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Sun R, Park KS, Comstock AH, McConnell A, Chen YC, Zhang P, Beratan D, You W, Hoffmann A, Yu ZG, Diao Y, Sun D. Inverse chirality-induced spin selectivity effect in chiral assemblies of π-conjugated polymers. NATURE MATERIALS 2024; 23:782-789. [PMID: 38491147 DOI: 10.1038/s41563-024-01838-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Accepted: 02/14/2024] [Indexed: 03/18/2024]
Abstract
Coupling of spin and charge currents to structural chirality in non-magnetic materials, known as chirality-induced spin selectivity, is promising for application in spintronic devices at room temperature. Although the chirality-induced spin selectivity effect has been identified in various chiral materials, its Onsager reciprocal process, the inverse chirality-induced spin selectivity effect, remains unexplored. Here we report the observation of the inverse chirality-induced spin selectivity effect in chiral assemblies of π-conjugated polymers. Using spin-pumping techniques, the inverse chirality-induced spin selectivity effect enables quantification of the magnitude of the longitudinal spin-to-charge conversion driven by chirality-induced spin selectivity in different chiral polymers. By widely tuning conductivities and supramolecular chiral structures via a printing method, we found a very long spin relaxation time of up to several nanoseconds parallel to the chiral axis. Our demonstration of the inverse chirality-induced spin selectivity effect suggests possibilities for elucidating the puzzling interplay between spin and chirality, and opens a route for spintronic applications using printable chiral assemblies.
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Affiliation(s)
- Rui Sun
- Department of Physics and Organic and Carbon Electronics Lab (ORaCEL), North Carolina State University, Raleigh, NC, USA
| | - Kyung Sun Park
- Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Andrew H Comstock
- Department of Physics and Organic and Carbon Electronics Lab (ORaCEL), North Carolina State University, Raleigh, NC, USA
| | - Aeron McConnell
- Department of Physics and Organic and Carbon Electronics Lab (ORaCEL), North Carolina State University, Raleigh, NC, USA
| | - Yen-Chi Chen
- Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Peng Zhang
- Department of Chemistry, Duke University, Durham, NC, USA
| | - David Beratan
- Department of Chemistry, Duke University, Durham, NC, USA
| | - Wei You
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Axel Hoffmann
- Department of Materials Science & Engineering and Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Zhi-Gang Yu
- Sivananthan Laboratories, Bolingbrook, Illinois, USA
| | - Ying Diao
- Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, IL, USA.
| | - Dali Sun
- Department of Physics and Organic and Carbon Electronics Lab (ORaCEL), North Carolina State University, Raleigh, NC, USA.
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2
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Vudya Sethu KK, Yasin F, Swerts J, Sorée B, De Boeck J, Kar GS, Garello K, Couet S. Spin-Orbit Torque Vector Quantification in Nanoscale Magnetic Tunnel Junctions. ACS NANO 2024; 18:13506-13516. [PMID: 38748456 DOI: 10.1021/acsnano.3c11289] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2024]
Abstract
Spin-orbit torques (SOT) allow ultrafast, energy-efficient toggling of magnetization state by an in-plane charge current for applications such as magnetic random-access memory (SOT-MRAM). Tailoring the SOT vector comprising of antidamping (TAD) and fieldlike (TFL) torques could lead to faster, more reliable, and low-power SOT-MRAM. Here, we establish a method to quantify the longitudinal (TAD) and transverse (TFL) components of the SOT vector and its efficiency χAD and χFL, respectively, in nanoscale three-terminal SOT magnetic tunnel junctions (SOT-MTJ). Modulation of nucleation or switching field (BSF) for magnetization reversal by SOT effective fields (BSOT) leads to the modification of SOT-MTJ hysteresis loop behavior from which χAD and χFL are quantified. Surprisingly, in nanoscale W/CoFeB SOT-MTJ, we find χFL to be (i) twice as large as χAD and (ii) 6 times as large as χFL in micrometer-sized W/CoFeB Hall-bar devices. Our quantification is supported by micromagnetic and macrospin simulations which reproduce experimental SOT-MTJ Stoner-Wohlfarth astroid behavior only for χFL > χAD. Additionally, from the threshold current for current-induced magnetization switching with a transverse magnetic field, we show that in SOT-MTJ, TFL plays a more prominent role in magnetization dynamics than TAD. Due to SOT-MRAM geometry and nanodimensionality, the potential role of nonlocal spin Hall spin current accumulated adjacent to the SOT-MTJ in the mediation of TFL and χFL amplification merits to be explored.
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Affiliation(s)
- Kiran Kumar Vudya Sethu
- IMEC, Kapledreef 75, 3001 Leuven, Belgium
- Department of Electrical Engineering, KU Leuven, Kasteelpark Arenberg 10, Leuven 3001, Belgium
| | | | | | - Bart Sorée
- IMEC, Kapledreef 75, 3001 Leuven, Belgium
- Department of Electrical Engineering, KU Leuven, Kasteelpark Arenberg 10, Leuven 3001, Belgium
- Physics Department, University of Antwerp, Groenenborgerlaan 171, Antwerpen B-2020, Belgium
| | - Johan De Boeck
- IMEC, Kapledreef 75, 3001 Leuven, Belgium
- Department of Electrical Engineering, KU Leuven, Kasteelpark Arenberg 10, Leuven 3001, Belgium
| | | | - Kevin Garello
- CEA, CNRS, Grenoble INP, SPINTEC, Université Grenoble Alpes, 38054 Grenoble, France
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3
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Hu S, Qiu X, Pan C, Zhu W, Guo Y, Shao DF, Yang Y, Zhang D, Jiang Y. Frontiers in all electrical control of magnetization by spin orbit torque. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2024; 36:253001. [PMID: 38467073 DOI: 10.1088/1361-648x/ad3270] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2024] [Accepted: 03/11/2024] [Indexed: 03/13/2024]
Abstract
Achieving all electrical control of magnetism without assistance of an external magnetic field has been highly pursued for spintronic applications. In recent years, the manipulation of magnetic states through spin-orbit torque (SOT) has emerged as a promising avenue for realizing energy-efficient spintronic memory and logic devices. Here, we provide a review of the rapidly evolving research frontiers in all electrical control of magnetization by SOT. The first part introduces the SOT mechanisms and SOT devices with different configurations. In the second part, the developments in all electrical SOT control of magnetization enabled by spin current engineering are introduced, which include the approaches of lateral symmetry breaking, crystalline structure engineering of spin source material, antiferromagnetic order and interface-generated spin current. The third part introduces all electrical SOT switching enabled by magnetization engineering of the ferromagnet, such as the interface/interlayer exchange coupling and tuning of anisotropy or magnetization. At last, we provide a summary and future perspectives for all electrical control of magnetization by SOT.
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Affiliation(s)
- Shuai Hu
- Institute of Quantum Materials and Devices, School of Electronic and Information Engineering; State Key Laboratory of Separation Membrane and Membrane Processes, Tiangong University, Tianjin 300387, People's Republic of China
| | - Xuepeng Qiu
- Shanghai Key Laboratory of Special Artificial Microstructure Materials and Technology and School of Physics Science and Engineering, Tongji University, Shanghai 200092, People's Republic of China
| | - Chang Pan
- Shanghai Key Laboratory of Special Artificial Microstructure Materials and Technology and School of Physics Science and Engineering, Tongji University, Shanghai 200092, People's Republic of China
| | - Wei Zhu
- Shanghai Key Laboratory of Special Artificial Microstructure Materials and Technology and School of Physics Science and Engineering, Tongji University, Shanghai 200092, People's Republic of China
| | - Yandong Guo
- Shanghai Key Laboratory of Special Artificial Microstructure Materials and Technology and School of Physics Science and Engineering, Tongji University, Shanghai 200092, People's Republic of China
| | - Ding-Fu Shao
- Key Laboratory of Materials Physics, Institute of Solid State Physics, HFIPS, Chinese Academy of Sciences, Hefei 230031, People's Republic of China
| | - Yumeng Yang
- School of Information Science and Technology, ShanghaiTech University, Shanghai 201210, People's Republic of China
- Shanghai Engineering Research Center of Energy Efficient and Custom AI IC, ShanghaiTech University, Shanghai 201210, People's Republic of China
| | - Delin Zhang
- Institute of Quantum Materials and Devices, School of Electronic and Information Engineering; State Key Laboratory of Separation Membrane and Membrane Processes, Tiangong University, Tianjin 300387, People's Republic of China
| | - Yong Jiang
- Institute of Quantum Materials and Devices, School of Electronic and Information Engineering; State Key Laboratory of Separation Membrane and Membrane Processes, Tiangong University, Tianjin 300387, People's Republic of China
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4
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Fang N, Wu C, Zhang Y, Li Z, Zhou Z. Perspectives: Light Control of Magnetism and Device Development. ACS NANO 2024; 18:8600-8625. [PMID: 38469753 DOI: 10.1021/acsnano.3c13002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/13/2024]
Abstract
Accurately controlling magnetic and spin states presents a significant challenge in spintronics, especially as demands for higher data storage density and increased processing speeds grow. Approaches such as light control are gradually supplanting traditional magnetic field methods. Traditionally, the modulation of magnetism was predominantly achieved through polarized light with the help of ultrafast light technologies. With the growing demand for energy efficiency and multifunctionality in spintronic devices, integrating photovoltaic materials into magnetoelectric systems has introduced more physical effects. This development suggests that sunlight will play an increasingly pivotal role in manipulating spin orientation in the future. This review introduces and concludes the influence of various light types on magnetism, exploring mechanisms such as magneto-optical (MO) effects, light-induced magnetic phase transitions, and spin photovoltaic effects. This review briefly summarizes recent advancements in the light control of magnetism, especially sunlight, and their potential applications, providing an optimistic perspective on future research directions in this area.
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Affiliation(s)
- Ning Fang
- School of Materials Science and Engineering, Changzhou University, Changzhou 213164, China
| | - Changqing Wu
- School of Environmental Science and Engineering, Jiangsu Key Laboratory of Advanced Catalytic Materials and Technology, School of Petrochemical Engineering, Changzhou University, Changzhou 213164, China
| | - Yuzhe Zhang
- School of Environmental Science and Engineering, Jiangsu Key Laboratory of Advanced Catalytic Materials and Technology, School of Petrochemical Engineering, Changzhou University, Changzhou 213164, China
| | - Zhongyu Li
- School of Environmental Science and Engineering, Jiangsu Key Laboratory of Advanced Catalytic Materials and Technology, School of Petrochemical Engineering, Changzhou University, Changzhou 213164, China
| | - Ziyao Zhou
- School of Materials Science and Engineering, Changzhou University, Changzhou 213164, China
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5
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Kumar A, Lin DJX, Das D, Huang L, Yap SLK, Tan HR, Tan HK, Lim RJJ, Toh YT, Chen S, Lim ST, Fong X, Ho P. Multistate Compound Magnetic Tunnel Junction Synapses for Digital Recognition. ACS APPLIED MATERIALS & INTERFACES 2024; 16:10335-10343. [PMID: 38376994 DOI: 10.1021/acsami.3c17195] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/22/2024]
Abstract
The quest to mimic the multistate synapses for bioinspired computing has triggered nascent research that leverages the well-established magnetic tunnel junction (MTJ) technology. Early works on the spin transfer torque MTJ-based artificial neural network (ANN) are susceptible to poor thermal reliability, high latency, and high critical current densities. Meanwhile, work on spin-orbit torque (SOT) MTJ-based ANN mainly utilized domain wall motion, which yields negligibly small readout signals differentiating consecutive states and has designs that are incompatible with technological scale-up. Here, we propose a multistate device concept built upon a compound MTJ consisting of multiple SOT-MTJs (number of MTJs, n = 1-4) on a shared write channel, mimicking the spin-based ANN. The n + 1 resistance states representing varying synaptic weights can be tuned by varying the voltage pulses (±1.5-1.8 V), pulse duration (100-300 ns), and applied in-plane fields (5.5-10.5 mT). A large TMR difference of more than 13.6% is observed between two consecutive states for the 4-cell compound MTJ, a 4-fold improvement from reported state-of-the-art spin-based synaptic devices. The ANN built upon the compound MTJ shows high learning accuracy for digital recognition tasks with incremental states and retraining, achieving test accuracy as high as 95.75% in the 4-cell compound MTJ. These results provide an industry-compatible platform to integrate these multistate SOT-MTJ synapses directly into neuromorphic architecture for in-memory and unconventional computing applications.
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Affiliation(s)
- Anuj Kumar
- Physics Department, National University of Singapore, 117551 Singapore
| | - Dennis J X Lin
- Institute of Materials Research and Engineering, A*STAR, 138634 Singapore
| | - Debasis Das
- Electrical and Computer Engineering Department, National University of Singapore, 117583 Singapore
| | - Lisen Huang
- Institute of Materials Research and Engineering, A*STAR, 138634 Singapore
| | - Sherry L K Yap
- Institute of Materials Research and Engineering, A*STAR, 138634 Singapore
| | - Hui Ru Tan
- Institute of Materials Research and Engineering, A*STAR, 138634 Singapore
| | - Hang Khume Tan
- Institute of Materials Research and Engineering, A*STAR, 138634 Singapore
| | - Royston J J Lim
- Institute of Materials Research and Engineering, A*STAR, 138634 Singapore
| | - Yeow Teck Toh
- Institute of Materials Research and Engineering, A*STAR, 138634 Singapore
| | - Shaohai Chen
- Institute of Materials Research and Engineering, A*STAR, 138634 Singapore
| | - Sze Ter Lim
- Institute of Materials Research and Engineering, A*STAR, 138634 Singapore
| | - Xuanyao Fong
- Electrical and Computer Engineering Department, National University of Singapore, 117583 Singapore
| | - Pin Ho
- Institute of Materials Research and Engineering, A*STAR, 138634 Singapore
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6
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Yang Q, Han D, Zhao S, Kang J, Wang F, Lee SC, Lei J, Lee KJ, Park BG, Yang H. Field-free spin-orbit torque switching in ferromagnetic trilayers at sub-ns timescales. Nat Commun 2024; 15:1814. [PMID: 38418454 PMCID: PMC10901790 DOI: 10.1038/s41467-024-46113-1] [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: 12/23/2022] [Accepted: 02/14/2024] [Indexed: 03/01/2024] Open
Abstract
Current-induced spin torques enable the electrical control of the magnetization with low energy consumption. Conventional magnetic random access memory (MRAM) devices rely on spin-transfer torque (STT), this however limits MRAM applications because of the nanoseconds incubation delay and associated endurance issues. A potential alternative to STT is spin-orbit torque (SOT). However, for practical, high-speed SOT devices, it must satisfy three conditions simultaneously, i.e., field-free switching at short current pulses, short incubation delay, and low switching current. Here, we demonstrate field-free SOT switching at sub-ns timescales in a CoFeB/Ti/CoFeB ferromagnetic trilayer, which satisfies all three conditions. In this trilayer, the bottom magnetic layer or its interface generates spin currents with polarizations in both in-plane and out-of-plane components. The in-plane component reduces the incubation time, while the out-of-plane component realizes field-free switching at a low current. Our results offer a field-free SOT solution for energy-efficient scalable MRAM applications.
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Affiliation(s)
- Qu Yang
- Department of Electrical and Computer Engineering, National University of Singapore, Singapore, 117576, Singapore
| | - Donghyeon Han
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Korea
| | - Shishun Zhao
- Department of Electrical and Computer Engineering, National University of Singapore, Singapore, 117576, Singapore
| | - Jaimin Kang
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Korea
| | - Fei Wang
- Department of Electrical and Computer Engineering, National University of Singapore, Singapore, 117576, Singapore
| | - Sung-Chul Lee
- Next Generation Process Development Team, Semiconductor R&D Center, Samsung Electronics Co. Ltd., Hwaseong, Gyeonggi, 18448, Korea
| | - Jiayu Lei
- Department of Electrical and Computer Engineering, National University of Singapore, Singapore, 117576, Singapore
| | - Kyung-Jin Lee
- Department of Physics, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Korea
| | - Byong-Guk Park
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Korea
| | - Hyunsoo Yang
- Department of Electrical and Computer Engineering, National University of Singapore, Singapore, 117576, Singapore.
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7
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Du Q, Wang W, Tang F, Su W, Wu J, Hu Z, Wang Z, Liu M. Ultralow Electric Current-Assisted Magnetization Switching due to Thermally Engineered Magnetic Anisotropy. ACS APPLIED MATERIALS & INTERFACES 2024; 16:7463-7469. [PMID: 38300878 DOI: 10.1021/acsami.3c17325] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2024]
Abstract
Control of magnetic anisotropy in thin films with perpendicular magnetic anisotropy is of paramount importance for the development of spintronics with ultralow-energy consumption and high density. Traditional magnetoelectric heterostructures utilized the synergistic effect of piezoelectricity and magnetostriction to realize the electric field control of magnetic anisotropy, resulting in additional fabrication and modulation processes and a complicated device architecture. Here, we have systematically investigated the electric current tuning of the magnetic properties of the metallic NiCo2O4 film with intrinsic perpendicular magnetic anisotropy. Ferrimagnetic-to-paramagnetic phase transition has been induced through Joule heating, resulting in a rapid decrease of both magnetic coercivity and moment. An ultralow current density of 2.5 × 104 A/cm2, which is 2 to 3 orders magnitude lower than that of conventional spin transfer torque devices, has been verified to be effective for the control of the magnetic anisotropy of NiCo2O4. Successful triggering of magnetic switching has been realized through the application of a current pulse. These findings provide new perspectives toward the electric control of magnetic anisotropy and design of spintronics with an ultralow driving current density.
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Affiliation(s)
- Qin Du
- State Key Laboratory for Manufacturing Systems Engineering, Electronic Materials Research Laboratory, School of Electronic Science and Engineering, Xi'an Jiaotong University, Xi'an 710049, China
| | - Wenli Wang
- State Key Laboratory for Manufacturing Systems Engineering, Electronic Materials Research Laboratory, School of Electronic Science and Engineering, Xi'an Jiaotong University, Xi'an 710049, China
| | - Fan Tang
- State Key Laboratory for Manufacturing Systems Engineering, Electronic Materials Research Laboratory, School of Electronic Science and Engineering, Xi'an Jiaotong University, Xi'an 710049, China
| | - Wei Su
- State Key Laboratory for Manufacturing Systems Engineering, Electronic Materials Research Laboratory, School of Electronic Science and Engineering, Xi'an Jiaotong University, Xi'an 710049, China
| | - Jingen Wu
- State Key Laboratory for Manufacturing Systems Engineering, Electronic Materials Research Laboratory, School of Electronic Science and Engineering, Xi'an Jiaotong University, Xi'an 710049, China
| | - Zhongqiang Hu
- State Key Laboratory for Manufacturing Systems Engineering, Electronic Materials Research Laboratory, School of Electronic Science and Engineering, Xi'an Jiaotong University, Xi'an 710049, China
| | - Zhiguang Wang
- State Key Laboratory for Manufacturing Systems Engineering, Electronic Materials Research Laboratory, School of Electronic Science and Engineering, Xi'an Jiaotong University, Xi'an 710049, China
| | - Ming Liu
- State Key Laboratory for Manufacturing Systems Engineering, Electronic Materials Research Laboratory, School of Electronic Science and Engineering, Xi'an Jiaotong University, Xi'an 710049, China
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8
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Zhu L. Switching of Perpendicular Magnetization by Spin-Orbit Torque. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2300853. [PMID: 37004142 DOI: 10.1002/adma.202300853] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2023] [Revised: 03/16/2023] [Indexed: 06/19/2023]
Abstract
Magnetic materials with strong perpendicular magnetic anisotropy are of great interest for the development of nonvolatile magnetic memory and computing technologies due to their high stabilities at the nanoscale. However, electrical switching of such perpendicular magnetization in an energy-efficient, deterministic, scalable manner has remained a big challenge. This problem has recently attracted enormous efforts in the field of spintronics. Here, recent advances and challenges in the understanding of the electrical generation of spin currents, the switching mechanisms and the switching strategies of perpendicular magnetization, the switching current density by spin-orbit torque of transverse spins, the choice of perpendicular magnetic materials are reviewed, and the progress in prototype perpendicular SOT memory and logic devices toward the goal of energy-efficient, dense, fast perpendicular spin-orbit torque applications is summarized.
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Affiliation(s)
- Lijun Zhu
- State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing, 100083, China
- College of Materials Science and Opto-Electronic Technology, University of Chinese Academy of Sciences, Beijing, 100049, China
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9
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Polley D, Pattabi A, Rastogi A, Jhuria K, Diaz E, Singh H, Lemaitre A, Hehn M, Gorchon J, Bokor J. Picosecond spin-orbit torque-induced coherent magnetization switching in a ferromagnet. SCIENCE ADVANCES 2023; 9:eadh5562. [PMID: 37672590 PMCID: PMC10482325 DOI: 10.1126/sciadv.adh5562] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Accepted: 08/04/2023] [Indexed: 09/08/2023]
Abstract
Electrically controllable nonvolatile magnetic memories show great potential for the replacement of conventional semiconductor-based memory technologies. Here, we experimentally demonstrate ultrafast spin-orbit torque (SOT)-induced coherent magnetization switching dynamics in a ferromagnet. We use an ultrafast photoconducting switch and a coplanar strip line to generate and guide a ~9-picosecond electrical pulse into a heavy metal/ferromagnet multilayer to induce ultrafast SOT. We then use magneto-optical probing to investigate the magnetization dynamics with sub-picosecond resolution. Ultrafast heating by the approximately 9 picosecond current pulse induces a thermal anisotropy torque which, in combination with the damping-like torque, coherently rotates the magnetization to obtain zero-crossing of magnetization in ~70 picoseconds. A macro-magnetic simulation coupled with an ultrafast heating model agrees well with the experiment and suggests coherent magnetization switching without any incubation delay on an unprecedented time scale. Our work proposes a unique magnetization switching mechanism toward markedly increasing the writing speed of SOT magnetic random-access memory devices.
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Affiliation(s)
- Debanjan Polley
- Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720, USA
- Department of Electrical Engineering and Computer Sciences, University of California, Berkeley, CA 94720, USA
- Department of Physics and Nanotechnology, SRM Institute of Science and Technology, Kattankulathur- 603 203, Tamil Nadu, India
| | - Akshay Pattabi
- Department of Electrical Engineering and Computer Sciences, University of California, Berkeley, CA 94720, USA
- Department of Engineering, University of San Francisco, San Francisco CA 94117, USA
| | - Ashwin Rastogi
- Department of Electrical Engineering and Computer Sciences, University of California, Berkeley, CA 94720, USA
| | - Kaushalya Jhuria
- Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720, USA
- Université de Lorraine, CNRS, IJL, Nancy, France
| | - Eva Diaz
- Université de Lorraine, CNRS, IJL, Nancy, France
| | - Hanuman Singh
- Department of Electrical Engineering and Computer Sciences, University of California, Berkeley, CA 94720, USA
| | - Aristide Lemaitre
- Université Paris-Saclay, CNRS, Centre de Nanosciences et de Nanotechnologies, 91120, Palaiseau, France
| | - Michel Hehn
- Université de Lorraine, CNRS, IJL, Nancy, France
| | - Jon Gorchon
- Université de Lorraine, CNRS, IJL, Nancy, France
| | - Jeffrey Bokor
- Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720, USA
- Department of Electrical Engineering and Computer Sciences, University of California, Berkeley, CA 94720, USA
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10
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Liu Q, Lin X, Zhu L. Absence of Spin-Orbit Torque and Discovery of Anisotropic Planar Nernst Effect in CoFe Single Crystal. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2023; 10:e2301409. [PMID: 37485640 PMCID: PMC10520638 DOI: 10.1002/advs.202301409] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2023] [Revised: 06/29/2023] [Indexed: 07/25/2023]
Abstract
Exploration of exotic spin polarizations in single crystals is of increasing interest. A current of longitudinal spins, the so-called "Dresselhaus-like" spin current, which is forbidden in materials lacking certain inversion asymmetries, is implied to be generated by a charge current at the interface of single-crystal CoFe. This work reports unambiguous evidence that there is no indication of spin current of any spin polarizations from the interface or bulk of single-crystalline CoFe and that the sin2φ second harmonic Hall voltage, which is previously assumed to signify Dresselhaus-like spin current, is not related to any spin currents but rather a planar Nernst voltage induced by a longitudinal temperature gradient within the sample. Such sin2φ signal is independent of large applied magnetic fields and interfacial spin-orbit coupling, inversely correlated to the heat capacity of the substrates and overlayers, quadratic in charge current, and appears also in polycrystalline ferromagnets. Strikingly, the planar Nernst effect (PNE) in the CoFe single crystal has a strong fourfold anisotropy and varies with the crystalline orientation. Such strong, anisotropic PNE has widespread impacts on the analyses of a variety of spintronic experiments and opens a new avenue for the development of PNE-based thermoelectric battery and sensor applications.
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Affiliation(s)
- Qianbiao Liu
- State Key Laboratory for Superlattices and MicrostructuresInstitute of SemiconductorsChinese Academy of SciencesBeijing100083China
| | - Xin Lin
- State Key Laboratory for Superlattices and MicrostructuresInstitute of SemiconductorsChinese Academy of SciencesBeijing100083China
- College of Materials Science and Opto‐Electronic TechnologyUniversity of Chinese Academy of SciencesBeijing100049China
| | - Lijun Zhu
- State Key Laboratory for Superlattices and MicrostructuresInstitute of SemiconductorsChinese Academy of SciencesBeijing100083China
- College of Materials Science and Opto‐Electronic TechnologyUniversity of Chinese Academy of SciencesBeijing100049China
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11
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Hadámek T, Jørstad NP, de Orio RL, Goes W, Selberherr S, Sverdlov V. A Comprehensive Study of Temperature and Its Effects in SOT-MRAM Devices. MICROMACHINES 2023; 14:1581. [PMID: 37630117 PMCID: PMC10456936 DOI: 10.3390/mi14081581] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2023] [Revised: 07/30/2023] [Accepted: 08/07/2023] [Indexed: 08/27/2023]
Abstract
We employ a fully three-dimensional model coupling magnetization, charge, spin, and temperature dynamics to study temperature effects in spin-orbit torque (SOT) magnetoresistive random access memory (MRAM). SOTs are included by considering spin currents generated through the spin Hall effect. We scale the magnetization parameters with the temperature. Numerical experiments show several time scales for temperature dynamics. The relatively slow temperature increase, after a rapid initial temperature rise, introduces an incubation time to the switching. Such a behavior cannot be reproduced with a constant temperature model. Furthermore, the critical SOT switching voltage is significantly reduced by the increased temperature. We demonstrate this phenomenon for switching of field-free SOT-MRAM. In addition, with an external-field-assisted switching, the critical SOT voltage shows a parabolic decrease with respect to the voltage applied across the magnetic tunnel junction (MTJ) of the SOT-MRAM cell, in agreement with recent experimental data.
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Affiliation(s)
- Tomáš Hadámek
- Christian Doppler Laboratory for Nonvolatile Magnetoresistive Memory and Logic, Institute for Microelectronics, TU Wien, Gußhausstraße 27-29, A-1040 Wien, Austria (V.S.)
| | - Nils Petter Jørstad
- Christian Doppler Laboratory for Nonvolatile Magnetoresistive Memory and Logic, Institute for Microelectronics, TU Wien, Gußhausstraße 27-29, A-1040 Wien, Austria (V.S.)
| | | | | | - Siegfried Selberherr
- Institute for Microelectronics, TU Wien, Gußhausstraße 27-29, A-1040 Wien, Austria
| | - Viktor Sverdlov
- Christian Doppler Laboratory for Nonvolatile Magnetoresistive Memory and Logic, Institute for Microelectronics, TU Wien, Gußhausstraße 27-29, A-1040 Wien, Austria (V.S.)
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12
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Kateel V, Krizakova V, Rao S, Cai K, Gupta M, Monteiro MG, Yasin F, Sorée B, De Boeck J, Couet S, Gambardella P, Kar GS, Garello K. Field-Free Spin-Orbit Torque Driven Switching of Perpendicular Magnetic Tunnel Junction through Bending Current. NANO LETTERS 2023. [PMID: 37295781 DOI: 10.1021/acs.nanolett.3c00639] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Current-induced spin-orbit torques (SOTs) enable fast and efficient manipulation of the magnetic state of magnetic tunnel junctions (MTJs), making them attractive for memory, in-memory computing, and logic applications. However, the requirement of the external magnetic field to achieve deterministic switching in perpendicularly magnetized SOT-MTJs limits its implementation for practical applications. Here, we introduce a field-free switching (FFS) solution for the SOT-MTJ device by shaping the SOT channel to create a "bend" in the SOT current. The resulting bend in the charge current creates a spatially nonuniform spin current, which translates into inhomogeneous SOT on an adjacent magnetic free layer enabling deterministic switching. We demonstrate FFS experimentally on scaled SOT-MTJs at nanosecond time scales. This proposed scheme is scalable, material-agnostic, and readily compatible with wafer-scale manufacturing, thus creating a pathway for developing purely current-driven SOT systems.
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Affiliation(s)
- Vaishnavi Kateel
- IMEC Kapeldreef 75, B-3001 Leuven, Belgium
- Department of Electrical Engineering ESAT, KU Leuven, Kasteelpark Arenberg 10, B-3001 Leuven, Belgium
| | - Viola Krizakova
- Department of Materials, ETH Zurich, 8093 Zürich, Switzerland
| | | | | | | | - Maxwel Gama Monteiro
- IMEC Kapeldreef 75, B-3001 Leuven, Belgium
- Department of Electrical Engineering ESAT, KU Leuven, Kasteelpark Arenberg 10, B-3001 Leuven, Belgium
| | | | - Bart Sorée
- IMEC Kapeldreef 75, B-3001 Leuven, Belgium
- Department of Electrical Engineering ESAT, KU Leuven, Kasteelpark Arenberg 10, B-3001 Leuven, Belgium
| | - Johan De Boeck
- IMEC Kapeldreef 75, B-3001 Leuven, Belgium
- Department of Electrical Engineering ESAT, KU Leuven, Kasteelpark Arenberg 10, B-3001 Leuven, Belgium
| | | | | | | | - Kevin Garello
- IMEC Kapeldreef 75, B-3001 Leuven, Belgium
- Univ. Grenoble Alpes, CEA, CNRS, Grenoble INP, SPINTEC, 38000 Grenoble, France
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13
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Dc M, Shao DF, Hou VDH, Vailionis A, Quarterman P, Habiboglu A, Venuti MB, Xue F, Huang YL, Lee CM, Miura M, Kirby B, Bi C, Li X, Deng Y, Lin SJ, Tsai W, Eley S, Wang WG, Borchers JA, Tsymbal EY, Wang SX. Observation of anti-damping spin-orbit torques generated by in-plane and out-of-plane spin polarizations in MnPd 3. NATURE MATERIALS 2023; 22:591-598. [PMID: 37012436 DOI: 10.1038/s41563-023-01522-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2020] [Accepted: 03/02/2023] [Indexed: 05/05/2023]
Abstract
Large spin-orbit torques (SOTs) generated by topological materials and heavy metals interfaced with ferromagnets are promising for next-generation magnetic memory and logic devices. SOTs generated from y spin originating from spin Hall and Edelstein effects can realize field-free magnetization switching only when the magnetization and spin are collinear. Here we circumvent the above limitation by utilizing unconventional spins generated in a MnPd3 thin film grown on an oxidized silicon substrate. We observe conventional SOT due to y spin, and out-of-plane and in-plane anti-damping-like torques originated from z spin and x spin, respectively, in MnPd3/CoFeB heterostructures. Notably, we have demonstrated complete field-free switching of perpendicular cobalt via out-of-plane anti-damping-like SOT. Density functional theory calculations show that the observed unconventional torques are due to the low symmetry of the (114)-oriented MnPd3 films. Altogether our results provide a path toward realization of a practical spin channel in ultrafast magnetic memory and logic devices.
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Affiliation(s)
- Mahendra Dc
- Department of Materials Science and Engineering, Stanford University, Stanford, CA, USA.
| | - Ding-Fu Shao
- Department of Physics and Astronomy & Nebraska Center for Materials and Nanoscience, University of Nebraska, Lincoln, NE, USA
| | | | - Arturas Vailionis
- Stanford Nano Shared Facilities, Stanford University, Stanford, CA, USA
- Department of Physics, Kaunas University of Technology, Kaunas, Lithuania
| | - P Quarterman
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, MD, USA
| | - Ali Habiboglu
- Department of Physics, University of Arizona, Tucson, AZ, USA
| | - M B Venuti
- Department of Physics, Colorado School of Mines, Golden, CO, USA
| | - Fen Xue
- Department of Electrical Engineering, Stanford University, Stanford, CA, USA
| | - Yen-Lin Huang
- Taiwan Semiconductor Manufacturing Company, Hsinchu, Taiwan
- Department of Materials Science and Engineering, National Yang Ming Chiao Tung University, Hsinchu, Taiwan
| | - Chien-Min Lee
- Taiwan Semiconductor Manufacturing Company, Hsinchu, Taiwan
| | - Masashi Miura
- Department of Materials Science and Engineering, Stanford University, Stanford, CA, USA
- Graduate School of Science and Technology, Seikei University, Tokyo, Japan
| | - Brian Kirby
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, MD, USA
| | - Chong Bi
- Department of Electrical Engineering, Stanford University, Stanford, CA, USA
| | - Xiang Li
- Department of Materials Science and Engineering, Stanford University, Stanford, CA, USA
- Department of Electrical Engineering, Stanford University, Stanford, CA, USA
| | - Yong Deng
- Department of Materials Science and Engineering, Stanford University, Stanford, CA, USA
| | - Shy-Jay Lin
- Taiwan Semiconductor Manufacturing Company, Hsinchu, Taiwan
| | - Wilman Tsai
- Department of Materials Science and Engineering, Stanford University, Stanford, CA, USA
| | - Serena Eley
- Department of Physics, Colorado School of Mines, Golden, CO, USA
| | - Wei-Gang Wang
- Department of Physics, University of Arizona, Tucson, AZ, USA
| | - Julie A Borchers
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, MD, USA
| | - Evgeny Y Tsymbal
- Department of Physics and Astronomy & Nebraska Center for Materials and Nanoscience, University of Nebraska, Lincoln, NE, USA
| | - Shan X Wang
- Department of Materials Science and Engineering, Stanford University, Stanford, CA, USA.
- Department of Electrical Engineering, Stanford University, Stanford, CA, USA.
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14
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Fiorentini S, Jørstad NP, Ender J, de Orio RL, Selberherr S, Bendra M, Goes W, Sverdlov V. Finite Element Approach for the Simulation of Modern MRAM Devices. MICROMACHINES 2023; 14:mi14050898. [PMID: 37241522 DOI: 10.3390/mi14050898] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2023] [Revised: 04/14/2023] [Accepted: 04/20/2023] [Indexed: 05/28/2023]
Abstract
Because of their nonvolatile nature and simple structure, the interest in MRAM devices has been steadily growing in recent years. Reliable simulation tools, capable of handling complex geometries composed of multiple materials, provide valuable help in improving the design of MRAM cells. In this work, we describe a solver based on the finite element implementation of the Landau-Lifshitz-Gilbert equation coupled to the spin and charge drift-diffusion formalism. The torque acting in all layers from different contributions is computed from a unified expression. In consequence of the versatility of the finite element implementation, the solver is applied to switching simulations of recently proposed structures based on spin-transfer torque, with a double reference layer or an elongated and composite free layer, and of a structure combining spin-transfer and spin-orbit torques.
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Affiliation(s)
- Simone Fiorentini
- Christian Doppler Laboratory for Nonvolatile Magnetoresistive Memory and Logic at the Institute for Microelectronics, TU Wien, Gußhausstraße 27-29/E360, 1040 Vienna, Austria
- Institute for Microelectronics, TU Wien, Gußhausstraße 27-29/E360, 1040 Vienna, Austria
| | - Nils Petter Jørstad
- Christian Doppler Laboratory for Nonvolatile Magnetoresistive Memory and Logic at the Institute for Microelectronics, TU Wien, Gußhausstraße 27-29/E360, 1040 Vienna, Austria
- Institute for Microelectronics, TU Wien, Gußhausstraße 27-29/E360, 1040 Vienna, Austria
| | - Johannes Ender
- Christian Doppler Laboratory for Nonvolatile Magnetoresistive Memory and Logic at the Institute for Microelectronics, TU Wien, Gußhausstraße 27-29/E360, 1040 Vienna, Austria
- Institute for Microelectronics, TU Wien, Gußhausstraße 27-29/E360, 1040 Vienna, Austria
| | | | - Siegfried Selberherr
- Institute for Microelectronics, TU Wien, Gußhausstraße 27-29/E360, 1040 Vienna, Austria
| | - Mario Bendra
- Christian Doppler Laboratory for Nonvolatile Magnetoresistive Memory and Logic at the Institute for Microelectronics, TU Wien, Gußhausstraße 27-29/E360, 1040 Vienna, Austria
- Institute for Microelectronics, TU Wien, Gußhausstraße 27-29/E360, 1040 Vienna, Austria
| | | | - Viktor Sverdlov
- Christian Doppler Laboratory for Nonvolatile Magnetoresistive Memory and Logic at the Institute for Microelectronics, TU Wien, Gußhausstraße 27-29/E360, 1040 Vienna, Austria
- Institute for Microelectronics, TU Wien, Gußhausstraße 27-29/E360, 1040 Vienna, Austria
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15
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Huang X, Zhang L, Tong L, Li Z, Peng Z, Lin R, Shi W, Xue KH, Dai H, Cheng H, de Camargo Branco D, Xu J, Han J, Cheng GJ, Miao X, Ye L. Manipulating exchange bias in 2D magnetic heterojunction for high-performance robust memory applications. Nat Commun 2023; 14:2190. [PMID: 37069179 PMCID: PMC10110563 DOI: 10.1038/s41467-023-37918-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Accepted: 04/05/2023] [Indexed: 04/19/2023] Open
Abstract
The exchange bias (EB) effect plays an undisputed role in the development of highly sensitive, robust, and high-density spintronic devices in magnetic data storage. However, the weak EB field, low blocking temperature, as well as the lack of modulation methods, seriously limit the application of EB in van der Waals (vdW) spintronic devices. Here, we utilized pressure engineering to tune the vdW spacing of the two-dimensional (2D) FePSe3/Fe3GeTe2 heterostructures. The EB field (HEB, from 29.2 mT to 111.2 mT) and blocking temperature (Tb, from 20 K to 110 K) are significantly enhanced, and a highly sensitive and robust spin valve is demonstrated. Interestingly, this enhancement of the EB effect was extended to exposed Fe3GeTe2, due to the single-domain nature of Fe3GeTe2. Our findings provide opportunities for the producing, exploring, and tuning of magnetic vdW heterostructures with strong interlayer coupling, thereby enabling customized 2D spintronic devices in the future.
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Affiliation(s)
- Xinyu Huang
- School of Integrated Circuits, Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan, 430074, China
- Hubei Yangtze Memory Laboratories, Wuhan, 430205, China
| | - Luman Zhang
- Wuhan National High Magnetic Field Center and Department of Physics, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Lei Tong
- School of Integrated Circuits, Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Zheng Li
- School of Integrated Circuits, Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Zhuiri Peng
- School of Integrated Circuits, Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Runfeng Lin
- School of Integrated Circuits, Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Wenhao Shi
- School of Integrated Circuits, Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Kan-Hao Xue
- School of Integrated Circuits, Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Hongwei Dai
- Wuhan National High Magnetic Field Center and Department of Physics, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Hui Cheng
- Wuhan National High Magnetic Field Center and Department of Physics, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Danilo de Camargo Branco
- School of Industrial Engineering and Birck Nanotechnology Centre, Purdue University, West Lafayette, IN, 47907, USA
| | - Jianbin Xu
- Department of Electronic Engineering, Materials Science and Technology Research Center, The Chinese University of Hong Kong, Hong Kong, China
| | - Junbo Han
- Wuhan National High Magnetic Field Center and Department of Physics, Huazhong University of Science and Technology, Wuhan, 430074, China.
| | - Gary J Cheng
- School of Industrial Engineering and Birck Nanotechnology Centre, Purdue University, West Lafayette, IN, 47907, USA.
| | - Xiangshui Miao
- School of Integrated Circuits, Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan, 430074, China.
- Hubei Yangtze Memory Laboratories, Wuhan, 430205, China.
| | - Lei Ye
- School of Integrated Circuits, Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan, 430074, China.
- Hubei Yangtze Memory Laboratories, Wuhan, 430205, China.
- State Key Laboratory of Infrared Physics, Shanghai Institute of Technical Physics Chinese Academy of Sciences, Shanghai, 200083, China.
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16
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Chen Z, Liu X, Jiang J, Li R, Wang Y, Guo L, Xu Y, Mi W. Modulating Exchange Bias, Anisotropic Magnetoresistance, and Planar Hall Resistance of Flexible Co/MnN Epitaxial Bilayers on Mica by Bending Strain. ACS APPLIED MATERIALS & INTERFACES 2023; 15:6209-6216. [PMID: 36654188 DOI: 10.1021/acsami.2c21780] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
The integration of ferromagnetic/antiferromagnetic bilayers with exchange bias effect on flexible substrates is crucial for flexible spintronics. Here, the epitaxial Co/MnN bilayers are deposited on mica by facing-target sputtering. A large in-plane exchange bias field (HEB) of 1800 Oe with a coercive field (HC) of 2750 Oe appears in the Co (3.8 nm)/MnN (15.0 nm) bilayer at 5 K after field cooling from 300 to 5 K. Effective interfacial exchange energy Jeff of the Co/MnN bilayer is 0.83 erg/cm2. The strain-induced maximum increase of HEB and HC reaches 18% and 21%, respectively, in the Co(3.8 nm)/MnN(15.0 nm) bilayer. Strain-modulated HEB is attributed to the change of interfacial exchange coupling between Co and MnN layers. HEB is inversely proportional to Co thickness but independent of MnN thickness. The change of HEB is less than 5% after 100 bending cycles, indicating mechanical durability. The out-of-plane exchange bias also appears since Co spins are not fully reversed due to the strong pinning effect. Anisotropic magnetoresistance (AMR) and planar Hall resistance (Rxy) show obvious hysteresis due to HEB. Exchange bias-induced phase difference of AMR and Rxy almost remains unchanged at different bending strains. The results provide the basis for understanding the bending strain tailored exchange bias.
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Affiliation(s)
- Zuolun Chen
- Tianjin Key Laboratory of Low Dimensional Materials Physics and Preparation Technology, School of Science, Tianjin University, Tianjin300354, China
| | - Xiang Liu
- College of Science, Civil Aviation University of China, Tianjin300300, China
| | - Jiawei Jiang
- Tianjin Key Laboratory of Low Dimensional Materials Physics and Preparation Technology, School of Science, Tianjin University, Tianjin300354, China
| | - Rui Li
- Tianjin Key Laboratory of Low Dimensional Materials Physics and Preparation Technology, School of Science, Tianjin University, Tianjin300354, China
| | - Yue Wang
- Tianjin Key Laboratory of Low Dimensional Materials Physics and Preparation Technology, School of Science, Tianjin University, Tianjin300354, China
| | - Liu Guo
- Tianjin Key Laboratory of Low Dimensional Materials Physics and Preparation Technology, School of Science, Tianjin University, Tianjin300354, China
| | - Yingdan Xu
- Tianjin Key Laboratory of Low Dimensional Materials Physics and Preparation Technology, School of Science, Tianjin University, Tianjin300354, China
| | - Wenbo Mi
- Tianjin Key Laboratory of Low Dimensional Materials Physics and Preparation Technology, School of Science, Tianjin University, Tianjin300354, China
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17
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Wang L, Xiong J, Cheng B, Dai Y, Wang F, Pan C, Cao T, Liu X, Wang P, Chen M, Yan S, Liu Z, Xiao J, Xu X, Wang Z, Shi Y, Cheong SW, Zhang H, Liang SJ, Miao F. Cascadable in-memory computing based on symmetric writing and readout. SCIENCE ADVANCES 2022; 8:eabq6833. [PMID: 36490344 DOI: 10.1126/sciadv.abq6833] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
The building block of in-memory computing with spintronic devices is mainly based on the magnetic tunnel junction with perpendicular interfacial anisotropy (p-MTJ). The resulting asymmetric write and readout operations impose challenges in downscaling and direct cascadability of p-MTJ devices. Here, we propose that a previously unimplemented symmetric write and readout mechanism can be realized in perpendicular-anisotropy spin-orbit (PASO) quantum materials based on Fe3GeTe2 and WTe2. We demonstrate that field-free and deterministic reversal of the perpendicular magnetization can be achieved using unconventional charge-to-z-spin conversion. The resulting magnetic state can be readily probed with its intrinsic inverse process, i.e., z-spin-to-charge conversion. Using the PASO quantum material as a fundamental building block, we implement the functionally complete set of logic-in-memory operations and a more complex nonvolatile half-adder logic function. Our work highlights the potential of PASO quantum materials for the development of scalable energy-efficient and ultrafast spintronic computing.
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Affiliation(s)
- Lizheng Wang
- National Laboratory of Solid State Microstructures, Institute of Brain-Inspired Intelligence, School of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
| | - Junlin Xiong
- National Laboratory of Solid State Microstructures, Institute of Brain-Inspired Intelligence, School of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
| | - Bin Cheng
- Institute of Interdisciplinary Physical Sciences, School of Science, Nanjing University of Science and Technology, Nanjing 210094, China
| | - Yudi Dai
- National Laboratory of Solid State Microstructures, Institute of Brain-Inspired Intelligence, School of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
| | - Fuyi Wang
- National Laboratory of Solid State Microstructures, Institute of Brain-Inspired Intelligence, School of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
| | - Chen Pan
- Institute of Interdisciplinary Physical Sciences, School of Science, Nanjing University of Science and Technology, Nanjing 210094, China
| | - Tianjun Cao
- National Laboratory of Solid State Microstructures, Institute of Brain-Inspired Intelligence, School of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
| | - Xiaowei Liu
- National Laboratory of Solid State Microstructures, Institute of Brain-Inspired Intelligence, School of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
| | - Pengfei Wang
- National Laboratory of Solid State Microstructures, Institute of Brain-Inspired Intelligence, School of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
| | - Moyu Chen
- National Laboratory of Solid State Microstructures, Institute of Brain-Inspired Intelligence, School of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
| | - Shengnan Yan
- National Laboratory of Solid State Microstructures, Institute of Brain-Inspired Intelligence, School of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
| | - Zenglin Liu
- National Laboratory of Solid State Microstructures, Institute of Brain-Inspired Intelligence, School of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
| | - Jingjing Xiao
- Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Xianghan Xu
- Center for Quantum Materials Synthesis, and Department of Physics and Astronomy, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA
| | - Zhenlin Wang
- National Laboratory of Solid State Microstructures, Institute of Brain-Inspired Intelligence, School of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
| | - Youguo Shi
- Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Sang-Wook Cheong
- Center for Quantum Materials Synthesis, and Department of Physics and Astronomy, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA
| | - Haijun Zhang
- National Laboratory of Solid State Microstructures, Institute of Brain-Inspired Intelligence, School of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
| | - Shi-Jun Liang
- National Laboratory of Solid State Microstructures, Institute of Brain-Inspired Intelligence, School of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
| | - Feng Miao
- National Laboratory of Solid State Microstructures, Institute of Brain-Inspired Intelligence, School of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
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18
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Ultrafast switching in synthetic antiferromagnet with bilayer rare-earth transition-metal ferrimagnets. Sci Rep 2022; 12:19945. [DOI: 10.1038/s41598-022-24234-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Accepted: 11/11/2022] [Indexed: 11/21/2022] Open
Abstract
AbstractIn spintronics, it is important to be able to manipulate magnetization rapidly and reliably. Several methods can control magnetization, such as by applying current pulses or magnetic fields. An applied current can reverse magnetization with nanosecond speed through the spin torque effect. For faster switching, subpicosecond switching with femtoseconds laser pulse has been achieved in amorphous rare-earth transition-metal ferrimagnets. In this study, we employed atomistic simulations to investigate ultrafast switching in a synthetic antiferromagnet with bilayer amorphous FeGd ferrimagnets. Using a two-temperature model, we demonstrated ultrafast switching in this synthetic antiferromagnet without external magnetic fields. Furthermore, we showed that if we initially stabilize a skyrmion in this heterostructure, the ultrafast laser can switch the skyrmion state using the same mechanism. Furthermore, this bilayer design allows the control of each ferrimagnetic layer individually and opens the possibility for a magnetic tunnel junction.
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19
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Samardak AY, Jeon YS, Samardak VY, Kozlov AG, Rogachev KA, Ognev AV, Jeong E, Kim GW, Ko MJ, Samardak AS, Kim YK. Interwire and Intrawire Magnetostatic Interactions in Fe-Au Barcode Nanowires with Alternating Ferromagnetically Strong and Weak Segments. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2022; 18:e2203555. [PMID: 36192153 DOI: 10.1002/smll.202203555] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Revised: 09/07/2022] [Indexed: 06/16/2023]
Abstract
Metallic barcode nanowires (BNWs) composed of repeating heterogeneous segments fabricated by template-assisted electrodeposition can offer extended functionality in magnetic, electrical, mechanical, and biomedical applications. The authors consider such nanostructures as a 3D system of magnetically interacting elements with magnetic behavior strongly affected by complex magnetostatic interactions. This study discusses the influence of geometrical parameters of segments on the character of their interactions and the overall magnetic behavior of the array of BNWs having alternating magnetization, because the Fe and Au segments are made of Fe-Au alloys with high and low magnetizations. By controlling the applied current densities and the elapsed time in the electrodeposition, the dimension of the Fe-Au BNWs can be regulated. This study reveals that the influence of the length of magnetically weak Au segments on the interaction field between nanowires is different for samples with magnetically strong 100 and 200 nm long Fe segments using the first-order reversal curve (FORC) diagram method. With the help of micromagnetic simulations, three types of magnetostatic interactions in the BNW arrays are discovered and analy. This study demonstrates that the dominating type of interaction depends on the geometric parameters of the Fe and Au segments and the interwire and intrawire distances.
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Affiliation(s)
- Aleksei Yu Samardak
- Institute of High Technologies and Advanced Materials, Far Eastern Federal University, Vladivostok, 690922, Russia
| | - Yoo Sang Jeon
- Center for Hydrogen·Fuel Cell Research, Korea Institute of Science and Technology (KIST), Seoul, 02792, Republic of Korea
| | - Vadim Yu Samardak
- Institute of High Technologies and Advanced Materials, Far Eastern Federal University, Vladivostok, 690922, Russia
| | - Alexey G Kozlov
- Institute of High Technologies and Advanced Materials, Far Eastern Federal University, Vladivostok, 690922, Russia
| | - Kirill A Rogachev
- Institute of High Technologies and Advanced Materials, Far Eastern Federal University, Vladivostok, 690922, Russia
| | - Alexey V Ognev
- Institute of High Technologies and Advanced Materials, Far Eastern Federal University, Vladivostok, 690922, Russia
| | - Eunjin Jeong
- Department of Materials Science and Engineering, Korea University, Seoul, 02841, Republic of Korea
| | - Gyu Won Kim
- Department of Materials Science and Engineering, Korea University, Seoul, 02841, Republic of Korea
| | - Min Jun Ko
- Department of Materials Science and Engineering, Korea University, Seoul, 02841, Republic of Korea
| | - Alexander S Samardak
- Institute of High Technologies and Advanced Materials, Far Eastern Federal University, Vladivostok, 690922, Russia
| | - Young Keun Kim
- Department of Materials Science and Engineering, Korea University, Seoul, 02841, Republic of Korea
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20
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Li Y, Zha X, Zhao Y, Lu Q, Li B, Li C, Zhou Z, Liu M. Enhancing the Spin-Orbit Torque Efficiency by the Insertion of a Sub-nanometer β-W Layer. ACS NANO 2022; 16:11852-11861. [PMID: 35912431 DOI: 10.1021/acsnano.2c00093] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Spin-orbit torque (SOT) efficiency is one of the key issues of spintronics. However, enhancing the SOT efficiency is usually limited by the positive correlation between resistivity and the spin Hall ratio, where a high resistivity often accompanies a large spin Hall ratio. Here, we demonstrate that sub-nanometer β-W intercalation has a considerable impact on the SOT efficiency in α-W (6 nm)/Co (8 nm)/Pt (3 nm) samples. The damping-like SOT efficiency per unit current density, ξDLj, of α-W (5.7 nm)/β-W (0.3 nm)/Co (8 nm)/Pt (3 nm) shows a ∼ 296% enhancement compared to that of the α-W/Co/Pt system. Meanwhile, a resistivity similar to that of α-W and the spin Hall ratio larger than β-W induce a giant damping-like SOT efficiency per applied electric field, ξDLE, which is about 12.1 times larger than that of β-W. Our findings will benefit the SOT devices by reducing energy consumption.
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Affiliation(s)
- Yaojin Li
- Electronic Materials Research Laboratory, Key Laboratory of the Ministry of Education & International Center for Dielectric Research, School of Electronics and Information Engineering, the International Joint Laboratory for Micro/Nano Manufacturing and Measurement Technology, Xi'an Jiaotong University, Xi'an 710049, China
| | - Xi Zha
- Electronic Materials Research Laboratory, Key Laboratory of the Ministry of Education & International Center for Dielectric Research, School of Electronics and Information Engineering, the International Joint Laboratory for Micro/Nano Manufacturing and Measurement Technology, Xi'an Jiaotong University, Xi'an 710049, China
| | - Yifan Zhao
- Electronic Materials Research Laboratory, Key Laboratory of the Ministry of Education & International Center for Dielectric Research, School of Electronics and Information Engineering, the International Joint Laboratory for Micro/Nano Manufacturing and Measurement Technology, Xi'an Jiaotong University, Xi'an 710049, China
| | - Qi Lu
- Electronic Materials Research Laboratory, Key Laboratory of the Ministry of Education & International Center for Dielectric Research, School of Electronics and Information Engineering, the International Joint Laboratory for Micro/Nano Manufacturing and Measurement Technology, Xi'an Jiaotong University, Xi'an 710049, China
| | - Boyan Li
- Electronic Materials Research Laboratory, Key Laboratory of the Ministry of Education & International Center for Dielectric Research, School of Electronics and Information Engineering, the International Joint Laboratory for Micro/Nano Manufacturing and Measurement Technology, Xi'an Jiaotong University, Xi'an 710049, China
| | - Chunlei Li
- Electronic Materials Research Laboratory, Key Laboratory of the Ministry of Education & International Center for Dielectric Research, School of Electronics and Information Engineering, the International Joint Laboratory for Micro/Nano Manufacturing and Measurement Technology, Xi'an Jiaotong University, Xi'an 710049, China
| | - Ziyao Zhou
- Electronic Materials Research Laboratory, Key Laboratory of the Ministry of Education & International Center for Dielectric Research, School of Electronics and Information Engineering, the International Joint Laboratory for Micro/Nano Manufacturing and Measurement Technology, Xi'an Jiaotong University, Xi'an 710049, China
| | - Ming Liu
- Electronic Materials Research Laboratory, Key Laboratory of the Ministry of Education & International Center for Dielectric Research, School of Electronics and Information Engineering, the International Joint Laboratory for Micro/Nano Manufacturing and Measurement Technology, Xi'an Jiaotong University, Xi'an 710049, China
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21
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Liu Y, Slagle K, Burch KS, Alicea J. Dynamical Anyon Generation in Kitaev Honeycomb Non-Abelian Spin Liquids. PHYSICAL REVIEW LETTERS 2022; 129:037201. [PMID: 35905346 DOI: 10.1103/physrevlett.129.037201] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Accepted: 06/22/2022] [Indexed: 06/15/2023]
Abstract
Relativistic Mott insulators known as "Kitaev materials" potentially realize spin liquids hosting non-Abelian anyons. Motivated by fault-tolerant quantum-computing applications in this setting, we introduce a dynamical anyon-generation protocol that exploits universal edge physics. The setup features holes in the spin liquid, which define energetically cheap locations for non-Abelian anyons, connected by a narrow bridge that can be tuned between spin liquid and topologically trivial phases. We show that modulating the bridge from trivial to spin liquid over intermediate time scales-quantified by analytics and extensive simulations-deposits non-Abelian anyons into the holes with O(1) probability. The required bridge manipulations can be implemented by integrating the Kitaev material into magnetic tunnel junction arrays that engender locally tunable exchange fields. Combined with existing readout strategies, our protocol reveals a path to topological qubit experiments in Kitaev materials at zero applied magnetic field.
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Affiliation(s)
- Yue Liu
- Department of Physics and Institute for Quantum Information and Matter, California Institute of Technology, Pasadena, California 91125, USA
| | - Kevin Slagle
- Department of Physics and Institute for Quantum Information and Matter, California Institute of Technology, Pasadena, California 91125, USA
- Walter Burke Institute for Theoretical Physics, California Institute of Technology, Pasadena, California 91125, USA
| | - Kenneth S Burch
- Department of Physics, Boston College, Chestnut Hill, Massachusetts 02467, USA
| | - Jason Alicea
- Department of Physics and Institute for Quantum Information and Matter, California Institute of Technology, Pasadena, California 91125, USA
- Walter Burke Institute for Theoretical Physics, California Institute of Technology, Pasadena, California 91125, USA
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22
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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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23
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Two-dimensional materials prospects for non-volatile spintronic memories. Nature 2022; 606:663-673. [PMID: 35732761 DOI: 10.1038/s41586-022-04768-0] [Citation(s) in RCA: 47] [Impact Index Per Article: 23.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Accepted: 04/19/2022] [Indexed: 01/12/2023]
Abstract
Non-volatile magnetic random-access memories (MRAMs), such as spin-transfer torque MRAM and next-generation spin-orbit torque MRAM, are emerging as key to enabling low-power technologies, which are expected to spread over large markets from embedded memories to the Internet of Things. Concurrently, the development and performances of devices based on two-dimensional van der Waals heterostructures bring ultracompact multilayer compounds with unprecedented material-engineering capabilities. Here we provide an overview of the current developments and challenges in regard to MRAM, and then outline the opportunities that can arise by incorporating two-dimensional material technologies. We highlight the fundamental properties of atomically smooth interfaces, the reduced material intermixing, the crystal symmetries and the proximity effects as the key drivers for possible disruptive improvements for MRAM at advanced technology nodes.
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24
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Calavalle F, Suárez-Rodríguez M, Martín-García B, Johansson A, Vaz DC, Yang H, Maznichenko IV, Ostanin S, Mateo-Alonso A, Chuvilin A, Mertig I, Gobbi M, Casanova F, Hueso LE. Gate-tuneable and chirality-dependent charge-to-spin conversion in tellurium nanowires. NATURE MATERIALS 2022; 21:526-532. [PMID: 35256792 DOI: 10.1038/s41563-022-01211-7] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2021] [Accepted: 01/24/2022] [Indexed: 06/14/2023]
Abstract
Chiral materials are an ideal playground for exploring the relation between symmetry, relativistic effects and electronic transport. For instance, chiral organic molecules have been intensively studied to electrically generate spin-polarized currents in the last decade, but their poor electronic conductivity limits their potential for applications. Conversely, chiral inorganic materials such as tellurium have excellent electrical conductivity, but their potential for enabling the electrical control of spin polarization in devices remains unclear. Here, we demonstrate the all-electrical generation, manipulation and detection of spin polarization in chiral single-crystalline tellurium nanowires. By recording a large (up to 7%) and chirality-dependent unidirectional magnetoresistance, we show that the orientation of the electrically generated spin polarization is determined by the nanowire handedness and uniquely follows the current direction, while its magnitude can be manipulated by an electrostatic gate. Our results pave the way for the development of magnet-free chirality-based spintronic devices.
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Affiliation(s)
| | | | | | - Annika Johansson
- Institute of Physics, Martin Luther University Halle-Wittenberg, Halle, Germany
- Max Planck Institute of Microstructure Physics, Halle, Germany
| | - Diogo C Vaz
- CIC nanoGUNE BRTA, Donostia-San Sebastian, Spain
| | - Haozhe Yang
- CIC nanoGUNE BRTA, Donostia-San Sebastian, Spain
| | - Igor V Maznichenko
- Institute of Physics, Martin Luther University Halle-Wittenberg, Halle, Germany
| | - Sergey Ostanin
- Institute of Physics, Martin Luther University Halle-Wittenberg, Halle, Germany
| | - Aurelio Mateo-Alonso
- IKERBASQUE, Basque Foundation for Science, Bilbao, Spain
- POLYMAT, University of the Basque Country UPV/EHU, Donostia-San Sebastian, Spain
| | - Andrey Chuvilin
- CIC nanoGUNE BRTA, Donostia-San Sebastian, Spain
- IKERBASQUE, Basque Foundation for Science, Bilbao, Spain
| | - Ingrid Mertig
- Institute of Physics, Martin Luther University Halle-Wittenberg, Halle, Germany
| | - Marco Gobbi
- CIC nanoGUNE BRTA, Donostia-San Sebastian, Spain.
- IKERBASQUE, Basque Foundation for Science, Bilbao, Spain.
- Centro de Física de Materiales CSIC-UPV/EHU, Donostia-San Sebastian, Spain.
| | - Fèlix Casanova
- CIC nanoGUNE BRTA, Donostia-San Sebastian, Spain.
- IKERBASQUE, Basque Foundation for Science, Bilbao, Spain.
| | - Luis E Hueso
- CIC nanoGUNE BRTA, Donostia-San Sebastian, Spain.
- IKERBASQUE, Basque Foundation for Science, Bilbao, Spain.
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25
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Magnetisation switching dynamics induced by combination of spin transfer torque and spin orbit torque. Sci Rep 2022; 12:3380. [PMID: 35233036 PMCID: PMC8888771 DOI: 10.1038/s41598-022-07277-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2021] [Accepted: 02/15/2022] [Indexed: 11/09/2022] Open
Abstract
We present a theoretical investigation of the magnetisation reversal process in CoFeB-based magnetic tunnel junctions (MTJs). We perform atomistic spin simulations of magnetisation dynamics induced by combination of spin orbit torque (SOT) and spin transfer torque (STT). Within the model the effect of SOT is introduced as a Slonczewski formalism, whereas the effect of STT is included via a spin accumulation model. We investigate a system of CoFeB/MgO/CoFeB coupled with a heavy metal layer where the charge current is injected into the plane of the heavy metal meanwhile the other charge current flows perpendicular into the MTJ structure. Our results reveal that SOT can assist the precessional switching induced by spin polarised current within a certain range of injected current densities yielding an efficient and fast reversal on the sub-nanosecond timescale. The combination of STT and SOT gives a promising pathway to improve high performance CoFeB-based devices with high speed and low power consumption.
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26
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Tsunegi S, Taniguchi T, Suzuki D, Yakushiji K, Fukushima A, Yuasa S, Kubota H. Control of the stochastic response of magnetization dynamics in spin-torque oscillator through radio-frequency magnetic fields. Sci Rep 2021; 11:16285. [PMID: 34381110 PMCID: PMC8357834 DOI: 10.1038/s41598-021-95636-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Accepted: 07/21/2021] [Indexed: 11/09/2022] Open
Abstract
Neuromorphic computing using spintronic devices, such as spin-torque oscillators (STOs), has been intensively studied for energy-efficient data processing. One of the critical issues in this application is stochasticity in magnetization dynamics, which limits the accuracy of computation. Such stochastic behavior, however, plays a key role in stochastic computing and machine learning. It is therefore important to develop methods for both suppressing and enhancing stochastic response in spintronic devices. We report on experimental investigations on control of stochastic quantity, such as the width of a distribution of transient time in magnetization dynamics in vortex-type STO. The spin-transfer effect can suppress stochasticity in transient dynamics from a non-oscillating to oscillating state, whereas an application of a radio-frequency magnetic field is effective in reducing stochasticity on the time evolution of the oscillating state.
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Affiliation(s)
- Sumito Tsunegi
- National Institute of Advanced Industrial Science and Technology (AIST), Research Center for Emerging Computing Technologies, Tsukuba, 305-8568, Japan. .,Japan Science and Technology Agency (JST), PRESTO, 4-1-8 Honcho, Kawaguchi, Saitama, 332-0012, Japan.
| | - Tomohiro Taniguchi
- National Institute of Advanced Industrial Science and Technology (AIST), Research Center for Emerging Computing Technologies, Tsukuba, 305-8568, Japan.
| | - Daiki Suzuki
- National Institute of Advanced Industrial Science and Technology (AIST), Research Center for Emerging Computing Technologies, Tsukuba, 305-8568, Japan
| | - Kay Yakushiji
- National Institute of Advanced Industrial Science and Technology (AIST), Research Center for Emerging Computing Technologies, Tsukuba, 305-8568, Japan
| | - Akio Fukushima
- National Institute of Advanced Industrial Science and Technology (AIST), Research Center for Emerging Computing Technologies, Tsukuba, 305-8568, Japan
| | - Shinji Yuasa
- National Institute of Advanced Industrial Science and Technology (AIST), Research Center for Emerging Computing Technologies, Tsukuba, 305-8568, Japan
| | - Hitoshi Kubota
- National Institute of Advanced Industrial Science and Technology (AIST), Research Center for Emerging Computing Technologies, Tsukuba, 305-8568, Japan
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27
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One RA, Béa H, Mican S, Joldos M, Veiga PB, Dieny B, Buda-Prejbeanu LD, Tiusan C. Route towards efficient magnetization reversal driven by voltage control of magnetic anisotropy. Sci Rep 2021; 11:8801. [PMID: 33888853 PMCID: PMC8062633 DOI: 10.1038/s41598-021-88408-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Accepted: 04/12/2021] [Indexed: 11/09/2022] Open
Abstract
The voltage controlled magnetic anisotropy (VCMA) becomes a subject of major interest for spintronics due to its promising potential outcome: fast magnetization manipulation in magnetoresistive random access memories with enhanced storage density and very low power consumption. Using a macrospin approach, we carried out a thorough analysis of the role of the VCMA on the magnetization dynamics of nanostructures with out-of-plane magnetic anisotropy. Diagrams of the magnetization switching have been computed depending on the material and experiment parameters (surface anisotropy, Gilbert damping, duration/amplitude of electric and magnetic field pulses) thus allowing predictive sets of parameters for optimum switching experiments. Two characteristic times of the trajectory of the magnetization were analyzed analytically and numerically setting a lower limit for the duration of the pulses. An interesting switching regime has been identified where the precessional reversal of magnetization does not depend on the voltage pulse duration. This represents a promising path for the magnetization control by VCMA with enhanced versatility.
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Affiliation(s)
- Roxana-Alina One
- Faculty of Physics, Babes-Bolyai University, Cluj-Napoca, Cluj, Romania.,Univ. Grenoble Alpes, CEA, CNRS, G-INP, IRIG-SPINTEC, Grenoble, France
| | - Hélène Béa
- Univ. Grenoble Alpes, CEA, CNRS, G-INP, IRIG-SPINTEC, Grenoble, France
| | - Sever Mican
- Faculty of Physics, Babes-Bolyai University, Cluj-Napoca, Cluj, Romania
| | - Marius Joldos
- Technical University of Cluj-Napoca, Cluj-Napoca, Romania
| | | | - Bernard Dieny
- Univ. Grenoble Alpes, CEA, CNRS, G-INP, IRIG-SPINTEC, Grenoble, France
| | | | - Coriolan Tiusan
- Faculty of Physics, Babes-Bolyai University, Cluj-Napoca, Cluj, Romania. .,Technical University of Cluj-Napoca, Cluj-Napoca, Romania.
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28
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Zhu L, Zhu L, Buhrman RA. Fully Spin-Transparent Magnetic Interfaces Enabled by the Insertion of a Thin Paramagnetic NiO Layer. PHYSICAL REVIEW LETTERS 2021; 126:107204. [PMID: 33784166 DOI: 10.1103/physrevlett.126.107204] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Revised: 10/24/2020] [Accepted: 02/16/2021] [Indexed: 06/12/2023]
Abstract
Spin backflow and spin-memory loss have been well established to considerably lower the interfacial spin transmissivity of metallic magnetic interfaces and thus the energy efficiency of spin-orbit torque technologies. Here, we report that spin backflow and spin-memory loss at Pt-based heavy metal-ferromagnet interfaces can be effectively eliminated by inserting an insulating paramagnetic NiO layer of optimum thickness. The latter enables the thermal magnon-mediated essentially unity spin-current transmission at room temperature due to considerably enhanced effective spin-mixing conductance of the interface. As a result, we obtain dampinglike spin-orbit torque efficiency per unit current density of up to 0.8 as detected by the standard technology ferromagnet FeCoB and others, which reaches the expected upper-limit spin Hall ratio of Pt. We establish that Pt/NiO and Pt-Hf/NiO are two energy-efficient, integration-friendly, and high-endurance spin-current generators that provide >100 times greater energy efficiency than sputter-deposited topological insulators BiSb and BiSe. Our finding will benefit spin-orbitronic research and advance spin-torque technologies.
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Affiliation(s)
- Lijun Zhu
- Cornell University, Ithaca, New York 14850, USA
- State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, P.O. Box 912, Beijing 100083, China
| | - Lujun Zhu
- College of Physics and Information Technology, Shaanxi Normal University, Xi'an 710062, China
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29
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Real-time Hall-effect detection of current-induced magnetization dynamics in ferrimagnets. Nat Commun 2021; 12:656. [PMID: 33510163 PMCID: PMC7843968 DOI: 10.1038/s41467-021-20968-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2020] [Accepted: 01/07/2021] [Indexed: 01/30/2023] Open
Abstract
Measurements of the transverse Hall resistance are widely used to investigate electron transport, magnetization phenomena, and topological quantum states. Owing to the difficulty of probing transient changes of the transverse resistance, the vast majority of Hall effect experiments are carried out in stationary conditions using either dc or ac. Here we present an approach to perform time-resolved measurements of the transient Hall resistance during current-pulse injection with sub-nanosecond temporal resolution. We apply this technique to investigate in real-time the magnetization reversal caused by spin-orbit torques in ferrimagnetic GdFeCo dots. Single-shot Hall effect measurements show that the current-induced switching of GdFeCo is widely distributed in time and characterized by significant activation delays, which limit the total switching speed despite the high domain-wall velocity typical of ferrimagnets. Our method applies to a broad range of current-induced phenomena and can be combined with non-electrical excitations to perform pump-probe Hall effect measurements.
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30
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Shao Q, Li P, Liu L, Yang H, Fukami S, Razavi A, Wu H, Wang K, Freimuth F, Mokrousov Y, Stiles MD, Emori S, Hoffmann A, Åkerman J, Roy K, Wang JP, Yang SH, Garello K, Zhang W. Roadmap of spin-orbit torques. IEEE TRANSACTIONS ON MAGNETICS 2021; 57:10.48550/arXiv.2104.11459. [PMID: 37057056 PMCID: PMC10091395 DOI: 10.48550/arxiv.2104.11459] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
Spin-orbit torque (SOT) is an emerging technology that enables the efficient manipulation of spintronic devices. The initial processes of interest in SOTs involved electric fields, spin-orbit coupling, conduction electron spins and magnetization. More recently interest has grown to include a variety of other processes that include phonons, magnons, or heat. Over the past decade, many materials have been explored to achieve a larger SOT efficiency. Recently, holistic design to maximize the performance of SOT devices has extended material research from a nonmagnetic layer to a magnetic layer. The rapid development of SOT has spurred a variety of SOT-based applications. In this Roadmap paper, we first review the theories of SOTs by introducing the various mechanisms thought to generate or control SOTs, such as the spin Hall effect, the Rashba-Edelstein effect, the orbital Hall effect, thermal gradients, magnons, and strain effects. Then, we discuss the materials that enable these effects, including metals, metallic alloys, topological insulators, two-dimensional materials, and complex oxides. We also discuss the important roles in SOT devices of different types of magnetic layers, such as magnetic insulators, antiferromagnets, and ferrimagnets. Afterward, we discuss device applications utilizing SOTs. We discuss and compare three-terminal and two-terminal SOT-magnetoresistive random-access memories (MRAMs); we mention various schemes to eliminate the need for an external field. We provide technological application considerations for SOT-MRAM and give perspectives on SOT-based neuromorphic devices and circuits. In addition to SOT-MRAM, we present SOT-based spintronic terahertz generators, nano-oscillators, and domain wall and skyrmion racetrack memories. This paper aims to achieve a comprehensive review of SOT theory, materials, and applications, guiding future SOT development in both the academic and industrial sectors.
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Affiliation(s)
- Qiming Shao
- Department of Electronic and Computer Engineering, Hong Kong University of Science and Technology
| | - Peng Li
- Department of Electrical and Computer Engineering, Auburn University
| | - Luqiao Liu
- Electrical Engineering and Computer Science, Massachusetts Institute of Technology
| | - Hyunsoo Yang
- Department of Electrical and Computer Engineering, National University of Singapore
| | - Shunsuke Fukami
- Research Institute of Electrical Communication, Tohoku University
| | - Armin Razavi
- Department of Electrical and Computer Engineering, University of California, Los Angeles
| | - Hao Wu
- Department of Electrical and Computer Engineering, University of California, Los Angeles
| | - Kang Wang
- Department of Electrical and Computer Engineering, University of California, Los Angeles
| | | | | | - Mark D Stiles
- Alternative Computing Group, National Institute of Standards and Technology
| | | | - Axel Hoffmann
- Department of Materials Science and Engineering, University of Illinois Urbana-Champaign
| | | | - Kaushik Roy
- Department of Electrical and Computer Engineering, Purdue University
| | - Jian-Ping Wang
- Electrical and Computer Engineering Department, University of Minnesota
| | | | - Kevin Garello
- IMEC, Leuven, Belgium; CEA-Spintec, Grenoble, France
| | - Wei Zhang
- Physics Department, Oakland University
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31
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Abstract
Science, engineering, and medicine ultimately demand fast information processing with ultra-low power consumption. The recently developed spin-orbit torque (SOT)-induced magnetization switching paradigm has been fueling opportunities for spin-orbitronic devices, i.e., enabling SOT memory and logic devices at sub-nano second and sub-picojoule regimes. Importantly, spin-orbitronic devices are intrinsic of nonvolatility, anti-radiation, unlimited endurance, excellent stability, and CMOS compatibility, toward emerging applications, e.g., processing in-memory, neuromorphic computing, probabilistic computing, and 3D magnetic random access memory. Nevertheless, the cutting-edge SOT-based devices and application remain at a premature stage owing to the lack of scalable methodology on the field-free SOT switching. Moreover, spin-orbitronics poises as an interdisciplinary field to be driven by goals of both fundamental discoveries and application innovations, to open fascinating new paths for basic research and new line of technologies. In this perspective, the specific challenges and opportunities are summarized to exert momentum on both research and eventual applications of spin-orbitronic devices.
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Affiliation(s)
- Yi Cao
- Beijing Academy of Quantum Information Sciences, Beijing 100193, P. R. China
| | - Guozhong Xing
- Key Laboratory of Microelectronic Devices & Integrated Technology, Institute of Microelectronics, Chinese Academy of Sciences, Beijing 100029, P. R. China
| | - Huai Lin
- Key Laboratory of Microelectronic Devices & Integrated Technology, Institute of Microelectronics, Chinese Academy of Sciences, Beijing 100029, P. R. China
| | - Nan Zhang
- State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, P. R. China
| | - Houzhi Zheng
- State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, P. R. China
| | - Kaiyou Wang
- Beijing Academy of Quantum Information Sciences, Beijing 100193, P. R. China
- State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, P. R. China
- Corresponding author
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