Article
Materials Science, Multidisciplinary
Miela J. Gross, Jackson J. Bauer, Supriya Ghosh, Subhajit Kundu, Kensuke Hayashi, Ethan R. Rosenberg, K. Andre Mkhoyan, Caroline A. Ross
Summary: The crystallization of rare earth iron garnet films on Si substrates provides a way to integrate these complex oxides into magnetic devices. The growth of dysprosium yttrium iron garnet films and the effect of Y:Dy ratio on magnetization and anisotropy were studied. In order to crystallize thinner films, tri-layer stacks were prepared and showed promising results.
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
(2022)
Review
Chemistry, Physical
Yucong Yang, Tao Liu, Lei Bi, Longjiang Deng
Summary: Magnetic garnets possess superior magnetic and optical properties, making them ideal for next-generation spintronic and photonic devices with low energy consumption, room temperature operation, and high integration density. Significant progress has been made in developing high-quality MG thin films and exploring their applications in spintronics and photonics.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Chemistry, Multidisciplinary
Hendrik Meer, Stephan Wust, Christin Schmitt, Paul Herrgen, Felix Fuhrmann, Steffen Hirtle, Beatrice Bednarz, Adithya Rajan, Rafael Ramos, Miguel Angel Nino, Michael Foerster, Florian Kronast, Armin Kleibert, Baerbel Rethfeld, Eiji Saitoh, Benjamin Stadtmueller, Martin Aeschlimann, Mathias Klaeui
Summary: The antiferromagnetic order in NiO/Pt thin film heterostructures can be altered by optical pulses. Using X-ray magnetic linear dichroism, the optically induced creation of antiferromagnetic domains can be visualized. The effect of different laser polarizations on domain formation can be studied to identify polarization-independent creation of 180 degrees domain walls and domains with different Neel vector orientations. By varying irradiation parameters, the switching mechanism was determined to be thermally induced. This study demonstrates the potential for optically creating antiferromagnetic domains, an important advancement in the functionalization of all optical switching mechanisms in antiferromagnets.
ADVANCED FUNCTIONAL MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Lakhan Bainsla, Akash Kumar, Ahmad A. Awad, Chunlei Wang, Mohammad Zahedinejad, Nilamani Behera, Himanshu Fulara, Roman Khymyn, Afshin Houshang, Jonas Weissenrieder, Johan Akerman
Summary: This study investigates the characteristics of ultrathin ferrimagnetic films, and for the first time, observes nearly compensated behavior in 2 nm thick Gd-x(Fe87.5Co12.5)(1-x) films, showing great potential for the development of ultrafast and energy efficient ferrimagnetic spintronic devices.
ADVANCED FUNCTIONAL MATERIALS
(2022)
Article
Chemistry, Multidisciplinary
Boris Seng, Daniel Schoenke, Javier Yeste, Robert M. Reeve, Nico Kerber, Daniel Lacour, Jean-Lois Bello, Nicolas Bergeard, Fabian Kammerbauer, Mona Bhukta, Tom Ferte, Christine Boeglin, Florin Radu, Radu Abrudan, Torsten Kachel, Stephane Mangin, Michel Hehn, Mathias Klaeui
Summary: Chiral spin structures in ferrimagnetic Ta/Ir/Fe/GdFeCo/Pt multilayers were studied using scanning electron microscopy with polarization analysis (SEMPA) as a function of temperature. GdFeCo ferrimagnet exhibited right-handed Neel-type domain wall (DW) spin textures over a large temperature range, indicating a negative Dzyaloshinskii-Moriya interaction from both the top Fe/Pt and Co/Pt interfaces. Measurements of the DW width and complementary magnetic characterization confirmed the relatively constant exchange stiffness with temperature, supporting theoretical predictions. Additionally, a pure Neel-type skyrmionium was identified through direct imaging, showing potential for application in next-generation spintronic devices due to the expected vanishing skyrmion Hall angle.
ADVANCED FUNCTIONAL MATERIALS
(2021)
Article
Multidisciplinary Sciences
F. Rahimi, A. Phirouznia
Summary: The spin-photo current in single layer stanene and germanene under a linearly polarized light is theoretically investigated, and it is found that a pure spin-photo current can be generated in two-dimensional lattices with large intrinsic spin-orbit coupling by considering the simultaneous effect of linear illumination and a vertical external electric field without any magnetic exchange element.
SCIENTIFIC REPORTS
(2022)
Article
Chemistry, Multidisciplinary
Tianhui Li, Long Liu, Xiaoguang Li, Xiaotian Zhao, Hongyu An, Kazuya Ando
Summary: A giant orbital-to-spin conversion is observed in Ta/Pt/Tm3Fe5O12 (TmIG) heterostructures, where orbital current generated from Ta through the orbital Hall effect (OHE) is converted to spin current in the interior of Pt. The torque generation efficiency is enhanced by an order of magnitude in the Ta/Pt/TmIG trilayer compared to the Pt/TmIG bilayer.
Article
Physics, Multidisciplinary
Andrzej Stupakiewicz, Takuya Satoh
Summary: This review discusses ultrafast magnetization dynamics in ferrimagnetic rare-earth iron garnets with different substitutions within the gigahertz to terahertz frequency range. The roles of spin-orbit and exchange interactions are detected using femtosecond laser pulses, showing all-optical control of spin-wave and exchange resonance modes. The study also observes the enhancement of exchange resonance modes through metal-bound surface plasmon-polaritons and the observation of exchange resonance mode in yttrium iron garnets using circularly polarized Raman spectroscopy.
JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN
(2021)
Article
Chemistry, Multidisciplinary
Yu Fu, Jing Li, Jules Papin, Paul Noel, Salvatore Teresi, Maxen Cosset-Cheneau, Cecile Grezes, Thomas Guillet, Candice Thomas, Yann-Michel Niquet, Philippe Ballet, Tristan Meunier, Jean-Philippe Attane, Albert Fert, Laurent Vila
Summary: Spin-orbit effects in topological insulators and at Rashba interfaces have led to various newly discovered effects. In this study, a bilinear magnetoresistance phenomenon was observed in strained HgTe, and its amplitude and sign could be controlled by adjusting the contributions from opposite surfaces using an electric gate.
Article
Materials Science, Multidisciplinary
Yanzhu Chen, Sheng-Jie Huang, Yi-Ting Hsu, Tzu-Chieh Wei
Summary: This study systematically obtains topological invariants for two-dimensional time-reversal symmetric superconductors with twofold rotational symmetry C2. It proposes four Z2 invariants to predict Majorana boundary types and demonstrates their effectiveness.
Article
Materials Science, Multidisciplinary
Katsuhiro Tanaka, Takuya Nomoto, Ryotaro Arita
Summary: We investigate the tunneling magnetoresistance (TMR) effect using lattice models for magnetic tunnel junctions (MTJs). By analyzing the local density of states (LDOS) at the center of the barrier, we find that it qualitatively traces the TMR effect. The LDOS contains information on the electrodes and electron tunneling, allowing for a more precise evaluation of tunneling conductance. Furthermore, our findings show that the TMR effect in ferrimagnetic MTJs can be influenced by interfacial magnetic structures, which can also be captured by the LDOS.
Review
Physics, Applied
Zeyu Zhang, Wenbo Mi
Summary: This review systematically summarizes and discusses the progress, fabrication methods, physical properties, tunable magnetic properties, and potential applications of Mn4N films and its heterostructures. These research findings provide important guidance for developing novel applications and designing functional devices.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2022)
Article
Nanoscience & Nanotechnology
Zhang Wei, Huang Tian Xun, Michel Hehn, Gregory Malinowski, Maxime Verges, Julius Hohlfeld, Quentin Remy, Daniel Lacour, Wang Xin Ran, Zhao Guo Ping, Pierre Vallobra, Xu Yong, Stephane Mangin, Zhao Wei Sheng
Summary: This study demonstrates that the laser-magnetic phase transition process induced by femtosecond laser pulses can be mediated by the transient inplane magnetization state, resulting in the formation of topological skyrmions in real time and space domains. By combining experiments and micromagnetic simulations, a two-step process for creating skyrmions through laser pulse irradiation is proposed.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Nanoscience & Nanotechnology
Wei Zhang, Tian Xun Huang, Michel Hehn, Gregory Malinowski, Maxime Verges, Julius Hohlfeld, Quentin Remy, Daniel Lacour, Xin Ran Wang, Guo Ping Zhao, Pierre Vallobra, Yong Xu, Stephane Mangin, Wei Sheng Zhao
Summary: Manipulating magnetic skyrmions using a femtosecond laser pulse has attracted attention due to their potential applications in energy-efficient information-storage devices. However, the mechanism for the creation of skyrmions induced by an fs laser is still unknown, and the challenge lies in understanding the transition from trivial to nontrivial magnetic states.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Chemistry, Multidisciplinary
Tianhui Li, Lin Liu, Zehan Chen, Wei Jia, Jianxin Ye, Xudong Cai, Doudou Huang, Wanshan Li, Fukang Chen, Xinjun Li, Jiahao Chen, Boxi Dong, Hang Xie, Anyuan Pan, Chao Zhi, Hongyu An
Summary: Studying the mechanism of the spin Hall effect in Pt/Tm3Fe5O12 heterostructures, we demonstrate the intrinsic contribution in the moderately dirty regime is responsible for the generation of this spin Hall effect, through tuning the properties of Pt and investigating the efficiency of spin-orbit torque generation.
Article
Chemistry, Multidisciplinary
Peng Li, Jinjun Ding, Steven S-L Zhang, James Kally, Timothy Pillsbury, Olle G. Heinonen, Gaurab Rimal, Chong Bi, August DeMann, Stuart B. Field, Weigang Wang, Jinke Tang, Jidong Samuel Jiang, Axel Hoffmann, Nitin Samarth, Mingzhong Wu
Summary: This study reports a genuine topological Hall effect in a TI/MI structure, where the contribution of skyrmions to the Hall effect outweighs the coexistence of magnetic phases.
Article
Engineering, Electrical & Electronic
Qiming Shao, Peng Li, Luqiao Liu, Hyunsoo Yang, Shunsuke Fukami, Armin Razavi, Hao Wu, Kang Wang, Frank Freimuth, Yuriy Mokrousov, Mark D. Stiles, Satoru Emori, Axel Hoffmann, Johan Akerman, Kaushik Roy, Jian-Ping Wang, See-Hun Yang, Kevin Garello, Wei Zhang
Summary: Spin-orbit torque (SOT) is an emerging technology that allows efficient manipulation of spintronic devices, with interest expanding to various processes beyond electric field manipulation. In the past decade, research has focused on exploring materials for larger SOT efficiency. Recent developments have extended material research to include processes involving phonons, magnons, and heat.
IEEE TRANSACTIONS ON MAGNETICS
(2021)
Article
Materials Science, Multidisciplinary
Peng Li, Lauren J. Riddiford, Chong Bi, Jacob J. Wisser, Xiao-Qi Sun, Arturas Vailionis, Michael J. Veit, Aaron Altman, Xiang Li, D. C. Mahendra, Shan X. Wang, Y. Suzuki, Satoru Emori
Summary: The study investigates spin-orbit torques in a model system of all-epitaxial ferrite/Pt bilayers to understand charge-spin interconversion in Pt, where the crystalline Pt film serves as the main source. A small fieldlike SOT independent of Pt thickness suggests a weak Rashba-Edelstein effect at the interface, while a sizable dampinglike SOT depending on Pt thickness indicates the dominance of an extrinsic spin-Hall effect and spin relaxation in the Pt film. The results reveal a large internal spin-Hall ratio in epitaxial Pt, providing insights into mechanisms crucial for spintronic devices.
PHYSICAL REVIEW MATERIALS
(2021)
Article
Chemistry, Multidisciplinary
Ruofan Li, Peng Li, Di Yi, Lauren J. Riddiford, Yahong Chai, Yuri Suzuki, Daniel C. Ralph, Tianxiang Nan
Summary: Magnon-mediated spin flow in magnetically ordered insulators enables long-distance spin-based information transport with low dissipation. In this study, anisotropy in magnon spin transport was observed in spinel ferrite, providing an approach for controlling magnonic devices via strain.
Article
Physics, Applied
David A. Smith, So Takei, Bella Brann, Lia Compton, Fernando Ramos-Diaz, Matthew J. Simmers, Satoru Emori
Summary: Propagation of easy-plane magnetic precession can be more efficient than conventional spin waves, using a motion of domain walls that transitions from diffusive to fluidlike as the density of domain walls increases. This transition is most evident in notched nanostrips, where domain walls are pinned by the notch defect in the diffusive regime but propagate essentially unimpeded in the fluidlike regime.
PHYSICAL REVIEW APPLIED
(2021)
Article
Engineering, Electrical & Electronic
Chunli Tang, Laith Alahmed, Jihao Xu, Maokang Shen, Nicholas Alex Jones, Mehdi Sadi, Ujjwal Guin, Wenfeng Zhao, Peng Li
Summary: A skyrmion-magnetic domain interconversion logic gate (SkyMDILogic) was designed as a model system to investigate the effects of temperature and structural defects. Micromagnetic simulations and an equivalent circuit model were used to study skyrmion movement and energy consumption at different temperatures. The study found that temperature significantly influences the stability and propagation of skyrmions, highlighting the importance of thermal and structural defect effects in logic gate designs.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2022)
Article
Physics, Applied
Youngmin Lim, Shuang Wu, David A. Smith, Christoph Klewe, Padraic Shafer, Satoru Emori
Summary: In this study, we examined the absorption of transverse spin currents in ferromagnetic NiCu alloy films and found that the coherence length increases with decreasing Curie temperature, affirming that spin currents are predominantly absorbed through the dephasing mechanism inside nanometer-thick ferromagnetic metals.
APPLIED PHYSICS LETTERS
(2022)
Article
Multidisciplinary Sciences
Hangtian Wang, Haichang Lu, Zongxia Guo, Ang Li, Peichen Wu, Jing Li, Weiran Xie, Zhimei Sun, Peng Li, Heloise Damas, Anna Maria Friedel, Sylvie Migot, Jaafar Ghanbaja, Luc Moreau, Yannick Fagot-Revurat, Sebastien Petit-Watelot, Thomas Hauet, John Robertson, Stephane Mangin, Weisheng Zhao, Tianxiao Nie
Summary: In this study, a large-scale iron-based vdW material Fe4GeTe2 with a high Curie temperature (Tc) of around 530 K was developed and its high-temperature ferromagnetism was confirmed by multiple characterizations. Theoretical calculations indicated that the interface-induced right shift of unpaired Fe d electrons' localized states is responsible for the enhanced Tc, which was confirmed by ultraviolet photoelectron spectroscopy. Additionally, by precisely tailoring Fe concentration, arbitrary control of magnetic anisotropy between out-of-plane and in-plane was achieved without inducing any phase disorders. This finding highlights the high potential of Fe4GeTe2 in spintronics, potentially enabling the room-temperature application of all-vdW spintronic devices.
NATURE COMMUNICATIONS
(2023)
Article
Physics, Applied
Peng Li, Sanyum Channa, Xiang Li, Laith Alahmed, Chunli Tang, Di Yi, Lauren Riddiford, Jacob Wisser, Purnima P. Balakrishnan, Xin Yu Zheng, Di Lu, Arturas Vailionis, Shan X. Wang, Yuri Suzuki
Summary: We demonstrate energy-efficient room-temperature spin-orbit-torque (SOT) switching in nanometer-thick CoFeB/SrIrO3 bilayers, despite the amorphous nature of CoFeB and the interface. The large spin Hall angle in SrIrO3 and the high spin transmission at the interface contribute to the SOT efficiency. Our bilayers exhibit significant SOT and effective spin Hall conductivity, as well as low critical current density for current-induced magnetization switching at room temperature. Our results show promise for heterostructures combining CoFeB with high spin-orbit-coupling oxides.
PHYSICAL REVIEW APPLIED
(2023)
Article
Materials Science, Multidisciplinary
Shuang Wu, David A. Smith, Prabandha Nakarmi, Anish Rai, Michael Clavel, Mantu K. Hudait, Jing Zhao, Claudia Mewes, Tim Mewes, Satoru Emori
Summary: This study investigates room-temperature magnetic relaxation in polycrystalline Fe films. It is found that the intrinsic Gilbert damping parameter remains unchanged regardless of the microstructural properties of the Fe films, contrary to intuition. This suggests that the room-temperature intrinsic Gilbert damping in Fe films is primarily determined by the bcc crystal structure within the nanoscale grains, with limited effects from grain boundaries and film roughness. In addition, the in-plane FMR linewidths of the Fe films exhibit nonlinear frequency dependencies, indicating the presence of strong extrinsic damping.
Article
Materials Science, Multidisciplinary
Xiang Li, Peng Li, Vincent D-H Hou, D. C. Mahendra, Chih-Hung Nien, Fen Xue, Di Yi, Chong Bi, Chien-Min Lee, Shy-Jay Lin, Wilman Tsai, Yuri Suzuki, Shan X. Wang
Summary: Disordered sputtered WTex thin films exhibit local chemical and structural order similar to Weyl semimetal WTe2, with properties consistent with semimetallic Weyl fermion behavior. Thermally annealed sputtered WTex films show large charge-to-spin conversion properties and electrical conductivity comparable to crystalline WTe2 flakes, with significant unidirectional spin Hall magnetoresistance in heterostructures. Furthermore, room-temperature damping-like SOT-driven magnetization switching of in-plane magnetized CoFeB is demonstrated in the study.
Article
Materials Science, Multidisciplinary
Youngmin Lim, Behrouz Khodadadi, Jie-Fang Li, Dwight Viehland, Aurelien Manchon, Satoru Emori
Summary: In this study, the dephasing length of transverse spin current in ferrimagnetic CoGd alloys was estimated, showing that it is about 4-5 times longer in nearly compensated CoGd than in ferromagnetic metals. The finding suggests that antiferromagnetic order can mitigate spin dephasing and that transverse spin current interacts more strongly with the Co sublattice. These results provide fundamental insights into the interplay between spin current and antiferromagnetic order for engineering spin torque effects in ferrimagnetic and antiferromagnetic metals.