, spin transport in CVD graphene has been measured over lengths up to 30 μm, which is on par with the best measurements made in single-crystal graphene. These results suggest that grain boundaries (GBs) in CVD graphene, while impeding charge transport, may have little effect on spin transport. However, to date very little is known about the true impact of disordered networks of GBs on spin relaxation. Here, by using first-principles simulations, we derive an effective tight-binding model of graphene GBs in the presence of spin-orbit coupling (SOC), which we then use to evaluate spin transport in realistic morphologies of polycrystalline graphene. The spin diffusion length is found to be independent of the grain size, and it is determined only by the strength of the substrate-induced SOC. This result is consistent with the D'yakonov-Perel' mechanism of spin relaxation in the diffusive regime, but we find that it also holds in the presence of quantum interference. These results clarify the role played by GBs and demonstrate that the average grain size does not dictate the upper limit for spin transport in CVD-grown graphene, a result of fundamental importance for optimizing large-scale graphene-based spintronic devices.
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Affiliation(s)
- Aron W Cummings
- Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and BIST , Campus UAB, Bellaterra , 08193 Barcelona , Spain
| | - Simon M-M Dubois
- Institute of Condensed Matter and Nanosciences , Université catholique de Louvain , B-1348 Louvain-la-Neuve , Belgium
| | - Jean-Christophe Charlier
- Institute of Condensed Matter and Nanosciences , Université catholique de Louvain , B-1348 Louvain-la-Neuve , Belgium
| | - Stephan Roche
- Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and BIST , Campus UAB, Bellaterra , 08193 Barcelona , Spain
- ICREA-Institució Catalana de Recerca i Estudis Avançats , 08010 Barcelona , Spain
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50
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Ghiasi TS, Kaverzin AA, Blah PJ, van Wees BJ. Charge-to-Spin Conversion by the Rashba-Edelstein Effect in Two-Dimensional van der Waals Heterostructures up to Room Temperature. NANO LETTERS 2019; 19:5959-5966. [PMID: 31408607 PMCID: PMC6746057 DOI: 10.1021/acs.nanolett.9b01611] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2019] [Revised: 07/25/2019] [Indexed: 05/21/2023]
Abstract
The proximity of a transition-metal dichalcogenide (TMD) to graphene imprints a rich spin texture in graphene and complements its high-quality charge/spin transport by inducing spin-orbit coupling (SOC). Rashba and valley-Zeeman SOCs are the origin of charge-to-spin conversion mechanisms such as the Rashba-Edelstein effect (REE) and spin Hall effect (SHE). In this work, we experimentally demonstrate for the first time charge-to-spin conversion due to the REE in a monolayer WS2-graphene van der Waals heterostructure. We measure the current-induced spin polarization up to room temperature and control it by a gate electric field. Our observation of the REE and the inverse of the effect (IREE) is accompanied by the SHE, which we discriminate by symmetry-resolved spin precession under oblique magnetic fields. These measurements also allow for the quantification of the efficiencies of charge-to-spin conversion by each of the two effects. These findings are a clear indication of induced Rashba and valley-Zeeman SOC in graphene that lead to the generation of spin accumulation and spin current without using ferromagnetic electrodes. These realizations have considerable significance for spintronic applications, providing accessible routes toward all-electrical spin generation and manipulation in two-dimensional materials.
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Affiliation(s)
- Talieh S. Ghiasi
- Zernike
Institute for Advanced Materials, University
of Groningen, Groningen, 9747 AG, The Netherlands
| | - Alexey A. Kaverzin
- Zernike
Institute for Advanced Materials, University
of Groningen, Groningen, 9747 AG, The Netherlands
| | - Patrick J. Blah
- Zernike
Institute for Advanced Materials, University
of Groningen, Groningen, 9747 AG, The Netherlands
| | - Bart J. van Wees
- Zernike
Institute for Advanced Materials, University
of Groningen, Groningen, 9747 AG, The Netherlands
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