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Zhang Q, Tao K, Jia C, Xu G, Chai G, Zuo Y, Cui B, Yang D, Xue D, Xi L. Large unidirectional spin Hall magnetoresistance in FeNi/Pt/Bi 2Se 3 trilayers by Pt interfacial engineering. Nat Commun 2024; 15:9450. [PMID: 39487155 PMCID: PMC11530670 DOI: 10.1038/s41467-024-53884-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2024] [Accepted: 10/25/2024] [Indexed: 11/04/2024] Open
Abstract
Unidirectional spin Hall magnetoresistance (USMR) has emerged as a promising candidate for magnetoresistive random-access memory (MRAM) technology. However, the realization of high signal-to-noise output signal in USMR devices has remained a challenge, primarily due to the limited USMR effect at room temperature. In this study, we report a large USMR effect in FeNi/Pt/Bi₂Se₃ trilayers through interfacial engineering with Pt to optimize the spin current transmission efficiency and electron-magnon scattering. Our devices exhibit a USMR value that is an order of magnitude higher than previously reported systems, reaching 30.6 ppm/MA/cm² at room temperature. First-principles calculations and experimental observations suggest that the Pt layer not only preserves the spin-momentum locked topological surface states in Bi₂Se₃ at the Fermi-level but also generates additional Rashba surface states within the Pt itself to enhance the effective SOT efficiency. Furthermore, we demonstrate that the two-terminal USMR-MRAM devices show robust output performance with 2nd harmonic resistance variation around 0.11 Ω/mA. Remarkably, the performance of these devices further improves at elevated temperatures, highlighting their potential for reliable operation in a wide range of environmental conditions. Our findings pave the way for future advancements in high-performance, energy-efficient spintronic memory devices.
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Affiliation(s)
- Qi Zhang
- Key Laboratory for Magnetism and Magnetic Materials of Ministry of Education, School of Physical Science and Technology, Lanzhou University, Lanzhou, PR China
| | - Kun Tao
- Key Laboratory for Magnetism and Magnetic Materials of Ministry of Education, School of Physical Science and Technology, Lanzhou University, Lanzhou, PR China
| | - Chenglong Jia
- Key Laboratory for Magnetism and Magnetic Materials of Ministry of Education, School of Physical Science and Technology, Lanzhou University, Lanzhou, PR China
| | - Guofu Xu
- Key Laboratory for Magnetism and Magnetic Materials of Ministry of Education, School of Physical Science and Technology, Lanzhou University, Lanzhou, PR China
| | - Guozhi Chai
- Key Laboratory for Magnetism and Magnetic Materials of Ministry of Education, School of Physical Science and Technology, Lanzhou University, Lanzhou, PR China
| | - Yalu Zuo
- Key Laboratory for Magnetism and Magnetic Materials of Ministry of Education, School of Physical Science and Technology, Lanzhou University, Lanzhou, PR China
| | - Baoshan Cui
- Key Laboratory for Magnetism and Magnetic Materials of Ministry of Education, School of Physical Science and Technology, Lanzhou University, Lanzhou, PR China
| | - Dezheng Yang
- Key Laboratory for Magnetism and Magnetic Materials of Ministry of Education, School of Physical Science and Technology, Lanzhou University, Lanzhou, PR China
| | - Desheng Xue
- Key Laboratory for Magnetism and Magnetic Materials of Ministry of Education, School of Physical Science and Technology, Lanzhou University, Lanzhou, PR China.
| | - Li Xi
- Key Laboratory for Magnetism and Magnetic Materials of Ministry of Education, School of Physical Science and Technology, Lanzhou University, Lanzhou, PR China.
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Zheng Z, Gu Y, Zhang Z, Zhang X, Zhao T, Li H, Ren L, Jia L, Xiao R, Zhou HA, Zhang Q, Shi S, Zhang Y, Zhao C, Shen L, Zhao W, Chen J. Coexistence of Magnon-Induced and Rashba-Induced Unidirectional Magnetoresistance in Antiferromagnets. NANO LETTERS 2023. [PMID: 37418477 DOI: 10.1021/acs.nanolett.3c01082] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/09/2023]
Abstract
Unidirectional magnetoresistance (UMR) has been intensively studied in ferromagnetic systems, which is mainly induced by spin-dependent and spin-flip electron scattering. Yet, UMR in antiferromagnetic (AFM) systems has not been fully understood to date. In this work, we reported UMR in a YFeO3/Pt heterostructure where YFeO3 is a typical AFM insulator. Magnetic-field dependence and temperature dependence of transport measurements indicate that magnon dynamics and interfacial Rashba splitting are two individual origins for AFM UMR, which is consistent with the UMR theory in ferromagnetic systems. We further established a comprehensive theoretical model that incorporates micromagnetic simulation, density functional theory calculation, and the tight-binding model, which explain the observed AFM UMR phenomenon well. Our work sheds light on the intrinsic transport property of the AFM system and may facilitate the development of AFM spintronic devices.
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Affiliation(s)
- Zhenyi Zheng
- Department of Materials Science and Engineering, National University of Singapore, Singapore 117575, Singapore
| | - Youdi Gu
- Department of Materials Science and Engineering, National University of Singapore, Singapore 117575, Singapore
| | - Zhizhong Zhang
- MIIT Key Laboratory of Spintronics, School of Integrated Circuit Science and Engineering, Beihang University, Beijing 100191, China
| | - Xiwen Zhang
- Department of Mechanical Engineering, National University of Singapore, Singapore 117575, Singapore
| | - Tieyang Zhao
- Department of Materials Science and Engineering, National University of Singapore, Singapore 117575, Singapore
| | - Huihui Li
- Beijing Superstring Academy of Memory Technology, Beijing 100176, China
| | - Lizhu Ren
- Department of Electrical and Computer Engineering, National University of Singapore, Singapore 117575, Singapore
| | - Lanxin Jia
- Department of Materials Science and Engineering, National University of Singapore, Singapore 117575, Singapore
| | - Rui Xiao
- Department of Materials Science and Engineering, National University of Singapore, Singapore 117575, Singapore
| | - Heng-An Zhou
- Department of Materials Science and Engineering, National University of Singapore, Singapore 117575, Singapore
| | - Qihan Zhang
- Department of Materials Science and Engineering, National University of Singapore, Singapore 117575, Singapore
| | - Shu Shi
- Department of Materials Science and Engineering, National University of Singapore, Singapore 117575, Singapore
| | - Yue Zhang
- MIIT Key Laboratory of Spintronics, School of Integrated Circuit Science and Engineering, Beihang University, Beijing 100191, China
| | - Chao Zhao
- Beijing Superstring Academy of Memory Technology, Beijing 100176, China
| | - Lei Shen
- Department of Mechanical Engineering, National University of Singapore, Singapore 117575, Singapore
| | - Weisheng Zhao
- MIIT Key Laboratory of Spintronics, School of Integrated Circuit Science and Engineering, Beihang University, Beijing 100191, China
| | - Jingsheng Chen
- Department of Materials Science and Engineering, National University of Singapore, Singapore 117575, Singapore
- Chongqing Research Institute, National University of Singapore, Chongqing 401120, China
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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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Abstract
Fabrication of high quality ferrimagnetic insulators is an essential step for ultrafast magnonics, which utilizes antiferromagnetic exchange of the ferrimagnetic materials. In this work, we deposit high-quality GdIG thin films on a (111)-oriented GGG substrate using the Metal Organic Decomposition (MOD) method, a simple and high throughput method for depositing thin film materials. We postannealed samples at various temperatures and examined the effect on structural properties such as crystallinity and surface morphology. We found a transition in the growth mode that radically changes the morphology of the film as a function of annealing temperature and obtained an optimal annealing temperature for a uniform thin film with high crystallinity. Optimized GdIG has a high potential for spin wave applications with a low damping parameter in the order of 10−3, which persists down to cryogenic temperatures.
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