Article
Chemistry, Multidisciplinary
Hyun-Joong Kim, Soong-Geun Je, Kyoung-Woong Moon, Won-Chang Choi, Seungmo Yang, Changsoo Kim, Bao Xuan Tran, Chanyong Hwang, Jung-Il Hong
Summary: Research has shown the programmable exchange-coupled DW motion in antiferromagnet/ferromagnet system, where the role of an external in-plane field is replaced by the exchange bias field from the antiferromagnetic layer, enabling external field-free modulations of DW motions. Furthermore, the direction of the exchange bias field can be reconfigured by simply injecting spin currents through the device, enabling electrical and programmable operations of the device.
Article
Materials Science, Multidisciplinary
Dong-Hyun Kim, Se-Hyeok Oh, Dong-Kyu Lee, Se Kwon Kim, Kyung-Jin Lee
Summary: The study investigates the modification of ferrimagnetic spin-wave dynamics induced by electrical current, showing that the sign of the Doppler shift is influenced by the handedness of spin waves. When electrons move in the same direction as spin-wave propagation, the attenuation lengths of both right- and left-handed spin waves increase.
Article
Physics, Multidisciplinary
Guangjian Gong, Yu Wang, Jingguo Hu
Summary: The track memory based on current driven magnetic domain wall motion is a potential device for the next generation of magnetic information storage. By investigating the physical mechanisms of spin wave assisting current driven domain wall motion, it has been found that the spin wave assistance can enhance or weaken the movement depending on the driving current and spin wave parameters.
Article
Engineering, Electrical & Electronic
Qiuyuan Wang, Yi Zeng, Kai Yuan, Qingqi Zeng, Pingfan Gu, Xiaolong Xu, Hanwen Wang, Zheng Han, Kentaro Nomura, Wenhong Wang, Enke Liu, Yanglong Hou, Yu Ye
Summary: The efficiency of spintronic devices can be improved by generating higher effective magnetic fields with lower working currents. Spin-transfer torques can drive magnetic domain wall motion in a device composed of a single material. Here, we report magnetism modulation in Co3Sn2S2-a magnetic Weyl semimetal-via spin-transfer-torque-driven domain wall motion. The threshold current density for driving domain wall motion is less than 5.1 x 10(5) A cm(-2) at zero external field and less than 1.5 x 10(5) A cm(-2) at a moderate external field (0.2 kOe). The spin-transfer-torque effective field can reach as high as 2.4-5.6 kOe MA(-1) cm(2) at 150 K.
NATURE ELECTRONICS
(2023)
Article
Materials Science, Multidisciplinary
J. Chureemart, S. Sampan-a-pai, S. Boonchui, R. W. Chantrell, P. Chureemart
Summary: The current-induced domain wall motion driven by spin Hall effect and spin-transfer torque was investigated using an atomistic model. It was found that domain walls were more easily moved with higher velocity and lower critical current density in the presence of spin Hall effect compared to spin torque.
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
(2021)
Article
Materials Science, Multidisciplinary
V. V. Yurlov, K. A. Zvezdin, P. N. Skirdkov, A. K. Zvezdin
Summary: This theoretical study focuses on the spin current excited dynamics of domain walls in ferrimagnets near the angular momentum compensation point. The analysis considers the effects of spin torques and external magnetic fields on the dynamics of domain walls. Different polarization directions of the spin current have different effects on the mobility of domain walls and the excitation of dynamics, with interesting implications for the behavior of domain walls in such systems.
Article
Materials Science, Multidisciplinary
Myeonghoe Kim, Seong-Hyub Lee, Minhwan Kim, Kitae Kim, Jaesung Yoon, Jung-Hyun Park, Sug -Bong Choe
Summary: The experimental observation shows that the Dzyaloshinskii-Moriya interaction (DMI) plays a decisive role in the domain-wall tilting for various films, indicating the dominance of DMI-induced mechanism in the efficient current-driven domain-wall motion for practical films.
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
(2022)
Article
Chemistry, Multidisciplinary
Durgesh Kumar, Hong Jing Chung, JianPeng Chan, Tianli Jin, Sze Ter Lim, Stuart S. P. Parkin, Rachid Sbiaa, S. N. Piramanayagam
Summary: Neuromorphic computing is a potential technology for low power intelligent devices. Spintronics-based neurons and synapses have higher endurance. By engineering the beta-W spin-orbit coupling material, we achieved low energy domain wall motion. The energy consumption for moving the domain wall is 27 aJ/bit, showing the potential for ultralow energy spin-based neuromorphic elements.
Article
Chemistry, Multidisciplinary
Durgesh Kumar, Hong Jing Chung, JianPeng Chan, Tianli Jin, Sze Ter Lim, Stuart S. P. Parkin, Rachid Sbiaa, S. N. Piramanayagam
Summary: Neuromorphic computing is a potential technology for low-power intelligent devices. Spintronics-based neurons and synapses have higher endurance, but low-energy domain wall devices are preferred for low-power devices. By engineering the beta-W spin-orbit coupling material, we achieve low-current density DW motion with ultralow energy consumption and current density reduction.
Article
Physics, Fluids & Plasmas
M. H. Jin, L. Xiong, N. J. Zhou, B. Zheng, T. J. Zhou
Summary: By numerically simulating the creep motion of a magnetic domain wall driven by electric current, we accurately determined the creep exponent and roughness exponent from scaling behaviors, finding that the adiabatic and nonadiabatic spin-transfer torques belong to different universality classes and exhibit different scaling relations. Our results are in line with experimental data, but surpass existing theoretical predictions, revealing the impact of disorder-induced pinning effect on altering the universality class of creep motion.
Article
Optics
Maturine Megne Foham, Paul Andre Paglan, Jean Pierre Nguenang
Summary: In this paper, we investigate the dynamics of a 180 degrees magnetic domain-wall driven by an electric current using cylindrical coordinates and adiabatic and non-adiabatic spin-transfer torques. We establish suitable expressions for characteristic parameters such as saturation distortion and critical electric current density, which are consistent with numerical simulations. We discuss the symmetry of these parameters and the domain-wall velocity with respect to the non-adiabatic spin-transfer parameter. To solve the equation of motion governing the domain-wall dynamics, we employ a Taylor expansion-based method, which provides analytical solutions that match with numerical results at different approximation orders.
EUROPEAN PHYSICAL JOURNAL D
(2023)
Article
Optics
Ken-ichi Aoshima, Nobuhiko Funabashi, Ryo Higashida, Mayumi Kawana, Shintaro Aso, Junichi Shibasaki, Yuta Yamaguchi, Kenji Machida
Summary: We have developed a magneto-optical spatial light modulator (MO-SLM) with a high pixel layout. The MO-SLM device pixel utilizes a magnetic nanowire made of Gd-Fe magneto-optical material to reverse magnetization. We successfully demonstrated the reconstruction of holographic images, showing large viewing zone angles and visualizing different depths of objects.
Article
Engineering, Electrical & Electronic
Zhen Cao, Shuai Zhang, Jian Zhang, Nuo Xu, Ruofan Li, Zhe Guo, Jijun Yun, Min Song, Qiming Zou, Li Xi, Oukjae Lee, Xiaofei Yang, Xuecheng Zou, Jeongmin Hong, Long You
Summary: A reliable physical unclonable function (PUF) design based on spin-orbit torque induced domain wall motion has been proposed and experimentally demonstrated. The device-to-device variation enables PUF functionality, while cycle-to-cycle variation in domain wall motion enables reconfigurable design. This anti-counterfeiting device based on domain wall motion shows good potential as a CMOS-compatible PUF for hardware security.
IEEE ELECTRON DEVICE LETTERS
(2021)
Article
Chemistry, Multidisciplinary
Ziyang Yu, Bin Gong, Lun Xiong, Xinran Du, Chenhuinan Wei, Rui Xiong, Zhihong Lu, Yue Zhang
Summary: This paper proposes a racetrack memory with the advantages of small size and high reading speed based on current-induced domain wall motion in a ferromagnetic nanowire. The enhancement of domain wall velocity can be achieved by inter-wire magnetostatic coupling in a double nanowire system. By adjusting the magnetic anisotropy constant difference, the manipulation of working current density is possible.
NANOSCALE ADVANCES
(2022)
Article
Materials Science, Multidisciplinary
I. L. Kindiak, P. N. Skirdkov, K. A. Tikhomirova, K. A. Zvezdin, E. G. Ekomasov, A. K. Zvezdin
Summary: This study presents a numerical and analytical investigation of the dynamics of domain walls in a magnetic tunnel junction with perpendicular magnetic anisotropy in a free layer. It explores the equilibrium states, symmetries of components of spin transfer torques, and stable DW motion under perpendicular current injection. The study also reports DW steady motion with velocities up to 200 m/s at current densities below 10^6 A/cm^2, demonstrating the Walker breakdown and investigating the dynamics of postthreshold DW motion for various configurations of torques and polarizer directions.
Article
Materials Science, Multidisciplinary
Franziska Martin, Kyujoon Lee, Maurice Schmitt, Anna Liedtke, Aga Shahee, Haakon Thomt Simensen, Tanja Scholz, Tom G. Saunderson, Dongwook Go, Martin Gradhand, Yuriy Mokrousov, Thibaud Denneulin, Andras Kovacs, Bettina Lotsch, Arne Brataas, Mathias Klaeui
Summary: We investigate the current-induced magnetisation manipulation in two-dimensional Fe3GeTe2 material and find that its crystalline structure allows for the presence of both interfacial and bulk spin-orbit torques, enabling efficient magnetisation switching without the need for complex multilayer engineering.
MATERIALS RESEARCH LETTERS
(2023)
Article
Physics, Applied
Marie-Luise Braatz, Nils-Eike Weber, Barthi Singh, Klaus Muellen, Xinliang Feng, Mathias Klaeui, Martin Gradhand
Summary: In this study, the structural and electronic properties of co-doped graphene were analyzed using Raman spectroscopy, magneto-transport, and Hall measurements. The results demonstrate the challenges in understanding the microscopic properties of graphene beyond simple preparation methods, as the introduction of dopants can have complex effects. Additionally, the inhomogeneities across individual graphene sheets pose challenges in interpreting measurements.
JOURNAL OF APPLIED PHYSICS
(2023)
Article
Physics, Applied
Hiroto Masuda, Yuta Yamane, Takeshi Seki, Klaus Raab, Takaaki Dohi, Rajkumar Modak, Ken-ichi Uchida, Jun'ichi Ieda, Mathias Klaui, Koki Takanashi
Summary: We report current-induced magnetization switching in Pt/Co/Ir/Co/Pt multilayers with different Ir layer thicknesses. The domain structures formed during switching vary depending on the magnetization alignment, either ferromagnetic or antiferromagnetic. Numerical calculations reveal the switching dynamics triggered by dual spin-orbit torques for both cases. Our findings deepen the understanding of the switching mechanism in magnetic multilayers and provide a pathway for designing spintronic devices with more efficient spin-orbit torque switching.
APPLIED PHYSICS LETTERS
(2023)
Article
Physics, Applied
H. Meer, O. Gomonay, A. Wittmann, M. Klaeui
Summary: Antiferromagnetic transition metal oxides are extensively studied in the field of spin-based electronics, commonly used as passive elements in exchange bias-based memory devices. Recent observations of long-distance spin transport, current-induced switching, and THz emission have renewed interest in these insulating materials, which are now considered attractive candidates for active elements in future spintronic devices. This article discusses promising materials systems and recent advances in reading and writing antiferromagnetic ordering, providing an overview of current research and potential future directions in the field of antiferromagnetic insulatronics.
APPLIED PHYSICS LETTERS
(2023)
Article
Physics, Applied
G. Masciocchi, M. Fattouhi, E. Spetzler, M. -A Syskaki, R. Lehndorff, E. Martinez, J. McCord, L. Lopez-Diaz, A. Kehlberger, M. Klaeui
Summary: In this work, the authors propose a CMOS-compatible and inexpensive method for applying local strain on a Si/SiOx substrate. They demonstrate how the magnetoelastic energy landscape created by a pair of openings can be used to create pinning sites in a magnetic nanowire, leading to changes in the local magnetic anisotropy. The experimental results are supported by simulations and calculations, and the authors discuss the potential applications of this technology.
APPLIED PHYSICS LETTERS
(2023)
Article
Physics, Applied
Oscar Lee, Robin Msiska, Maarten A. Brems, Mathias Klaeui, Hidekazu Kurebayashi, Karin Everschor-Sitte
Summary: Learning and pattern recognition require memory, which is simulated artificially in conventional CMOS hardware. Dynamical systems naturally provide the necessary memory, complexity, and nonlinearity for unconventional computing approaches. This article focuses on reservoir computing and provides an overview of key physical reservoir works, particularly in the promising platform of magnetic structures, such as skyrmions, for low-power applications. The article also discusses skyrmion-based implementations of Brownian computing, leveraging thermal fluctuations in skyrmion systems, and outlines the important challenges in this field.
APPLIED PHYSICS LETTERS
(2023)
Article
Physics, Applied
Giovanni Masciocchi, Thomas J. Kools, Pingzhi Li, Adrien A. D. Petrillo, Bert Koopmans, Reinoud Lavrijsen, Andreas Kehlberger, Mathias Klaeui
Summary: In this work, the effects of strain on the perpendicular magnetic anisotropy and magnetization compensation of Co/Gd and Co/Gd/Co/Gd synthetic ferrimagnets are systematically studied. It is found that the presence of in-plane strain increases the perpendicular magnetic anisotropy in the bilayer system. The magnetization compensation of the quadlayer system is not altered by external strain, indicating the resilience of the Co/Gd ferrimagnets against strain. These findings make them suitable candidates for spintronics applications.
JOURNAL OF APPLIED PHYSICS
(2023)
Article
Chemistry, Physical
Yael Kapon, Fabian Kammerbauer, Shira Yochelis, Mathias Klaeui, Yossi Paltiel
Summary: Chiral molecules have the potential to create new magnetic devices by locally manipulating the magnetic properties of metallic surfaces. By chemisorbing onto ferromagnets, chiral polypeptides can induce magnetization locally through spin exchange interactions. In this study, magneto-optical Kerr microscopy was used to directly image surface magnetization changes induced by chiral molecules, demonstrating their ability to control and manipulate magnetization.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Physics, Multidisciplinary
Fabian Kammerbauer, Frank Freimuth, Robert Froemter, Yuriy Mokrousov, Mathias Klaeui
Summary: The Dzyaloshinskii-Moriya interaction (DMI) is crucial in the design of advanced spintronic devices, enabling the stabilization of domain walls and topologically non-trivial magnetic textures. This review focuses on the potential to manipulate DMI through electrical fields and currents, offering post-growth control over the sign and strength of DMI. The effects of currents and fields are discussed from both a theoretical and experimental perspective.
JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN
(2023)
Article
Chemistry, Multidisciplinary
Fabian Kammerbauer, Won-Young Choi, Frank Freimuth, Kyujoon Lee, Robert Froemter, Dong-Soo Han, Reinoud Lavrijsen, Henk J. M. Swagten, Yuriy Mokrousov, Mathias Klaeui
Summary: The recently discovered interlayer Dzyaloshinskii-Moriya interaction (IL-DMI) in multilayers with perpendicular magnetic anisotropy can stabilize intriguing spin textures such as Hopfions. To control the IL-DMI, the influence of an electric current on a synthetic antiferromagnet with growth-induced IL-DMI was investigated. The study revealed that the azimuthal dependence of IL-DMI shifts with increasing current, suggesting the presence of an additional current-induced term that linearly increases the IL-DMI in the direction of current flow, opening the possibility of easily manipulating 3D spin textures by currents.
Article
Chemistry, Physical
Gokaran Shukla, Hasan M. Abdullah, Avijeet Ray, Shubham Tyagi, Aurelien Manchon, Stefano Sanvito, Udo Schwingenschlogl
Summary: In this study, we investigate the possibility of using ZnSe and ZnTe as tunnel barrier materials in magnetic spin valves. Our calculations reveal that in the Fe/ZnSe/Fe junction, a tunneling-like transport occurs with a symmetry-filtering mechanism resulting in a potentially large tunneling magnetoresistance (TMR) ratio. In the Fe/ZnTe/Fe junction, only a giant magnetoresistance effect is observed. These findings provide evidence for the utilization of chalcogenide-based tunnel barriers in spintronics devices.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2023)
Article
Materials Science, Multidisciplinary
Tobias Dannegger, Andras Deak, Levente Rozsa, E. Galindez-Ruales, Shubhankar Das, Eunchong Baek, Mathias Klaeui, Laszlo Szunyogh, Ulrich Nowak
Summary: In this study, ab initio calculations were performed to investigate the tensorial exchange interactions of hematite, and a semiclassical Heisenberg spin model was used to understand its magnetic properties. Atomistic spin dynamics simulations were carried out to calculate the equilibrium properties and phase transitions of hematite, particularly the Morin transition. The computed isotropic and Dzyaloshinskii-Moriya interactions were found to agree well with experimental measurements of the Neel temperature and weak ferromagnetic canting angle. Our simulations revealed the delicate balance between dipole-dipole interactions and on-site anisotropies in determining the magnetic phase of the material. Comparison with spin-Hall magnetoresistance measurements on a hematite single crystal showed deviations of the critical behavior at low temperatures, which were attributed to the quantum nature of the fluctuations driving the phase transitions.
Article
Materials Science, Multidisciplinary
Arnab Bose, Fabian Kammerbauer, Rahul Gupta, Dongwook Go, Yuriy Mokrousov, Gerhard Jakob, Mathias Klaeui
Summary: We report and quantify a large orbital-Hall torque generated by Nb and Ru in this study, identified by the strong dependence of the torques on the ferromagnets. We observed a strong enhancement in the dampinglike torques measured in Nb (or Ru)/Ni bilayers compared to Nb (or Ru)/FeCoB bilayers, including a sign reversal in the case of Nb/(Ni or FeCoB) samples. Furthermore, we discovered a significant increase in the measured torques with the increase of ferromagnetic Ni thickness, which may indicate the unique signature of long-range action of the orbital-Hall torques.
Article
Materials Science, Multidisciplinary
Diego Garcia Ovalle, Armando Pezo, Aurelien Manchon
Summary: Spin-orbit torques in noncentrosymmetric polycrystalline magnetic heterostructures are usually described in terms of field-like and damping-like torques. However, based on symmetry arguments, it was recently proposed that systems belonging to the C3v point group display unconventional spin-orbit torques that can promote field-free switching. In this work, the general form of these torques in C3v crystals is analyzed using invariant theory, and several new components arising from the coexistence of threefold rotation and mirror symmetries are uncovered. Tight binding model and first principles simulations show that these unconventional torque components arise from the onset of trigonal warping of the Fermi surface and can be comparable in magnitude to the damping-like torque, indicating the importance of Fermi surface warping for field-free switching in low symmetry crystals.
Article
Materials Science, Multidisciplinary
Eun-Sang Park, Dong-Kyu Lee, Fei Xue, Byoung-Chul Min, Hyun Cheol Koo, Paul M. Haney, Kyoung-Whan Kim, Kyung-Jin Lee
Summary: The symmetry of normal metal/ferromagnet bilayers allows spin-orbit torques (SOTs) to have two distinct angular dependences on the magnetization direction. The most studied forms of SOT are the lowest-order SOT, which consist of fieldlike and dampinglike torques. There are also higher-order SOT forms that have different spin polarization and an additional factor of magnetization direction dependence. This study measures both the lowest-order and higher-order angular dependences of SOTs in three types of bilayers and finds that the higher-order SOT is dominant for one type of bilayer while negligible for the others. Macrospin simulations show that higher-order SOT can significantly affect magnetization dynamics, which aligns with SOT-induced switching experiments.
