1
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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. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024; 36:e2312008. [PMID: 38501999 DOI: 10.1002/adma.202312008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [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 are 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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2
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Huang L, Liao L, Qiu H, Chen X, Bai H, Han L, Zhou Y, Su Y, Zhou Z, Pan F, Jin B, Song C. Antiferromagnetic magnonic charge current generation via ultrafast optical excitation. Nat Commun 2024; 15:4270. [PMID: 38769299 PMCID: PMC11106255 DOI: 10.1038/s41467-024-48391-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2023] [Accepted: 04/30/2024] [Indexed: 05/22/2024] Open
Abstract
Néel spin-orbit torque allows a charge current pulse to efficiently manipulate the Néel vector in antiferromagnets, which offers a unique opportunity for ultrahigh density information storage with high speed. However, the reciprocal process of Néel spin-orbit torque, the generation of ultrafast charge current in antiferromagnets has not been demonstrated. Here, we show the experimental observation of charge current generation in antiferromagnetic metallic Mn2Au thin films using ultrafast optical excitation. The ultrafast laser pulse excites antiferromagnetic magnons, resulting in instantaneous non-equilibrium spin polarization at the antiferromagnetic spin sublattices with broken spatial symmetry. Then the charge current is generated directly via spin-orbit fields at the two sublattices, which is termed as the reciprocal phenomenon of Néel spin-orbit torque, and the associated THz emission can be detected at room temperature. Besides the fundamental significance on the Onsager reciprocity, the observed magnonic charge current generation in antiferromagnet would advance the development of antiferromagnetic THz emitter.
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Affiliation(s)
- Lin Huang
- Key Laboratory of Advanced Materials (MOE), School of Materials Science and Engineering, Tsinghua University, Beijing, China
| | - Liyang Liao
- Key Laboratory of Advanced Materials (MOE), School of Materials Science and Engineering, Tsinghua University, Beijing, China
- Institute for Solid State Physics, University of Tokyo, Kashiwa, Japan
| | - Hongsong Qiu
- Research Institute of Superconductor Electronics (RISE), School of Electronic Science and Engineering, Nanjing University, Nanjing, China
| | - Xianzhe Chen
- Department of Materials Science and Engineering, University of California, Berkeley, CA, USA
| | - Hua Bai
- Key Laboratory of Advanced Materials (MOE), School of Materials Science and Engineering, Tsinghua University, Beijing, China
| | - Lei Han
- Key Laboratory of Advanced Materials (MOE), School of Materials Science and Engineering, Tsinghua University, Beijing, China
| | - Yongjian Zhou
- Key Laboratory of Advanced Materials (MOE), School of Materials Science and Engineering, Tsinghua University, Beijing, China
| | - Yichen Su
- Key Laboratory of Advanced Materials (MOE), School of Materials Science and Engineering, Tsinghua University, Beijing, China
| | - Zhiyuan Zhou
- Key Laboratory of Advanced Materials (MOE), School of Materials Science and Engineering, Tsinghua University, Beijing, China
| | - Feng Pan
- Key Laboratory of Advanced Materials (MOE), School of Materials Science and Engineering, Tsinghua University, Beijing, China
| | - Biaobing Jin
- Research Institute of Superconductor Electronics (RISE), School of Electronic Science and Engineering, Nanjing University, Nanjing, China.
| | - Cheng Song
- Key Laboratory of Advanced Materials (MOE), School of Materials Science and Engineering, Tsinghua University, Beijing, China.
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3
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Han L, Luo X, Xu Y, Bai H, Zhu W, Zhu Y, Yu G, Song C, Pan F. Electrical-Controllable Antiferromagnet-Based Tunnel Junction. NANO LETTERS 2024; 24:4165-4171. [PMID: 38534019 DOI: 10.1021/acs.nanolett.4c00084] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/28/2024]
Abstract
An electrical-controllable antiferromagnet tunnel junction is a key goal in spintronics, holding immense promise for ultradense and ultrastable antiferromagnetic memory with high processing speed for modern information technology. Here, we have advanced toward this goal by achieving an electrical-controllable antiferromagnet-based tunnel junction of Pt/Co/Pt/Co/IrMn/MgO/Pt. The exchange coupling between antiferromagnetic IrMn and Co/Pt perpendicular magnetic multilayers results in the formation of an interfacial exchange bias and exchange spring in IrMn. Encoding information states "0" and "1" is realized through the exchange spring in IrMn, which can be electrically written by spin-orbit torque switching with high cyclability and electrically read by antiferromagnetic tunneling anisotropic magnetoresistance. Combining spin-orbit torque switching of both exchange spring and exchange bias, a 16 Boolean logic operation is successfully demonstrated. With both memory and logic functionalities integrated into our electrically controllable antiferromagnetic-based tunnel junction, we chart the course toward high-performance antiferromagnetic logic-in-memory.
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Affiliation(s)
- Lei Han
- Key Laboratory of Advanced Materials (MOE), School of Materials Science and Engineering, Tsinghua University, Beijing 100084, China
| | - Xuming Luo
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Yingqian Xu
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Hua Bai
- Key Laboratory of Advanced Materials (MOE), School of Materials Science and Engineering, Tsinghua University, Beijing 100084, China
| | - Wenxuan Zhu
- Key Laboratory of Advanced Materials (MOE), School of Materials Science and Engineering, Tsinghua University, Beijing 100084, China
| | - Yuxiang Zhu
- Key Laboratory of Advanced Materials (MOE), School of Materials Science and Engineering, Tsinghua University, Beijing 100084, China
| | - Guoqiang Yu
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Cheng Song
- Key Laboratory of Advanced Materials (MOE), School of Materials Science and Engineering, Tsinghua University, Beijing 100084, China
| | - Feng Pan
- Key Laboratory of Advanced Materials (MOE), School of Materials Science and Engineering, Tsinghua University, Beijing 100084, China
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4
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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. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024; 36:e2310379. [PMID: 38183310 DOI: 10.1002/adma.202310379] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [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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5
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Schmitt C, Rajan A, Beneke G, Kumar A, Sparmann T, Meer H, Bednarz B, Ramos R, Niño MA, Foerster M, Saitoh E, Kläui M. Mechanisms of Electrical Switching of Ultrathin CoO/Pt Bilayers. NANO LETTERS 2024; 24:1471-1476. [PMID: 38216142 PMCID: PMC10853954 DOI: 10.1021/acs.nanolett.3c02890] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Revised: 12/21/2023] [Accepted: 12/21/2023] [Indexed: 01/14/2024]
Abstract
We study current-induced switching of the Néel vector in CoO/Pt bilayers to understand the underlying antiferromagnetic switching mechanism. Surprisingly, we find that for ultrathin CoO/Pt bilayers electrical pulses along the same path can lead to an increase or decrease of the spin Hall magnetoresistance signal, depending on the current density of the pulse. By comparing these results to XMLD-PEEM imaging of the antiferromagnetic domain structure before and after the application of current pulses, we reveal the details of the reorientation of the Néel vector in ultrathin CoO(4 nm). This allows us to understand how opposite resistance changes can result from a thermomagnetoelastic switching mechanism. Importantly, our spatially resolved imaging shows that regions where the current pulses are applied and regions further away exhibit different switched spin structures, which can be explained by a spin-orbit torque-based switching mechanism that can dominate in very thin films.
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Affiliation(s)
- Christin Schmitt
- Institute
of Physics, Johannes Gutenberg University
Mainz, 55099 Mainz, Germany
| | - Adithya Rajan
- Institute
of Physics, Johannes Gutenberg University
Mainz, 55099 Mainz, Germany
| | - Grischa Beneke
- Institute
of Physics, Johannes Gutenberg University
Mainz, 55099 Mainz, Germany
| | - Aditya Kumar
- Institute
of Physics, Johannes Gutenberg University
Mainz, 55099 Mainz, Germany
| | - Tobias Sparmann
- Institute
of Physics, Johannes Gutenberg University
Mainz, 55099 Mainz, Germany
| | - Hendrik Meer
- Institute
of Physics, Johannes Gutenberg University
Mainz, 55099 Mainz, Germany
| | - Beatrice Bednarz
- Institute
of Physics, Johannes Gutenberg University
Mainz, 55099 Mainz, Germany
| | - Rafael Ramos
- WPI-Advanced
Institute for Materials Research, Tohoku
University, Sendai 980-8577, Japan
| | - Miguel Angel Niño
- ALBA
Synchrotron Light Facility, 08290 Cerdanyola del Valles (Barcelona), Spain
| | - Michael Foerster
- ALBA
Synchrotron Light Facility, 08290 Cerdanyola del Valles (Barcelona), 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
- The
Institute of AI and Beyond, The University
of Tokyo, Tokyo 113-8656, Japan
- Center
for
Spintronics Research Network, Tohoku University, Sendai 980-8577, Japan
- Department
of Applied Physics, The University of Tokyo, Tokyo 113-8656, Japan
| | - Mathias Kläui
- Institute
of Physics, Johannes Gutenberg University
Mainz, 55099 Mainz, Germany
- Graduate
School of Excellence Materials Science in Mainz, 55128 Mainz, Germany
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6
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Han L, Fu X, Peng R, Cheng X, Dai J, Liu L, Li Y, Zhang Y, Zhu W, Bai H, Zhou Y, Liang S, Chen C, Wang Q, Chen X, Yang L, Zhang Y, Song C, Liu J, Pan F. Electrical 180° switching of Néel vector in spin-splitting antiferromagnet. SCIENCE ADVANCES 2024; 10:eadn0479. [PMID: 38277463 PMCID: PMC10816707 DOI: 10.1126/sciadv.adn0479] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2023] [Accepted: 12/26/2023] [Indexed: 01/28/2024]
Abstract
Antiferromagnetic spintronics have attracted wide attention due to its great potential in constructing ultradense and ultrafast antiferromagnetic memory that suits modern high-performance information technology. The electrical 180° switching of Néel vector is a long-term goal for developing electrical-controllable antiferromagnetic memory with opposite Néel vectors as binary "0" and "1." However, the state-of-art antiferromagnetic switching mechanisms have long been limited for 90° or 120° switching of Néel vector, which unavoidably require multiple writing channels that contradict ultradense integration. Here, we propose a deterministic switching mechanism based on spin-orbit torque with asymmetric energy barrier and experimentally achieve electrical 180° switching of spin-splitting antiferromagnet Mn5Si3. Such a 180° switching is read out by the Néel vector-induced anomalous Hall effect. On the basis of our writing and readout methods, we fabricate an antiferromagnet device with electrical-controllable high- and low-resistance states that accomplishes robust write and read cycles. Besides fundamental advance, our work promotes practical spin-splitting antiferromagnetic devices based on spin-splitting antiferromagnet.
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Affiliation(s)
- Lei Han
- Key Laboratory of Advanced Materials (MOE), School of Materials Science and Engineering, Tsinghua University, Beijing 100084, China
| | - Xizhi Fu
- Department of Physics, Hong Kong University of Science and Technology, Hong Kong 999077, China
| | - Rui Peng
- Department of Physics, Hong Kong University of Science and Technology, Hong Kong 999077, China
| | - Xingkai Cheng
- Department of Physics, Hong Kong University of Science and Technology, Hong Kong 999077, China
| | - Jiankun Dai
- Key Laboratory of Advanced Materials (MOE), School of Materials Science and Engineering, Tsinghua University, Beijing 100084, China
| | - Liangyang Liu
- State Key Laboratory of Low Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084, China
| | - Yidian Li
- State Key Laboratory of Low Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084, China
| | - Yichi Zhang
- Key Laboratory of Advanced Materials (MOE), School of Materials Science and Engineering, Tsinghua University, Beijing 100084, China
| | - Wenxuan Zhu
- Key Laboratory of Advanced Materials (MOE), School of Materials Science and Engineering, Tsinghua University, Beijing 100084, China
| | - Hua Bai
- Key Laboratory of Advanced Materials (MOE), School of Materials Science and Engineering, Tsinghua University, Beijing 100084, China
| | - Yongjian Zhou
- Key Laboratory of Advanced Materials (MOE), School of Materials Science and Engineering, Tsinghua University, Beijing 100084, China
| | - Shixuan Liang
- Key Laboratory of Advanced Materials (MOE), School of Materials Science and Engineering, Tsinghua University, Beijing 100084, China
| | - Chong Chen
- Key Laboratory of Advanced Materials (MOE), School of Materials Science and Engineering, Tsinghua University, Beijing 100084, China
| | - Qian Wang
- Key Laboratory of Advanced Materials (MOE), School of Materials Science and Engineering, Tsinghua University, Beijing 100084, China
| | - Xianzhe Chen
- Key Laboratory of Advanced Materials (MOE), School of Materials Science and Engineering, Tsinghua University, Beijing 100084, China
| | - Luyi Yang
- State Key Laboratory of Low Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084, China
- Frontier Science Center for Quantum Information, Beijing 100084, China
- Collaborative Innovation Center of Quantum Matter, Beijing 100084, China
| | - Yang Zhang
- Department of Physics and Astronomy, University of Tennessee, Knoxville, TN 37996, USA
- Min H. Kao Department of Electrical Engineering and Computer Science, University of Tennessee, Knoxville, TN 37996, USA
| | - Cheng Song
- Key Laboratory of Advanced Materials (MOE), School of Materials Science and Engineering, Tsinghua University, Beijing 100084, China
| | - Junwei Liu
- Department of Physics, Hong Kong University of Science and Technology, Hong Kong 999077, China
| | - Feng Pan
- Key Laboratory of Advanced Materials (MOE), School of Materials Science and Engineering, Tsinghua University, Beijing 100084, China
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7
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Zhou Y, Guo T, Han L, Liao L, He W, Wan C, Chen C, Wang Q, Qiao L, Bai H, Zhu W, Zhang Y, Chen R, Han X, Pan F, Song C. Spin-torque-driven antiferromagnetic resonance. SCIENCE ADVANCES 2024; 10:eadk7935. [PMID: 38215195 PMCID: PMC10786412 DOI: 10.1126/sciadv.adk7935] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2023] [Accepted: 12/14/2023] [Indexed: 01/14/2024]
Abstract
The intrinsic fast dynamics make antiferromagnetic spintronics a promising avenue for faster data processing. Ultrafast antiferromagnetic resonance-generated spin current provides valuable access to antiferromagnetic spin dynamics. However, the inverse effect, spin-torque-driven antiferromagnetic resonance (ST-AFMR), which is attractive for practical utilization of fast devices but seriously impeded by difficulties in controlling and detecting Néel vectors, remains elusive. We observe ST-AFMR in Y3Fe5O12/α-Fe2O3/Pt at room temperature. The Néel vector oscillates and contributes to voltage signal owing to antiferromagnetic negative spin Hall magnetoresistance-induced spin rectification effect, which has the opposite sign to ferromagnets. The Néel vector in antiferromagnetic α-Fe2O3 is strongly coupled to the magnetization in Y3Fe5O12 buffer, resulting in the convenient control of Néel vectors. ST-AFMR experiment is bolstered by micromagnetic simulations, where both the Néel vector and the canted moment of α-Fe2O3 are in elliptic resonance. These findings shed light on the spin current-induced dynamics in antiferromagnets and represent a step toward electrically controlled antiferromagnetic terahertz emitters.
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Affiliation(s)
- Yongjian Zhou
- Key Laboratory of Advanced Materials (MOE), School of Materials Science and Engineering, Tsinghua University, Beijing 100084, P. R. China
| | - Tingwen Guo
- Key Laboratory of Advanced Materials (MOE), School of Materials Science and Engineering, Tsinghua University, Beijing 100084, P. R. China
- LSI, CEA/DRF/IRAMIS, CNRS, Ecole Polytechnique, Institut Polytechnique de Paris, F-91128 Palaiseau, France
| | - Lei Han
- Key Laboratory of Advanced Materials (MOE), School of Materials Science and Engineering, Tsinghua University, Beijing 100084, P. R. China
| | - Liyang Liao
- Key Laboratory of Advanced Materials (MOE), School of Materials Science and Engineering, Tsinghua University, Beijing 100084, P. R. China
| | - Wenqing He
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, P. R. China
| | - Caihua Wan
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, P. R. China
| | - Chong Chen
- Key Laboratory of Advanced Materials (MOE), School of Materials Science and Engineering, Tsinghua University, Beijing 100084, P. R. China
| | - Qian Wang
- Key Laboratory of Advanced Materials (MOE), School of Materials Science and Engineering, Tsinghua University, Beijing 100084, P. R. China
| | - Leilei Qiao
- Key Laboratory of Advanced Materials (MOE), School of Materials Science and Engineering, Tsinghua University, Beijing 100084, P. R. China
| | - Hua Bai
- Key Laboratory of Advanced Materials (MOE), School of Materials Science and Engineering, Tsinghua University, Beijing 100084, P. R. China
| | - Wenxuan Zhu
- Key Laboratory of Advanced Materials (MOE), School of Materials Science and Engineering, Tsinghua University, Beijing 100084, P. R. China
| | - Yichi Zhang
- Key Laboratory of Advanced Materials (MOE), School of Materials Science and Engineering, Tsinghua University, Beijing 100084, P. R. China
| | - Ruyi Chen
- Key Laboratory of Advanced Materials (MOE), School of Materials Science and Engineering, Tsinghua University, Beijing 100084, P. R. China
| | - Xiufeng Han
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, P. R. China
| | - Feng Pan
- Key Laboratory of Advanced Materials (MOE), School of Materials Science and Engineering, Tsinghua University, Beijing 100084, P. R. China
| | - Cheng Song
- Key Laboratory of Advanced Materials (MOE), School of Materials Science and Engineering, Tsinghua University, Beijing 100084, P. R. China
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8
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Ren L, Liu L, Song X, Zhao T, Xing X, Feng YP, Chen J, Teo KL. Manipulation of the Topological Ferromagnetic State in a Weyl Semimetal by Spin-Orbit Torque. NANO LETTERS 2023; 23:3394-3400. [PMID: 37043331 DOI: 10.1021/acs.nanolett.3c00410] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
Magnetic Weyl semimetals (MWSMs) exhibit unconventional transport phenomena, such as large anomalous Hall (and Nernst) effects, which are absent in spatial inversion asymmetry WSMs. Compared with its nonmagnetic counterpart, the magnetic state of a MWSM provides an alternative way for the modulation of topology. Spin-orbit torque (SOT), as an effective means of electrically controlling the magnetic states of ferromagnets, may be used to manipulate the topological magnetic states of MWSMs. Here we confirm the MWSM state of high-quality Co2MnGa film by systematically investigating the transport measurements and demonstrating that the magnetization and topology of Co2MnGa can be electrically manipulated. The electrical and magnetic optical measurements further reveal that the current-induced SOT switches the topological magnetic state in a 180-degree manner by applying positive/negative current pulses and in a 90-degree manner by alternately applying two orthogonal current pulses. This work opens up more opportunities for spintronic applications based on topological materials.
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Affiliation(s)
- Lizhu Ren
- Department of Electrical and Computer Engineering, National University of Singapore, 117576, Singapore
| | - Liang Liu
- Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240, China
- Department of Materials Science and Engineering, National University of Singapore, 117575, Singapore
| | - Xiaohe Song
- Integrative Sciences and Engineering Programme, NUS Graduate School, National University of Singapore, 119077, Singapore
- Department of Physics, National University of Singapore, 117551, Singapore
| | - Tieyang Zhao
- Department of Materials Science and Engineering, National University of Singapore, 117575, Singapore
| | - Xiangjun Xing
- School of Physics and Optoelectronic Engineering, Guangdong University of Technology, Guangzhou 510006, China
| | - Yuan Ping Feng
- Department of Physics, National University of Singapore, 117551, Singapore
| | - Jingsheng Chen
- Department of Materials Science and Engineering, National University of Singapore, 117575, Singapore
| | - Kie Leong Teo
- Department of Electrical and Computer Engineering, National University of Singapore, 117576, Singapore
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9
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Qiu H, Seifert TS, Huang L, Zhou Y, Kašpar Z, Zhang C, Wu J, Fan K, Zhang Q, Wu D, Kampfrath T, Song C, Jin B, Chen J, Wu P. Terahertz Spin Current Dynamics in Antiferromagnetic Hematite. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2023:e2300512. [PMID: 37083225 DOI: 10.1002/advs.202300512] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Revised: 03/10/2023] [Indexed: 05/03/2023]
Abstract
An important vision of modern magnetic research is to use antiferromagnets (AFMs) as controllable and active ultrafast components in spintronic devices. Hematite (α-Fe2 O3 ) is a promising model material in this respect because its pronounced Dzyaloshinskii-Moriya interaction leads to the coexistence of antiferromagnetism and weak ferromagnetism. Here, femtosecond laser pulses are used to drive terahertz (THz) spin currents from α-Fe2 O3 into an adjacent Pt layer. Two contributions to the generation of the spin current with distinctly different dynamics are found: the impulsive stimulated Raman scatting that relies on the AFM order and the ultrafast spin Seebeck effect that relies on the net magnetization. The total THz spin current dynamics can be manipulated by a medium-strength magnetic field below 1 T. The control of the THz spin current achieved in α-Fe2 O3 opens the pathway toward tailoring the exact spin current dynamics from ultrafast AFM spin sources.
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Affiliation(s)
- Hongsong Qiu
- Research Institute of Superconductor Electronics (RISE), School of Electronic Science and Engineering, Nanjing University, Nanjing, 210023, P. R. China
| | - Tom S Seifert
- Department of Physics, Freie Universität Berlin, 14195, Berlin, Germany
| | - Lin Huang
- Key Laboratory of Advanced Materials (MOE), School of Materials Science and Engineering, Tsinghua University, Beijing, 100084, P. R. China
| | - Yongjian Zhou
- Key Laboratory of Advanced Materials (MOE), School of Materials Science and Engineering, Tsinghua University, Beijing, 100084, P. R. China
| | - Zdeněk Kašpar
- Department of Physics, Freie Universität Berlin, 14195, Berlin, Germany
| | - Caihong Zhang
- Research Institute of Superconductor Electronics (RISE), School of Electronic Science and Engineering, Nanjing University, Nanjing, 210023, P. R. China
| | - Jingbo Wu
- Research Institute of Superconductor Electronics (RISE), School of Electronic Science and Engineering, Nanjing University, Nanjing, 210023, P. R. China
| | - Kebin Fan
- Research Institute of Superconductor Electronics (RISE), School of Electronic Science and Engineering, Nanjing University, Nanjing, 210023, P. R. China
| | - Qi Zhang
- Department of Physics, Nanjing University, Nanjing, 210023, P. R. China
| | - Di Wu
- National Laboratory of Solid State Microstructures, Jiangsu Provincial Key Laboratory for Nanotechnology, Collaborative Innovation Center of Advanced Microstructures and Department of Physics, Nanjing University, Nanjing, 210023, P. R. China
| | - Tobias Kampfrath
- Department of Physics, Freie Universität Berlin, 14195, Berlin, Germany
| | - Cheng Song
- Key Laboratory of Advanced Materials (MOE), School of Materials Science and Engineering, Tsinghua University, Beijing, 100084, P. R. China
| | - Biaobing Jin
- Research Institute of Superconductor Electronics (RISE), School of Electronic Science and Engineering, Nanjing University, Nanjing, 210023, P. R. China
| | - Jian Chen
- Research Institute of Superconductor Electronics (RISE), School of Electronic Science and Engineering, Nanjing University, Nanjing, 210023, P. R. China
| | - Peiheng Wu
- Research Institute of Superconductor Electronics (RISE), School of Electronic Science and Engineering, Nanjing University, Nanjing, 210023, P. R. China
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10
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Cheng Y, Tang J, Michel JJ, Chong SK, Yang F, Cheng R, Wang KL. Unidirectional Spin Hall Magnetoresistance in Antiferromagnetic Heterostructures. PHYSICAL REVIEW LETTERS 2023; 130:086703. [PMID: 36898091 DOI: 10.1103/physrevlett.130.086703] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Accepted: 01/31/2023] [Indexed: 06/18/2023]
Abstract
Unidirectional spin Hall magnetoresistance (USMR) has been widely reported in the heavy metal/ferromagnet bilayer systems. We observe the USMR in Pt/α-Fe_{2}O_{3} bilayers where the α-Fe_{2}O_{3} is an antiferromagnetic (AFM) insulator. Systematic field and temperature dependent measurements confirm the magnonic origin of the USMR. The appearance of AFM-USMR is driven by the imbalance of creation and annihilation of AFM magnons by spin orbit torque due to the thermal random field. However, unlike its ferromagnetic counterpart, theoretical modeling reveals that the USMR in Pt/α-Fe_{2}O_{3} is determined by the antiferromagtic magnon number with a non-monotonic field dependence. Our findings extend the generality of the USMR which pave the ways for the highly sensitive detection of AFM spin state.
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Affiliation(s)
- Yang Cheng
- Department of Electrical and Computer Engineering, and Department of Physics and Astronomy, University of California, Los Angeles, California 90095, USA
| | - Junyu Tang
- Department of Physics and Astronomy, University of California, Riverside, California 92521, USA
| | - Justin J Michel
- Department of Physics, The Ohio State University, Columbus, Ohio 43210, USA
| | - Su Kong Chong
- Department of Electrical and Computer Engineering, and Department of Physics and Astronomy, University of California, Los Angeles, California 90095, USA
| | - Fengyuan Yang
- Department of Physics, The Ohio State University, Columbus, Ohio 43210, USA
| | - Ran Cheng
- Department of Physics and Astronomy, University of California, Riverside, California 92521, USA
- Department of Electrical and Computer Engineering, University of California, Riverside, California 92521, USA
| | - Kang L Wang
- Department of Electrical and Computer Engineering, and Department of Physics and Astronomy, University of California, Los Angeles, California 90095, USA
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11
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Deng Y, Liu X, Chen Y, Du Z, Jiang N, Shen C, Zhang E, Zheng H, Lu HZ, Wang K. All-electrical switching of a topological non-collinear antiferromagnet at room temperature. Natl Sci Rev 2023; 10:nwac154. [PMID: 36872930 PMCID: PMC9977383 DOI: 10.1093/nsr/nwac154] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Accepted: 07/31/2022] [Indexed: 11/14/2022] Open
Abstract
Non-collinear antiferromagnetic Weyl semimetals, combining the advantages of a zero stray field and ultrafast spin dynamics, as well as a large anomalous Hall effect and the chiral anomaly of Weyl fermions, have attracted extensive interest. However, the all-electrical control of such systems at room temperature, a crucial step toward practical application, has not been reported. Here, using a small writing current density of around 5 × 106 A·cm-2, we realize the all-electrical current-induced deterministic switching of the non-collinear antiferromagnet Mn3Sn, with a strong readout signal at room temperature in the Si/SiO2/Mn3Sn/AlOx structure, and without external magnetic field or injected spin current. Our simulations reveal that the switching originates from the current-induced intrinsic non-collinear spin-orbit torques in Mn3Sn itself. Our findings pave the way for the development of topological antiferromagnetic spintronics.
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Affiliation(s)
- Yongcheng Deng
- State Key Laboratory for Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China.,Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xionghua Liu
- State Key Laboratory for Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China.,Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yiyuan Chen
- Institute for Quantum Science and Engineering and Department of Physics, Southern University of Science and Technology (SUSTech), Shenzhen 518055, China.,International Quantum Academy, Shenzhen 518048, China
| | - Zongzheng Du
- Institute for Quantum Science and Engineering and Department of Physics, Southern University of Science and Technology (SUSTech), Shenzhen 518055, China.,International Quantum Academy, Shenzhen 518048, China
| | - Nai Jiang
- State Key Laboratory for Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China.,Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Chao Shen
- State Key Laboratory for Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China.,Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Enze Zhang
- State Key Laboratory for Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China.,Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Houzhi Zheng
- State Key Laboratory for Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China.,Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Hai-Zhou Lu
- Institute for Quantum Science and Engineering and Department of Physics, Southern University of Science and Technology (SUSTech), Shenzhen 518055, China.,International Quantum Academy, Shenzhen 518048, China
| | - Kaiyou Wang
- State Key Laboratory for Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China.,Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China.,Beijing Academy of Quantum Information Sciences, Beijing 100193, China.,Center for Excellence in Topological Quantum Computation, University of Chinese Academy of Sciences, Beijing 100049, China
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12
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Cheng J, Miao BF, Liu Z, Yang M, He K, Zeng YL, Niu H, Yang X, Wang ZQ, Hong XH, Fu SJ, Sun L, Liu Y, Wu YZ, Yuan Z, Ding HF. Coherent Picture on the Pure Spin Transport between Ag/Bi and Ferromagnets. PHYSICAL REVIEW LETTERS 2022; 129:097203. [PMID: 36083669 DOI: 10.1103/physrevlett.129.097203] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Accepted: 07/26/2022] [Indexed: 06/15/2023]
Abstract
In a joint effort of both experiments and first-principles calculations, we resolve a hotly debated controversy and provide a coherent picture on the pure spin transport between Ag/Bi and ferromagnets. We demonstrate a strong inverse Rashba-Edelstein effect (IREE) at the interface in between Ag/Bi with a ferromagnetic metal (FM) but not with a ferromagnetic insulator. This is in sharp contrast to the previously claimed IREE at Ag/Bi interface or inverse spin Hall effect dominated spin transport. A more than one order of magnitude modulation of IREE signal is realized for different Ag/Bi-FM interfaces, casting strong tunability and a new direction for searching efficient spintronics materials.
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Affiliation(s)
- J Cheng
- National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing 210093, People's Republic of China
| | - B F Miao
- National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing 210093, People's Republic of China
- Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, People's Republic of China
| | - Z Liu
- Center for Advanced Quantum Studies and Department of Physics, Beijing Normal University, Beijing 100875, People's Republic of China
| | - M Yang
- National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing 210093, People's Republic of China
| | - K He
- National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing 210093, People's Republic of China
| | - Y L Zeng
- National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing 210093, People's Republic of China
| | - H Niu
- National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing 210093, People's Republic of China
| | - X Yang
- National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing 210093, People's Republic of China
| | - Z Q Wang
- National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing 210093, People's Republic of China
| | - X H Hong
- National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing 210093, People's Republic of China
| | - S J Fu
- National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing 210093, People's Republic of China
| | - L Sun
- National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing 210093, People's Republic of China
- Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, People's Republic of China
| | - Y Liu
- Center for Advanced Quantum Studies and Department of Physics, Beijing Normal University, Beijing 100875, People's Republic of China
| | - Y Z Wu
- Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, People's Republic of China
- Department of Physics, Fudan University, 220 Handan Road, Shanghai 200433, People's Republic of China
| | - Z Yuan
- Center for Advanced Quantum Studies and Department of Physics, Beijing Normal University, Beijing 100875, People's Republic of China
| | - H F Ding
- National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing 210093, People's Republic of China
- Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, People's Republic of China
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13
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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. PHYSICAL REVIEW LETTERS 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] [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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14
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Third harmonic characterization of antiferromagnetic heterostructures. Nat Commun 2022; 13:3659. [PMID: 35760929 PMCID: PMC9237044 DOI: 10.1038/s41467-022-31451-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [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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15
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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. SCIENCE ADVANCES 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] [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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16
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Cogulu E, Zhang H, Statuto NN, Cheng Y, Yang F, Cheng R, Kent AD. Quantifying Spin-Orbit Torques in Antiferromagnet-Heavy-Metal Heterostructures. PHYSICAL REVIEW LETTERS 2022; 128:247204. [PMID: 35776458 DOI: 10.1103/physrevlett.128.247204] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Accepted: 06/02/2022] [Indexed: 06/15/2023]
Abstract
The effect of spin currents on the magnetic order of insulating antiferromagnets (AFMs) is of fundamental interest and can enable new applications. Toward this goal, characterizing the spin-orbit torques (SOTs) associated with AFM-heavy-metal (HM) interfaces is important. Here we report the full angular dependence of the harmonic Hall voltages in a predominantly easy-plane AFM, epitaxial c-axis oriented α-Fe_{2}O_{3} films, with an interface to Pt. By modeling the harmonic Hall signals together with the α-Fe_{2}O_{3} magnetic parameters, we determine the amplitudes of fieldlike and dampinglike SOTs. Out-of-plane field scans are shown to be essential to determining the dampinglike component of the torques. In contrast to ferromagnetic-heavy-metal heterostructures, our results demonstrate that the fieldlike torques are significantly larger than the dampinglike torques, which we correlate with the presence of a large imaginary component of the interface spin-mixing conductance. Our work demonstrates a direct way of characterizing SOTs in AFM-HM heterostructures.
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Affiliation(s)
- Egecan Cogulu
- Center for Quantum Phenomena, Department of Physics, New York University, New York 10003, USA
| | - Hantao Zhang
- Department of Electrical and Computer Engineering, University of California, Riverside, California 92521, USA
| | - Nahuel N Statuto
- Center for Quantum Phenomena, Department of Physics, New York University, New York 10003, USA
| | - Yang Cheng
- Department of Physics, The Ohio State University, Columbus, Ohio 43210, USA
| | - Fengyuan Yang
- Department of Physics, The Ohio State University, Columbus, Ohio 43210, USA
| | - Ran Cheng
- Department of Electrical and Computer Engineering, University of California, Riverside, California 92521, USA
- Department of Physics and Astronomy, University of California, Riverside, California 92521, USA
| | - Andrew D Kent
- Center for Quantum Phenomena, Department of Physics, New York University, New York 10003, USA
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17
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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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
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18
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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. PHYSICAL REVIEW LETTERS 2022; 128:137201. [PMID: 35426702 DOI: 10.1103/physrevlett.128.137201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [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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19
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Current-induced Néel order switching facilitated by magnetic phase transition. Nat Commun 2022; 13:1629. [PMID: 35347132 PMCID: PMC8960908 DOI: 10.1038/s41467-022-29170-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [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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20
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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. SCIENCE ADVANCES 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] [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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21
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Wang H, Xiao Y, Guo M, Lee-Wong E, Yan GQ, Cheng R, Du CR. Spin Pumping of an Easy-Plane Antiferromagnet Enhanced by Dzyaloshinskii-Moriya Interaction. PHYSICAL REVIEW LETTERS 2021; 127:117202. [PMID: 34558931 DOI: 10.1103/physrevlett.127.117202] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Revised: 04/05/2021] [Accepted: 08/02/2021] [Indexed: 06/13/2023]
Abstract
Recently, antiferromagnets have received revived interest due to their significant potential for developing next-generation ultrafast magnetic storage. Here, we report dc spin pumping by the acoustic resonant mode in a canted easy-plane antiferromagnet α-Fe_{2}O_{3} enabled by the Dzyaloshinskii-Moriya interaction. Systematic angle and frequency-dependent measurements demonstrate that the observed spin-pumping signals arise from resonance-induced spin injection and inverse spin Hall effect in α-Fe_{2}O_{3}-metal heterostructures, mimicking the behavior of spin pumping in conventional ferromagnet-nonmagnet systems. The pure spin current nature is further corroborated by reversal of the polarity of spin-pumping signals when the spin detector is switched from platinum to tungsten which has an opposite sign of the spin Hall angle. Our results reveal the intriguing physics underlying the low-frequency spin dynamics and transport in canted easy-plane antiferromagnet-based heterostructures.
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Affiliation(s)
- Hailong Wang
- Center for Memory and Recording Research, University of California, San Diego, La Jolla, California 92093, USA
| | - Yuxuan Xiao
- Center for Memory and Recording Research, University of California, San Diego, La Jolla, California 92093, USA
| | - Mingda Guo
- Department of Physics and Astronomy, University of California, Riverside, California 92521, USA
| | - Eric Lee-Wong
- Department of Physics, University of California, San Diego, La Jolla, California 92093, USA
| | - Gerald Q Yan
- Department of Physics, University of California, San Diego, La Jolla, California 92093, USA
| | - Ran Cheng
- Department of Physics and Astronomy, University of California, Riverside, California 92521, USA
- Department of Electrical and Computer Engineering, University of California, Riverside, California 92521, USA
| | - Chunhui Rita Du
- Center for Memory and Recording Research, University of California, San Diego, La Jolla, California 92093, USA
- Department of Physics, University of California, San Diego, La Jolla, California 92093, USA
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22
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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 APPLIED MATERIALS & 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] [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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23
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Kim H, Je S, Moon K, Choi W, Yang S, Kim C, Tran BX, Hwang C, Hong J. Programmable Dynamics of Exchange-Biased Domain Wall via Spin-Current-Induced Antiferromagnet Switching. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2021; 8:e2100908. [PMID: 34263557 PMCID: PMC8425944 DOI: 10.1002/advs.202100908] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Revised: 05/12/2021] [Indexed: 06/13/2023]
Abstract
Magnetic domain wall (DW) motion in perpendicularly magnetized materials is drawing increased attention due to the prospect of new type of information storage devices, such as racetrack memory. To augment the functionalities of DW motion-based devices, it is essential to improve controllability over the DW motion. Other than electric current, which is known to induce unidirectional shifting of a train of DWs, an application of in-plane magnetic field also enables the control of DW dynamics by rotating the DW magnetization and consequently modulating the inherited chiral DW structure. Applying an external bias field, however, is not a viable approach for the miniaturization of the devices as the external field acts globally. Here, the programmable exchange-coupled DW motion in the antiferromagnet (AFM)/ferromagnet (FM) system is demonstrated, where the role of an external in-plane field is replaced by the exchange bias field from AFM layer, enabling the external field-free modulations of DW motions. Interestingly, the direction of the exchange bias field can also be reconfigured by simply injecting spin currents through the device, enabling electrical and programmable operations of the device. Furthermore, the result inspires a prototype DW motion-based device based on the AFM/FM heterostructure, that could be easily integrated in logic devices.
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Affiliation(s)
- Hyun‐Joong Kim
- Quantum Technology InstituteKorea Research Institute of Standards and Science (KRISS)267 Gajeong‐roDaejeon34113Republic of Korea
- Department of Emerging Materials ScienceDaegu Gyeongbuk Institute of Science and Technology (DGIST)333 Techno jungang‐daeroDaegu42988Republic of Korea
| | - Soong‐Geun Je
- Department of PhysicsChonnam National University77 Yongbong‐roGwangju61186Republic of Korea
| | - Kyoung‐Woong Moon
- Quantum Technology InstituteKorea Research Institute of Standards and Science (KRISS)267 Gajeong‐roDaejeon34113Republic of Korea
| | - Won‐Chang Choi
- Department of Emerging Materials ScienceDaegu Gyeongbuk Institute of Science and Technology (DGIST)333 Techno jungang‐daeroDaegu42988Republic of Korea
| | - Seungmo Yang
- Quantum Technology InstituteKorea Research Institute of Standards and Science (KRISS)267 Gajeong‐roDaejeon34113Republic of Korea
| | - Changsoo Kim
- Quantum Technology InstituteKorea Research Institute of Standards and Science (KRISS)267 Gajeong‐roDaejeon34113Republic of Korea
| | - Bao Xuan Tran
- Department of Emerging Materials ScienceDaegu Gyeongbuk Institute of Science and Technology (DGIST)333 Techno jungang‐daeroDaegu42988Republic of Korea
| | - Chanyong Hwang
- Quantum Technology InstituteKorea Research Institute of Standards and Science (KRISS)267 Gajeong‐roDaejeon34113Republic of Korea
| | - Jung‐Il Hong
- Department of Emerging Materials ScienceDaegu Gyeongbuk Institute of Science and Technology (DGIST)333 Techno jungang‐daeroDaegu42988Republic of Korea
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24
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Observation of current-induced switching in non-collinear antiferromagnetic IrMn 3 by differential voltage measurements. Nat Commun 2021; 12:3828. [PMID: 34158511 PMCID: PMC8219769 DOI: 10.1038/s41467-021-24237-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [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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25
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Reversible hydrogen control of antiferromagnetic anisotropy in α-Fe 2O 3. Nat Commun 2021; 12:1668. [PMID: 33712582 PMCID: PMC7954816 DOI: 10.1038/s41467-021-21807-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Accepted: 02/04/2021] [Indexed: 11/14/2022] Open
Abstract
Antiferromagnetic insulators are a ubiquitous class of magnetic materials, holding the promise of low-dissipation spin-based computing devices that can display ultra-fast switching and are robust against stray fields. However, their imperviousness to magnetic fields also makes them difficult to control in a reversible and scalable manner. Here we demonstrate a novel proof-of-principle ionic approach to control the spin reorientation (Morin) transition reversibly in the common antiferromagnetic insulator α-Fe2O3 (haematite) – now an emerging spintronic material that hosts topological antiferromagnetic spin-textures and long magnon-diffusion lengths. We use a low-temperature catalytic-spillover process involving the post-growth incorporation or removal of hydrogen from α-Fe2O3 thin films. Hydrogenation drives pronounced changes in its magnetic anisotropy, Néel vector orientation and canted magnetism via electron injection and local distortions. We explain these effects with a detailed magnetic anisotropy model and first-principles calculations. Tailoring our work for future applications, we demonstrate reversible control of the room-temperature spin-state by doping/expelling hydrogen in Rh-substituted α-Fe2O3. One major challenge for antiferromagnetic spintronics is how to control the antiferromagnetic state. Here Jani et al. demonstrate the reversible ionic control of the room-temperature magnetic anisotropy and spin reorientation transition in haematite, via the incorporation and removal of hydrogen.
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26
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Antiferromagnetic half-skyrmions and bimerons at room temperature. Nature 2021; 590:74-79. [PMID: 33536652 DOI: 10.1038/s41586-021-03219-6] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Accepted: 11/16/2020] [Indexed: 01/30/2023]
Abstract
In the quest for post-CMOS (complementary metal-oxide-semiconductor) technologies, driven by the need for improved efficiency and performance, topologically protected ferromagnetic 'whirls' such as skyrmions1-8 and their anti-particles have shown great promise as solitonic information carriers in racetrack memory-in-logic or neuromorphic devices1,9-11. However, the presence of dipolar fields in ferromagnets, which restricts the formation of ultrasmall topological textures3,6,8,9,12, and the deleterious skyrmion Hall effect, when skyrmions are driven by spin torques9,10,12, have thus far inhibited their practical implementation. Antiferromagnetic analogues, which are predicted to demonstrate relativistic dynamics, fast deflection-free motion and size scaling, have recently become the subject of intense focus9,13-19, but they have yet to be experimentally demonstrated in natural antiferromagnetic systems. Here we realize a family of topological antiferromagnetic spin textures in α-Fe2O3-an Earth-abundant oxide insulator-capped with a platinum overlayer. By exploiting a first-order analogue of the Kibble-Zurek mechanism20,21, we stabilize exotic merons and antimerons (half-skyrmions)8 and their pairs (bimerons)16,22, which can be erased by magnetic fields and regenerated by temperature cycling. These structures have characteristic sizes of the order of 100 nanometres and can be chemically controlled via precise tuning of the exchange and anisotropy, with pathways through which further scaling may be achieved. Driven by current-based spin torques from the heavy-metal overlayer, some of these antiferromagnetic textures could emerge as prime candidates for low-energy antiferromagnetic spintronics at room temperature1,9-11,23.
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27
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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: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [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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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 APPLIED MATERIALS & 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] [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. PHYSICAL REVIEW LETTERS 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] [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. NATURE NANOTECHNOLOGY 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] [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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