Article
Chemistry, Physical
Yongcheng Deng, Runze Li, Xionghua Liu
Summary: Research shows that even thin Mn3Sn films as thin as 20 nm exhibit a significant anomalous Hall effect, which varies depending on the relative crystalline structure of different thickness samples. Additionally, a phase diagram of the AHE in Mn3Sn films annealed at different temperatures with different thicknesses was obtained, and current-induced antiferromagnetic state switching was achieved in Mn3Sn (20 nm) / Pt (4 nm) samples. These findings could potentially advance the development of antiferromagnetic spintronics.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Materials Science, Multidisciplinary
Shaohai Chen, Xinyu Shu, Jing Zhou, Chenghang Zhou, Qidong Xie, Tieyang Zhao, Liang Liu, Weinan Lin, Jingsheng Chen
Summary: In this study, AFM Mn2Au films with different crystal structures were systematically investigated, and it was demonstrated that single-crystal Mn2Au possesses a significantly higher spin torque efficiency (xi(DL)) of approximately 0.333 compared to polycrystalline Mn2Au. Furthermore, the integration of interfacial effects in the single-crystal Mn2Au/Py system increased the effective xi(DL) to 0.731, more than two times larger than that reported for the Mn2Au/CoFeB system. This research highlights the potential of Mn2Au as an efficient SOT source and its application in future AFM material-based SOT integration technology.
SCIENCE CHINA-MATERIALS
(2021)
Article
Physics, Applied
Xupeng Zhao, Siwei Mao, Hailong Wang, Dahai Wei, Jianhua Zhao
Summary: This study reports spin-orbit torque-induced magnetization switching in L1(0)-MnGa/FeMn/Pt trilayers, utilizing an antiferromagnetic FeMn layer to achieve field-free spin-orbit torque switching. The research found that the spin transmission efficiency decreases monotonically with increasing FeMn thickness, with a peak in the damping-like spin-orbit torque efficiency at 1.5nm FeMn thickness. These results demonstrate the effectiveness of emerging spintronic devices containing antiferromagnetic elements.
APPLIED PHYSICS LETTERS
(2021)
Article
Chemistry, Multidisciplinary
Chuangtang Wang, Yihao Xu, Yongmin Liu
Summary: This study explores the generation and manipulation of spin currents through comprehensive investigation of helicity-driven optical spin-orbit torque in metal/ferromagnetic metal heterostructures. Experimental results demonstrate a tenfold enhancement in optical spin-orbit torque quantum efficiency for gold compared to platinum under visible laser pumping, and reveal the impact of photon energy-dependent spin transport in the system, providing insights for efficient spin transport.
ADVANCED FUNCTIONAL MATERIALS
(2023)
Article
Physics, Applied
Ke Tang, Zhenchao Wen, Yong-Chang Lau, Hiroaki Sukegawa, Takeshi Seki, Seiji Mitani
Summary: This study investigates magnetization switching induced by spin-orbit torque in Co2MnGa magnetic Weyl semimetal thin films, demonstrating a relatively large spin Hall efficiency and exploring various characteristics such as second harmonic signals, thickness dependence of spin Hall efficiency, and shift of anomalous Hall loops under applied currents. The research contributes to understanding mechanisms of spin-current generation and potential applications of magnetic WSMs in spintronic devices.
APPLIED PHYSICS LETTERS
(2021)
Article
Physics, Applied
Bharat Grover, Binoy Krishna Hazra, Tianping Ma, Banabir Pal, Nirel Bernstein, Amit Rothschild, Abhay Kant Srivastava, Samiran Choudhury, Georg Woltersdorf, Amir Capua, Stuart S. P. Parkin
Summary: In this study, the dependence of the spin Hall angle θSH was investigated in epitaxial Al2O3/Pt, MgO/Pt films using a spin-torque driven ferromagnetic resonance method. It was found that the electrical technique had limitations in accurately quantifying θSH at high current densities and could result in erroneous values, particularly for films with large inhomogeneous broadening. The study also revealed a strong dependence of θSH on the crystallographic direction.
APPLIED PHYSICS LETTERS
(2022)
Article
Physics, Applied
Longjie Yu, Shutaro Karube, Min Liu, Masakiyo Tsunoda, Mikihiko Oogane, Yasuo Ando
Summary: Non-collinear antiferromagnets possess topological spin structure, allowing for the manipulation of charge-spin conversion. In this study, we investigate the unconventional spin-orbit torque of L1(2)-ordered Mn3Pt with a triangular spin structure.
APPLIED PHYSICS EXPRESS
(2022)
Article
Multidisciplinary Sciences
Tomoya Higo, Kouta Kondou, Takuya Nomoto, Masanobu Shiga, Shoya Sakamoto, Xianzhe Chen, Daisuke Nishio-Hamane, Ryotaro Arita, Yoshichika Otani, Shinji Miwa, Satoru Nakatsuji
Summary: This study demonstrates the perpendicular and full spin-orbit torque switching of an antiferromagnetic binary state. The researchers use the chiral antiferromagnet Mn3Sn and fabricate heavy-metal/Mn3Sn heterostructures by molecular beam epitaxy. The experimental results show that the perpendicular octupole polarization in a 30-nanometre-thick Mn3Sn film can achieve 100% switching with a critical current density of less than 15 megaamperes per square centimetre. The study reveals the significance of the perpendicular geometry between the current-induced spin accumulation and the octupole polarization for spin-orbit torque efficiency.
Article
Nanoscience & Nanotechnology
Dequan Meng, Shiwei Chen, Chuantong Ren, Jiaxu Li, Guibin Lan, Chaozhong Li, Yong Liu, Yurong Su, Guoqiang Yu, Guozhi Chai, Rui Xiong, Weisheng Zhao, Guang Yang, Shiheng Liang
Summary: The study demonstrates deterministic perpendicular magnetization switching in Mn3Sn/CoTb bilayers by employing a textured Mn3Sn film as the spin source. It highlights the significant contribution of the out-of-plane polarized spin current (sigma z) generated from Mn3Sn to the spin-orbit torque (SOT) effect. This underscores the critical role of crystal quality and strain in controlling spin diffusion with different spin polarizations.
ADVANCED ELECTRONIC MATERIALS
(2023)
Article
Nanoscience & Nanotechnology
Yong-Chang Lau, Takeshi Seki, Koki Takanashi
Summary: This study presents a systematic comparative analysis of spin Hall efficiency in highly face-centered cubic (fcc) Pt-Al alloy films and poorly crystallized Pt-Al alloy films. The results indicate that fcc Pt100-xAlx alloy films grown on MgO exhibit outstanding charge-spin conversion efficiency, showing the potential for reducing power consumption compared to polycrystalline bilayers on SiO2. Improving the crystallinity of fcc Pt-based alloys is shown to be crucial for achieving large spin Hall efficiency and low power consumption.
Article
Chemistry, Multidisciplinary
Yuhan Liang, Dingsong Jiang, Yahong Chai, Yue Wang, Hetian Chen, Jing Ma, Pu Yu, Di Yi, Tianxiang Nan
Summary: In this study, we observed magnon spin transport through multiferroic BiFeO3 thin films in a spin pumping experiment at room temperature. The experimental results showed that the magnon spin transport efficiency is very high when the thickness of the BiFeO3 films exceeds 80 nm.
ADVANCED FUNCTIONAL MATERIALS
(2023)
Article
Physics, Applied
Yuta Kobayashi, Yoichi Shiota, Hideki Narita, Teruo Ono, Takahiro Moriyama
Summary: The study reveals that the Joule heating induced by voltage pulses can cause a magnetic phase transition in D0(19)-Mn3Sn, altering the energy landscape relevant to spin-orbit torque switching. This poses challenges in accurately determining the thermal stability factor and highlights the importance of cautious estimation.
APPLIED PHYSICS LETTERS
(2023)
Article
Multidisciplinary Sciences
Binoy K. Hazra, Banabir Pal, Jae-Chun Jeon, Robin R. Neumann, Boerge Goebel, Bharat Grover, Hakan Deniz, Andriy Styervoyedov, Holger Meyerheim, Ingrid Mertig, See-Hun Yang, Stuart S. P. Parkin
Summary: The generation of a robust spin current with both in-plane and out-of-plane spin polarization is demonstrated in epitaxial thin films of the chiral antiferromagnet Mn3Sn in proximity to permalloy thin layers. The in-plane polarized spin current is generated from the interior of Mn3Sn and follows its temperature dependence, while the out-of-plane polarized spin current arises from the spin swapping effect at the Mn3Sn/permalloy interface.
NATURE COMMUNICATIONS
(2023)
Article
Physics, Applied
Fu Liu, Jinli Yao, Chenglong Jia, Changjun Jiang
Summary: By changing the direction of applied radio frequency microwave currents, we demonstrate a significant conversion anisotropy of up to 400% in fourfold-symmetric anisotropy Fe films on MgO(100) substrate. The fourfold-symmetric anisotropy stems from large emergent spin-orbit coupling in Fe films with local lattice distortions. Our findings provide a simple route for designing future energy-efficient magnetic devices.
PHYSICAL REVIEW APPLIED
(2023)
Article
Physics, Multidisciplinary
Shutaro Karube, Takahiro Tanaka, Daichi Sugawara, Naohiro Kadoguchi, Makoto Kohda, Junsaku Nitta
Summary: The study investigates the generation of spin-splitter torque in collinear antiferromagnetic RuO2, revealing different spin current polarizations on various crystal planes. By utilizing this spin-splitter torque, field-free switching of ferromagnetic materials can be achieved, contributing to the development of antiferromagnetic spin-orbitronics.
PHYSICAL REVIEW LETTERS
(2022)
Article
Chemistry, Physical
Lin Huang, Yongjian Zhou, Tingwen Guo, Dong Han, Yu Gu, Cheng Song, Feng Pan
Summary: This study investigates the correlation between magnetic properties and thermal expansion in cold-drawn Fe-36Ni wires, finding that the variation trend of magnetic properties is consistent with that of thermal expansion and is influenced by heat treatment. Differential thermal analysis shows that crystalline transitions may cause abrupt changes in magnetic properties and thermal expansion coefficient.
Article
Chemistry, Multidisciplinary
Xinyi Li, Yanan Zhong, Hang Chen, Jianshi Tang, Xiaojian Zheng, Wen Sun, Yang Li, Dong Wu, Bin Gao, Xiaolin Hu, He Qian, Huaqiang Wu
Summary: This study utilizes transition metal oxide-based memristors as artificial dendrites and spike-firing soma to construct dendritic neuron units, achieving high-efficiency spatial-temporal information processing. A hardware-implemented dendritic neural network improves accuracy for human motion recognition and exhibits a 1000x advantage in power efficiency compared to a graphics processing unit.
ADVANCED MATERIALS
(2023)
Article
Multidisciplinary Sciences
Wenxuan Zhu, Cheng Song, Qian Wang, Hua Bai, Siqi Yin, Feng Pan
Summary: A novel van der Waals ferromagnet PtTe2Ge1/3 with high air stability and above room-temperature Curie temperature has been synthesized through a displacement reaction in Pt/Cr2Ge2Te6 heterostructure. This work demonstrates the unique anti-metal-activity-order reaction tendency in 2D transition-metal magnets and advances progress towards practical 2D spintronics.
NATIONAL SCIENCE REVIEW
(2023)
Article
Nanoscience & Nanotechnology
Qian Wang, Youdi Gu, Chong Chen, Leilei Qiao, Feng Pan, Cheng Song
Summary: In this study, researchers discovered that classical transition-metal oxide (TMO) brownmillerite SrCoO2.5 films can transition to a metastable perovskite phase in a weak acidic solution. This metastable perovskite exhibits strong ferromagnetism and greatly elevated electrical conductivity, similar to prototypical perovskite SrCoO3. Two possible mechanisms were proposed to explain this phenomenon, with the control experiments indicating that the dominant process is active oxygen filling.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Chemistry, Multidisciplinary
Tiantian Wei, Yuyao Lu, Fan Zhang, Jianshi Tang, Bin Gao, Pu Yu, He Qian, Huaqiang Wu
Summary: In this study, the conductive filaments (CFs) with different morphologies after forming, set, and reset operations in HfOx-based memristor devices are clearly revealed for the first time through 3D reconstruction of conductive atomic force microscopy (c-AFM) images. Multiple CFs are successfully observed in devices with three different resistive states, exhibiting hourglass, inverted-cone, and short-cone morphologies. The rupture location of CFs after the reset operation is also clearly observed. These findings provide insights into the resistive switching mechanism and can contribute to the design and optimization of oxide-based memristors for memory and computing applications.
ADVANCED MATERIALS
(2023)
Article
Engineering, Electrical & Electronic
Xueqi Li, Liyang Pan, Junyi Wang, Bin Gao, Jianshi Tang, He Qian, Huaqiang Wu
Summary: This article proposes a novel dual-step page forming method that can realize low-current forming and improve a bit error rate (BER). Based on this technique, a no-verify page-forming scheme is proposed and can achieve a fast-forming speed of 7.56 Mb/s.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2023)
Article
Materials Science, Multidisciplinary
Lin Huang, Tingwen Guo, Yongjian Zhou, Dong Han, Yu Gu, Cheng Song, Feng Pan
Summary: This study examines the impact of the casting process on the magnetic properties and thermal expansion of Fe-Ni Invar alloy. The results show that post-annealing at different temperatures can lead to changes in saturation magnetization and thermal expansion coefficient. X-ray diffraction and differential thermal analysis were used to analyze the underlying reasons for these property differences.
JOURNAL OF MAGNETICS
(2022)
Article
Physics, Applied
Peisen Liu, Sulei Fu, Rongxuan Su, Huiping Xu, Boyuan Xiao, Cheng Song, Fei Zeng, Feng Pan
Summary: This paper reports a longitudinal leaky surface acoustic wave (LLSAW) mode acoustic resonator with a large electromechanical coupling factor, high operating frequency, and efficient spurious suppression. It systematically investigates the design spaces such as supporting substrate, propagation angle, and lithium niobate (LN) thickness, and demonstrates a high-performance LLSAW resonator with a large kt(2) without interference from other spurious modes. The fabricated LLSAW resonators exhibit a near spurious-free response with an operating frequency over 6 GHz and a kt(2) as large as 22.7%.
APPLIED PHYSICS LETTERS
(2023)
Article
Engineering, Electrical & Electronic
Ruofei Hu, Jianshi Tang, Yue Xi, Zhixing Jiang, Yuyao Lu, Bin Gao, He Qian, Huaqiang Wu
Summary: A nitrogen-oxyanion-doped hafnium oxide RRAM with improved forming voltage, on/off ratio, and endurance is demonstrated. The critical electric field of N-doped RRAM for forming is 40% lower than that of undoped RRAM. The N-doped RRAM achieves 3x improvement in on/off ratio and 10x improvement in endurance at the forming voltage of 2 V, which is suitable for integration with advanced silicon technology nodes.
IEEE ELECTRON DEVICE LETTERS
(2023)
Article
Engineering, Electrical & Electronic
Yudeng Lin, Jianshi Tang, Bin Gao, Qingtian Zhang, He Qian, Huaqiang Wu
Summary: Deep learning models implemented using memristors offer high scalability and energy efficiency for resource-constrained edge computing applications. However, the inherent physical randomness of memristors leads to significant performance degradation. In this study, a unified architecture incorporating a Bayesian-based training method and lightweight transfer scheme is proposed to address the robustness, energy, and time consumption issues caused by memristor variations. Experimental results demonstrate that this architecture can double the speed and energy efficiency of deploying deep learning models.
IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS II-EXPRESS BRIEFS
(2023)
Article
Engineering, Electrical & Electronic
Yudeng Lin, Jianshi Tang, Bin Gao, Qi Qin, Qingtian Zhang, He Qian, Huaqiang Wu
Summary: Resistive random access memory (RRAM)-based neuromorphic hardware accelerators are attractive for neural network acceleration due to their high energy efficiency. However, the variations of RRAM can cause significant conductance deviation and performance degradation. A novel write-verify scheme is proposed to transfer weights with different acceptable error margins, achieving a high-speed and high-efficiency write-verify process.
IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS II-EXPRESS BRIEFS
(2023)
Article
Engineering, Electrical & Electronic
Rongxuan Su, Sulei Fu, Junyao Shen, Zengtian Lu, Huiping Xu, Rui Wang, Cheng Song, Fei Zeng, Weibiao Wang, Feng Pan
Summary: In this study, a 32-degree Y-X LiNbO3/SiO2/Si heterostructure with high electro-mechanical coupling coefficient was constructed to develop a SAW filter with excellent RF performance for 5G NR. The fabricated filter exhibited a large bandwidth, low insertion loss, and flat passband, demonstrating the potential for commercial implementation of SAW filters in 5G NR.
IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES
(2023)
Article
Chemistry, Analytical
Huiping Xu, Sulei Fu, Rongxuan Su, Peisen Liu, Rui Wang, Fei Zeng, Cheng Song, Weibiao Wang, Feng Pan
Summary: In response to the demand for highly integrated and miniaturized radio frequency front-end (RFFE) modules, multi-passband filters that support multi-channel compounding have become the focus. This study proposes a new design of a dual-passband surface acoustic wave (SAW) filter based on a 32 degrees YX-LiNbO3 (LN)/SiO2/SiC multilayered structure. The filter is of a standalone ladder topology and consists of dual-mode resonators that simultaneously excite the shear horizontal (SH) mode and high-order SH mode through electrode thickness modulation. The fabricated dual-band filter shows compact layout and diminished area occupancy, making it a promising solution for high-performance dual-passband SAW filter for sub-6 GHz RF application.
Article
Quantum Science & Technology
Qin Wan, Fei Zeng, Junwei Yu, Tongjin Chen, Ziao Lu, Feng Pan
Summary: Research and development of memristor-based neuromorphic networks has reached large-scale application stage, but a thorough understanding of the adopted memristors is still lacking. In this study, a method to manipulate the local activity of NbO quantum dot (QD) system by creating an electrode tip is proposed, enabling reversible nucleation behavior and periodic pulsing. These mechanisms contribute to the information-energy conversion in the QD system and provide a more precise and low energy-consumption approach for neuromorphic computing.
ADVANCED QUANTUM TECHNOLOGIES
(2023)
Article
Materials Science, Multidisciplinary
Shixuan Liang, Lei Han, Yunfeng You, Hua Bai, Feng Pan, Cheng Song
Summary: Out-of-plane spin polarization (crz), generated by triangular spin configuration in non-collinear antiferromagnets, including IrMn3, has potential applications for magnetic memory. Our study demonstrates that the interface between IrMn3 and permalloy also contributes to the generation of crz, and interfacial crz can be eliminated by inserting Cu. We propose that the interface-relevant crz is independent of exchange coupling and suggest possible origins. These findings enrich the understanding of crz in antiferromagnet/ferromagnet bilayers and propose a potential path for optimizing low-power magnetic memories.
