1
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Liang H, Wei Y, Ji Y. Magnetic-responsive Covalent Adaptable Networks. Chem Asian J 2023; 18:e202201177. [PMID: 36645376 DOI: 10.1002/asia.202201177] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Revised: 01/07/2023] [Accepted: 01/16/2023] [Indexed: 01/17/2023]
Abstract
Covalent adaptable networks (CANs) are reprocessable polymers whose structural arrangement is based on the recombination of dynamic covalent bonds. Composite materials prepared by incorporating magnetic particles into CANs attract much attention due to their remote and precise control, fast response speed, high biological safety and strong penetration of magnetic stimuli. These properties often involve magnetothermal effect and direct magnetic-field guidance. Besides, some of them can also respond to light, electricity or pH values. Thus, they are favorable for soft actuators since various functions are achieved such as magnetic-assisted self-healing (heating or at ambient temperature), welding (on land or under water), shape-morphing, and so on. Although magnetic CANs just start to be studied in recent two years, their advances are promised to expand the practical applications in both cutting-edge academic and engineering fields. This review aims to summarize recent progress in magnetic-responsive CANs, including their design, synthesis and application.
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Affiliation(s)
- Huan Liang
- The Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology (Ministry of Education), Department of Chemistry, Tsinghua University, Beijing, 100084, P. R. China
| | - Yen Wei
- The Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology (Ministry of Education), Department of Chemistry, Tsinghua University, Beijing, 100084, P. R. China.,Department of Chemistry, Center for Nanotechnology and Institute of Biomedical Technology, Chung-Yuan Christian University Chung-Li, 32023, Taiwan, P. R. China
| | - Yan Ji
- The Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology (Ministry of Education), Department of Chemistry, Tsinghua University, Beijing, 100084, P. R. China
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2
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Polarization-controlled tunable directional spin-driven photocurrents in a magnetic metamaterial with threefold rotational symmetry. Nat Commun 2022; 13:6708. [PMID: 36344506 PMCID: PMC9640558 DOI: 10.1038/s41467-022-34374-7] [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: 05/20/2022] [Accepted: 10/21/2022] [Indexed: 11/09/2022] Open
Abstract
Future spintronics and quantum technologies will require a portfolio of techniques for manipulating electron spins in functional nanodevices. Especially, the establishment of the methods to control spin current is the key ingredient essential for the transfer and processing of information, enabling faster and low-energy operation. However, a universal method for manipulating spin currents with full-directional controllability and tunable magnitude has not been established. Here we show that an artificial material called a magnetic metamaterial (MM), which possesses a novel spintronic functionality not exhibited by the original substance, generates photo-driven ultrafast spin currents at room temperature via the magneto-photogalvanic effect. By tuning the polarization state of the excitation light, these spin currents can be directed with tunable magnitude along an arbitrary direction in the two-dimensional plane of the MM. This new concept may guide the design and creation of artificially engineered opto-spintronic functionalities beyond the limitations of conventional material science. By carefully structuring and patterning a material, it is possible to introduce emergent properties that would otherwise not exist. These metamaterials have allowed the development of a wide variety of new optical properties. Here, Matsubara et al present a magnetic metamaterial, where spin-currents can be directed by tuning the polarization of the incident light.
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3
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Cai L, Yu C, Zhao W, Li Y, Feng H, Zhou HA, Wang L, Zhang X, Zhang Y, Shi Y, Zhang J, Yang L, Jiang W. The Giant Spin-to-Charge Conversion of the Layered Rashba Material BiTeI. NANO LETTERS 2022; 22:7441-7448. [PMID: 36099337 DOI: 10.1021/acs.nanolett.2c02354] [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
Rashba spin-orbit coupling (SOC) could facilitate an efficient interconversion between spin and charge currents. Among various systems, BiTeI holds one of the largest Rashba-type spin splittings. Unlike other Rashba systems (e.g., Bi/Ag and Bi2Se3), an experimental investigation of the spin-to-charge interconversion in BiTeI remains to be explored. Through performing an angle-resolved photoemission spectroscopy (ARPES) measurement, such a large Rashba-type spin splitting with a Rashba parameter αR = 3.68 eV Å is directly identified. By studying the spin pumping effect in the BiTeI/NiFe bilayer, we reveal a very large inverse Rashba-Edelstein length λIREE ≈ 1.92 nm of BiTeI at room temperature. Furthermore, the λIREE monotonously increases to 5.00 nm at 60 K, indicating an enhanced Rashba SOC at low temperature. These results suggest that BiTeI films with the giant Rashba SOC are promising for achieving efficient spin-to-charge interconversion, which could be implemented for building low-power-consumption spin-orbitronic devices.
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Affiliation(s)
- Li Cai
- State Key Laboratory of Low-Dimensional Quantum Physics and Department of Physics, Tsinghua University, Beijing 100084, China
- Frontier Science Center for Quantum Information, Tsinghua University, Beijing 100084, China
- Collaborative Innovation Center of Quantum Matter, Beijing 100084, China
| | - Chenglin Yu
- State Key Laboratory of Low-Dimensional Quantum Physics and Department of Physics, Tsinghua University, Beijing 100084, China
- Frontier Science Center for Quantum Information, Tsinghua University, Beijing 100084, China
- Collaborative Innovation Center of Quantum Matter, Beijing 100084, China
| | - Wenxuan Zhao
- State Key Laboratory of Low-Dimensional Quantum Physics and Department of Physics, Tsinghua University, Beijing 100084, China
- Frontier Science Center for Quantum Information, Tsinghua University, Beijing 100084, China
- Collaborative Innovation Center of Quantum Matter, Beijing 100084, China
| | - Yong Li
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Hongmei Feng
- State Key Laboratory of Low-Dimensional Quantum Physics and Department of Physics, Tsinghua University, Beijing 100084, China
- Frontier Science Center for Quantum Information, Tsinghua University, Beijing 100084, China
- Collaborative Innovation Center of Quantum Matter, Beijing 100084, China
| | - Heng-An Zhou
- State Key Laboratory of Low-Dimensional Quantum Physics and Department of Physics, Tsinghua University, Beijing 100084, China
- Frontier Science Center for Quantum Information, Tsinghua University, Beijing 100084, China
- Collaborative Innovation Center of Quantum Matter, Beijing 100084, China
| | - Ledong Wang
- State Key Laboratory of Low-Dimensional Quantum Physics and Department of Physics, Tsinghua University, Beijing 100084, China
- Frontier Science Center for Quantum Information, Tsinghua University, Beijing 100084, China
- Collaborative Innovation Center of Quantum Matter, Beijing 100084, China
| | - Xiaofang Zhang
- Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, China
| | - Ying Zhang
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, China
| | - Youguo Shi
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Jinsong Zhang
- State Key Laboratory of Low-Dimensional Quantum Physics and Department of Physics, Tsinghua University, Beijing 100084, China
- Frontier Science Center for Quantum Information, Tsinghua University, Beijing 100084, China
- Collaborative Innovation Center of Quantum Matter, Beijing 100084, China
| | - Lexian Yang
- State Key Laboratory of Low-Dimensional Quantum Physics and Department of Physics, Tsinghua University, Beijing 100084, China
- Frontier Science Center for Quantum Information, Tsinghua University, Beijing 100084, China
- Collaborative Innovation Center of Quantum Matter, Beijing 100084, China
| | - Wanjun Jiang
- State Key Laboratory of Low-Dimensional Quantum Physics and Department of Physics, Tsinghua University, Beijing 100084, China
- Frontier Science Center for Quantum Information, Tsinghua University, Beijing 100084, China
- Collaborative Innovation Center of Quantum Matter, Beijing 100084, China
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4
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Feng T, Wang P, Wu D. 金属/铁磁绝缘体异质结中的自旋霍尔磁电阻. CHINESE SCIENCE BULLETIN-CHINESE 2022. [DOI: 10.1360/tb-2022-0186] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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5
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Zhao M, Kim D, Lee YH, Yang H, Cho S. Quantum Sensing of Thermoelectric Power in Low-Dimensional Materials. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2021:e2106871. [PMID: 34889480 DOI: 10.1002/adma.202106871] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Revised: 11/26/2021] [Indexed: 06/13/2023]
Abstract
Thermoelectric power, has been extensively studied in low-dimensional materials where quantum confinement and spin textures can largely modulate thermopower generation. In addition to classical and macroscopic values, thermopower also varies locally over a wide range of length scales, and is fundamentally linked to electron wave functions and phonon propagation. Various experimental methods for the quantum sensing of localized thermopower have been suggested, particularly based on scanning probe microscopy. Here, critical advances in the quantum sensing of thermopower are introduced, from the atomic to the several-hundred-nanometer scales, including the unique role of low-dimensionality, defects, spins, and relativistic effects for optimized power generation. Investigating the microscopic nature of thermopower in quantum materials can provide insights useful for the design of advanced materials for future thermoelectric applications. Quantum sensing techniques for thermopower can pave the way to practical and novel energy devices for a sustainable society.
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Affiliation(s)
- Mali Zhao
- Interdisciplinary Materials Research Center, College of Materials Science and Engineering, Tongji University, Shanghai, 201804, People's Republic of China
- Department of Energy Science, Sungkyunkwan University, Suwon, 16419, Korea
| | - Dohyun Kim
- Department of Energy Science, Sungkyunkwan University, Suwon, 16419, Korea
| | - Young Hee Lee
- Department of Energy Science, Sungkyunkwan University, Suwon, 16419, Korea
- Center for Integrated Nanostructure Physics (CINAP), Institute for Basic Science, Suwon, 16419, Korea
| | - Heejun Yang
- Department of Physics, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Korea
| | - Suyeon Cho
- Division of Chemical Engineering and Materials Science, Ewha Womans University, Seoul, 03760, Korea
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6
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Ishii S, Miura A, Nagao T, Uchida KI. Simultaneous harvesting of radiative cooling and solar heating for transverse thermoelectric generation. SCIENCE AND TECHNOLOGY OF ADVANCED MATERIALS 2021; 22:441-448. [PMID: 34248419 PMCID: PMC8245095 DOI: 10.1080/14686996.2021.1920820] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Revised: 04/19/2021] [Accepted: 04/19/2021] [Indexed: 06/13/2023]
Abstract
For any thermoelectric effects to be achieved, a thermoelectric material must have hot and cold sides. Typically, the hot side can be easily obtained by excess heat. However, the passive cooling method is often limited to convective heat transfer to the surroundings. Since thermoelectric voltage is proportional to the temperature difference between the hot and cold sides, efficient passive cooling to increase the temperature gradient is of critical importance. Here, we report simultaneous harvesting of radiative cooling at the top and solar heating at the bottom to enhance the temperature gradient for a transverse thermoelectric effect which generates thermoelectric voltage perpendicular to the temperature gradient. We demonstrate this concept by using the spin Seebeck effect and confirm that the spin Seebeck device shows the highest thermoelectric voltage when both radiative cooling and solar heating are utilized. Furthermore, the device generates thermoelectric voltage even at night through radiative cooling which enables continuous energy harvesting throughout a day. Planar geometry and scalable fabrication process are advantageous for energy harvesting applications.
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Affiliation(s)
- Satoshi Ishii
- International Center for Materials Nanoarchitectonics (MANA), National Institute for Materials Science (NIMS), Tsukuba, Japan
- Faculty of Pure and Applied Physics, University of Tsukuba, Tsukuba, Japan
- PRESTO, Japan Science and Technology Agency, Saitama, Japan
| | - Asuka Miura
- Research Center for Magnetic and Spintronic Materials, National Institute for Materials Science (NIMS), Tsukuba, Japan
| | - Tadaaki Nagao
- International Center for Materials Nanoarchitectonics (MANA), National Institute for Materials Science (NIMS), Tsukuba, Japan
- Department of Condensed Matter Physics, Graduate School of Science, Hokkaido University, Sapporo, Japan
| | - Ken-ichi Uchida
- Faculty of Pure and Applied Physics, University of Tsukuba, Tsukuba, Japan
- Research Center for Magnetic and Spintronic Materials, National Institute for Materials Science (NIMS), Tsukuba, Japan
- Institute for Materials Research, Tohoku University, Sendai, Japan
- Center for Spintronics Research Network, Tohoku University, Sendai, Japan
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7
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Zhang C, Bartell JM, Karsch JC, Gray I, Fuchs GD. Nanoscale Magnetization and Current Imaging Using Time-Resolved Scanning-Probe Magnetothermal Microscopy. NANO LETTERS 2021; 21:4966-4972. [PMID: 34100623 DOI: 10.1021/acs.nanolett.1c00704] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Magnetic microscopy that combines nanoscale spatial resolution with picosecond scale temporal resolution uniquely enables direct observation of the spatiotemporal magnetic phenomena that are relevant to future high-speed, high-density magnetic storage and logic technologies. Magnetic microscopes that combine these metrics has been limited to facility-level instruments. To address this gap in lab-accessible spatiotemporal imaging, we develop a time-resolved near-field magnetic microscope based on magnetothermal interactions. We demonstrate both magnetization and current density imaging modalities, each with spatial resolution that far surpasses the optical diffraction limit. In addition, we study the near-field and time-resolved characteristics of our signal and find that our instrument possesses a spatial resolution on the scale of 100 nm and a temporal resolution below 100 ps. Our results demonstrate an accessible and comparatively low-cost approach to nanoscale spatiotemporal magnetic microscopy in a table-top form to aid the science and technology of dynamic magnetic devices with complex spin textures.
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Affiliation(s)
- Chi Zhang
- School of Applied and Engineering Physics, Cornell University, Ithaca, New York 14853, United States
| | - Jason M Bartell
- School of Applied and Engineering Physics, Cornell University, Ithaca, New York 14853, United States
| | - Jonathan C Karsch
- School of Applied and Engineering Physics, Cornell University, Ithaca, New York 14853, United States
| | - Isaiah Gray
- School of Applied and Engineering Physics, Cornell University, Ithaca, New York 14853, United States
| | - Gregory D Fuchs
- School of Applied and Engineering Physics, Cornell University, Ithaca, New York 14853, United States
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8
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Shilina PV, Ignatyeva DO, Kapralov PO, Sekatskii SK, Nur-E-Alam M, Vasiliev M, Alameh K, Achanta VG, Song Y, Hamidi SM, Zvezdin AK, Belotelov VI. Nanophotonic structures with optical surface modes for tunable spin current generation. NANOSCALE 2021; 13:5791-5799. [PMID: 33704301 DOI: 10.1039/d0nr08692d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
We propose a novel type of photonic-crystal (PC)-based nanostructures for efficient and tunable optically-induced spin current generation via the spin Seebeck and inverse spin Hall effects. It has been experimentally demonstrated that optical surface modes localized at the PC surface covered by ferromagnetic layer and materials with giant spin-orbit coupling (SOC) notably increase the efficiency of the optically-induced spin current generation, and provides its tunability by modifying the light wavelength or angle of incidence. Up to 100% of the incident light power can be transferred to heat within the SOC layer and, therefore, to the spin current. Importantly, the high efficiency becomes accessible even for ultra-thin SOC layers. Moreover, the surface patterning of the PC-based spintronic nanostructure allows for the local generation of spin currents at the pattern scales rather than the diameter of the laser beam.
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Affiliation(s)
- P V Shilina
- National Research University Higher School of Economics, Moscow 101000, Russia.
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9
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Gupta V, Cham TM, Stiehl GM, Bose A, Mittelstaedt JA, Kang K, Jiang S, Mak KF, Shan J, Buhrman RA, Ralph DC. Manipulation of the van der Waals Magnet Cr 2Ge 2Te 6 by Spin-Orbit Torques. NANO LETTERS 2020; 20:7482-7488. [PMID: 32975955 DOI: 10.1021/acs.nanolett.0c02965] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
We report measurements of current-induced thermoelectric and spin-orbit torque effects within devices in which multilayers of the semiconducting two-dimensional van der Waals magnet Cr2Ge2Te6 (CGT) are integrated with Pt and Ta metal overlayers. We show that the magnetic orientation of the CGT can be detected accurately either electrically (using an anomalous Hall effect) or optically (using magnetic circular dichroism) with good consistency. The samples exhibit large thermoelectric effects, but nevertheless, the spin-orbit torque can be measured quantitatively using the angle-dependent second harmonic Hall technique. For CGT/Pt, we measure the spin-orbit torque efficiency to be similar to conventional metallic-ferromagnet/Pt devices with the same Pt resistivity. The interfacial transparency for spin currents is therefore similar in both classes of devices. Our results demonstrate the promise of incorporating semiconducting 2D magnets within spin-orbitronic and magneto-thermal devices.
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Affiliation(s)
- Vishakha Gupta
- Cornell University, Ithaca, New York 14850, United States
| | - Thow Min Cham
- Cornell University, Ithaca, New York 14850, United States
| | | | - Arnab Bose
- Cornell University, Ithaca, New York 14850, United States
| | | | - Kaifei Kang
- Cornell University, Ithaca, New York 14850, United States
| | - Shengwei Jiang
- Cornell University, Ithaca, New York 14850, United States
| | - Kin Fai Mak
- Cornell University, Ithaca, New York 14850, United States
| | - Jie Shan
- Cornell University, Ithaca, New York 14850, United States
| | | | - Daniel C Ralph
- Cornell University, Ithaca, New York 14850, United States
- Kavli Institute at Cornell, Ithaca, New York 14853, United States
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10
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Tu S, Ziman T, Yu G, Wan C, Hu J, Wu H, Wang H, Liu M, Liu C, Guo C, Zhang J, Cabero Z MA, Zhang Y, Gao P, Liu S, Yu D, Han X, Hallsteinsen I, Gilbert DA, Matsuo M, Ohnuma Y, Wölfle P, Wang KL, Ansermet JP, Maekawa S, Yu H. Record thermopower found in an IrMn-based spintronic stack. Nat Commun 2020; 11:2023. [PMID: 32332726 PMCID: PMC7181642 DOI: 10.1038/s41467-020-15797-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2019] [Accepted: 03/25/2020] [Indexed: 11/25/2022] Open
Abstract
The Seebeck effect converts thermal gradients into electricity. As an approach to power technologies in the current Internet-of-Things era, on-chip energy harvesting is highly attractive, and to be effective, demands thin film materials with large Seebeck coefficients. In spintronics, the antiferromagnetic metal IrMn has been used as the pinning layer in magnetic tunnel junctions that form building blocks for magnetic random access memories and magnetic sensors. Spin pumping experiments revealed that IrMn Néel temperature is thickness-dependent and approaches room temperature when the layer is thin. Here, we report that the Seebeck coefficient is maximum at the Néel temperature of IrMn of 0.6 to 4.0 nm in thickness in IrMn-based half magnetic tunnel junctions. We obtain a record Seebeck coefficient 390 (±10) μV K-1 at room temperature. Our results demonstrate that IrMn-based magnetic devices could harvest the heat dissipation for magnetic sensors, thus contributing to the Power-of-Things paradigm.
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Affiliation(s)
- Sa Tu
- Fert Beijing Institute, BDBC, School of Microelectronics, Beihang University, 100191, Beijing, China
| | - Timothy Ziman
- Institut Laue-Langevin, 38042, Grenoble, France
- Université de Grenobles-Alpes, and CNRS, LPMMC, 38042, Grenoble, France
- Kavli Institute for Theoretical Sciences, University of Chinese Academy of Sciences, 100190, Beijing, China
| | - Guoqiang Yu
- Department of Electrical Engineering, University of California, Los Angeles, CA, 90095, USA
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 100190, Beijing, China
| | - Caihua Wan
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 100190, Beijing, China
| | - Junfeng Hu
- Fert Beijing Institute, BDBC, School of Microelectronics, Beihang University, 100191, Beijing, China
- Institute of Physics, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015, Lausanne, Switzerland
| | - Hao Wu
- Department of Electrical Engineering, University of California, Los Angeles, CA, 90095, USA
| | - Hanchen Wang
- Fert Beijing Institute, BDBC, School of Microelectronics, Beihang University, 100191, Beijing, China
| | - Mengchao Liu
- Electron Microscopy Laboratory, School of Physics, Peking University, 100871, Beijing, China
| | - Chuanpu Liu
- Fert Beijing Institute, BDBC, School of Microelectronics, Beihang University, 100191, Beijing, China
| | - Chenyang Guo
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 100190, Beijing, China
| | - Jianyu Zhang
- Fert Beijing Institute, BDBC, School of Microelectronics, Beihang University, 100191, Beijing, China
| | - Marco A Cabero Z
- Fert Beijing Institute, BDBC, School of Microelectronics, Beihang University, 100191, Beijing, China
- Shenzhen Institute for Quantum Science and Engineering (SIQSE), and Department of Physics, Southern University of Science and Technology (SUSTech), 518055, Shenzhen, China
| | - Youguang Zhang
- Fert Beijing Institute, BDBC, School of Microelectronics, Beihang University, 100191, Beijing, China
| | - Peng Gao
- Electron Microscopy Laboratory, School of Physics, Peking University, 100871, Beijing, China
- International Center for Quantum Materials, School of Physics, Peking University, 100871, Beijing, China
- Collaborative Innovation Center of Quantum Matter, 100871, Beijing, China
| | - Song Liu
- Shenzhen Institute for Quantum Science and Engineering (SIQSE), and Department of Physics, Southern University of Science and Technology (SUSTech), 518055, Shenzhen, China
| | - Dapeng Yu
- Electron Microscopy Laboratory, School of Physics, Peking University, 100871, Beijing, China
- Shenzhen Institute for Quantum Science and Engineering (SIQSE), and Department of Physics, Southern University of Science and Technology (SUSTech), 518055, Shenzhen, China
| | - Xiufeng Han
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 100190, Beijing, China
| | - Ingrid Hallsteinsen
- Department of Electronic Systems, Norwegian University of Science and Technology, Trondheim, 7491, Norway
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Dustin A Gilbert
- Material Science and Engineering Department, University of Tennessee, Knoxville, TN, 37996, USA
| | - Mamoru Matsuo
- Kavli Institute for Theoretical Sciences, University of Chinese Academy of Sciences, 100190, Beijing, China
- RIKEN Center for Emergent Matter Science (CEMS), Wako, 351-0198, Japan
| | - Yuichi Ohnuma
- Kavli Institute for Theoretical Sciences, University of Chinese Academy of Sciences, 100190, Beijing, China
| | - Peter Wölfle
- Institute for Theory of Condensed Matter, Karlsruhe Institute of Technology, 76049, Karlsruhe, Germany
| | - Kang L Wang
- Department of Electrical Engineering, University of California, Los Angeles, CA, 90095, USA
| | - Jean-Philippe Ansermet
- Institute of Physics, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015, Lausanne, Switzerland
| | - Sadamichi Maekawa
- Kavli Institute for Theoretical Sciences, University of Chinese Academy of Sciences, 100190, Beijing, China
- RIKEN Center for Emergent Matter Science (CEMS), Wako, 351-0198, Japan
| | - Haiming Yu
- Fert Beijing Institute, BDBC, School of Microelectronics, Beihang University, 100191, Beijing, China.
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11
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Iguchi R, Kasai S, Koshikawa K, Chinone N, Suzuki S, Uchida KI. Thermoelectric microscopy of magnetic skyrmions. Sci Rep 2019; 9:18443. [PMID: 31804550 PMCID: PMC6895239 DOI: 10.1038/s41598-019-54833-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2019] [Accepted: 11/12/2019] [Indexed: 11/11/2022] Open
Abstract
The magnetic skyrmion is a nanoscale topological object characterized by the winding of magnetic moments, appearing in magnetic materials with broken inversion symmetry. Because of its low current threshold for driving the skyrmion motion, they have been intensely studied toward novel storage applications by using electron-beam, X-ray, and visible light microscopies. Here, we demonstrate another imaging method for skyrmions by using spin-caloritronic phenomena, that is, the spin Seebeck and anomalous Nernst effects, as a probe of magnetic texture. We scanned a focused heating spot on a Hall-cross shaped MgO/CoFeB/Ta/W multilayer film and mapped the magnitude as well as the direction of the resultant thermoelectric current due to the spin-caloritronic phenomena. Our experimental and calculation reveal that the characteristic patterns in the thermoelectric signal distribution reflect the skyrmions’ magnetic texture. The thermoelectric microscopy will be a complementary and useful imaging technique for the development of skyrmion devices owing to the unique symmetry of the spin-caloritronic phenomena.
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Affiliation(s)
- Ryo Iguchi
- National Institute for Materials Science, Tsukuba, 305-0047, Japan.
| | - Shinya Kasai
- National Institute for Materials Science, Tsukuba, 305-0047, Japan.,PRESTO, Japan Science and Technology Agency, Saitama, 332-0012, Japan
| | | | | | | | - Ken-Ichi Uchida
- National Institute for Materials Science, Tsukuba, 305-0047, Japan.,Department of Mechanical Engineering, The University of Tokyo, Tokyo, 113-8656, Japan.,Center for Spintronics Research Network, Tohoku University, Sendai, 980-8577, Japan
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12
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Reichlova H, Janda T, Godinho J, Markou A, Kriegner D, Schlitz R, Zelezny J, Soban Z, Bejarano M, Schultheiss H, Nemec P, Jungwirth T, Felser C, Wunderlich J, Goennenwein STB. Imaging and writing magnetic domains in the non-collinear antiferromagnet Mn 3Sn. Nat Commun 2019; 10:5459. [PMID: 31784509 PMCID: PMC6884521 DOI: 10.1038/s41467-019-13391-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Accepted: 11/04/2019] [Indexed: 11/08/2022] Open
Abstract
Non-collinear antiferromagnets are revealing many unexpected phenomena and they became crucial for the field of antiferromagnetic spintronics. To visualize and prepare a well-defined domain structure is of key importance. The spatial magnetic contrast, however, remains extraordinarily difficult to be observed experimentally. Here, we demonstrate a magnetic imaging technique based on a laser induced local thermal gradient combined with detection of the anomalous Nernst effect. We employ this method in one the most actively studied representatives of this class of materials-Mn3Sn. We demonstrate that the observed contrast is of magnetic origin. We further show an algorithm to prepare a well-defined domain pattern at room temperature based on heat assisted recording principle. Our study opens up a prospect to study spintronics phenomena in non-collinear antiferromagnets with spatial resolution.
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Affiliation(s)
- Helena Reichlova
- Institut für Festkörper- und Materialphysik and Würzburg-Dresden Cluster of Excellence ct.qmat, Technische Universität Dresden, 01062, Dresden, Germany.
| | - Tomas Janda
- Faculty of Mathematics and Physics, Charles University, Ke Karlovu 3, 121 16, Prague 2, Czech Republic
| | - Joao Godinho
- Faculty of Mathematics and Physics, Charles University, Ke Karlovu 3, 121 16, Prague 2, Czech Republic
- Institute of Physics, Czech Academy of Sciences, Cukrovarnická 10, 162 00, Praha 6, Czech Republic
| | - Anastasios Markou
- Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Straße 40, 01187, Dresden, Germany
| | - Dominik Kriegner
- Institute of Physics, Czech Academy of Sciences, Cukrovarnická 10, 162 00, Praha 6, Czech Republic
- Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Straße 40, 01187, Dresden, Germany
| | - Richard Schlitz
- Institut für Festkörper- und Materialphysik and Würzburg-Dresden Cluster of Excellence ct.qmat, Technische Universität Dresden, 01062, Dresden, Germany
| | - Jakub Zelezny
- Institute of Physics, Czech Academy of Sciences, Cukrovarnická 10, 162 00, Praha 6, Czech Republic
| | - Zbynek Soban
- Institute of Physics, Czech Academy of Sciences, Cukrovarnická 10, 162 00, Praha 6, Czech Republic
| | - Mauricio Bejarano
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Ion Beam Physics and Materials Research, Bautzner Landstraße 400, 01328, Dresden, Germany
| | - Helmut Schultheiss
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Ion Beam Physics and Materials Research, Bautzner Landstraße 400, 01328, Dresden, Germany
| | - Petr Nemec
- Faculty of Mathematics and Physics, Charles University, Ke Karlovu 3, 121 16, Prague 2, Czech Republic
| | - Tomas Jungwirth
- Institute of Physics, Czech Academy of Sciences, Cukrovarnická 10, 162 00, Praha 6, Czech Republic
- School of Physics and Astronomy, University of Nottingham, NG7 2RD, Nottingham, UK
| | - Claudia Felser
- Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Straße 40, 01187, Dresden, Germany
| | - Joerg Wunderlich
- Institute of Physics, Czech Academy of Sciences, Cukrovarnická 10, 162 00, Praha 6, Czech Republic
- Hitachi Cambridge Laboratory, Cambridge, CB3 0HE, UK
| | - Sebastian T B Goennenwein
- Institut für Festkörper- und Materialphysik and Würzburg-Dresden Cluster of Excellence ct.qmat, Technische Universität Dresden, 01062, Dresden, Germany
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13
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Anomalous Nernst effect in stressed magnetostrictive film grown onto flexible substrate. Sci Rep 2019; 9:15338. [PMID: 31653963 PMCID: PMC6814768 DOI: 10.1038/s41598-019-51971-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Accepted: 09/19/2019] [Indexed: 11/09/2022] Open
Abstract
The anomalous Nernst effect in nanostructured magnetic materials is a key phenomenon to optimally control and employ the internal energy dissipated in electronic devices, being dependent on, for instance, the magnetic anisotropy of the active element. Thereby, here, we report a theoretical and experimental investigation of the magnetic properties and anomalous Nernst effect in a flexible magnetostrictive film with induced uniaxial magnetic anisotropy and under external stress. Specifically, we calculate the magnetization behavior and the thermoelectric voltage response from a theoretical approach for a planar geometry, with magnetic free energy density that takes into account the induced uniaxial and magnetoelastic anisotropy contributions. Experimentally, we verify modifications of the effective magnetic anisotropy by changing the external stress, and explore the anomalous Nernst effect, a powerful tool to investigate the magnetic properties of magnetostrictive materials. We find quantitative agreement between experiment and numerical calculations, thus elucidating the magnetic behavior and thermoelectric voltage response. Besides, we provide evidence to confirm the validity of the theoretical approach to describe the magnetic properties and anomalous Nernst effect in ferromagnetic magnetostrictive films having uniaxial magnetic anisotropy and submitted to external stress. Hence, the results place flexible magnetostrictive systems as promising candidates for active elements in functionalized touch electronic devices.
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14
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Zhang XP, Bergeret FS, Golovach VN. Theory of Spin Hall Magnetoresistance from a Microscopic Perspective. NANO LETTERS 2019; 19:6330-6337. [PMID: 31378061 DOI: 10.1021/acs.nanolett.9b02459] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
We present a theory of the spin Hall magnetoresistance of metals in contact with magnetic insulators. We express the spin mixing conductances, which govern the phenomenology of the effect, in terms of the microscopic parameters of the interface and the spin-spin correlation functions of the local moments on the surface of the magnetic insulator. The magnetic-field and temperature dependence of the spin mixing conductances leads to a rich behavior of the resistance due to an interplay between the Hanle effect and the spin mixing at the interface. We describe an unusual negative magnetoresistance originating from a nonlocal Hanle effect. Our theory provides a useful tool for understanding the experiments on heavy metals in contact with magnetic insulators of different kinds, and it enables the spin Hall magnetoresistance effect to be used as a technique to study magnetism at interfaces.
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Affiliation(s)
- Xian-Peng Zhang
- Donostia International Physics Center (DIPC) , 20018 Donostia-San Sebastián , Basque Country , Spain
- Centro de Física de Materiales (CFM-MPC) , Centro Mixto CSIC-UPV/EHU , 20018 Donostia-San Sebastián , Basque Country , Spain
| | - F Sebastian Bergeret
- Donostia International Physics Center (DIPC) , 20018 Donostia-San Sebastián , Basque Country , Spain
- Centro de Física de Materiales (CFM-MPC) , Centro Mixto CSIC-UPV/EHU , 20018 Donostia-San Sebastián , Basque Country , Spain
| | - Vitaly N Golovach
- Donostia International Physics Center (DIPC) , 20018 Donostia-San Sebastián , Basque Country , Spain
- Centro de Física de Materiales (CFM-MPC) , Centro Mixto CSIC-UPV/EHU , 20018 Donostia-San Sebastián , Basque Country , Spain
- Departamento de Física de Materiales UPV/EHU , 20018 Donostia-San Sebastián , Basque Country , Spain
- IKERBASQUE, Basque Foundation for Science , 48013 Bilbao , Basque Country , Spain
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15
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Precise Determination of the Temperature Gradients in Laser-irradiated Ultrathin Magnetic Layers for the Analysis of Thermal Spin Current. Sci Rep 2018; 8:11337. [PMID: 30054593 PMCID: PMC6063919 DOI: 10.1038/s41598-018-29702-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2018] [Accepted: 07/16/2018] [Indexed: 11/22/2022] Open
Abstract
We investigated the temperature distribution induced by laser irradiation of ultrathin magnetic films by applying a finite element method (FEM) to the finite difference time domain (FDTD) representation for the analysis of thermal induced spin currents. The dependency of the thermal gradient (∇T) of ultrathin magnetic films on material parameters, including the reflectivity and absorption coefficient were evaluated by examining optical effects, which indicates that reflectance (R) and the apparent absorption coefficient (α*) play important roles in the calculation of ∇T for ultrathin layers. The experimental and calculated values of R and α* for the ultrathin magnetic layers irradiated by laser-driven heat sources estimated using the combined FDTD and FEM method are in good agreement for the amorphous CoFeB and crystalline Co layers of thicknesses ranging from 3~20 nm. Our results demonstrate that the optical parameters are crucial for the estimation of the temperature gradient induced by laser illumination for the study of thermally generated spin currents and related phenomena.
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16
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Liu YS, Dong YJ, Zhang J, Yu HL, Feng JF, Yang XF. Multi-functional spintronic devices based on boron- or aluminum-doped silicene nanoribbons. NANOTECHNOLOGY 2018; 29:125201. [PMID: 29355833 DOI: 10.1088/1361-6528/aaa999] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Zigzag silicene nanoribbons (ZSiNRs) in the ferromagnetic edge ordering have a metallic behavior, which limits their applications in spintronics. Here a robustly half-metallic property is achieved by the boron substitution doping at the edge of ZSiNRs. When the impurity atom is replaced by the aluminum atom, the doped ZSiNRs possess a spin semiconducting property. Its band gap is suppressed with the increase of ribbon's width, and a pure thermal spin current is achieved by modulating ribbon's width. Moreover, a negative differential thermoelectric resistance in the thermal charge current appears as the temperature gradient increases, which originates from the fact that the spin-up and spin-down thermal charge currents have diverse increasing rates at different temperature gradient regions. Our results put forward a promising route to design multi-functional spintronic devices which may be applied in future low-power-consumption technologies.
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Affiliation(s)
- Y S Liu
- College of Physics and Electronic Engineering, Changshu Institute of Technology, Changshu 215500, People's Republic of China
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17
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Cornelissen LJ, Liu J, van Wees BJ, Duine RA. Spin-Current-Controlled Modulation of the Magnon Spin Conductance in a Three-Terminal Magnon Transistor. PHYSICAL REVIEW LETTERS 2018; 120:097702. [PMID: 29547318 DOI: 10.1103/physrevlett.120.097702] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2017] [Indexed: 06/08/2023]
Abstract
Efficient manipulation of magnon spin transport is crucial for developing magnon-based spintronic devices. In this Letter, we provide proof of principle of a method for modulating the diffusive transport of thermal magnons in an yttrium iron garnet channel between injector and detector contacts. The magnon spin conductance of the channel is altered by increasing or decreasing the magnon chemical potential via spin Hall injection of magnons by a third modulator electrode. We obtain a modulation efficiency of 1.6%/mA at T=250 K. Finite element modeling shows that this could be increased to well above 10%/mA by reducing the thickness of the channel, providing interesting prospects for the development of thermal-magnon-based logic circuits.
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Affiliation(s)
- L J Cornelissen
- Physics of Nanodevices, Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - J Liu
- Physics of Nanodevices, Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - B J van Wees
- Physics of Nanodevices, Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - R A Duine
- Institute for Theoretical Physics and Center for Extreme Matter and Emergent Phenomena, Utrecht University, Leuvenlaan 4, 3584 CE Utrecht, The Netherlands and Department of Applied Physics, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands
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18
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Dong BW, Cramer J, Ganzhorn K, Yuan HY, Guo EJ, Goennenwein STB, Kläui M. Spin Hall magnetoresistance in the non-collinear ferrimagnet GdIG close to the compensation temperature. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2018; 30:035802. [PMID: 29186002 DOI: 10.1088/1361-648x/aa9e26] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
We investigate the spin Hall magnetoresistance (SMR) in a gadolinium iron garnet (GdIG)/platinum (Pt) heterostructure by angular dependent magnetoresistance measurements. The magnetic structure of the ferromagnetic insulator GdIG is non-collinear near the compensation temperature, while it is collinear far from the compensation temperature. In the collinear regime, the SMR signal in GdIG is consistent with the usual [Formula: see text] relation well established in the collinear magnet yttrium iron garnet, with [Formula: see text] the angle between magnetization and spin Hall spin polarization direction. In the non-collinear regime, both an SMR signal with inverted sign and a more complex angular dependence with four maxima are observed within one sweep cycle. The number of maxima as well as the relative strength of different maxima depend strongly on temperature and field strength. Our results evidence a complex SMR behavior in the non-collinear magnetic regime that goes beyond the conventional formalism developed for collinear magnetic structures.
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Affiliation(s)
- Bo-Wen Dong
- School of Materials Science and Engineering, University of Science and Technology Beijing, 100083 Beijing, People's Republic of China. Graduate School of Excellence Materials Science in Mainz (MAINZ), 55128 Mainz, Germany. Institute of Physics, Johannes Gutenberg-Universität Mainz, 55099 Mainz, Germany
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19
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Lange M, Guénon S, Lever F, Kleiner R, Koelle D. A high-resolution combined scanning laser and widefield polarizing microscope for imaging at temperatures from 4 K to 300 K. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2017; 88:123705. [PMID: 29289195 DOI: 10.1063/1.5009529] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Polarized light microscopy, as a contrast-enhancing technique for optically anisotropic materials, is a method well suited for the investigation of a wide variety of effects in solid-state physics, as, for example, birefringence in crystals or the magneto-optical Kerr effect (MOKE). We present a microscopy setup that combines a widefield microscope and a confocal scanning laser microscope with polarization-sensitive detectors. By using a high numerical aperture objective, a spatial resolution of about 240 nm at a wavelength of 405 nm is achieved. The sample is mounted on a 4He continuous flow cryostat providing a temperature range between 4 K and 300 K, and electromagnets are used to apply magnetic fields of up to 800 mT with variable in-plane orientation and 20 mT with out-of-plane orientation. Typical applications of the polarizing microscope are the imaging of the in-plane and out-of-plane magnetization via the longitudinal and polar MOKE, imaging of magnetic flux structures in superconductors covered with a magneto-optical indicator film via the Faraday effect, or imaging of structural features, such as twin-walls in tetragonal SrTiO3. The scanning laser microscope furthermore offers the possibility to gain local information on electric transport properties of a sample by detecting the beam-induced voltage change across a current-biased sample. This combination of magnetic, structural, and electric imaging capabilities makes the microscope a viable tool for research in the fields of oxide electronics, spintronics, magnetism, and superconductivity.
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Affiliation(s)
- M Lange
- Physikalisches Institut-Experimentalphysik II and Center for Quantum Science (CQ) in LISA, Universität Tübingen, D-72076 Tübingen, Germany
| | - S Guénon
- Physikalisches Institut-Experimentalphysik II and Center for Quantum Science (CQ) in LISA, Universität Tübingen, D-72076 Tübingen, Germany
| | - F Lever
- Physikalisches Institut-Experimentalphysik II and Center for Quantum Science (CQ) in LISA, Universität Tübingen, D-72076 Tübingen, Germany
| | - R Kleiner
- Physikalisches Institut-Experimentalphysik II and Center for Quantum Science (CQ) in LISA, Universität Tübingen, D-72076 Tübingen, Germany
| | - D Koelle
- Physikalisches Institut-Experimentalphysik II and Center for Quantum Science (CQ) in LISA, Universität Tübingen, D-72076 Tübingen, Germany
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20
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Longitudinal spin Seebeck coefficient: heat flux vs. temperature difference method. Sci Rep 2017; 7:46752. [PMID: 28440288 DOI: 10.1038/srep46752] [Citation(s) in RCA: 64] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2017] [Accepted: 03/21/2017] [Indexed: 11/08/2022] Open
Abstract
The determination of the longitudinal spin Seebeck effect (LSSE) coefficient is currently plagued by a large uncertainty due to the poor reproducibility of the experimental conditions used in its measurement. In this work we present a detailed analysis of two different methods used for the determination of the LSSE coefficient. We have performed LSSE experiments in different laboratories, by using different setups and employing both the temperature difference method and the heat flux method. We found that the lack of reproducibility can be mainly attributed to the thermal contact resistance between the sample and the thermal baths which generate the temperature gradient. Due to the variation of the thermal resistance, we found that the scaling of the LSSE voltage to the heat flux through the sample rather than to the temperature difference across the sample greatly reduces the uncertainty. The characteristics of a single YIG/Pt LSSE device obtained with two different setups was (1.143 ± 0.007) 10-7 Vm/W and (1.101 ± 0.015) 10-7 Vm/W with the heat flux method and (2.313 ± 0.017) 10-7 V/K and (4.956 ± 0.005) 10-7 V/K with the temperature difference method. This shows that systematic errors can be considerably reduced with the heat flux method.
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21
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Lin W, Chien CL. Electrical Detection of Spin Backflow from an Antiferromagnetic Insulator/Y_{3}Fe_{5}O_{12} Interface. PHYSICAL REVIEW LETTERS 2017; 118:067202. [PMID: 28234519 DOI: 10.1103/physrevlett.118.067202] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2016] [Indexed: 06/06/2023]
Abstract
Spin Hall magnetoresistance (SMR) has been observed in Pt/NiO/Y_{3}Fe_{5}O_{12} (YIG) heterostructures with characteristics very different from those in Pt/YIG. This phenomenon indicates that a spin current generated by the spin Hall effect in Pt transmits through the insulating NiO and is reflected from the NiO/YIG interface. The SMR in Pt/NiO/YIG shows a strong temperature dependence dominated by effective spin conductance, due to antiferromagnetic magnons and spin fluctuation. Inverted SMR has been observed below a temperature which increases with the NiO thickness, suggesting a spin-flip reflection from the antiferromagnetic NiO exchange coupled with the YIG.
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Affiliation(s)
- Weiwei Lin
- Department of Physics and Astronomy, Johns Hopkins University, Baltimore, Maryland 21218, USA
| | - C L Chien
- Department of Physics and Astronomy, Johns Hopkins University, Baltimore, Maryland 21218, USA
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22
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Zhu L, Li R, Yao K. Temperature-controlled colossal magnetoresistance and perfect spin Seebeck effect in hybrid graphene/boron nitride nanoribbons. Phys Chem Chem Phys 2017; 19:4085-4092. [PMID: 28111668 DOI: 10.1039/c6cp07179a] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Thermal spin transport properties of graphene and hexagonal boron nitride nanoribbon heterojunctions have been investigated using density functional theory calculations combined with the Keldysh nonequilibrium Green's function approach. The results showed that the perfect spin Seebeck effect and analogy negative differential thermoelectric resistance occurred in the device under a temperature difference without a gate or bias voltage. An intriguing thermally induced colossal magnetoresistance without gate regulation was also observed, which can be switched between a positive and negative value with temperature control. It was also found that the unit number of zigzag graphene nanoribbons and boron nitride nanoribbons can tune the electronic band structure and the energy gap of the heterostructure, and then modulate the thermal spin transport properties. The results suggest that graphene and hexagonal boron nitride nanoribbon heterostructures may have potential applications in graphene-based nanodevices.
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Affiliation(s)
- Lin Zhu
- School of Physics and Wuhan National High Magnetic Field Center, Huazhong University of Science and Technology, Wuhan 430074, China.
| | - Ruimin Li
- School of Physics and Wuhan National High Magnetic Field Center, Huazhong University of Science and Technology, Wuhan 430074, China.
| | - Kailun Yao
- School of Physics and Wuhan National High Magnetic Field Center, Huazhong University of Science and Technology, Wuhan 430074, China.
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23
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Reimer O, Meier D, Bovender M, Helmich L, Dreessen JO, Krieft J, Shestakov AS, Back CH, Schmalhorst JM, Hütten A, Reiss G, Kuschel T. Quantitative separation of the anisotropic magnetothermopower and planar Nernst effect by the rotation of an in-plane thermal gradient. Sci Rep 2017; 7:40586. [PMID: 28094279 PMCID: PMC5240136 DOI: 10.1038/srep40586] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2016] [Accepted: 12/08/2016] [Indexed: 11/08/2022] Open
Abstract
A thermal gradient as the driving force for spin currents plays a key role in spin caloritronics. In this field the spin Seebeck effect (SSE) is of major interest and was investigated in terms of in-plane thermal gradients inducing perpendicular spin currents (transverse SSE) and out-of-plane thermal gradients generating parallel spin currents (longitudinal SSE). Up to now all spincaloric experiments employ a spatially fixed thermal gradient. Thus, anisotropic measurements with respect to well defined crystallographic directions were not possible. Here we introduce a new experiment that allows not only the in-plane rotation of the external magnetic field, but also the rotation of an in-plane thermal gradient controlled by optical temperature detection. As a consequence, the anisotropic magnetothermopower and the planar Nernst effect in a permalloy thin film can be measured simultaneously. Thus, the angular dependence of the magnetothermopower with respect to the magnetization direction reveals a phase shift, that allows the quantitative separation of the thermopower, the anisotropic magnetothermopower and the planar Nernst effect.
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Affiliation(s)
- Oliver Reimer
- Center for Spinelectronic Materials and Devices, Department of Physics, Bielefeld University, Universitätsstraße 25, 33615 Bielefeld, Germany
| | - Daniel Meier
- Center for Spinelectronic Materials and Devices, Department of Physics, Bielefeld University, Universitätsstraße 25, 33615 Bielefeld, Germany
| | - Michel Bovender
- Center for Spinelectronic Materials and Devices, Department of Physics, Bielefeld University, Universitätsstraße 25, 33615 Bielefeld, Germany
| | - Lars Helmich
- Center for Spinelectronic Materials and Devices, Department of Physics, Bielefeld University, Universitätsstraße 25, 33615 Bielefeld, Germany
| | - Jan-Oliver Dreessen
- Center for Spinelectronic Materials and Devices, Department of Physics, Bielefeld University, Universitätsstraße 25, 33615 Bielefeld, Germany
| | - Jan Krieft
- Center for Spinelectronic Materials and Devices, Department of Physics, Bielefeld University, Universitätsstraße 25, 33615 Bielefeld, Germany
| | - Anatoly S. Shestakov
- Institute of Experimental and Applied Physics, University of Regensburg, Universitätsstraße 31, 93040 Regensburg, Germany
| | - Christian H. Back
- Institute of Experimental and Applied Physics, University of Regensburg, Universitätsstraße 31, 93040 Regensburg, Germany
| | - Jan-Michael Schmalhorst
- Center for Spinelectronic Materials and Devices, Department of Physics, Bielefeld University, Universitätsstraße 25, 33615 Bielefeld, Germany
| | - Andreas Hütten
- Center for Spinelectronic Materials and Devices, Department of Physics, Bielefeld University, Universitätsstraße 25, 33615 Bielefeld, Germany
| | - Günter Reiss
- Center for Spinelectronic Materials and Devices, Department of Physics, Bielefeld University, Universitätsstraße 25, 33615 Bielefeld, Germany
| | - Timo Kuschel
- Center for Spinelectronic Materials and Devices, Department of Physics, Bielefeld University, Universitätsstraße 25, 33615 Bielefeld, Germany
- Physics of Nanodevices, Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
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24
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Adatom-induced local reconstructions in zigzag silicene nanoribbons: Spin semiconducting properties and large spin thermopowers. Chem Phys Lett 2017. [DOI: 10.1016/j.cplett.2016.11.049] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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25
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Huang X, Dai Z, Huang L, Lu G, Liu M, Piao H, Kim DH, Yu SC, Pan L. Spin Hall magnetoresistance in Co 2FeSi/Pt thin films: dependence on Pt thickness and temperature. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2016; 28:476006. [PMID: 27667821 DOI: 10.1088/0953-8984/28/47/476006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
We have investigated the temperature and the Pt layer thickness dependence of the magnetoresistances (MRs) in Co2FeSi/Pt thin films. Based on the field dependent measurements, it can be seen that the spin-current-induced spin Hall magnetoresistance (SMR) plays the dominant role in the MRs in the Co2FeSi/Pt bilayers in the whole temperature range. Meanwhile, a quite small part of anisotropic magnetoresistance (AMR) existed in the MRs. It proved to be originated from magnetic proximity effect (MPE) by measuring the Pt thickness and temperature dependence of the AMR. Moreover, the Co2FeSi layer thickness has much weaker effect on the SMR and AMR compared to the Pt layer thickness. These results indicate that the Co2FeSi/Pt interface is beneficial to be used in the spin-current-induced physical phenomena.
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Affiliation(s)
- Xiufeng Huang
- College of Science, China Three Gorges of University, Yichang 443002, Hubei, People's Republic of China
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26
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Taniguchi T, Grollier J, Stiles MD. Spin-transfer torque in ferromagnetic bilayers generated by anomalous Hall effect and anisotropic magnetoresistance. PROCEEDINGS OF SPIE--THE INTERNATIONAL SOCIETY FOR OPTICAL ENGINEERING 2016; 9931:99310W. [PMID: 28057977 PMCID: PMC5207049 DOI: 10.1117/12.2235822] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/25/2024]
Abstract
We propose an experimental scheme to determine the spin-transfer torque efficiency excited by the spin-orbit interaction in ferromagnetic bilayers from the measurement of the longitudinal magnetoresistace. Solving a diffusive spin-transport theory with appropriate boundary conditions gives an analytical formula of the longitudinal charge current density. The longitudinal charge current has a term that is proportional to the square of the spin-transfer torque efficiency and that also depends on the ratio of the film thickness to the spin diffusion length of the ferromagnet. Extracting this contribution from measurements of the longitudinal resistivity as a function of the thickness can give the spin-transfer torque efficiency.
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Affiliation(s)
- Tomohiro Taniguchi
- National Institute of Advanced Industrial Science and Technology (AIST), Spintronics Research Center, Tsukuba, Ibaraki 305-8568, Japan
| | - Julie Grollier
- Unité Mixte de Physique CNRS/Thales and Université Paris Sud 11, 1 Avenue Fresnel, 91767 Palaiseau, France
| | - M D Stiles
- Center for Nanoscale Science and Technology, National Institute of Standards and Technology, Gaithersburg, Maryland 20899-6202, USA
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27
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Götte M, Joppe M, Dahm T. Pure spin current devices based on ferromagnetic topological insulators. Sci Rep 2016; 6:36070. [PMID: 27782187 PMCID: PMC5080548 DOI: 10.1038/srep36070] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2016] [Accepted: 10/07/2016] [Indexed: 11/11/2022] Open
Abstract
Two-dimensional topological insulators possess two counter propagating edge channels with opposite spin direction. Recent experimental progress allowed to create ferromagnetic topological insulators realizing a quantum anomalous Hall (QAH) state. In the QAH state one of the two edge channels disappears due to the strong ferromagnetic exchange field. We investigate heterostructures of topological insulators and ferromagnetic topological insulators by means of numerical transport calculations. We show that spin current flow in such heterostructures can be controlled with high fidelity. Specifically, we propose spintronic devices that are capable of creating, switching and detecting pure spin currents using the same technology. In these devices electrical currents are directly converted into spin currents, allowing a high conversion efficiency. Energy independent transport properties in combination with large bulk gaps in some topological insulator materials may allow operation even at room temperature.
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Affiliation(s)
- Matthias Götte
- Universität Bielefeld, Fakultät für Physik, Postfach 100131, D-33501 Bielefeld, Germany
| | - Michael Joppe
- Universität Bielefeld, Fakultät für Physik, Postfach 100131, D-33501 Bielefeld, Germany
| | - Thomas Dahm
- Universität Bielefeld, Fakultät für Physik, Postfach 100131, D-33501 Bielefeld, Germany
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28
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Chen YT, Takahashi S, Nakayama H, Althammer M, Goennenwein STB, Saitoh E, Bauer GEW. Theory of spin Hall magnetoresistance (SMR) and related phenomena. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2016; 28:103004. [PMID: 26881498 DOI: 10.1088/0953-8984/28/10/103004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
We review the so-called spin Hall magnetoresistance (SMR) in bilayers of a magnetic insulator and a metal, in which spin currents are generated in the normal metal by the spin Hall effect. The associated angular momentum transfer to the ferromagnetic layer and thereby the electrical resistance is modulated by the angle between the applied current and the magnetization direction. The SMR provides a convenient tool to non-invasively measure the magnetization direction and spin-transfer torque to an insulator. We introduce the minimal theoretical instruments to calculate the SMR, i.e. spin diffusion theory and quantum mechanical boundary conditions. This leads to a small set of parameters that can be fitted to experiments. We discuss the limitations of the theory as well as alternative mechanisms such as the ferromagnetic proximity effect and Rashba spin-orbit torques, and point out new developments.
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Affiliation(s)
- Yan-Ting Chen
- RIKEN Center for Emergent Matter Science (CEMS), 2-1 Hirosawa, Wako, Saitama 351-0198, Japan. Kavli Institute of NanoScience, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft, The Netherlands
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29
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Kim J, Sheng P, Takahashi S, Mitani S, Hayashi M. Spin Hall Magnetoresistance in Metallic Bilayers. PHYSICAL REVIEW LETTERS 2016; 116:097201. [PMID: 26991195 DOI: 10.1103/physrevlett.116.097201] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2015] [Indexed: 06/05/2023]
Abstract
Spin Hall magnetoresistance (SMR) is studied in metallic bilayers that consist of a heavy metal (HM) layer and a ferromagnetic metal (FM) layer. We find a nearly tenfold increase of SMR in W/CoFeB compared to previously studied HM/ferromagnetic insulator systems. The SMR increases with decreasing temperature despite the negligible change in the W layer resistivity. A model is developed to account for the absorption of the longitudinal spin current to the FM layer, one of the key characteristics of a metallic ferromagnet. We find that the model not only quantitatively describes the HM layer thickness dependence of SMR, allowing accurate estimation of the spin Hall angle and the spin diffusion length of the HM layer, but also can account for the temperature dependence of SMR by assuming a temperature dependent spin polarization of the FM layer. These results illustrate the unique role a metallic ferromagnetic layer plays in defining spin transmission across the HM/FM interface.
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Affiliation(s)
- Junyeon Kim
- National Institute for Materials Science, Tsukuba 305-0047, Japan
| | - Peng Sheng
- National Institute for Materials Science, Tsukuba 305-0047, Japan
| | - Saburo Takahashi
- Institute for Materials Research, Tohoku University, Sendai 980-8577, Japan
| | - Seiji Mitani
- National Institute for Materials Science, Tsukuba 305-0047, Japan
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30
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Wang S, Zou L, Zhang X, Cai J, Wang S, Shen B, Sun J. Spin Seebeck effect and spin Hall magnetoresistance at high temperatures for a Pt/yttrium iron garnet hybrid structure. NANOSCALE 2015; 7:17812-17819. [PMID: 26455519 DOI: 10.1039/c5nr05484b] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Based on unique experimental setups, the temperature dependences of the longitudinal spin Seebeck effect (LSSE) and spin Hall magnetoresistance (SMR) of the Pt/yttrium iron garnet (Pt/YIG) hybrid structure are determined in a wide temperature range up to the Curie temperature of YIG. From a theoretical analysis of the experimental relationship between the SMR and temperature, the spin mixing conductance of the Pt/YIG interface is deduced as a function of temperature. Adopting the deduced spin mixing conductance, the temperature dependence of the LSSE is well reproduced based on the magnon spin current theory. Our research sheds new light on the controversy about the theoretical models for the LSSE.
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Affiliation(s)
- Shuanhu Wang
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, People's Republic of China.
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31
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Takei S, Tserkovnyak Y. Nonlocal Magnetoresistance Mediated by Spin Superfluidity. PHYSICAL REVIEW LETTERS 2015; 115:156604. [PMID: 26550744 DOI: 10.1103/physrevlett.115.156604] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2015] [Indexed: 06/05/2023]
Abstract
The electrical response of two diffusive metals is studied when they are linked by a magnetic insulator hosting a topologically stable (superfluid) spin current. We discuss how charge currents in the metals induce a spin supercurrent state, which in turn generates a magnetoresistance that depends on the topology of the electrical circuit. This magnetoresistance relies on phase coherence over the entire magnet and gives direct evidence for spin superfluidity. We show that driving the magnet with an ac current allows coherent spin transport even in the presence of U(1)-breaking magnetic anisotropy that can preclude dc superfluid transport. Spin transmission in the ac regime shows a series of resonance peaks as a function of frequency. The peak locations, heights, and widths can be used to extract static interfacial properties, e.g., the spin-mixing conductance and effective spin Hall angle, and to probe dynamic properties such as the spin-wave dispersion. Thus, ac transport may provide a simpler route to realizing nonequilbrium coherent spin transport and a useful way to characterize the magnetic system, serving as a precursor to the realization of dc superfluid spin transport.
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Affiliation(s)
- So Takei
- Department of Physics and Astronomy, University of California, Los Angeles, California 90095, USA
| | - Yaroslav Tserkovnyak
- Department of Physics and Astronomy, University of California, Los Angeles, California 90095, USA
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32
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Bartell JM, Ngai DH, Leng Z, Fuchs GD. Towards a table-top microscope for nanoscale magnetic imaging using picosecond thermal gradients. Nat Commun 2015; 6:8460. [PMID: 26419515 PMCID: PMC4598727 DOI: 10.1038/ncomms9460] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2015] [Accepted: 08/23/2015] [Indexed: 11/18/2022] Open
Abstract
Research advancement in magnetoelectronics is challenged by the lack of a table-top magnetic measurement technique with the simultaneous temporal and spatial resolution necessary for characterizing magnetization dynamics in devices of interest, such as magnetic memory and spin torque oscillators. Although magneto-optical microscopy provides superb temporal resolution, its spatial resolution is fundamentally limited by optical diffraction. To address this challenge, we study heat rather than light as a vehicle to stroboscopically transduce a local magnetic moment into an electrical signal while retaining picosecond temporal resolution. Using this concept, we demonstrate spatiotemporal magnetic microscopy using the time-resolved anomalous Nernst effect (TRANE). Experimentally and with supporting numerical calculations, we find that TRANE microscopy has temporal resolution below 30 ps and spatial resolution determined by the area of thermal excitation. Based on these findings, we suggest a route to exceed the limits imposed by far-field optical diffraction.
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Affiliation(s)
- J. M. Bartell
- School of Applied and Engineering Physics, Cornell University, Ithaca, New York 14853, USA
| | - D. H. Ngai
- School of Applied and Engineering Physics, Cornell University, Ithaca, New York 14853, USA
| | - Z. Leng
- School of Applied and Engineering Physics, Cornell University, Ithaca, New York 14853, USA
| | - G. D. Fuchs
- School of Applied and Engineering Physics, Cornell University, Ithaca, New York 14853, USA
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33
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Meier D, Reinhardt D, van Straaten M, Klewe C, Althammer M, Schreier M, Goennenwein STB, Gupta A, Schmid M, Back CH, Schmalhorst JM, Kuschel T, Reiss G. Longitudinal spin Seebeck effect contribution in transverse spin Seebeck effect experiments in Pt/YIG and Pt/NFO. Nat Commun 2015; 6:8211. [PMID: 26394541 PMCID: PMC4598359 DOI: 10.1038/ncomms9211] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2014] [Accepted: 07/30/2015] [Indexed: 10/27/2022] Open
Abstract
The spin Seebeck effect, the generation of a spin current by a temperature gradient, has attracted great attention, but the interplay over a millimetre range along a thin ferromagnetic film as well as unintended side effects which hinder an unambiguous detection have evoked controversial discussions. Here, we investigate the inverse spin Hall voltage of a 10 nm thin Pt strip deposited on the magnetic insulators Y3Fe5O12 and NiFe2O4 with a temperature gradient in the film plane. We show characteristics typical of the spin Seebeck effect, although we do not observe the most striking features of the transverse spin Seebeck effect. Instead, we attribute the observed voltages to the longitudinal spin Seebeck effect generated by a contact tip induced parasitic out-of-plane temperature gradient, which depends on material, diameter and temperature of the tip.
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Affiliation(s)
- Daniel Meier
- Department of Physics, Center for Spinelectronic Materials and Devices, Bielefeld University, Universitätsstraße 25, 33615 Bielefeld, Germany
| | - Daniel Reinhardt
- Department of Physics, Center for Spinelectronic Materials and Devices, Bielefeld University, Universitätsstraße 25, 33615 Bielefeld, Germany
| | - Michael van Straaten
- Department of Physics, Center for Spinelectronic Materials and Devices, Bielefeld University, Universitätsstraße 25, 33615 Bielefeld, Germany
| | - Christoph Klewe
- Department of Physics, Center for Spinelectronic Materials and Devices, Bielefeld University, Universitätsstraße 25, 33615 Bielefeld, Germany
| | - Matthias Althammer
- Walther-Meissner-Institut, Bayerische Akademie der Wissenschaften, Walther-Meissner-Strasse 8, 85748 Garching, Germany
| | - Michael Schreier
- Walther-Meissner-Institut, Bayerische Akademie der Wissenschaften, Walther-Meissner-Strasse 8, 85748 Garching, Germany.,Physik-Department, Technische Universität München, James-Franck-Str. 1, 85748 Garching, Germany
| | - Sebastian T B Goennenwein
- Walther-Meissner-Institut, Bayerische Akademie der Wissenschaften, Walther-Meissner-Strasse 8, 85748 Garching, Germany.,Nanosystems Initiative Munich (NIM), Schellingstraße 4, 80799 München, Germany
| | - Arunava Gupta
- Center for Materials for Information Technology, University of Alabama, Tuscaloosa, Alabama 35487, USA
| | - Maximilian Schmid
- Institute of Experimental and Applied Physics, University of Regensburg, Universitätsstraße 31, 93040 Regensburg, Germany
| | - Christian H Back
- Institute of Experimental and Applied Physics, University of Regensburg, Universitätsstraße 31, 93040 Regensburg, Germany
| | - Jan-Michael Schmalhorst
- Department of Physics, Center for Spinelectronic Materials and Devices, Bielefeld University, Universitätsstraße 25, 33615 Bielefeld, Germany
| | - Timo Kuschel
- Department of Physics, Center for Spinelectronic Materials and Devices, Bielefeld University, Universitätsstraße 25, 33615 Bielefeld, Germany
| | - Günter Reiss
- Department of Physics, Center for Spinelectronic Materials and Devices, Bielefeld University, Universitätsstraße 25, 33615 Bielefeld, Germany
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34
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Kehlberger A, Ritzmann U, Hinzke D, Guo EJ, Cramer J, Jakob G, Onbasli MC, Kim DH, Ross CA, Jungfleisch MB, Hillebrands B, Nowak U, Kläui M. Length Scale of the Spin Seebeck Effect. PHYSICAL REVIEW LETTERS 2015; 115:096602. [PMID: 26371671 DOI: 10.1103/physrevlett.115.096602] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2015] [Indexed: 05/12/2023]
Abstract
We investigate the origin of the spin Seebeck effect in yttrium iron garnet (YIG) samples for film thicknesses from 20 nm to 50 μm at room temperature and 50 K. Our results reveal a characteristic increase of the longitudinal spin Seebeck effect amplitude with the thickness of the insulating ferrimagnetic YIG, which levels off at a critical thickness that increases with decreasing temperature. The observed behavior cannot be explained as an interface effect or by variations of the material parameters. Comparison to numerical simulations of thermal magnonic spin currents yields qualitative agreement for the thickness dependence resulting from the finite magnon propagation length. This allows us to trace the origin of the observed signals to genuine bulk magnonic spin currents due to the spin Seebeck effect ruling out an interface origin and allowing us to gauge the reach of thermally excited magnons in this system for different temperatures. At low temperature, even quantitative agreement with the simulations is found.
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Affiliation(s)
- Andreas Kehlberger
- Institute of Physics, Johannes Gutenberg-University Mainz, 55099 Mainz, Germany
| | - Ulrike Ritzmann
- Department of Physics, University of Konstanz, D-78457 Konstanz, Germany
| | - Denise Hinzke
- Department of Physics, University of Konstanz, D-78457 Konstanz, Germany
| | - Er-Jia Guo
- Institute of Physics, Johannes Gutenberg-University Mainz, 55099 Mainz, Germany
| | - Joel Cramer
- Institute of Physics, Johannes Gutenberg-University Mainz, 55099 Mainz, Germany
| | - Gerhard Jakob
- Institute of Physics, Johannes Gutenberg-University Mainz, 55099 Mainz, Germany
| | - Mehmet C Onbasli
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - Dong Hun Kim
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - Caroline A Ross
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - Matthias B Jungfleisch
- Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439, USA
- Fachbereich Physik and Landesforschungszentrum OPTIMAS, Technische Universität Kaiserslautern, Kaiserslautern 67663, Germany
| | - Burkard Hillebrands
- Fachbereich Physik and Landesforschungszentrum OPTIMAS, Technische Universität Kaiserslautern, Kaiserslautern 67663, Germany
| | - Ulrich Nowak
- Department of Physics, University of Konstanz, D-78457 Konstanz, Germany
| | - Mathias Kläui
- Institute of Physics, Johannes Gutenberg-University Mainz, 55099 Mainz, Germany
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35
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Thermoelectric Signal Enhancement by Reconciling the Spin Seebeck and Anomalous Nernst Effects in Ferromagnet/Non-magnet Multilayers. Sci Rep 2015; 5:10249. [PMID: 26020492 PMCID: PMC4447118 DOI: 10.1038/srep10249] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2014] [Accepted: 04/08/2015] [Indexed: 11/15/2022] Open
Abstract
The utilization of ferromagnetic (FM) materials in thermoelectric devices allows one to have a simpler structure and/or independent control of electric and thermal conductivities, which may further remove obstacles for this technology to be realized. The thermoelectricity in FM/non-magnet (NM) heterostructures using an optical heating source is studied as a function of NM materials and a number of multilayers. It is observed that the overall thermoelectric signal in those structures which is contributed by spin Seebeck effect and anomalous Nernst effect (ANE) is enhanced by a proper selection of NM materials with a spin Hall angle that matches to the sign of the ANE. Moreover, by an increase of the number of multilayer, the thermoelectric voltage is enlarged further and the device resistance is reduced, simultaneously. The experimental observation of the improvement of thermoelectric properties may pave the way for the realization of magnetic-(or spin-) based thermoelectric devices.
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36
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Yang XF, Wang HL, Chen YS, Kuang YW, Hong XK, Liu YS, Feng JF, Wang XF. Giant spin thermoelectric effects in all-carbon nanojunctions. Phys Chem Chem Phys 2015; 17:22815-22. [DOI: 10.1039/c5cp02779a] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We investigate the thermospin properties of an all-carbon nanojunction constructed by a graphene nanoflake (GNF) and zigzag-edged graphene nanoribbons (ZGNRs), bridged by the carbon atomic chains.
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Affiliation(s)
- X. F. Yang
- College of Physics and Engineering
- Changshu Institute of Technology and Jiangsu Laboratory of Advanced Functional materials
- Changshu 215500
- China
| | - H. L. Wang
- College of Physics and Engineering
- Changshu Institute of Technology and Jiangsu Laboratory of Advanced Functional materials
- Changshu 215500
- China
| | - Y. S. Chen
- College of Physics and Engineering
- Changshu Institute of Technology and Jiangsu Laboratory of Advanced Functional materials
- Changshu 215500
- China
| | - Y. W. Kuang
- College of Physics and Engineering
- Changshu Institute of Technology and Jiangsu Laboratory of Advanced Functional materials
- Changshu 215500
- China
| | - X. K. Hong
- College of Physics and Engineering
- Changshu Institute of Technology and Jiangsu Laboratory of Advanced Functional materials
- Changshu 215500
- China
| | - Y. S. Liu
- College of Physics and Engineering
- Changshu Institute of Technology and Jiangsu Laboratory of Advanced Functional materials
- Changshu 215500
- China
| | - J. F. Feng
- College of Physics and Engineering
- Changshu Institute of Technology and Jiangsu Laboratory of Advanced Functional materials
- Changshu 215500
- China
| | - X. F. Wang
- Department of physics
- Soochow University
- Suzhou 215006
- China
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37
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Liu YS, Zhang X, Yang XF, Hong XK, Feng JF, Si MS, Wang XF. Spin caloritronics of blue phosphorene nanoribbons. Phys Chem Chem Phys 2015; 17:10462-7. [DOI: 10.1039/c5cp00391a] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
We report a first-principles study of the magnetic properties and spin caloritronics of zigzag-type blue phosphorene nanoribbons (zBPNRs).
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Affiliation(s)
- Y. S. Liu
- College of Physics and Engineering
- Changshu Institute of Technology and Jiangsu Laboratory of Advanced Functional materials
- Changshu 215500
- China
| | - X. Zhang
- College of Physics and Engineering
- Changshu Institute of Technology and Jiangsu Laboratory of Advanced Functional materials
- Changshu 215500
- China
| | - X. F. Yang
- College of Physics and Engineering
- Changshu Institute of Technology and Jiangsu Laboratory of Advanced Functional materials
- Changshu 215500
- China
| | - X. K. Hong
- College of Physics and Engineering
- Changshu Institute of Technology and Jiangsu Laboratory of Advanced Functional materials
- Changshu 215500
- China
| | - J. F. Feng
- College of Physics and Engineering
- Changshu Institute of Technology and Jiangsu Laboratory of Advanced Functional materials
- Changshu 215500
- China
| | - M. S. Si
- Key Laboratory for Magnetism and Magnetic Materials of the Ministry of Education
- Lanzhou University
- Lanzhou 730000
- China
| | - X. F. Wang
- College of Physics
- Optoelectronics and Energy
- Soochow University
- Suzhou
- China
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38
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Magnetic thin-film insulator with ultra-low spin wave damping for coherent nanomagnonics. Sci Rep 2014; 4:6848. [PMID: 25355200 PMCID: PMC4213793 DOI: 10.1038/srep06848] [Citation(s) in RCA: 151] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2014] [Accepted: 10/03/2014] [Indexed: 11/18/2022] Open
Abstract
Wave control in the solid state has opened new avenues in modern information technology. Surface-acoustic-wave-based devices are found as mass market products in 100 millions of cellular phones. Spin waves (magnons) would offer a boost in today's data handling and security implementations, i.e., image processing and speech recognition. However, nanomagnonic devices realized so far suffer from the relatively short damping length in the metallic ferromagnets amounting to a few 10 micrometers typically. Here we demonstrate that nm-thick YIG films overcome the damping chasm. Using a conventional coplanar waveguide we excite a large series of short-wavelength spin waves (SWs). From the data we estimate a macroscopic of damping length of about 600 micrometers. The intrinsic damping parameter suggests even a record value about 1 mm allowing for magnonics-based nanotechnology with ultra-low damping. In addition, SWs at large wave vector are found to exhibit the non-reciprocal properties relevant for new concepts in nanoscale SW-based logics. We expect our results to provide the basis for coherent data processing with SWs at GHz rates and in large arrays of cellular magnetic arrays, thereby boosting the envisioned image processing and speech recognition.
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39
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Uchida K, Ishida M, Kikkawa T, Kirihara A, Murakami T, Saitoh E. Longitudinal spin Seebeck effect: from fundamentals to applications. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2014; 26:343202. [PMID: 25105889 DOI: 10.1088/0953-8984/26/34/343202] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The spin Seebeck effect refers to the generation of spin voltage as a result of a temperature gradient in ferromagnetic or ferrimagnetic materials. When a conductor is attached to a magnet under a temperature gradient, the thermally generated spin voltage in the magnet injects a spin current into the conductor, which in turn produces electric voltage owing to the spin-orbit interaction. The spin Seebeck effect is of increasing importance in spintronics, since it enables direct generation of a spin current from heat and appears in a variety of magnets ranging from metals and semiconductors to insulators. Recent studies on the spin Seebeck effect have been conducted mainly in paramagnetic metal/ferrimagnetic insulator junction systems in the longitudinal configuration in which a spin current flowing parallel to the temperature gradient is measured. This 'longitudinal spin Seebeck effect' (LSSE) has been observed in various sample systems and exclusively established by separating the spin-current contribution from extrinsic artefacts, such as conventional thermoelectric and magnetic proximity effects. The LSSE in insulators also provides a novel and versatile pathway to thermoelectric generation in combination of the inverse spin-Hall effects. In this paper, we review basic experiments on the LSSE and discuss its potential thermoelectric applications with several demonstrations.
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Affiliation(s)
- K Uchida
- Institute for Materials Research, Tohoku University, Sendai 980-8577, Japan. PRESTO, Japan Science and Technology Agency, Saitama 332-0012, Japan
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40
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van Hoogdalem KA, Albert M, Simon P, Loss D. Proposal for a quantum magnetic RC circuit. PHYSICAL REVIEW LETTERS 2014; 113:037201. [PMID: 25083661 DOI: 10.1103/physrevlett.113.037201] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2014] [Indexed: 06/03/2023]
Abstract
We propose a setup that is the spin analog of the charge-based quantum RC circuit. We define and compute the spin capacitance and the spin resistance of the circuit for both ferromagnetic and antiferromagnetic systems. We find that the antiferromagnetic setup has universal properties, but the ferromagnetic setup does not. We discuss how to use the proposed setup as a quantum source of spin excitations, and put forward two possible experimental realizations, using either ultracold atoms in optical lattices or artificially engineered atomic-spin chains.
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Affiliation(s)
- Kevin A van Hoogdalem
- Department of Physics, University of Basel, Klingelbergstrasse 82, CH-4056 Basel, Switzerland
| | - Mathias Albert
- Laboratoire de Physique des Solides, CNRS, Université Paris-Sud, 91405 Orsay, France
| | - Pascal Simon
- Laboratoire de Physique des Solides, CNRS, Université Paris-Sud, 91405 Orsay, France
| | - Daniel Loss
- Department of Physics, University of Basel, Klingelbergstrasse 82, CH-4056 Basel, Switzerland
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41
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Flipse J, Dejene FK, Wagenaar D, Bauer GEW, Ben Youssef J, van Wees BJ. Observation of the spin Peltier effect for magnetic insulators. PHYSICAL REVIEW LETTERS 2014; 113:027601. [PMID: 25062233 DOI: 10.1103/physrevlett.113.027601] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2013] [Indexed: 06/03/2023]
Abstract
We report the observation of the spin Peltier effect (SPE) in the ferrimagnetic insulator yttrium iron garnet (YIG), i.e., a heat current generated by a spin current flowing through a platinum (Pt)|YIG interface. The effect can be explained by the spin transfer torque that transforms the spin current in the Pt into a magnon current in the YIG. Via magnon-phonon interactions the magnetic fluctuations modulate the phonon temperature that is detected by a thermopile close to the interface. By finite-element modeling we verify the reciprocity between the spin Peltier and spin Seebeck effect. The observed strong coupling between thermal magnons and phonons in YIG is attractive for nanoscale cooling techniques.
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Affiliation(s)
- J Flipse
- Physics of Nanodevices, Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - F K Dejene
- Physics of Nanodevices, Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - D Wagenaar
- Physics of Nanodevices, Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - G E W Bauer
- Kavli Institute of NanoScience, Delft University of Technology, 2628 CJ Delft, The Netherlands and Institute for Materials Research and WPI-AIMR, Tohoku University, 980-8577 Sendai, Japan
| | - J Ben Youssef
- Université de Bretagne Occidentale, Laboratoire de Magnétisme de Bretagne CNRS, 6 Avenue Le Gorgeu, 29285 Brest, France
| | - B J van Wees
- Physics of Nanodevices, Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
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42
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Miao BF, Huang SY, Qu D, Chien CL. Physical origins of the new magnetoresistance in Pt/YIG. PHYSICAL REVIEW LETTERS 2014; 112:236601. [PMID: 24972219 DOI: 10.1103/physrevlett.112.236601] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2013] [Indexed: 06/03/2023]
Abstract
A new type of magnetoresistance (MR) observed in Pt/YIG when nominally nonmagnetic Pt comes in contact with a ferrimagnetic insulator yttrium iron garnet (YIG) has drawn intense experimental and theoretical interest. In this Letter, we experimentally demonstrate two physical origins of the new MR: a spin current across the Pt/YIG interface and the magnetic proximity effect. The new MR can also be reproduced when Pt is in contact with a nonmagnetic insulator doped with a few percent of Fe impurities. By tuning the YIG surface and inserting an Au layer between the Pt and YIG, we are able to separate the two contributions.
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Affiliation(s)
- B F Miao
- Department of Physics and Astronomy, Johns Hopkins University, Baltimore, Maryland 21218, USA and National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing 210093, People's Republic of China
| | - S Y Huang
- Department of Physics and Astronomy, Johns Hopkins University, Baltimore, Maryland 21218, USA
| | - D Qu
- Department of Physics and Astronomy, Johns Hopkins University, Baltimore, Maryland 21218, USA
| | - C L Chien
- Department of Physics and Astronomy, Johns Hopkins University, Baltimore, Maryland 21218, USA
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43
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Yang XF, Zhang X, Hong XK, Liu YS, Feng JF, Wang XF, Zhang CW. Temperature-controlled giant thermal magnetoresistance behaviors in doped zigzag-edged silicene nanoribbons. RSC Adv 2014. [DOI: 10.1039/c4ra07791a] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Based on the nonequilibrium Green's function (NEGF) method combined with density functional theory (DFT), we investigate the spin-dependent thermoelectric transport properties of zigzag-edged silicene nanoribbons (ZSiNRs) doped by an Al–P bonded pair at different edge positions.
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Affiliation(s)
- X. F. Yang
- College of Physics and Engineering
- Changshu Institute of Technology and Jiangsu Laboratory of Advanced Functional Materials
- Changshu 215500, China
| | - X. Zhang
- College of Physics and Engineering
- Changshu Institute of Technology and Jiangsu Laboratory of Advanced Functional Materials
- Changshu 215500, China
| | - X. K. Hong
- College of Physics and Engineering
- Changshu Institute of Technology and Jiangsu Laboratory of Advanced Functional Materials
- Changshu 215500, China
| | - Y. S. Liu
- College of Physics and Engineering
- Changshu Institute of Technology and Jiangsu Laboratory of Advanced Functional Materials
- Changshu 215500, China
| | - J. F. Feng
- College of Physics and Engineering
- Changshu Institute of Technology and Jiangsu Laboratory of Advanced Functional Materials
- Changshu 215500, China
| | - X. F. Wang
- Department of Physics
- Soochow University
- Suzhou 215006, China
| | - C. W. Zhang
- School of Physics and Technology
- University of Jinan
- Jinan, China
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44
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Ni Y, Yao K, Fu H, Gao G, Zhu S, Wang S. Spin seebeck effect and thermal colossal magnetoresistance in graphene nanoribbon heterojunction. Sci Rep 2013; 3:1380. [PMID: 23459307 PMCID: PMC3587885 DOI: 10.1038/srep01380] [Citation(s) in RCA: 70] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2012] [Accepted: 02/20/2013] [Indexed: 11/25/2022] Open
Abstract
Spin caloritronics devices are very important for future development of low-power-consumption technology. We propose a new spin caloritronics device based on zigzag graphene nanoribbon (ZGNR), which is a heterojunction consisting of single-hydrogen-terminated ZGNR (ZGNR-H) and double-hydrogen-terminated ZGNR (ZGNR-H2). We predict that spin-up and spin-down currents flowing in opposite directions can be induced by temperature difference instead of external electrical bias. The thermal spin-up current is considerably large and greatly improved compared with previous work in graphene. Moreover, the thermal colossal magnetoresistance is obtained in our research, which could be used to fabricate highly-efficient spin caloritronics MR devices.
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Affiliation(s)
- Yun Ni
- School of Physics and Wuhan National High Magnetic Field Center, Huazhong University of Science and Technology, Wuhan 430074, China
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45
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Weiler M, Althammer M, Schreier M, Lotze J, Pernpeintner M, Meyer S, Huebl H, Gross R, Kamra A, Xiao J, Chen YT, Jiao H, Bauer GEW, Goennenwein STB. Experimental test of the spin mixing interface conductivity concept. PHYSICAL REVIEW LETTERS 2013; 111:176601. [PMID: 24206509 DOI: 10.1103/physrevlett.111.176601] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2013] [Indexed: 05/20/2023]
Abstract
We perform a quantitative, comparative study of the spin pumping, spin Seebeck, and spin Hall magnetoresistance effects, all detected via the inverse spin Hall effect in a series of over 20 yttrium iron garnet/Pt samples. Our experimental results fully support present, exclusively spin current-based, theoretical models using a single set of plausible parameters for spin mixing conductance, spin Hall angle, and spin diffusion length. Our findings establish the purely spintronic nature of the aforementioned effects and provide a quantitative description, in particular, of the spin Seebeck effect.
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Affiliation(s)
- Mathias Weiler
- Walther-Meißner-Institut, Bayerische Akademie der Wissenschaften, 85748 Garching, Germany
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46
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Wegrowe JE. Transport equations of energy for ferromagnetic insulators in contact with electrodes. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2013; 25:366003. [PMID: 23941895 DOI: 10.1088/0953-8984/25/36/366003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
A phenomenological derivation of the transport equations for ferromagnetic moments and associated energy and heat is proposed. The model describes the transfer of energy through an interface composed of a ferromagnetic insulator in contact with normal electrodes. A reduction method applied to the ferromagnetic degrees of freedom allows a two-channel model to be defined for the transport of magnetic moments. It is shown that a heat current flowing into the insulating ferromagnet-produced e.g. by electromagnetic resonance, thermal gradient, magneto-mechanical or magneto-optical excitations-can generate a magneto-voltaic potential and a pure spin-current in the non-ferromagnetic electrode.
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Affiliation(s)
- J-E Wegrowe
- Ecole Polytechnique, LSI, CNRS and CEA/DSM/IRAMIS, Palaiseau F-91128, France.
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47
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Miao BF, Huang SY, Qu D, Chien CL. Inverse spin Hall effect in a ferromagnetic metal. PHYSICAL REVIEW LETTERS 2013; 111:066602. [PMID: 23971597 DOI: 10.1103/physrevlett.111.066602] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2013] [Indexed: 06/02/2023]
Abstract
The inverse spin Hall effect (ISHE) has been observed only in nonmagnetic metals, such as Pt and Au, with a strong spin-orbit coupling. We report the observation of ISHE in a ferromagnetic permalloy (Py) on ferromagnetic insulator yttrium iron garnet (YIG). Through controlling the spin current injection by altering the Py-YIG interface, we have isolated the spin current contribution and demonstrated the ISHE in a ferromagnetic metal, the reciprocal phenomenon of the anomalous Hall effect. A large spin Hall angle in Py, determined from Py thin films of different thicknesses, indicates many other ferromagnetic metals may be exploited as superior pure spin current detectors and for applications in spin current.
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Affiliation(s)
- B F Miao
- Department of Physics and Astronomy, Johns Hopkins University, Baltimore, Maryland 21218, USA
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48
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Nakayama H, Althammer M, Chen YT, Uchida K, Kajiwara Y, Kikuchi D, Ohtani T, Geprägs S, Opel M, Takahashi S, Gross R, Bauer GEW, Goennenwein STB, Saitoh E. Spin Hall magnetoresistance induced by a nonequilibrium proximity effect. PHYSICAL REVIEW LETTERS 2013; 110:206601. [PMID: 25167435 DOI: 10.1103/physrevb.87.144411] [Citation(s) in RCA: 124] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2012] [Indexed: 05/27/2023]
Abstract
We report anisotropic magnetoresistance in Pt|Y(3)Fe(5)O(12) bilayers. In spite of Y(3)Fe(5)O(12) being a very good electrical insulator, the resistance of the Pt layer reflects its magnetization direction. The effect persists even when a Cu layer is inserted between Pt and Y(3)Fe(5)O(12), excluding the contribution of induced equilibrium magnetization at the interface. Instead, we show that the effect originates from concerted actions of the direct and inverse spin Hall effects and therefore call it "spin Hall magnetoresistance."
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Affiliation(s)
- H Nakayama
- Institute for Materials Research, Tohoku University, Sendai 980-8577, Japan and Laboratory for Nanoelectronics and Spintronics, Research Institute of Electrical Communication, Tohoku University, Sendai 980-8577, Japan
| | - M Althammer
- Walther-Meißner-Institut, Bayerische Akademie der Wissenschaften, 85748 Garching, Germany and Center for Materials Information Technology MINT and Department of Chemistry, University of Alabama, Tuscaloosa, Alabama 35487, USA
| | - Y-T Chen
- Kavli Institute of NanoScience, Delft University of Technology, 2628 CJ Delft, The Netherlands
| | - K Uchida
- Institute for Materials Research, Tohoku University, Sendai 980-8577, Japan and PRESTO, Japan Science and Technology Agency, Saitama 332-0012, Japan
| | - Y Kajiwara
- Institute for Materials Research, Tohoku University, Sendai 980-8577, Japan
| | - D Kikuchi
- Institute for Materials Research, Tohoku University, Sendai 980-8577, Japan and WPI Advanced Institute for Materials Research, Tohoku University, Sendai 980-8577, Japan
| | - T Ohtani
- Institute for Materials Research, Tohoku University, Sendai 980-8577, Japan
| | - S Geprägs
- Walther-Meißner-Institut, Bayerische Akademie der Wissenschaften, 85748 Garching, Germany
| | - M Opel
- Walther-Meißner-Institut, Bayerische Akademie der Wissenschaften, 85748 Garching, Germany
| | - S Takahashi
- Institute for Materials Research, Tohoku University, Sendai 980-8577, Japan
| | - R Gross
- Walther-Meißner-Institut, Bayerische Akademie der Wissenschaften, 85748 Garching, Germany and Physik-Department, Technische Universität München, 85748 Garching, Germany
| | - G E W Bauer
- Institute for Materials Research, Tohoku University, Sendai 980-8577, Japan and Kavli Institute of NanoScience, Delft University of Technology, 2628 CJ Delft, The Netherlands and WPI Advanced Institute for Materials Research, Tohoku University, Sendai 980-8577, Japan
| | - S T B Goennenwein
- Walther-Meißner-Institut, Bayerische Akademie der Wissenschaften, 85748 Garching, Germany
| | - E Saitoh
- Institute for Materials Research, Tohoku University, Sendai 980-8577, Japan and WPI Advanced Institute for Materials Research, Tohoku University, Sendai 980-8577, Japan and CREST, Japan Science and Technology Agency, Tokyo 102-0076, Japan and The Advanced Science Research Center, Japan Atomic Energy Agency, Tokai 319-1195, Japan
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49
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Nakayama H, Althammer M, Chen YT, Uchida K, Kajiwara Y, Kikuchi D, Ohtani T, Geprägs S, Opel M, Takahashi S, Gross R, Bauer GEW, Goennenwein STB, Saitoh E. Spin Hall magnetoresistance induced by a nonequilibrium proximity effect. PHYSICAL REVIEW LETTERS 2013; 110:206601. [PMID: 25167435 DOI: 10.1103/physrevlett.110.206601] [Citation(s) in RCA: 172] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2012] [Indexed: 06/03/2023]
Abstract
We report anisotropic magnetoresistance in Pt|Y(3)Fe(5)O(12) bilayers. In spite of Y(3)Fe(5)O(12) being a very good electrical insulator, the resistance of the Pt layer reflects its magnetization direction. The effect persists even when a Cu layer is inserted between Pt and Y(3)Fe(5)O(12), excluding the contribution of induced equilibrium magnetization at the interface. Instead, we show that the effect originates from concerted actions of the direct and inverse spin Hall effects and therefore call it "spin Hall magnetoresistance."
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Affiliation(s)
- H Nakayama
- Institute for Materials Research, Tohoku University, Sendai 980-8577, Japan and Laboratory for Nanoelectronics and Spintronics, Research Institute of Electrical Communication, Tohoku University, Sendai 980-8577, Japan
| | - M Althammer
- Walther-Meißner-Institut, Bayerische Akademie der Wissenschaften, 85748 Garching, Germany and Center for Materials Information Technology MINT and Department of Chemistry, University of Alabama, Tuscaloosa, Alabama 35487, USA
| | - Y-T Chen
- Kavli Institute of NanoScience, Delft University of Technology, 2628 CJ Delft, The Netherlands
| | - K Uchida
- Institute for Materials Research, Tohoku University, Sendai 980-8577, Japan and PRESTO, Japan Science and Technology Agency, Saitama 332-0012, Japan
| | - Y Kajiwara
- Institute for Materials Research, Tohoku University, Sendai 980-8577, Japan
| | - D Kikuchi
- Institute for Materials Research, Tohoku University, Sendai 980-8577, Japan and WPI Advanced Institute for Materials Research, Tohoku University, Sendai 980-8577, Japan
| | - T Ohtani
- Institute for Materials Research, Tohoku University, Sendai 980-8577, Japan
| | - S Geprägs
- Walther-Meißner-Institut, Bayerische Akademie der Wissenschaften, 85748 Garching, Germany
| | - M Opel
- Walther-Meißner-Institut, Bayerische Akademie der Wissenschaften, 85748 Garching, Germany
| | - S Takahashi
- Institute for Materials Research, Tohoku University, Sendai 980-8577, Japan
| | - R Gross
- Walther-Meißner-Institut, Bayerische Akademie der Wissenschaften, 85748 Garching, Germany and Physik-Department, Technische Universität München, 85748 Garching, Germany
| | - G E W Bauer
- Institute for Materials Research, Tohoku University, Sendai 980-8577, Japan and Kavli Institute of NanoScience, Delft University of Technology, 2628 CJ Delft, The Netherlands and WPI Advanced Institute for Materials Research, Tohoku University, Sendai 980-8577, Japan
| | - S T B Goennenwein
- Walther-Meißner-Institut, Bayerische Akademie der Wissenschaften, 85748 Garching, Germany
| | - E Saitoh
- Institute for Materials Research, Tohoku University, Sendai 980-8577, Japan and WPI Advanced Institute for Materials Research, Tohoku University, Sendai 980-8577, Japan and CREST, Japan Science and Technology Agency, Tokyo 102-0076, Japan and The Advanced Science Research Center, Japan Atomic Energy Agency, Tokai 319-1195, Japan
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50
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Lu YM, Choi Y, Ortega CM, Cheng XM, Cai JW, Huang SY, Sun L, Chien CL. Pt magnetic polarization on Y3Fe5O12 and magnetotransport characteristics. PHYSICAL REVIEW LETTERS 2013; 110:147207. [PMID: 25167034 DOI: 10.1103/physrevlett.110.147207] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2012] [Indexed: 06/03/2023]
Abstract
Thin Pt films on an yttrium iron garnet (YIG = Y(3)Fe(5)O(12)) show ferromagneticlike transport properties, which may impact the functionality of Pt in spin current detection, but do not provide direct quantitative information on the Pt magnetization. We report magnetic x-ray magnetic circular dichroism measurements of YIG/Pt(1.5 nm) showing an average Pt moment of 0.054 μ(B) at 300 K and 0.076 μ(B) at 20 K. This observation indicates strong proximity effects and induced magnetic ordering in Pt on magnetic insulators and their contribution to the spin-related measurements should not be neglected. The transport characteristics also suggest considerable modifications in the Pt electronic structure due to magnetic ordering.
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Affiliation(s)
- Y M Lu
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Y Choi
- Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - C M Ortega
- Department of Mechanical Engineering and Texas Center for Superconductivity (TcSUH), University of Houston, Houston, Texas 77204, USA
| | - X M Cheng
- Department of Physics, Bryn Mawr College, Bryn Mawr, Pennsylvania 19010, USA
| | - J W Cai
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - S Y Huang
- Department of Physics and Astronomy, Johns Hopkins University, Baltimore, Maryland 21218, USA
| | - L Sun
- Department of Mechanical Engineering and Texas Center for Superconductivity (TcSUH), University of Houston, Houston, Texas 77204, USA
| | - C L Chien
- Department of Physics and Astronomy, Johns Hopkins University, Baltimore, Maryland 21218, USA
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