1
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Chen H, Liu L, Zhou X, Meng Z, Wang X, Duan Z, Zhao G, Yan H, Qin P, Liu Z. Emerging Antiferromagnets for Spintronics. Adv Mater 2024; 36:e2310379. [PMID: 38183310 DOI: 10.1002/adma.202310379] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2023] [Revised: 12/18/2023] [Indexed: 01/08/2024]
Abstract
Antiferromagnets constitute promising contender materials for next-generation spintronic devices with superior stability, scalability, and dynamics. Nevertheless, the perception of well-established ferromagnetic spintronics underpinned by spontaneous magnetization seemed to indicate the inadequacy of antiferromagnets for spintronics-their compensated magnetization has been perceived to result in uncontrollable antiferromagnetic order and subtle magnetoelectronic responses. However, remarkable advancements have been achieved in antiferromagnetic spintronics in recent years, with consecutive unanticipated discoveries substantiating the feasibility of antiferromagnet-centered spintronic devices. It is emphasized that, distinct from ferromagnets, the richness in complex antiferromagnetic crystal structures is the unique and essential virtue of antiferromagnets that can open up their endless possibilities of novel phenomena and functionality for spintronics. In this Perspective, the recent progress in antiferromagnetic spintronics is reviewed, with a particular focus on that based on several kinds of antiferromagnets with special antiferromagnetic crystal structures. The latest developments in efficiently manipulating antiferromagnetic order, exploring novel antiferromagnetic physical responses, and demonstrating prototype antiferromagnetic spintronic devices are discussed. An outlook on future research directions is also provided. It is hoped that this Perspective can serve as guidance for readers who are interested in this field and encourage unprecedented studies on antiferromagnetic spintronic materials, phenomena, and devices.
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Affiliation(s)
- Hongyu Chen
- School of Materials Science and Engineering, Beihang University, Beijing, 100191, China
| | - Li Liu
- School of Materials Science and Engineering, Beihang University, Beijing, 100191, China
| | - Xiaorong Zhou
- School of Materials Science and Engineering, Beihang University, Beijing, 100191, China
| | - Ziang Meng
- School of Materials Science and Engineering, Beihang University, Beijing, 100191, China
| | - Xiaoning Wang
- School of Materials Science and Engineering, Beihang University, Beijing, 100191, China
| | - Zhiyuan Duan
- School of Materials Science and Engineering, Beihang University, Beijing, 100191, China
| | - Guojian Zhao
- School of Materials Science and Engineering, Beihang University, Beijing, 100191, China
| | - Han Yan
- School of Materials Science and Engineering, Beihang University, Beijing, 100191, China
| | - Peixin Qin
- School of Materials Science and Engineering, Beihang University, Beijing, 100191, China
| | - Zhiqi Liu
- School of Materials Science and Engineering, Beihang University, Beijing, 100191, China
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2
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Shi J, Arpaci S, Lopez-Dominguez V, Sangwan VK, Mahfouzi F, Kim J, Athas JG, Hamdi M, Aygen C, Arava H, Phatak C, Carpentieri M, Jiang JS, Grayson MA, Kioussis N, Finocchio G, Hersam MC, Khalili Amiri P. Electrically Controlled All-Antiferromagnetic Tunnel Junctions on Silicon with Large Room-Temperature Magnetoresistance. Adv Mater 2024:e2312008. [PMID: 38501999 DOI: 10.1002/adma.202312008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2023] [Revised: 02/11/2024] [Indexed: 03/20/2024]
Abstract
Antiferromagnetic (AFM) materials are a pathway to spintronic memory and computing devices with unprecedented speed, energy efficiency, and bit density. Realizing this potential requires AFM devices with simultaneous electrical writing and reading of information, which are also compatible with established silicon-based manufacturing. Recent experiments have shown tunneling magnetoresistance (TMR) readout in epitaxial AFM tunnel junctions. However, these TMR structures are not grown using a silicon-compatible deposition process, and controlling their AFM order required external magnetic fields. Here it is shown three-terminal AFM tunnel junctions based on the noncollinear antiferromagnet PtMn3 , sputter-deposited on silicon. The devices simultaneously exhibit electrical switching using electric currents, and electrical readout by a large room-temperature TMR effect. First-principles calculations explain the TMR in terms of the momentum-resolved spin-dependent tunneling conduction in tunnel junctions with noncollinear AFM electrodes.
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Affiliation(s)
- Jiacheng Shi
- Department of Electrical and Computer Engineering, Northwestern University, Evanston, IL, 60208, USA
| | - Sevdenur Arpaci
- Department of Electrical and Computer Engineering, Northwestern University, Evanston, IL, 60208, USA
- Applied Physics Program, Northwestern University, Evanston, IL, 60208, USA
| | - Victor Lopez-Dominguez
- Department of Electrical and Computer Engineering, Northwestern University, Evanston, IL, 60208, USA
- Institute of Advanced Materials (INAM), Universitat Jaume I, Castellón, 12006, Spain
| | - Vinod K Sangwan
- Department of Materials Science and Engineering, Northwestern University, Evanston, IL, 60208, USA
| | - Farzad Mahfouzi
- Department of Physics and Astronomy, California State University Northridge, Northridge, CA, 91330, USA
| | - Jinwoong Kim
- Department of Physics and Astronomy, California State University Northridge, Northridge, CA, 91330, USA
| | - Jordan G Athas
- Department of Electrical and Computer Engineering, Northwestern University, Evanston, IL, 60208, USA
| | - Mohammad Hamdi
- Department of Electrical and Computer Engineering, Northwestern University, Evanston, IL, 60208, USA
| | - Can Aygen
- Department of Electrical and Computer Engineering, Northwestern University, Evanston, IL, 60208, USA
| | - Hanu Arava
- Materials Science Division, Argonne National Laboratory, Lemont, IL, 60439, USA
| | - Charudatta Phatak
- Materials Science Division, Argonne National Laboratory, Lemont, IL, 60439, USA
| | - Mario Carpentieri
- Department of Electrical and Information Engineering, Politecnico di Bari, Bari, 70125, Italy
| | - Jidong S Jiang
- Materials Science Division, Argonne National Laboratory, Lemont, IL, 60439, USA
| | - Matthew A Grayson
- Department of Electrical and Computer Engineering, Northwestern University, Evanston, IL, 60208, USA
- Applied Physics Program, Northwestern University, Evanston, IL, 60208, USA
| | - Nicholas Kioussis
- Department of Physics and Astronomy, California State University Northridge, Northridge, CA, 91330, USA
| | - Giovanni Finocchio
- Department of Mathematical and Computer Sciences, Physical Sciences and Earth Sciences, University of Messina, Messina, 98166, Italy
| | - Mark C Hersam
- Department of Electrical and Computer Engineering, Northwestern University, Evanston, IL, 60208, USA
- Applied Physics Program, Northwestern University, Evanston, IL, 60208, USA
- Department of Materials Science and Engineering, Northwestern University, Evanston, IL, 60208, USA
- Department of Chemistry, Northwestern University, Evanston, IL, 60208, USA
| | - Pedram Khalili Amiri
- Department of Electrical and Computer Engineering, Northwestern University, Evanston, IL, 60208, USA
- Applied Physics Program, Northwestern University, Evanston, IL, 60208, USA
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3
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Wang C, Du Y, Zhao Y, He Z, Wang S, Zhang Y, Jiang Y, Du Y, Wu J, Jiang Z, Liu M. Solar-Powered Switch of Antiferromagnetism/Ferromagnetism in Flexible Spintronics. Nanomaterials (Basel) 2023; 13:3158. [PMID: 38133055 PMCID: PMC10745959 DOI: 10.3390/nano13243158] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2023] [Revised: 12/13/2023] [Accepted: 12/15/2023] [Indexed: 12/23/2023]
Abstract
The flexible electronics have application prospects in many fields, including as wearable devices and in structural detection. Spintronics possess the merits of a fast response and high integration density, opening up possibilities for various applications. However, the integration of miniaturization on flexible substrates is impeded inevitably due to the high Joule heat from high current density (1012 A/m2). In this study, a prototype flexible spintronic with device antiferromagnetic/ferromagnetic heterojunctions is proposed. The interlayer coupling strength can be obviously altered by sunlight soaking via direct photo-induced electron doping. With the assistance of a small magnetic field (±125 Oe), the almost 180° flip of magnetization is realized. Furthermore, the magnetoresistance changes (15~29%) of flexible spintronics on fingers receiving light illumination are achieved successfully, exhibiting the wearable application potential. Our findings develop flexible spintronic sensors, expanding the vision for the novel generation of photovoltaic/spintronic devices.
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Affiliation(s)
- Chenying Wang
- State Key Laboratory for Manufacturing Systems Engineering, International Joint Laboratory for Micro/Nano Manufacturing and Measurement Technologies, School of Instrument Science and Technology, Xi’an Jiaotong University, Xi’an 710049, China;
| | - Yujing Du
- State Key Laboratory for Manufacturing Systems Engineering, Electronic Materials Research Laboratory, Key Laboratory of the Ministry of Education, School of Electronic Science and Engineering, Xi’an Jiaotong University, Xi’an 710049, China; (Y.D.); (Z.H.); (Y.J.); (Y.D.); (J.W.)
| | - Yifan Zhao
- State Key Laboratory for Manufacturing Systems Engineering, International Joint Laboratory for Micro/Nano Manufacturing and Measurement Technologies, School of Instrument Science and Technology, Xi’an Jiaotong University, Xi’an 710049, China;
- State Key Laboratory for Manufacturing Systems Engineering, Electronic Materials Research Laboratory, Key Laboratory of the Ministry of Education, School of Electronic Science and Engineering, Xi’an Jiaotong University, Xi’an 710049, China; (Y.D.); (Z.H.); (Y.J.); (Y.D.); (J.W.)
| | - Zhexi He
- State Key Laboratory for Manufacturing Systems Engineering, Electronic Materials Research Laboratory, Key Laboratory of the Ministry of Education, School of Electronic Science and Engineering, Xi’an Jiaotong University, Xi’an 710049, China; (Y.D.); (Z.H.); (Y.J.); (Y.D.); (J.W.)
| | - Song Wang
- State Key Laboratory for Manufacturing Systems Engineering, International Joint Laboratory for Micro/Nano Manufacturing and Measurement Technologies, School of Mechanical Engineering, Xi’an Jiaotong University, Xi’an 710049, China; (S.W.); (Y.Z.); (Z.J.)
| | - Yaxin Zhang
- State Key Laboratory for Manufacturing Systems Engineering, International Joint Laboratory for Micro/Nano Manufacturing and Measurement Technologies, School of Mechanical Engineering, Xi’an Jiaotong University, Xi’an 710049, China; (S.W.); (Y.Z.); (Z.J.)
| | - Yuxuan Jiang
- State Key Laboratory for Manufacturing Systems Engineering, Electronic Materials Research Laboratory, Key Laboratory of the Ministry of Education, School of Electronic Science and Engineering, Xi’an Jiaotong University, Xi’an 710049, China; (Y.D.); (Z.H.); (Y.J.); (Y.D.); (J.W.)
| | - Yongjun Du
- State Key Laboratory for Manufacturing Systems Engineering, Electronic Materials Research Laboratory, Key Laboratory of the Ministry of Education, School of Electronic Science and Engineering, Xi’an Jiaotong University, Xi’an 710049, China; (Y.D.); (Z.H.); (Y.J.); (Y.D.); (J.W.)
| | - Jingen Wu
- State Key Laboratory for Manufacturing Systems Engineering, Electronic Materials Research Laboratory, Key Laboratory of the Ministry of Education, School of Electronic Science and Engineering, Xi’an Jiaotong University, Xi’an 710049, China; (Y.D.); (Z.H.); (Y.J.); (Y.D.); (J.W.)
| | - Zhuangde Jiang
- State Key Laboratory for Manufacturing Systems Engineering, International Joint Laboratory for Micro/Nano Manufacturing and Measurement Technologies, School of Mechanical Engineering, Xi’an Jiaotong University, Xi’an 710049, China; (S.W.); (Y.Z.); (Z.J.)
| | - Ming Liu
- State Key Laboratory for Manufacturing Systems Engineering, Electronic Materials Research Laboratory, Key Laboratory of the Ministry of Education, School of Electronic Science and Engineering, Xi’an Jiaotong University, Xi’an 710049, China; (Y.D.); (Z.H.); (Y.J.); (Y.D.); (J.W.)
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4
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Liu W, Liu L, Cui B, Cheng S, Wu X, Cheng B, Miao T, Ren X, Chu R, Liu M, Zhao X, Wu S, Qin H, Hu J. Manipulation of Spin-Orbit Torque in Tungsten Oxide/Manganite Heterostructure by Ionic Liquid Gating and Orbit Engineering. ACS Nano 2023. [PMID: 37988035 DOI: 10.1021/acsnano.3c06686] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2023]
Abstract
Spin-orbit coupling (SOC) is the interaction between electron's spin and orbital motion, which could realize a charge-to-spin current conversion and enable an innovative method to switch the magnetization by spin-orbit torque (SOT). Varied techniques have been developed to manipulate and improve the SOT, but the role of the orbit degree of freedom, which should have a crucial bearing on the SOC and SOT, is still confusing. Here, we find that the charge-to-spin current conversion and SOT in W3O8-δ/(La, Sr)MnO3 could be produced or eliminated by ionic liquid gating. Through tuning the preferential occupancy of Mn/W-d electrons from the in-plane (dx2-y2) to out-of-plane (d3z2-r2) orbit, the SOT damping-like field efficiency is nearly doubled due to the enhanced spin Hall effect and interfacial Rashba-Edelstein effect. These findings not only offer intriguing opportunities to control the SOT for high-efficient spintronic devices but also could be a fundamental step toward spin-orbitronics in the future.
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Affiliation(s)
- Weikang Liu
- School of Physics, State Key Laboratory for Crystal Materials, Shandong University, Jinan 250100, China
| | - Liang Liu
- School of Physics, State Key Laboratory for Crystal Materials, Shandong University, Jinan 250100, China
| | - Bin Cui
- School of Physics, State Key Laboratory for Crystal Materials, Shandong University, Jinan 250100, China
| | - Shaobo Cheng
- Henan Key Laboratory of Diamond Optoelectronic Materials and Devices, School of Physics and Microelectronics, Zhengzhou University, Zhengzhou 450000, China
| | - Xinyi Wu
- School of Physics, State Key Laboratory for Crystal Materials, Shandong University, Jinan 250100, China
| | - Bin Cheng
- School of Physics, State Key Laboratory for Crystal Materials, Shandong University, Jinan 250100, China
| | - Tingting Miao
- School of Physics, State Key Laboratory for Crystal Materials, Shandong University, Jinan 250100, China
| | - Xue Ren
- School of Physics, State Key Laboratory for Crystal Materials, Shandong University, Jinan 250100, China
| | - Ruiyue Chu
- School of Physics, State Key Laboratory for Crystal Materials, Shandong University, Jinan 250100, China
| | - Min Liu
- School of Physics, State Key Laboratory for Crystal Materials, Shandong University, Jinan 250100, China
| | - Xiangxiang Zhao
- School of Physics, State Key Laboratory for Crystal Materials, Shandong University, Jinan 250100, China
| | - Shuyun Wu
- School of Physics, State Key Laboratory for Crystal Materials, Shandong University, Jinan 250100, China
| | - Hongwei Qin
- School of Physics, State Key Laboratory for Crystal Materials, Shandong University, Jinan 250100, China
| | - Jifan Hu
- School of Physics, State Key Laboratory for Crystal Materials, Shandong University, Jinan 250100, China
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5
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Yoon JY, Zhang P, Chou CT, Takeuchi Y, Uchimura T, Hou JT, Han J, Kanai S, Ohno H, Fukami S, Liu L. Handedness anomaly in a non-collinear antiferromagnet under spin-orbit torque. Nat Mater 2023; 22:1106-1113. [PMID: 37537356 DOI: 10.1038/s41563-023-01620-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2023] [Accepted: 06/23/2023] [Indexed: 08/05/2023]
Abstract
Non-collinear antiferromagnets are an emerging family of spintronic materials because they not only possess the general advantages of antiferromagnets but also enable more advanced functionalities. Recently, in an intriguing non-collinear antiferromagnet Mn3Sn, where the octupole moment is defined as the collective magnetic order parameter, spin-orbit torque (SOT) switching has been achieved in seemingly the same protocol as in ferromagnets. Nevertheless, it is fundamentally important to explore the unknown octupole moment dynamics and contrast it with the magnetization vector of ferromagnets. Here we report a handedness anomaly in the SOT-driven dynamics of Mn3Sn: when spin current is injected, the octupole moment rotates in the opposite direction to the individual moments, leading to a SOT switching polarity distinct from ferromagnets. By using second-harmonic and d.c. magnetometry, we track the SOT effect onto the octupole moment during its rotation and reveal that the handedness anomaly stems from the interactions between the injected spin and the unique chiral-spin structure of Mn3Sn. We further establish the torque balancing equation of the magnetic octupole moment and quantify the SOT efficiency. Our finding provides a guideline for understanding and implementing the electrical manipulation of non-collinear antiferromagnets, which in nature differs from the well-established collinear magnets.
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Affiliation(s)
- Ju-Young Yoon
- Laboratory for Nanoelectronics and Spintronics, Research Institute of Electrical Communication, Tohoku University, Sendai, Japan
- Graduate School of Engineering, Tohoku University, Sendai, Japan
- Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Pengxiang Zhang
- Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Chung-Tao Chou
- Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA, USA
- Department of Physics, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Yutaro Takeuchi
- WPI-Advanced Institute for Materials Research, Tohoku University, Sendai, Japan
| | - Tomohiro Uchimura
- Laboratory for Nanoelectronics and Spintronics, Research Institute of Electrical Communication, Tohoku University, Sendai, Japan
- Graduate School of Engineering, Tohoku University, Sendai, Japan
| | - Justin T Hou
- Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Jiahao Han
- Laboratory for Nanoelectronics and Spintronics, Research Institute of Electrical Communication, Tohoku University, Sendai, Japan.
| | - Shun Kanai
- Laboratory for Nanoelectronics and Spintronics, Research Institute of Electrical Communication, Tohoku University, Sendai, Japan
- Graduate School of Engineering, Tohoku University, Sendai, Japan
- WPI-Advanced Institute for Materials Research, Tohoku University, Sendai, Japan
- Center for Science and Innovation in Spintronics, Tohoku University, Sendai, Japan
- Division for the Establishment of Frontier Sciences of Organization for Advanced Studies, Tohoku University, Sendai, Japan
| | - Hideo Ohno
- Laboratory for Nanoelectronics and Spintronics, Research Institute of Electrical Communication, Tohoku University, Sendai, Japan
- Graduate School of Engineering, Tohoku University, Sendai, Japan
- WPI-Advanced Institute for Materials Research, Tohoku University, Sendai, Japan
- Center for Science and Innovation in Spintronics, Tohoku University, Sendai, Japan
- Center for Innovative Integrated Electronic Systems, Tohoku University, Sendai, Japan
| | - Shunsuke Fukami
- Laboratory for Nanoelectronics and Spintronics, Research Institute of Electrical Communication, Tohoku University, Sendai, Japan.
- Graduate School of Engineering, Tohoku University, Sendai, Japan.
- WPI-Advanced Institute for Materials Research, Tohoku University, Sendai, Japan.
- Center for Science and Innovation in Spintronics, Tohoku University, Sendai, Japan.
- Center for Innovative Integrated Electronic Systems, Tohoku University, Sendai, Japan.
- Inamori Research Institute for Science, Kyoto, Japan.
| | - Luqiao Liu
- Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA, USA.
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6
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Abstract
Antiferromagnets have attracted extensive interest as a material platform in spintronics. So far, antiferromagnet-enabled spin-orbitronics, spin-transfer electronics and spin caloritronics have formed the bases of antiferromagnetic spintronics. Spin transport and manipulation based on coherent antiferromagnetic dynamics have recently emerged, pushing the developing field of antiferromagnetic spintronics towards a new stage distinguished by the features of spin coherence. In this Review, we categorize and analyse the critical effects that harness the coherence of antiferromagnets for spintronic applications, including spin pumping from monochromatic antiferromagnetic magnons, spin transmission via phase-correlated antiferromagnetic magnons, electrically induced spin rotation and ultrafast spin-orbit effects in antiferromagnets. We also discuss future opportunities in research and applications stimulated by the principles, materials and phenomena of coherent antiferromagnetic spintronics.
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Affiliation(s)
- Jiahao Han
- Research Institute of Electrical Communication, Tohoku University, Sendai, Japan.
| | - Ran Cheng
- Department of Electrical and Computer Engineering, University of California Riverside, Riverside, CA, USA
- Department of Physics and Astronomy, University of California Riverside, Riverside, CA, USA
| | - Luqiao Liu
- Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Hideo Ohno
- Research Institute of Electrical Communication, Tohoku University, Sendai, Japan
- Center for Science and Innovation in Spintronics, Tohoku University, Sendai, Japan
- Center for Innovative Integrated Electronic Systems, Tohoku University, Sendai, Japan
- WPI-Advanced Institute for Materials Research, Tohoku University, Sendai, Japan
| | - Shunsuke Fukami
- Research Institute of Electrical Communication, Tohoku University, Sendai, Japan.
- Center for Science and Innovation in Spintronics, Tohoku University, Sendai, Japan.
- Center for Innovative Integrated Electronic Systems, Tohoku University, Sendai, Japan.
- WPI-Advanced Institute for Materials Research, Tohoku University, Sendai, Japan.
- Inamori Research Institute of Science, Kyoto, Japan.
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7
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Reimers S, Lytvynenko Y, Niu YR, Golias E, Sarpi B, Veiga LSI, Denneulin T, Kovács A, Dunin-Borkowski RE, Bläßer J, Kläui M, Jourdan M. Current-driven writing process in antiferromagnetic Mn 2Au for memory applications. Nat Commun 2023; 14:1861. [PMID: 37012272 PMCID: PMC10070341 DOI: 10.1038/s41467-023-37569-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Accepted: 03/22/2023] [Indexed: 04/05/2023] Open
Abstract
Current pulse driven Néel vector rotation in metallic antiferromagnets is one of the most promising concepts in antiferromagnetic spintronics. We show microscopically that the Néel vector of epitaxial thin films of the prototypical compound Mn2Au can be reoriented reversibly in the complete area of cross shaped device structures using single current pulses. The resulting domain pattern with aligned staggered magnetization is long term stable enabling memory applications. We achieve this switching with low heating of ≈20 K, which is promising regarding fast and efficient devices without the need for thermal activation. Current polarity dependent reversible domain wall motion demonstrates a Néel spin-orbit torque acting on the domain walls.
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Affiliation(s)
- S Reimers
- Institut für Physik, Johannes Gutenberg-Universität Mainz, Mainz, Germany
| | - Y Lytvynenko
- Institut für Physik, Johannes Gutenberg-Universität Mainz, Mainz, Germany
- Institute of Magnetism of the NAS of Ukraine and MES of Ukraine, Kyiv, Ukraine
| | - Y R Niu
- MAX IV Laboratory, Lund, Sweden
| | | | - B Sarpi
- Diamond Light Source, Chilton, Didcot, Oxfordshire, UK
| | - L S I Veiga
- Diamond Light Source, Chilton, Didcot, Oxfordshire, UK
| | - T Denneulin
- Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons, Forschungszentrum Jülich, Jülich, Germany
| | - A Kovács
- Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons, Forschungszentrum Jülich, Jülich, Germany
| | - R E Dunin-Borkowski
- Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons, Forschungszentrum Jülich, Jülich, Germany
| | - J Bläßer
- Institut für Physik, Johannes Gutenberg-Universität Mainz, Mainz, Germany
| | - M Kläui
- Institut für Physik, Johannes Gutenberg-Universität Mainz, Mainz, Germany
| | - M Jourdan
- Institut für Physik, Johannes Gutenberg-Universität Mainz, Mainz, Germany.
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8
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Zhu L, Ralph DC. Strong variation of spin-orbit torques with relative spin relaxation rates in ferrimagnets. Nat Commun 2023; 14:1778. [PMID: 36997579 PMCID: PMC10063689 DOI: 10.1038/s41467-023-37506-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Accepted: 03/20/2023] [Indexed: 04/03/2023] Open
Abstract
Spin-orbit torques (SOTs) have been widely understood as an interfacial transfer of spin that is independent of the bulk properties of the magnetic layer. Here, we report that SOTs acting on ferrimagnetic FexTb1-x layers decrease and vanish upon approaching the magnetic compensation point because the rate of spin transfer to the magnetization becomes much slower than the rate of spin relaxation into the crystal lattice due to spin-orbit scattering. These results indicate that the relative rates of competing spin relaxation processes within magnetic layers play a critical role in determining the strength of SOTs, which provides a unified understanding for the diverse and even seemingly puzzling SOT phenomena in ferromagnetic and compensated systems. Our work indicates that spin-orbit scattering within the magnet should be minimized for efficient SOT devices. We also find that the interfacial spin-mixing conductance of interfaces of ferrimagnetic alloys (such as FexTb1-x) is as large as that of 3d ferromagnets and insensitive to the degree of magnetic compensation.
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Affiliation(s)
- Lijun Zhu
- State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing, 100083, China.
- College of Materials Science and Opto-Electronic Technology, University of Chinese Academy of Sciences, Beijing, 100049, China.
| | - Daniel C Ralph
- Cornell University, Ithaca, NY, 14850, USA
- Kavli Institute at Cornell, Ithaca, NY, 14850, USA
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9
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Chen W, Gu M, Li J, Wang P, Liu Q. Role of Hidden Spin Polarization in Nonreciprocal Transport of Antiferromagnets. Phys Rev Lett 2022; 129:276601. [PMID: 36638296 DOI: 10.1103/physrevlett.129.276601] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Revised: 08/04/2022] [Accepted: 11/22/2022] [Indexed: 06/17/2023]
Abstract
The discovery of hidden spin polarization (HSP) in centrosymmetric nonmagnetic crystals, i.e., spatially distributed spin polarization originated from local symmetry breaking, has promised an expanded material pool for future spintronics. However, the measurements of such exotic effects have been limited to subtle space- and momentum-resolved techniques, unfortunately, hindering their applications. Here, we theoretically predict macroscopic non-reciprocal transports induced by HSP when coupling another spatially distributed quantity, such as staggered local moments in a space-time PT-symmetric antiferromagnet. By using a four-band model Hamiltonian, we demonstrate that HSP plays a crucial role in determining the asymmetric bands with respect to opposite momenta. Such band asymmetry leads to non-reciprocal nonlinear conductivity, exemplified by tetragonal CuMnAs via first-principles calculations. We further provide the material design principles for large nonlinear conductivity, including two-dimensional nature, multiple band crossings near the Fermi level, and symmetry protected HSP. Our Letter not only reveals direct spintronic applications of HSP (such as Néel order detection), but also sheds light on finding observables of other hidden effects, such as hidden optical polarization and hidden Berry curvature.
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Affiliation(s)
- Weizhao Chen
- Shenzhen Institute for Quantum Science and Engineering and Department of Physics, Southern University of Science and Technology, Shenzhen 518055, China
| | - Mingqiang Gu
- Shenzhen Institute for Quantum Science and Engineering and Department of Physics, Southern University of Science and Technology, Shenzhen 518055, China
| | - Jiayu Li
- Shenzhen Institute for Quantum Science and Engineering and Department of Physics, Southern University of Science and Technology, Shenzhen 518055, China
| | - Panshuo Wang
- Shenzhen Institute for Quantum Science and Engineering and Department of Physics, Southern University of Science and Technology, Shenzhen 518055, China
| | - Qihang Liu
- Shenzhen Institute for Quantum Science and Engineering and Department of Physics, Southern University of Science and Technology, Shenzhen 518055, China
- Guangdong Provincial Key Laboratory of Computational Science and Material Design, Southern University of Science and Technology, Shenzhen 518055, China
- Shenzhen Key Laboratory of Advanced Quantum Functional Materials and Devices, Southern University of Science and Technology, Shenzhen 518055, China
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10
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Xu J, He J, Zhou JS, Qu D, Huang SY, Chien CL. Observation of Vector Spin Seebeck Effect in a Noncollinear Antiferromagnet. Phys Rev Lett 2022; 129:117202. [PMID: 36154395 DOI: 10.1103/physrevlett.129.117202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2022] [Revised: 05/16/2022] [Accepted: 08/15/2022] [Indexed: 06/16/2023]
Abstract
Spintronic phenomena to date have been established in magnets with collinear moments, where the spin injection through the spin Seebeck effect (SSE) is always along the out-of-plane direction. Here, we report the observation of a vector SSE in a noncollinear antiferromagnet (AF) LuFeO_{3}, where temperature gradient along the out-of-plane and also the in-plane directions can both inject a pure spin current and generate a voltage in the heavy metal via the inverse spin Hall effect (ISHE). We show that the thermovoltages are due to the magnetization from canted spins in LuFeO_{3}. Furthermore, in contrast to the challenges of generating, manipulating, and detecting spin current in collinear AFs, the vector SSE in LuFeO_{3} is readily viable in zero magnetic field and can be controlled by a small magnetic field of about 150 Oe at room temperature. The noncollinear AFs expand new realms for exploring spin phenomena and provide a new route to low-field antiferromagnetic spin caloritronics and magnonics.
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Affiliation(s)
- Jinsong Xu
- Department of Physics and Astronomy, Johns Hopkins University, Baltimore, Maryland 21218, USA
| | - Jiaming He
- Department of Mechanical Engineering, University of Texas at Austin, Austin, Texas 78712, USA
| | - J-S Zhou
- Department of Mechanical Engineering, University of Texas at Austin, Austin, Texas 78712, USA
| | - Danru Qu
- Center for Condensed Matter Sciences, National Taiwan University, Taipei 10617, Taiwan
| | - Ssu-Yen Huang
- Department of Physics, National Taiwan University, Taipei 10617, Taiwan
| | - C L Chien
- Department of Physics and Astronomy, Johns Hopkins University, Baltimore, Maryland 21218, USA
- Department of Physics, National Taiwan University, Taipei 10617, Taiwan
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11
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Zhang P, Chou CT, Yun H, McGoldrick BC, Hou JT, Mkhoyan KA, Liu L. Control of Néel Vector with Spin-Orbit Torques in an Antiferromagnetic Insulator with Tilted Easy Plane. Phys Rev Lett 2022; 129:017203. [PMID: 35841567 DOI: 10.1103/physrevlett.129.017203] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2022] [Revised: 04/29/2022] [Accepted: 06/02/2022] [Indexed: 05/27/2023]
Abstract
Injecting spin currents into antiferromagnets and realizing efficient spin-orbit-torque switching represents a challenging topic. Because of the diminishing magnetic susceptibility, current-induced antiferromagnetic dynamics remain poorly characterized, complicated by spurious effects. Here, by growing a thin film antiferromagnet, α-Fe_{2}O_{3}, along its nonbasal plane orientation, we realize a configuration where the spin-orbit torque from an injected spin current can unambiguously rotate and switch the Néel vector within the tilted easy plane, with an efficiency comparable to that of classical ferrimagnetic insulators. Our study introduces a new platform for quantitatively characterizing switching and oscillation dynamics in antiferromagnets.
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Affiliation(s)
- Pengxiang Zhang
- Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - Chung-Tao Chou
- Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
- Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - Hwanhui Yun
- Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, Minnesota 55455, USA
| | - Brooke C McGoldrick
- Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - Justin T Hou
- Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - K Andre Mkhoyan
- Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, Minnesota 55455, USA
| | - Luqiao Liu
- Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
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12
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Cheng Y, Cogulu E, Resnick RD, Michel JJ, Statuto NN, Kent AD, Yang F. Third harmonic characterization of antiferromagnetic heterostructures. Nat Commun 2022; 13:3659. [PMID: 35760929 DOI: 10.1038/s41467-022-31451-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Accepted: 06/17/2022] [Indexed: 11/19/2022] Open
Abstract
Electrical switching of antiferromagnets is an exciting recent development in spintronics, which promises active antiferromagnetic devices with high speed and low energy cost. In this emerging field, there is an active debate about the mechanisms of current-driven switching of antiferromagnets. For heavy-metal/ferromagnet systems, harmonic characterization is a powerful tool to quantify current-induced spin-orbit torques and spin Seebeck effect and elucidate current-induced switching. However, harmonic measurement of spin-orbit torques has never been verified in antiferromagnetic heterostructures. Here, we report harmonic measurements in Pt/α-Fe2O3 bilayers, which are explained by our modeling of higher-order harmonic voltages. As compared with ferromagnetic heterostructures where all current-induced effects appear in the second harmonic signals, the damping-like torque and thermally-induced magnetoelastic effect contributions in Pt/α-Fe2O3 emerge in the third harmonic voltage. Our results provide a new path to probe the current-induced magnetization dynamics in antiferromagnets, promoting the application of antiferromagnetic spintronic devices. Harmonic measurements have been used extensively in ferromagnetic/heavy metal heterostructures to characterize the magnetization dynamic; however, it has remained unclear about whether such techniques could be applied to antiferromagnetic devices. Here, Cheng et al demonstrate such a harmonic measurement approach in an antiferromagnet.
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13
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Pal B, Hazra BK, Göbel B, Jeon JC, Pandeya AK, Chakraborty A, Busch O, Srivastava AK, Deniz H, Taylor JM, Meyerheim H, Mertig I, Yang SH, Parkin SSP. Setting of the magnetic structure of chiral kagome antiferromagnets by a seeded spin-orbit torque. Sci Adv 2022; 8:eabo5930. [PMID: 35704587 PMCID: PMC9200275 DOI: 10.1126/sciadv.abo5930] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Accepted: 04/29/2022] [Indexed: 06/03/2023]
Abstract
The current-induced spin-orbit torque switching of ferromagnets has had huge impact in spintronics. However, short spin-diffusion lengths limit the thickness of switchable ferromagnetic layers, thereby limiting their thermal stability. Here, we report a previously unobserved seeded spin-orbit torque (SSOT) by which current can set the magnetic states of even thick layers of the chiral kagome antiferromagnet Mn3Sn. The mechanism involves setting the orientation of the antiferromagnetic domains in a thin region at the interface with spin currents arising from an adjacent heavy metal while also heating the layer above its magnetic ordering temperature. This interface region seeds the resulting spin texture of the entire layer as it cools down and, thereby, overcomes the thickness limitation of conventional spin-orbit torques. SSOT switching in Mn3Sn can be extended beyond chiral antiferromagnets to diverse magnetic systems and provides a path toward the development of highly efficient, high-speed, and thermally stable spintronic devices.
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Affiliation(s)
- Banabir Pal
- Max Planck Institute of Microstructure Physics, Weinberg 2, 06120 Halle, Germany
| | - Binoy K. Hazra
- Max Planck Institute of Microstructure Physics, Weinberg 2, 06120 Halle, Germany
| | - Börge Göbel
- Institute of Physics, Martin Luther University Halle-Wittenberg, 06099 Halle, Germany
| | - Jae-Chun Jeon
- Max Planck Institute of Microstructure Physics, Weinberg 2, 06120 Halle, Germany
| | - Avanindra K. Pandeya
- Max Planck Institute of Microstructure Physics, Weinberg 2, 06120 Halle, Germany
| | - Anirban Chakraborty
- Max Planck Institute of Microstructure Physics, Weinberg 2, 06120 Halle, Germany
| | - Oliver Busch
- Institute of Physics, Martin Luther University Halle-Wittenberg, 06099 Halle, Germany
| | - Abhay K. Srivastava
- Max Planck Institute of Microstructure Physics, Weinberg 2, 06120 Halle, Germany
| | - Hakan Deniz
- Max Planck Institute of Microstructure Physics, Weinberg 2, 06120 Halle, Germany
| | - James M. Taylor
- Max Planck Institute of Microstructure Physics, Weinberg 2, 06120 Halle, Germany
| | - Holger Meyerheim
- Max Planck Institute of Microstructure Physics, Weinberg 2, 06120 Halle, Germany
| | - Ingrid Mertig
- Institute of Physics, Martin Luther University Halle-Wittenberg, 06099 Halle, Germany
| | - See-Hun Yang
- Max Planck Institute of Microstructure Physics, Weinberg 2, 06120 Halle, Germany
| | - Stuart S. P. Parkin
- Max Planck Institute of Microstructure Physics, Weinberg 2, 06120 Halle, Germany
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14
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Dong J, Li X, Gurung G, Zhu M, Zhang P, Zheng F, Tsymbal EY, Zhang J. Tunneling Magnetoresistance in Noncollinear Antiferromagnetic Tunnel Junctions. Phys Rev Lett 2022; 128:197201. [PMID: 35622046 DOI: 10.1103/physrevlett.128.197201] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Revised: 02/18/2022] [Accepted: 04/21/2022] [Indexed: 06/15/2023]
Abstract
Antiferromagnetic (AFM) spintronics has emerged as a subfield of spintronics driven by the advantages of antiferromagnets producing no stray fields and exhibiting ultrafast magnetization dynamics. The efficient method to detect an AFM order parameter, known as the Néel vector, by electric means is critical to realize concepts of AFM spintronics. Here, we demonstrate that noncollinear AFM metals, such as Mn_{3}Sn, exhibit a momentum dependent spin polarization which can be exploited in AFM tunnel junctions to detect the Néel vector. Using first-principles calculations, we predict a tunneling magnetoresistance (TMR) effect as high as 300% in AFM tunnel junctions with Mn_{3}Sn electrodes, where the junction resistance depends on the relative orientation of their Néel vectors and exhibits four nonvolatile resistance states. We argue that the spin-split band structure and the related TMR effect can also be realized in other noncollinear AFM metals like Mn_{3}Ge, Mn_{3}Ga, Mn_{3}Pt, and Mn_{3}GaN. Our work provides a robust method for detecting the Néel vector in noncollinear antiferromagnets via the TMR effect, which may be useful for their application in AFM spintronic devices.
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Affiliation(s)
- Jianting Dong
- School of Physics and Wuhan National High Magnetic Field Center, Huazhong University of Science and Technology, 430074 Wuhan, China
| | - Xinlu Li
- School of Physics and Wuhan National High Magnetic Field Center, Huazhong University of Science and Technology, 430074 Wuhan, China
| | - Gautam Gurung
- Department of Physics and Astronomy & Nebraska Center for Materials and Nanoscience, University of Nebraska, Lincoln, Nebraska 68588, USA
| | - Meng Zhu
- School of Physics and Wuhan National High Magnetic Field Center, Huazhong University of Science and Technology, 430074 Wuhan, China
| | - Peina Zhang
- School of Physics and Wuhan National High Magnetic Field Center, Huazhong University of Science and Technology, 430074 Wuhan, China
| | - Fanxing Zheng
- School of Physics and Wuhan National High Magnetic Field Center, Huazhong University of Science and Technology, 430074 Wuhan, China
| | - Evgeny Y Tsymbal
- Department of Physics and Astronomy & Nebraska Center for Materials and Nanoscience, University of Nebraska, Lincoln, Nebraska 68588, USA
| | - Jia Zhang
- School of Physics and Wuhan National High Magnetic Field Center, Huazhong University of Science and Technology, 430074 Wuhan, China
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15
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Xiong D, Jiang Y, Shi K, Du A, Yao Y, Guo Z, Zhu D, Cao K, Peng S, Cai W, Zhu D, Zhao W. Antiferromagnetic spintronics: An overview and outlook. Fundamental Research 2022. [DOI: 10.1016/j.fmre.2022.03.016] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
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16
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Xu J, Xia J, Zhang X, Zhou C, Shi D, Chen H, Wu T, Li Q, Ding H, Zhou Y, Wu Y. Exchange-Torque-Triggered Fast Switching of Antiferromagnetic Domains. Phys Rev Lett 2022; 128:137201. [PMID: 35426702 DOI: 10.1103/physrevlett.128.137201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Revised: 01/27/2022] [Accepted: 03/04/2022] [Indexed: 06/14/2023]
Abstract
The antiferromagnet is considered to be a promising hosting material for the next generation of magnetic storage due to its high stability and stray-field-free property. Understanding the switching properties of the antiferromagnetic (AFM) domain state is critical for developing AFM spintronics. By utilizing the magneto-optical birefringence effect, we experimentally demonstrate the switching rate of the AFM domain can be enhanced by more than 2 orders of magnitude through applying an alternating square-wave field on a single crystalline Fe/CoO bilayer. The observed extraordinary speed can be much faster than that triggered by a constant field with the same amplitude. The effect can be understood as the efficient suppression of the pinning of AFM domain walls by the strong exchange torque triggered by the reversal of the Fe magnetization, as revealed by spin dynamics simulations. Our finding opens up new opportunities to design the antiferromagnet-based spintronic devices utilizing the ferromagnet-antiferromagnet heterostructure.
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Affiliation(s)
- Jia Xu
- Department of Physics and State Key Laboratory of Surface Physics, Fudan University, Shanghai 200433, China
- Institute of Physics, Shaanxi University of Technology, Hanzhong 723001, China
| | - Jing Xia
- School of Science and Engineering, The Chinese University of Hong Kong, Shenzhen, Guangdong 518172, China
- College of Physics and Electronic Engineering, Sichuan Normal University, Chengdu 610068, China
| | - Xichao Zhang
- Department of Electrical and Computer Engineering, Shinshu University, 4-17-1 Wakasato, Nagano 380-8553, Japan
| | - Chao Zhou
- Department of Physics and State Key Laboratory of Surface Physics, Fudan University, Shanghai 200433, China
- Institute of Physics, Shaanxi University of Technology, Hanzhong 723001, China
| | - Dong Shi
- Department of Physics and State Key Laboratory of Surface Physics, Fudan University, Shanghai 200433, China
| | - Haoran Chen
- Department of Physics and State Key Laboratory of Surface Physics, Fudan University, Shanghai 200433, China
| | - Tong Wu
- Department of Physics and State Key Laboratory of Surface Physics, Fudan University, Shanghai 200433, China
| | - Qian Li
- National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei 230029, China
| | - Haifeng Ding
- National Laboratory of Solid State Microstructures, Department of Physics, Nanjing University, Nanjing 210093, China
| | - Yan Zhou
- School of Science and Engineering, The Chinese University of Hong Kong, Shenzhen, Guangdong 518172, China
| | - Yizheng Wu
- Department of Physics and State Key Laboratory of Surface Physics, Fudan University, Shanghai 200433, China
- Shanghai Research Center for Quantum Sciences, Shanghai 201315, China
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17
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Wu H, Zhang H, Wang B, Groß F, Yang CY, Li G, Guo C, He H, Wong K, Wu D, Han X, Lai CH, Gräfe J, Cheng R, Wang KL. Current-induced Néel order switching facilitated by magnetic phase transition. Nat Commun 2022; 13:1629. [PMID: 35347132 DOI: 10.1038/s41467-022-29170-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2021] [Accepted: 02/11/2022] [Indexed: 11/24/2022] Open
Abstract
Terahertz (THz) spin dynamics and vanishing stray field make antiferromagnetic (AFM) materials the most promising candidate for the next-generation magnetic memory technology with revolutionary storage density and writing speed. However, owing to the extremely large exchange energy barriers, energy-efficient manipulation has been a fundamental challenge in AFM systems. Here, we report an electrical writing of antiferromagnetic orders through a record-low current density on the order of 106 A cm−2 facilitated by the unique AFM-ferromagnetic (FM) phase transition in FeRh. By introducing a transient FM state via current-induced Joule heating, the spin-orbit torque can switch the AFM order parameter by 90° with a reduced writing current density similar to ordinary FM materials. This mechanism is further verified by measuring the temperature and magnetic bias field dependences, where the X-ray magnetic linear dichroism (XMLD) results confirm the AFM switching besides the electrical transport measurement. Our findings demonstrate the exciting possibility of writing operations in AFM-based devices with a lower current density, opening a new pathway towards pure AFM memory applications. Electrical manipulation of antiferromagnetic order is crucial for future memory devices, but existing switching schemes require a large current density. Here, the authors achieve record low current density switching in FeRh by taking advantage of its antiferromagnetic to ferromagnetic phase transition.
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18
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Wang H, Zhang S, McLaughlin NJ, Flebus B, Huang M, Xiao Y, Liu C, Wu M, Fullerton EE, Tserkovnyak Y, Du CR. Noninvasive measurements of spin transport properties of an antiferromagnetic insulator. Sci Adv 2022; 8:eabg8562. [PMID: 34995122 PMCID: PMC8741188 DOI: 10.1126/sciadv.abg8562] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Accepted: 11/15/2021] [Indexed: 06/14/2023]
Abstract
Antiferromagnetic insulators (AFIs) are of substantial interest because of their potential in the development of next-generation spintronic devices. One major effort in this emerging field is to harness AFIs for long-range spin information communication and storage. Here, we report a noninvasive method to optically access the intrinsic spin transport properties of an archetypical AFI α-Fe2O3 via nitrogen-vacancy (NV) quantum spin sensors. By NV relaxometry measurements, we successfully detect the frequency-dependent dynamic fluctuations of the spin density of α-Fe2O3 along the Néel order parameter, from which an intrinsic spin diffusion constant of α-Fe2O3 is experimentally measured in the absence of external spin biases. Our results highlight the significant opportunity offered by NV centers in diagnosing the underlying spin transport properties in a broad range of high-frequency magnetic materials such as two-dimensional magnets, spin liquids, and magnetic Weyl semimetals, which are challenging to access by the conventional measurement techniques.
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Affiliation(s)
- Hailong Wang
- Center for Memory and Recording Research, University of California, San Diego, La Jolla, CA 92093, USA
| | - Shu Zhang
- Department of Physics and Astronomy, University of California, Los Angeles, Los Angeles, CA 90095,, USA
| | - Nathan J. McLaughlin
- Department of Physics, University of California, San Diego, La Jolla, CA 92093, USA
| | - Benedetta Flebus
- Department of Physics, The University of Texas at Austin, Austin, TX 78712, USA
- Department of Physics, Boston College, Chestnut Hill, MA 02467, USA
| | - Mengqi Huang
- Department of Physics, University of California, San Diego, La Jolla, CA 92093, USA
| | - Yuxuan Xiao
- Center for Memory and Recording Research, University of California, San Diego, La Jolla, CA 92093, USA
| | - Chuanpu Liu
- Department of Physics, Colorado State University, Fort Collins, CO 80523, USA
| | - Mingzhong Wu
- Department of Physics, Colorado State University, Fort Collins, CO 80523, USA
| | - Eric E. Fullerton
- Center for Memory and Recording Research, University of California, San Diego, La Jolla, CA 92093, USA
| | - Yaroslav Tserkovnyak
- Department of Physics and Astronomy, University of California, Los Angeles, Los Angeles, CA 90095,, USA
| | - Chunhui Rita Du
- Center for Memory and Recording Research, University of California, San Diego, La Jolla, CA 92093, USA
- Department of Physics, University of California, San Diego, La Jolla, CA 92093, USA
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19
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Arekapudi SSPK, Bülz D, Ganss F, Samad F, Luo C, Zahn DRT, Lenz K, Salvan G, Albrecht M, Hellwig O. Highly Tunable Magnetic and Magnetotransport Properties of Exchange Coupled Ferromagnet/Antiferromagnet-Based Heterostructures. ACS Appl Mater Interfaces 2021; 13:59497-59510. [PMID: 34870974 DOI: 10.1021/acsami.1c18017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Antiferromagnets (AFMs) with zero net magnetization are proposed as active elements in future spintronic devices. Depending on the critical film thickness and measurement temperature, bimetallic Mn-based alloys and transition-metal oxide-based AFMs can host various coexisting ordered, disordered, and frustrated AFM phases. Such coexisting phases in the exchange coupled ferromagnetic (FM)/AFM-based heterostructures can result in unusual magnetic and magnetotransport phenomena. Here, we integrate chemically disordered AFM γ-IrMn3 thin films with coexisting AFM phases into complex exchange coupled MgO(001)/γ-Ni3Fe/γ-IrMn3/γ-Ni3Fe/CoO heterostructures and study the structural, magnetic, and magnetotransport properties in various magnetic field cooling states. In particular, we unveil the impact of rotating the relative orientation of the thermally disordered and reversible AFM moments with respect to the irreversible AFM moments on the magnetic and magnetotransport properties of the exchange coupled heterostructures. We further reveal that the persistence of thermally disordered and reversible AFM moments is crucial for achieving highly tunable magnetic properties and multilevel magnetoresistance states. We anticipate that the presented approach and the heterostructure architecture can be utilized in future spintronic devices to manipulate the thermally disordered and reversible AFM moments at the nanoscale.
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Affiliation(s)
| | - Daniel Bülz
- Institute of Physics, Chemnitz University of Technology, 09107 Chemnitz, Germany
| | - Fabian Ganss
- Institute of Physics, Chemnitz University of Technology, 09107 Chemnitz, Germany
| | - Fabian Samad
- Institute of Physics, Chemnitz University of Technology, 09107 Chemnitz, Germany
- Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstrasse 400, 01328 Dresden, Germany
| | - Chen Luo
- Helmholtz-Zentrum Berlin für Materialien und Energie, Albert-Einstein-Strasse 15, 12489 Berlin, Germany
- Institute of Experimental Physics of Functional Spin Systems, Technical University Munich, James-Franck-Str. 1, 85748 Garching b. München, Germany
| | - Dietrich R T Zahn
- Institute of Physics, Chemnitz University of Technology, 09107 Chemnitz, Germany
| | - Kilian Lenz
- Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstrasse 400, 01328 Dresden, Germany
| | - Georgeta Salvan
- Institute of Physics, Chemnitz University of Technology, 09107 Chemnitz, Germany
| | - Manfred Albrecht
- Institute of Physics, University of Augsburg, Universitätsstraße 1, 86159 Augsburg, Germany
| | - Olav Hellwig
- Institute of Physics, Chemnitz University of Technology, 09107 Chemnitz, Germany
- Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstrasse 400, 01328 Dresden, Germany
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20
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Abstract
Electric currents carrying a net spin polarization are widely used in spintronics, whereas globally spin-neutral currents are expected to play no role in spin-dependent phenomena. Here we show that, in contrast to this common expectation, spin-independent conductance in compensated antiferromagnets and normal metals can be efficiently exploited in spintronics, provided their magnetic space group symmetry supports a non-spin-degenerate Fermi surface. Due to their momentum-dependent spin polarization, such antiferromagnets can be used as active elements in antiferromagnetic tunnel junctions (AFMTJs) and produce a giant tunneling magnetoresistance (TMR) effect. Using RuO2 as a representative compensated antiferromagnet exhibiting spin-independent conductance along the [001] direction but a non-spin-degenerate Fermi surface, we design a RuO2/TiO2/RuO2 (001) AFMTJ, where a globally spin-neutral charge current is controlled by the relative orientation of the Néel vectors of the two RuO2 electrodes, resulting in the TMR effect as large as ~500%. These results are expanded to normal metals which can be used as a counter electrode in AFMTJs with a single antiferromagnetic layer or other elements in spintronic devices. Our work uncovers an unexplored potential of the materials with no global spin polarization for utilizing them in spintronics.
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Affiliation(s)
- Ding-Fu Shao
- Department of Physics and Astronomy & Nebraska Center for Materials and Nanoscience, University of Nebraska, Lincoln, NE, 68588-0299, USA.
| | - Shu-Hui Zhang
- grid.48166.3d0000 0000 9931 8406College of Mathematics and Physics, Beijing University of Chemical Technology, Beijing, 100029 People’s Republic of China
| | - Ming Li
- grid.24434.350000 0004 1937 0060Department of Physics and Astronomy & Nebraska Center for Materials and Nanoscience, University of Nebraska, Lincoln, NE 68588-0299 USA
| | - Chang-Beom Eom
- grid.14003.360000 0001 2167 3675Department of Materials Science and Engineering, University of Wisconsin-Madison, Madison, WI 3706 US
| | - Evgeny Y. Tsymbal
- grid.24434.350000 0004 1937 0060Department of Physics and Astronomy & Nebraska Center for Materials and Nanoscience, University of Nebraska, Lincoln, NE 68588-0299 USA
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21
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Stebliy ME, Kolesnikov AG, Bazrov MA, Letushev ME, Ognev AV, Davydenko AV, Stebliy EV, Kozlov AG, Wang X, Wan C, Fang C, Zhao M, Han X, Samardak AS. Current-Induced Manipulation of the Exchange Bias in a Pt/Co/NiO Structure. ACS Appl Mater Interfaces 2021; 13:42258-42265. [PMID: 34427434 DOI: 10.1021/acsami.1c12683] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
An experimental study of the phenomenon of electric current influence on the value and orientation of the exchange bias field (HEB) in the Pt/Co/NiO structure is carried out. Depending on the direction of the magnetization in a ferromagnet (FM) layer and the current pulse amplitude, the value of the HEB field can be changed repeatedly in the range of ±7.5 mT. A few experiments are performed to separate the contributions from two current-induced effects: (i) an injection of the spin current into an antiferromagnet layer (AFM) and (ii) Joule heating. As a result, we conclude that the modification in the HEB field during current pulse transmission in the Pt/Co/NiO structure is due to heating and the low value of Néel temperature (TN = 162 °C). This fact explains the absence of the exchange bias effect on the spin-orbit torque (SOT)-assisted magnetization switching. The most striking observation to emerge from the experimental data analysis is that depending on the initial spin configuration of the domain structure in the FM layer and the current pulse amplitude, the exchange bias can be changed locally. This opens up prospects for creating exchange-coupled FM/AFM structures with dynamically tuned parameters of the exchange bias, which can be used for the development of magnetic memory, neuromorphic, and logic devices based on magnetic nanosystems.
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Affiliation(s)
- Maksim E Stebliy
- School of Natural Sciences, Far Eastern Federal University, Vladivostok 690922, Russia
| | | | - Michail A Bazrov
- School of Natural Sciences, Far Eastern Federal University, Vladivostok 690922, Russia
| | - Michail E Letushev
- School of Natural Sciences, Far Eastern Federal University, Vladivostok 690922, Russia
| | - Alexey V Ognev
- School of Natural Sciences, Far Eastern Federal University, Vladivostok 690922, Russia
| | - Aleksandr V Davydenko
- School of Natural Sciences, Far Eastern Federal University, Vladivostok 690922, Russia
| | - Ekaterina V Stebliy
- School of Natural Sciences, Far Eastern Federal University, Vladivostok 690922, Russia
| | - Aleksei G Kozlov
- School of Natural Sciences, Far Eastern Federal University, Vladivostok 690922, Russia
| | - Xiao Wang
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Caihua Wan
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Chi Fang
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Mingkun Zhao
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Xiufeng Han
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Alexander S Samardak
- School of Natural Sciences, Far Eastern Federal University, Vladivostok 690922, Russia
- National Research South Ural State University, Chelyabinsk 454080, Russia
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22
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Arpaci S, Lopez-Dominguez V, Shi J, Sánchez-Tejerina L, Garesci F, Wang C, Yan X, Sangwan VK, Grayson MA, Hersam MC, Finocchio G, Khalili Amiri P. Observation of current-induced switching in non-collinear antiferromagnetic IrMn 3 by differential voltage measurements. Nat Commun 2021; 12:3828. [PMID: 34158511 DOI: 10.1038/s41467-021-24237-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Accepted: 06/09/2021] [Indexed: 11/19/2022] Open
Abstract
There is accelerating interest in developing memory devices using antiferromagnetic (AFM) materials, motivated by the possibility for electrically controlling AFM order via spin-orbit torques, and its read-out via magnetoresistive effects. Recent studies have shown, however, that high current densities create non-magnetic contributions to resistive switching signals in AFM/heavy metal (AFM/HM) bilayers, complicating their interpretation. Here we introduce an experimental protocol to unambiguously distinguish current-induced magnetic and nonmagnetic switching signals in AFM/HM structures, and demonstrate it in IrMn3/Pt devices. A six-terminal double-cross device is constructed, with an IrMn3 pillar placed on one cross. The differential voltage is measured between the two crosses with and without IrMn3 after each switching attempt. For a wide range of current densities, reversible switching is observed only when write currents pass through the cross with the IrMn3 pillar, eliminating any possibility of non-magnetic switching artifacts. Micromagnetic simulations support our findings, indicating a complex domain-mediated switching process. Anti-ferromagnetic based memories have a wide range of advantages over their ferromagnetic counterparts, however, their electrical signatures of switching are complicated by spurious signals. Here, Arpaci et al demonstrate an experimental method to distinguish between anti-ferromagnetic switching, and such spurious signatures.
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23
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Tsai H, Higo T, Kondou K, Sakamoto S, Kobayashi A, Matsuo T, Miwa S, Otani Y, Nakatsuji S. Large Hall Signal due to Electrical Switching of an Antiferromagnetic Weyl Semimetal State. Small Science 2021. [DOI: 10.1002/smsc.202000025] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Affiliation(s)
- Hanshen Tsai
- Institute for Solid State Physics University of Tokyo Kashiwa Chiba 277-8581 Japan
- CREST Japan Science and Technology Agency Kawaguchi Saitama 332-0012 Japan
| | - Tomoya Higo
- Institute for Solid State Physics University of Tokyo Kashiwa Chiba 277-8581 Japan
- CREST Japan Science and Technology Agency Kawaguchi Saitama 332-0012 Japan
| | - Kouta Kondou
- Institute for Solid State Physics University of Tokyo Kashiwa Chiba 277-8581 Japan
- CREST Japan Science and Technology Agency Kawaguchi Saitama 332-0012 Japan
- RIKEN Center for Emergent Matter Science (CEMS) Wako Saitama 351-0198 Japan
| | - Shoya Sakamoto
- Institute for Solid State Physics University of Tokyo Kashiwa Chiba 277-8581 Japan
| | - Ayuko Kobayashi
- Institute for Solid State Physics University of Tokyo Kashiwa Chiba 277-8581 Japan
| | - Takumi Matsuo
- Institute for Solid State Physics University of Tokyo Kashiwa Chiba 277-8581 Japan
| | - Shinji Miwa
- Institute for Solid State Physics University of Tokyo Kashiwa Chiba 277-8581 Japan
- CREST Japan Science and Technology Agency Kawaguchi Saitama 332-0012 Japan
- Trans-scale Quantum Science Institute University of Tokyo Bunkyo-ku Tokyo 113-0033 Japan
| | - Yoshichika Otani
- Institute for Solid State Physics University of Tokyo Kashiwa Chiba 277-8581 Japan
- CREST Japan Science and Technology Agency Kawaguchi Saitama 332-0012 Japan
- RIKEN Center for Emergent Matter Science (CEMS) Wako Saitama 351-0198 Japan
- Trans-scale Quantum Science Institute University of Tokyo Bunkyo-ku Tokyo 113-0033 Japan
| | - Satoru Nakatsuji
- Institute for Solid State Physics University of Tokyo Kashiwa Chiba 277-8581 Japan
- CREST Japan Science and Technology Agency Kawaguchi Saitama 332-0012 Japan
- Trans-scale Quantum Science Institute University of Tokyo Bunkyo-ku Tokyo 113-0033 Japan
- Department of Physics University of Tokyo Bunkyo-ku Tokyo 113-0033 Japan
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24
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Meer H, Schreiber F, Schmitt C, Ramos R, Saitoh E, Gomonay O, Sinova J, Baldrati L, Kläui M. Direct Imaging of Current-Induced Antiferromagnetic Switching Revealing a Pure Thermomagnetoelastic Switching Mechanism in NiO. Nano Lett 2021; 21:114-119. [PMID: 33306407 DOI: 10.1021/acs.nanolett.0c03367] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
We unravel the origin of current-induced magnetic switching of insulating antiferromagnet/heavy metal systems. We utilize concurrent transport and magneto-optical measurements to image the switching of antiferromagnetic domains in specially engineered devices of NiO/Pt bilayers. Different electrical pulsing and device geometries reveal different final states of the switching with respect to the current direction. We can explain these through simulations of the temperature-induced strain, and we identify the thermomagnetoelastic switching mechanism combined with thermal excitations as the origin, in which the final state is defined by the strain distributions and heat is required to switch the antiferromagnetic domains. We show that such a potentially very versatile noncontact mechanism can explain the previously reported contradicting observations of the switching final state, which were attributed to spin-orbit torque mechanisms.
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Affiliation(s)
- Hendrik Meer
- Institute of Physics, Johannes Gutenberg-University Mainz, 55128 Mainz, Germany
| | - Felix Schreiber
- Institute of Physics, Johannes Gutenberg-University Mainz, 55128 Mainz, Germany
| | - Christin Schmitt
- Institute of Physics, Johannes Gutenberg-University Mainz, 55128 Mainz, Germany
| | - Rafael Ramos
- WPI-Advanced Institute for Materials Research, Tohoku University, Sendai 980-8577, Japan
- Centro de Investigación en Química Biolóxica e Materiais Moleculares (CIQUS), Departamento de Química-Física, Universidade de Santiago de Compostela, Santiago de Compostela 15782, Spain
| | - Eiji Saitoh
- WPI-Advanced Institute for Materials Research, Tohoku University, Sendai 980-8577, Japan
- Institute for Materials Research, Tohoku University, Sendai 980-8577, Japan
- Advanced Science Research Center, Japan Atomic Energy Agency, Tokai 319-1195, Japan
- Center for Spintronics Research Network, Tohoku University, Sendai 980-8577, Japan
- Department of Applied Physics, The University of Tokyo, Tokyo 113-8656, Japan
| | - Olena Gomonay
- Institute of Physics, Johannes Gutenberg-University Mainz, 55128 Mainz, Germany
| | - Jairo Sinova
- Institute of Physics, Johannes Gutenberg-University Mainz, 55128 Mainz, Germany
- Institut of Physics, Academy of Sciences of the Czech Republic, Praha 11720, Czech Republic
- Graduate School of Excellence Materials Science in Mainz, 55128 Mainz, Germany
| | - Lorenzo Baldrati
- Institute of Physics, Johannes Gutenberg-University Mainz, 55128 Mainz, Germany
| | - Mathias Kläui
- Institute of Physics, Johannes Gutenberg-University Mainz, 55128 Mainz, Germany
- Graduate School of Excellence Materials Science in Mainz, 55128 Mainz, Germany
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25
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Zhao Y, Zhao S, Wang L, Wang S, Du Y, Zhao Y, Jin S, Min T, Tian B, Jiang Z, Zhou Z, Liu M. Photovoltaic modulation of ferromagnetism within a FM metal/P-N junction Si heterostructure. Nanoscale 2021; 13:272-279. [PMID: 33332513 DOI: 10.1039/d0nr07911a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Obtaining small, fast, and energy-efficient spintronic devices requires a new way of manipulating spin states in an effective manner. Here, a prototype photovoltaic spintronic device with a p-n junction Si wafer is proposed which generates photo-induced electrons and changes the ferromagnetism by interfacial charge doping. A ferromagnetic resonance field change of 48.965 mT and 11.306 mT is achieved in Co and CoFeB thin films under sunlight illumination, respectively. The transient reflection (TR) analysis and the first principles calculation reveal the photovoltaic electrons that are doped into the magnetic layer and alter its Fermi level, correspondingly. This finding provides a new method of magnetism modulation and demonstrates a solar-driven spintronic device with abundant energy supply, which may further expand the landscape of spintronics research.
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Affiliation(s)
- Yifan Zhao
- Electronic Materials Research Laboratory, Key Laboratory of the Ministry of Education & International Center for Dielectric Research, School of Electronic and Information Engineering, and State Key Laboratory for Mechanical Behavior of Materials, the International Joint Laboratory for Micro/Nano Manufacturing and Measurement Technology, Xi'an Jiaotong University, Xi'an 710049, China.
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26
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DuttaGupta S, Kurenkov A, Tretiakov OA, Krishnaswamy G, Sala G, Krizakova V, Maccherozzi F, Dhesi SS, Gambardella P, Fukami S, Ohno H. Spin-orbit torque switching of an antiferromagnetic metallic heterostructure. Nat Commun 2020; 11:5715. [PMID: 33177506 PMCID: PMC7658218 DOI: 10.1038/s41467-020-19511-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2020] [Accepted: 10/14/2020] [Indexed: 11/09/2022] Open
Abstract
The ability to represent information using an antiferromagnetic material is attractive for future antiferromagnetic spintronic devices. Previous studies have focussed on the utilization of antiferromagnetic materials with biaxial magnetic anisotropy for electrical manipulation. A practical realization of these antiferromagnetic devices is limited by the requirement of material-specific constraints. Here, we demonstrate current-induced switching in a polycrystalline PtMn/Pt metallic heterostructure. A comparison of electrical transport measurements in PtMn with and without the Pt layer, corroborated by x-ray imaging, reveals reversible switching of the thermally-stable antiferromagnetic Néel vector by spin-orbit torques. The presented results demonstrate the potential of polycrystalline metals for antiferromagnetic spintronics.
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Affiliation(s)
- Samik DuttaGupta
- Center for Science and Innovation in Spintronics, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, 980-8577, Japan. .,Center for Spintronics Research Network, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, 980-8577, Japan. .,Laboratory for Nanoelectronics and Spintronics, Research Institute of Electrical Communication, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, 980-8577, Japan.
| | - A Kurenkov
- Center for Science and Innovation in Spintronics, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, 980-8577, Japan.,Center for Spintronics Research Network, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, 980-8577, Japan.,Laboratory for Nanoelectronics and Spintronics, Research Institute of Electrical Communication, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, 980-8577, Japan
| | - Oleg A Tretiakov
- School of Physics, The University of New South Wales, Sydney, 2052, Australia
| | - G Krishnaswamy
- Laboratory for Magnetism and Interface Physics, Department of Materials, ETH Zurich, 8093, Zurich, Switzerland
| | - G Sala
- Laboratory for Magnetism and Interface Physics, Department of Materials, ETH Zurich, 8093, Zurich, Switzerland
| | - V Krizakova
- Laboratory for Magnetism and Interface Physics, Department of Materials, ETH Zurich, 8093, Zurich, Switzerland
| | - F Maccherozzi
- Diamond Light Source, Chilton, Didcot, Oxfordshire, OX11 0DE, United Kingdom
| | - S S Dhesi
- Diamond Light Source, Chilton, Didcot, Oxfordshire, OX11 0DE, United Kingdom
| | - P Gambardella
- Laboratory for Magnetism and Interface Physics, Department of Materials, ETH Zurich, 8093, Zurich, Switzerland
| | - S Fukami
- Center for Science and Innovation in Spintronics, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, 980-8577, Japan.,Center for Spintronics Research Network, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, 980-8577, Japan.,Laboratory for Nanoelectronics and Spintronics, Research Institute of Electrical Communication, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, 980-8577, Japan.,Center for Innovative Integrated Electronic Systems, Tohoku University, 468-1 Aramaki Aza Aoba, Aoba-ku, Sendai, 980-0845, Japan.,WPI Advanced Institute for Materials Research, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, 980-8577, Japan
| | - H Ohno
- Center for Science and Innovation in Spintronics, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, 980-8577, Japan.,Center for Spintronics Research Network, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, 980-8577, Japan.,Laboratory for Nanoelectronics and Spintronics, Research Institute of Electrical Communication, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, 980-8577, Japan.,Center for Innovative Integrated Electronic Systems, Tohoku University, 468-1 Aramaki Aza Aoba, Aoba-ku, Sendai, 980-0845, Japan.,WPI Advanced Institute for Materials Research, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, 980-8577, Japan
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27
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Abstract
Science, engineering, and medicine ultimately demand fast information processing with ultra-low power consumption. The recently developed spin-orbit torque (SOT)-induced magnetization switching paradigm has been fueling opportunities for spin-orbitronic devices, i.e., enabling SOT memory and logic devices at sub-nano second and sub-picojoule regimes. Importantly, spin-orbitronic devices are intrinsic of nonvolatility, anti-radiation, unlimited endurance, excellent stability, and CMOS compatibility, toward emerging applications, e.g., processing in-memory, neuromorphic computing, probabilistic computing, and 3D magnetic random access memory. Nevertheless, the cutting-edge SOT-based devices and application remain at a premature stage owing to the lack of scalable methodology on the field-free SOT switching. Moreover, spin-orbitronics poises as an interdisciplinary field to be driven by goals of both fundamental discoveries and application innovations, to open fascinating new paths for basic research and new line of technologies. In this perspective, the specific challenges and opportunities are summarized to exert momentum on both research and eventual applications of spin-orbitronic devices.
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Affiliation(s)
- Yi Cao
- Beijing Academy of Quantum Information Sciences, Beijing 100193, P. R. China
| | - Guozhong Xing
- Key Laboratory of Microelectronic Devices & Integrated Technology, Institute of Microelectronics, Chinese Academy of Sciences, Beijing 100029, P. R. China
| | - Huai Lin
- Key Laboratory of Microelectronic Devices & Integrated Technology, Institute of Microelectronics, Chinese Academy of Sciences, Beijing 100029, P. R. China
| | - Nan Zhang
- State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, P. R. China
| | - Houzhi Zheng
- State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, P. R. China
| | - Kaiyou Wang
- Beijing Academy of Quantum Information Sciences, Beijing 100193, P. R. China
- State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, P. R. China
- Corresponding author
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28
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Cao Q, Lü W, Wang XR, Guan X, Wang L, Yan S, Wu T, Wang X. Nonvolatile Multistates Memories for High-Density Data Storage. ACS Appl Mater Interfaces 2020; 12:42449-42471. [PMID: 32812741 DOI: 10.1021/acsami.0c10184] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
In the current information age, the realization of memory devices with energy efficient design, high storage density, nonvolatility, fast access, and low cost is still a great challenge. As a promising technology to meet these stringent requirements, nonvolatile multistates memory (NMSM) has attracted lots of attention over the past years. Owing to the capability to store data in more than a single bit (0 or 1), the storage density is dramatically enhanced without scaling down the memory cell, making memory devices more efficient and less expensive. Multistates in a single cell also provide an unconventional in-memory computing platform beyond the Von Neumann architecture and enable neuromorphic computing with low power consumption. In this review, an in-depth perspective is presented on the recent progress and challenges on the device architectures, material innovation, working mechanisms of various types of NMSMs, including flash, magnetic random-access memory (MRAM), resistive random-access memory (RRAM), ferroelectric random-access memory (FeRAM), and phase-change memory (PCM). The intriguing properties and performance of these NMSMs, which are the key to realizing highly integrated memory hierarchy, are discussed and compared.
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Affiliation(s)
- Qiang Cao
- Spintronics Institute, University of Jinan, Jinan 250022, China
| | - Weiming Lü
- Spintronics Institute, University of Jinan, Jinan 250022, China
| | - X Renshaw Wang
- School of Physical and Mathematical Sciences & School of Electrical and Electronic Engineering, Nanyang Technological University, 639798 Singapore
| | - Xinwei Guan
- School of Materials Science and Engineering, University of New South Wales, Sydney, New South Wales 2052, Australia
| | - Lan Wang
- School of Science, ARC Centre of Excellence in Future Low-Energy Electronics Technologies, RMIT University, Melbourne, Victoria 3001, Australia
| | - Shishen Yan
- Spintronics Institute, University of Jinan, Jinan 250022, China
| | - Tom Wu
- School of Materials Science and Engineering, University of New South Wales, Sydney, New South Wales 2052, Australia
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29
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Baldrati L, Schmitt C, Gomonay O, Lebrun R, Ramos R, Saitoh E, Sinova J, Kläui M. Efficient Spin Torques in Antiferromagnetic CoO/Pt Quantified by Comparing Field- and Current-Induced Switching. Phys Rev Lett 2020; 125:077201. [PMID: 32857543 DOI: 10.1103/physrevlett.125.077201] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Revised: 07/02/2020] [Accepted: 07/10/2020] [Indexed: 06/11/2023]
Abstract
We achieve current-induced switching in collinear insulating antiferromagnetic CoO/Pt, with fourfold in-plane magnetic anisotropy. This is measured electrically by spin Hall magnetoresistance and confirmed by the magnetic field-induced spin-flop transition of the CoO layer. By applying current pulses and magnetic fields, we quantify the efficiency of the acting current-induced torques and estimate a current-field equivalence ratio of 4×10^{-11} T A^{-1} m^{2}. The Néel vector final state (n⊥j) is in line with a thermomagnetoelastic switching mechanism for a negative magnetoelastic constant of the CoO.
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Affiliation(s)
- L Baldrati
- Institute of Physics, Johannes Gutenberg-University Mainz, 55128 Mainz, Germany
| | - C Schmitt
- Institute of Physics, Johannes Gutenberg-University Mainz, 55128 Mainz, Germany
| | - O Gomonay
- Institute of Physics, Johannes Gutenberg-University Mainz, 55128 Mainz, Germany
| | - R Lebrun
- Institute of Physics, Johannes Gutenberg-University Mainz, 55128 Mainz, Germany
- Unité Mixte de Physique CNRS, Thales, Université Paris-Sud, Université Paris-Saclay, Palaiseau 91767, France
| | - R Ramos
- WPI-Advanced Institute for Materials Research, Tohoku University, Sendai 980-8577, Japan
| | - E Saitoh
- WPI-Advanced Institute for Materials Research, Tohoku University, Sendai 980-8577, Japan
- Institute for Materials Research, Tohoku University, Sendai 980-8577, Japan
- Advanced Science Research Center, Japan Atomic Energy Agency, Tokai 319-1195, Japan
- Center for Spintronics Research Network, Tohoku University, Sendai 980-8577, Japan
- Department of Applied Physics, The University of Tokyo, Tokyo 113-8656, Japan
| | - J Sinova
- Institute of Physics, Johannes Gutenberg-University Mainz, 55128 Mainz, Germany
- Institute of Physics, Academy of Sciences of the Czech Republic, Praha 11720, Czech Republic
- Graduate School of Excellence Materials Science in Mainz, 55128 Mainz, Germany
| | - M Kläui
- Institute of Physics, Johannes Gutenberg-University Mainz, 55128 Mainz, Germany
- Graduate School of Excellence Materials Science in Mainz, 55128 Mainz, Germany
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30
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Han J, Zhang P, Bi Z, Fan Y, Safi TS, Xiang J, Finley J, Fu L, Cheng R, Liu L. Birefringence-like spin transport via linearly polarized antiferromagnetic magnons. Nat Nanotechnol 2020; 15:563-568. [PMID: 32483320 DOI: 10.1038/s41565-020-0703-8] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Accepted: 04/29/2020] [Indexed: 05/12/2023]
Abstract
Antiferromagnets (AFMs) possess great potential in spintronics because of their immunity to external magnetic disturbance, the absence of a stray field or the resonance in the terahertz range1,2. The coupling of insulating AFMs to spin-orbit materials3-7 enables spin transport via AFM magnons. In particular, spin transmission over several micrometres occurs in some AFMs with easy-axis anisotropy8,9. Easy-plane AFMs with two orthogonal, linearly polarized magnon eigenmodes own unique advantages for low-energy control of ultrafast magnetic dynamics2. However, it is commonly conceived that these magnon modes are less likely to transmit spins because of their vanishing angular momentum9-11. Here we report experimental evidence that an easy-plane insulating AFM, an α-Fe2O3 thin film, can efficiently transmit spins over micrometre distances. The spin decay length shows an unconventional temperature dependence that cannot be captured considering solely thermal magnon scatterings. We interpret our observations in terms of an interference of two linearly polarized, propagating magnons in analogy to the birefringence effect in optics. Furthermore, our devices can realize a bi-stable spin-current switch with a 100% on/off ratio under zero remnant magnetic field. These findings provide additional tools for non-volatile, low-field control of spin transport in AFM systems.
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Affiliation(s)
- Jiahao Han
- Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Pengxiang Zhang
- Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Zhen Bi
- Department of Physics, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Yabin Fan
- Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Taqiyyah S Safi
- Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Junxiang Xiang
- Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Joseph Finley
- Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Liang Fu
- Department of Physics, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Ran Cheng
- Department of Electrical and Computer Engineering, University of California, Riverside, CA, USA
| | - Luqiao Liu
- Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA, USA.
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31
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Yan H, Feng Z, Qin P, Zhou X, Guo H, Wang X, Chen H, Zhang X, Wu H, Jiang C, Liu Z. Electric-Field-Controlled Antiferromagnetic Spintronic Devices. Adv Mater 2020; 32:e1905603. [PMID: 32048366 DOI: 10.1002/adma.201905603] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2019] [Revised: 11/21/2019] [Indexed: 06/10/2023]
Abstract
In recent years, the field of antiferromagnetic spintronics has been substantially advanced. Electric-field control is a promising approach for achieving ultralow power spintronic devices via suppressing Joule heating. Here, cutting-edge research, including electric-field modulation of antiferromagnetic spintronic devices using strain, ionic liquids, dielectric materials, and electrochemical ionic migration, is comprehensively reviewed. Various emergent topics such as the Néel spin-orbit torque, chiral spintronics, topological antiferromagnetic spintronics, anisotropic magnetoresistance, memory devices, 2D magnetism, and magneto-ionic modulation with respect to antiferromagnets are examined. In conclusion, the possibility of realizing high-quality room-temperature antiferromagnetic tunnel junctions, antiferromagnetic spin logic devices, and artificial antiferromagnetic neurons is highlighted. It is expected that this work provides an appropriate and forward-looking perspective that will promote the rapid development of this field.
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Affiliation(s)
- Han Yan
- School of Materials Science and Engineering, Beihang University, Beijing, 100191, China
| | - Zexin Feng
- School of Materials Science and Engineering, Beihang University, Beijing, 100191, China
| | - Peixin Qin
- School of Materials Science and Engineering, Beihang University, Beijing, 100191, China
| | - Xiaorong Zhou
- School of Materials Science and Engineering, Beihang University, Beijing, 100191, China
| | - Huixin Guo
- School of Materials Science and Engineering, Beihang University, Beijing, 100191, China
| | - Xiaoning Wang
- School of Materials Science and Engineering, Beihang University, Beijing, 100191, China
| | - Hongyu Chen
- School of Materials Science and Engineering, Beihang University, Beijing, 100191, China
| | - Xin Zhang
- School of Materials Science and Engineering, Beihang University, Beijing, 100191, China
| | - Haojiang Wu
- School of Materials Science and Engineering, Beihang University, Beijing, 100191, China
| | - Chengbao Jiang
- School of Materials Science and Engineering, Beihang University, Beijing, 100191, China
| | - Zhiqi Liu
- School of Materials Science and Engineering, Beihang University, Beijing, 100191, China
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32
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Cheng Y, Yu S, Zhu M, Hwang J, Yang F. Electrical Switching of Tristate Antiferromagnetic Néel Order in α-Fe_{2}O_{3} Epitaxial Films. Phys Rev Lett 2020; 124:027202. [PMID: 32004028 DOI: 10.1103/physrevlett.124.027202] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Revised: 11/04/2019] [Indexed: 06/10/2023]
Abstract
We demonstrate nondecaying, steplike electrical switching of tristate Néel order in Pt/α-Fe_{2}O_{3} bilayers detected by the spin-Hall induced anomalous Hall effect. The as-grown Pt/α-Fe_{2}O_{3} bilayers exhibit sawtooth switching behavior generated by current pulses. After annealing by a high pulse current, the Hall signals reveal single-pulse saturated, nondecaying, steplike switching. Together with control experiments, we show that the sawtooth switching is due to an artifact of Pt while the actual spin-orbit torque induced antiferromagnetic switching is steplike. Our Monte Carlo simulations explain the switching behavior of α-Fe_{2}O_{3} Néel order among three in-plane easy axes.
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Affiliation(s)
- Yang Cheng
- Department of Physics, The Ohio State University, Columbus, Ohio 43210, USA
| | - Sisheng Yu
- Department of Physics, The Ohio State University, Columbus, Ohio 43210, USA
| | - Menglin Zhu
- Department of Materials Science and Engineering, The Ohio State University, Columbus, Ohio 43212, USA
| | - Jinwoo Hwang
- Department of Materials Science and Engineering, The Ohio State University, Columbus, Ohio 43212, USA
| | - Fengyuan Yang
- Department of Physics, The Ohio State University, Columbus, Ohio 43210, USA
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Zhang P, Finley J, Safi T, Liu L. Quantitative Study on Current-Induced Effect in an Antiferromagnet Insulator/Pt Bilayer Film. Phys Rev Lett 2019; 123:247206. [PMID: 31922833 DOI: 10.1103/physrevlett.123.247206] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2019] [Revised: 10/01/2019] [Indexed: 06/10/2023]
Abstract
A quantitative investigation of the current-induced torque in antiferromagnets represents a great challenge due to the lack of an independent method for controlling Néel vectors. By utilizing an antiferromagnetic insulator with the Dzyaloshinskii-Moriya interaction α-Fe_{2}O_{3}, we show that the Néel vector can be controlled with a moderate external field, which is further utilized to calibrate the current-induced magnetic dynamics. We find that the current-induced magnetoresistance change in antiferromagnets can be complicated by resistive switching that does not have a magnetic origin. By excluding nonmagnetic switching and comparing the current-induced dynamics with the field-induced one, we determine the nature and magnitude of current-induced effects in Pt/α-Fe_{2}O_{3} bilayer films.
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Affiliation(s)
- Pengxiang Zhang
- Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - Joseph Finley
- Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - Taqiyyah Safi
- Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - Luqiao Liu
- Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
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