Article
Materials Science, Multidisciplinary
Yaqian Guo, Hui Liu, Oleg Janson, Ion Cosma Fulga, Jeroen van den Brink, Jorge I. Facio
Summary: It has been discovered that collinear antiferromagnets, depending on their symmetries, can break the spin degeneracy in momentum space without spin-orbit coupling. These systems, known as altermagnets, are characterized by a spin-momentum texture determined by crystal and magnetic structure. This study focuses on q = 0 antiferromagnetic compounds in the MAGNDATA database and introduces numerical measures for average momentum-space spin splitting, analyzing over sixty compounds including CoF2, FeSO4F, LiFe2F6, RuO2, CrNb4S8, and CrSb.
MATERIALS TODAY PHYSICS
(2023)
Article
Chemistry, Multidisciplinary
Jinwu Wei, Xiao Wang, Baoshan Cui, Chenyang Guo, Hongjun Xu, Yao Guang, Yuqiang Wang, Xuming Luo, Caihua Wan, Jiafeng Feng, Hongxiang Wei, Gen Yin, Xiufeng Han, Guoqiang Yu
Summary: Synthetic antiferromagnets (SAFs) show potential in next-generation spintronic devices due to zero net magnetization and high thermal stability, despite typically requiring an in-plane effective magnetic field. A new study demonstrates field-free switching in an all-SAF system with significantly reduced net magnetization, showing robustness up to approximately 460 K.
ADVANCED FUNCTIONAL MATERIALS
(2022)
Article
Physics, Applied
Longjie Yu, Shutaro Karube, Min Liu, Masakiyo Tsunoda, Mikihiko Oogane, Yasuo Ando
Summary: Non-collinear antiferromagnets possess topological spin structure, allowing for the manipulation of charge-spin conversion. In this study, we investigate the unconventional spin-orbit torque of L1(2)-ordered Mn3Pt with a triangular spin structure.
APPLIED PHYSICS EXPRESS
(2022)
Article
Materials Science, Multidisciplinary
Wasim Akram, Manisha Bansal, Reshma Peremadathil Pradeep, Aswathi Kaipamangalath, Samir Kumar Giri, Tuhin Maity
Summary: We observed an enhancement of inverse magnetocaloric effect (MCE) in SmCaCoMnO6 (94%) and SmMnO3 (6%) nanocomposite due to the crossover from random field (RF) to spin glass (SG) under external magnetic field. This crossover is usually observed in diluted antiferromagnet and dilute dipole-coupled Ising ferromagnet systems, but in our study, it occurs in a ferrimagnetic and antiferromagnetic nanocomposite. The enhanced inverse MCE is the result of the field-induced RF-SG crossover, which leads to highly H-dependent ΔS in the SG regime.
Article
Physics, Multidisciplinary
Dongwook Go, Moritz Sallermann, Fabian R. Lux, Stefan Bluegel, Olena Gomonay, Yuriy Mokrousov
Summary: In this study, we propose the concept of noncollinear spin current and demonstrate its existence in nonmagnetic crystals. Through experimental verification, this opens up a new avenue for electric control of complex spin structures in noncollinear antiferromagnets.
PHYSICAL REVIEW LETTERS
(2022)
Article
Physics, Applied
Lijun Zhu, Robert A. Buhrman
Summary: After a decade of intensive theoretical and experimental explorations, it remains in dispute whether interfacial spin-orbit coupling at metallic magnetic interfaces can effectively generate a spin current. Utilizing Ti/Fe-Co-B bilayers with unique properties, the study found no significant charge-to-spin conversion at magnetic interfaces, even with stronger ISOC than a typical Pt/ferromagnet interface. Additionally, a minimal orbital Hall effect was observed in 3d Ti.
PHYSICAL REVIEW APPLIED
(2021)
Article
Materials Science, Multidisciplinary
Ritwik Mondal, Levente Rozsa
Summary: The spin-wave spectrum in ferromagnets and two-sublattice antiferromagnets in the presence of inertial effects is calculated in this study. It is found that the hybridization between precession and nutation spin waves leads to the renormalization of frequencies, group velocities, effective gyromagnetic ratios, and effective damping parameters. Possible ways of distinguishing between inertial dynamics and similar effects explained within conventional models are discussed.
Article
Multidisciplinary Sciences
Leonardo S. Lima
Summary: Transport in non-Hermitian quantum systems is investigated, specifically focusing on the Lieb lattice and the integrable Ising chain. The study aims to understand the influence of non-Hermitian parameters on spin conductivity and transport coefficients. The results show that the non-Hermitian parameters have minimal impact on conductivity in both the Ising model and noninteracting fermion models, with the opening of a gap in the spectrum also affecting longitudinal conductivity.
SCIENTIFIC REPORTS
(2023)
Article
Chemistry, Multidisciplinary
Hongsong Qiu, Tom S. S. Seifert, Lin Huang, Yongjian Zhou, Zdenek Kaspar, Caihong Zhang, Jingbo Wu, Kebin Fan, Qi Zhang, Di Wu, Tobias Kampfrath, Cheng Song, Biaobing Jin, Jian Chen, Peiheng Wu
Summary: An important vision in modern magnetic research is to use antiferromagnets (AFMs) as controllable and active ultrafast components in spintronic devices. Hematite (alpha-Fe2O3) is a promising model material for this purpose due to its pronounced Dzyaloshinskii-Moriya interaction, which leads to the coexistence of antiferromagnetism and weak ferromagnetism. In this study, femtosecond laser pulses were utilized to drive terahertz (THz) spin currents from alpha-Fe2O3 into an adjacent Pt layer. The generated spin current exhibited two distinct dynamic contributions: impulsive stimulated Raman scattering, relying on the AFM order, and ultrafast spin Seebeck effect, relying on net magnetization. The dynamics of the THz spin current could be controlled by a medium-strength magnetic field below 1 T. This control opens up the possibility of tailoring exact spin current dynamics from ultrafast AFM spin sources.
Article
Materials Science, Multidisciplinary
Mike A. Lund, Akshaykumar Salimath, Kjetil M. D. Hals
Summary: The study theoretically investigates the ac spin pumping of noncollinear antiferromagnets, demonstrating that the spin orientation of the pumped spin current can be controlled by exciting different spin-wave modes. Additionally, it is found that the three spin-wave bands of the kagome antiferromagnet generate spin currents with mutually orthogonal polarization directions.
Article
Chemistry, Multidisciplinary
Lin-Ding Yuan, Alex Zunger
Summary: Recent studies have found that energy bands in antiferromagnets can be spin-split even without the presence of spin-orbit coupling. Materials with specific symmetries can enable spin-split antiferromagnetic spintronics without using heavy-atom compounds. This study reveals that the symmetry conditions enabling spin-split antiferromagnets can be explained in terms of local motif pairs, such as octahedra or tetrahedra, each carrying opposite magnetic moments.
ADVANCED MATERIALS
(2023)
Article
Physics, Multidisciplinary
Weizhao Chen, Mingqiang Gu, Jiayu Li, Panshuo Wang, Qihang Liu
Summary: This study theoretically predicts the macroscopic non-reciprocal transport effects induced by HSP in certain materials, providing potential material applications for future spintronics. The study also provides material design principles for achieving large nonlinear conductivity.
PHYSICAL REVIEW LETTERS
(2022)
Article
Multidisciplinary Sciences
Hai-Yang Ma, Mengli Hu, Nana Li, Jianpeng Liu, Wang Yao, Jin-Feng Jia, Junwei Liu
Summary: The study introduces a new type of spin-valley locking enabled by crystalline symmetry, allowing for the generation of valley polarizations, net magnetization, and non-collinear spin currents, providing new possibilities for multifunctional antiferromagnetic materials.
NATURE COMMUNICATIONS
(2021)
Article
Physics, Multidisciplinary
Xing Chen, Cuixiu Zheng, Yu Zhang, Sai Zhou, Yaowen Liu, Zongzhi Zhang
Summary: The investigation of magnetic excitations in interlayer exchange-coupled synthetic antiferromagnets with perpendicular magnetic anisotropy reveals new spin wave and polarization modes, as well as dynamic properties under bias magnetic fields. These findings provide fundamental insight into the potential spintronic applications of these materials.
NEW JOURNAL OF PHYSICS
(2021)
Article
Physics, Multidisciplinary
Sungsoo Hahn, Byungmin Sohn, Minjae Kim, Jeong Rae Kim, Soonsang Huh, Younsik Kim, Wonshik Kyung, Minsoo Kim, Donghan Kim, Youngdo Kim, Tae Won Noh, Ji Hoon Shim, Changyoung Kim
Summary: In situ angle-resolved photoemission spectroscopy (ARPES) and spin-resolved ARPES (SARPES) experiments were conducted to investigate the relationship between electronic band structures and ferromagnetism in SrRuO3 (SRO) thin films. The results showed clear spin-lifted band structures with spin polarization strongly dependent on momentum. As temperature increased, the spin-splitting gap decreased and band dispersions became incoherent, indicating spin-dependent electron correlations in SRO. This finding helps to explain the connection between ferromagnetism and electronic structure in SRO, which has been debated for decades.
PHYSICAL REVIEW LETTERS
(2021)
Article
Physics, Applied
Daisuke Kan, Takahiro Moriyama, Ryotaro Aso, Shinji Horai, Yuichi Shimakawa
Summary: We grew epitaxial thin films of hematite on Al2O3 substrates and investigated their magnetic properties. The films undergo Morin transition at higher temperatures when grown at lower temperatures. The magnetic properties were characterized by spin Hall magnetoresistance, revealing tri-axial magnetic anisotropy and large changes in SMR ratio associated with Neel vector re-orientation due to Morin transition.
APPLIED PHYSICS LETTERS
(2022)
Article
Oncology
Kyotaro Fukuta, Kiyotaka Iihara, Takahiro Moriyama, Ryoichi Nakanishi, Hirofumi Izaki, Kazuya Kanda, Tohru Inai, Eiji Kudo, Tomoya Fukawa, Kunihisa Yamaguchi, Yasuyo Yamamoto, Masayuki Takahashi, Yasushi Sutou, Hiro-Omi Kanayama
Summary: The micropapillary variant of urothelial carcinoma (MPUC) is an aggressive form of urothelial carcinoma with high metastatic potential and a poor prognosis. Regular screening is recommended for its early detection in hemodialysis patients.
CASE REPORTS IN ONCOLOGY
(2022)
Article
Oncology
Kyotaro Fukuta, Ryoichi Nakanishi, Takahiro Moriyama, Hirofumi Izaki, Takumi Kakimoto, Takeshi Oya, Tomoya Fukawa, Kunihisa Yamaguchi, Yasuyo Yamamoto, Masayuki Takahashi, Yasushi Sutou, Hiro-omi Kanayama
Summary: High-grade renal mucinous tubular and spindle cell carcinoma (MTSCC) is a rare subtype of renal cell carcinoma. We reported a case of high-grade renal MTSCC treated with laparoscopic radical nephrectomy, and the patient remained recurrence- and metastasis-free after 6 months.
CASE REPORTS IN ONCOLOGY
(2022)
Article
Physics, Applied
Yuta Kobayashi, Motoi Kimata, Daisuke Kan, Tetsuya Ikebuchi, Yoichi Shiota, Hiroshi Kohno, Yuichi Shimakawa, Teruo Ono, Takahiro Moriyama
Summary: This study investigates the relationship between anomalous Hall conductivity and the chemical order parameter in chiral antiferromagnetic L1(2)-Mn3Ir (111)-oriented films. The results show that the anomalous Hall conductivity is more pronounced in (111)-oriented films compared to (001)-oriented films, consistent with the theoretical prediction. It is also found that the anomalous Hall conductivity strongly depends on the longitudinal conductivity, suggesting a possible extrinsic contribution.
JAPANESE JOURNAL OF APPLIED PHYSICS
(2022)
Article
Materials Science, Multidisciplinary
Mikiya Yamamoto, Shinya Masaki, Yoichi Shiota, Takahiro Moriyama, Takeshi Kato, Teruo Ono, Mutsuhiro Shima, Keisuke Yamada
Summary: We investigated the dependence of the longitudinal spin Seebeck effect (LSSE) voltage on the Bi composition, film thickness, and annealing temperature (Ta) in BixY3-xFe5O12 (Bi-YIG) films. The LSSE coefficient tended to increase with increasing Bi composition, indicating that Bi substitution enhanced the interface effect and induced effective spin current conversion. Additionally, annealing the Bi-YIG films at 973 K resulted in a larger LSSE, likely due to reduced cracks and smoother surface conditions.
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
(2022)
Editorial Material
Multidisciplinary Sciences
Kab-Jin Kim, Kyung-Jin Lee
Summary: Applying strain to an antiferromagnetic material allows its magnetization to be fully switched with an electric current, making it significant for next-generation magnetic memory devices.
Article
Multidisciplinary Sciences
Jong-Guk Choi, Jaehyeon Park, Min-Gu Kang, Doyoon Kim, Jae-Sung Rieh, Kyung-Jin Lee, Kab-Jin Kim, Byong-Guk Park
Summary: This study shows that the frequency of SHNOs can be controlled up to 2.1 GHz by an electric field, enabling large frequency tuning. The voltage-controlled frequency tuning of SHNOs facilitates the development of energy-efficient neuromorphic devices. Additionally, repetitive voltage pulses can be used to cumulatively control the frequency, mimicking the functions of biological synapses.
NATURE COMMUNICATIONS
(2022)
Article
Chemistry, Multidisciplinary
Moojune Song, Mujin You, Seungmo Yang, Tae-Seong Ju, Kyoung-Woong Moon, Chanyong Hwang, Kyoung-Whan Kim, Albert Min Gyu Park, Kab-Jin Kim
Summary: The scaling law explains the universality in nature, and it is found in this study that the dynamics of weakly driven magnetic skyrmions are different from that of the magnetic domain wall, which is caused by a general principle beyond the topological charge.
ADVANCED MATERIALS
(2022)
Article
Physics, Applied
Daiju Hayashi, Yoichi Shiota, Mio Ishibashi, Ryusuke Hisatomi, Takahiro Moriyama, Teruo Ono
Summary: We investigated the coherently excited propagating magnons in in-plane magnetized synthetic antiferromagnets using heterodyne-magnetooptical Kerr effect technique. Under an in-plane magnetic field at a 45-degree angle away from the magnon propagation direction, we observed mode splitting of the magnon dispersion relation due to magnon-magnon coupling between acoustic and optical magnon modes. Strong coupling with a cooperativity of 8.4 +/- 1.3 was achieved for finite wavenumber. These results provide a deep understanding of the properties of coherently excited magnons in synthetic antiferromagnets, which will be helpful for designing advanced magnonic devices.
APPLIED PHYSICS EXPRESS
(2023)
Article
Physics, Applied
Yuta Kobayashi, Yoichi Shiota, Hideki Narita, Teruo Ono, Takahiro Moriyama
Summary: The study reveals that the Joule heating induced by voltage pulses can cause a magnetic phase transition in D0(19)-Mn3Sn, altering the energy landscape relevant to spin-orbit torque switching. This poses challenges in accurately determining the thermal stability factor and highlights the importance of cautious estimation.
APPLIED PHYSICS LETTERS
(2023)
Article
Multidisciplinary Sciences
Zhenya Zhang, Fumiya Sekiguchi, Takahiro Moriyama, Shunsuke C. Furuya, Masahiro Sato, Takuya Satoh, Yu Mukai, Koichiro Tanaka, Takafumi Yamamoto, Hiroshi Kageyama, Yoshihiko Kanemitsu, Hideki Hirori
Summary: The authors studied HoFeO3 crystal using multicycle THz magnetic pulses enhanced strongly by spiral-shaped microstructure. The observed Faraday ellipticity demonstrates second- and third-order harmonics of the magnetization oscillation and an asymmetric oscillation behavior. The ability to drive a spin system to state far from the equilibrium is indispensable for investigating spin structures of antiferromagnets and their functional nonlinearities for spintronics.
NATURE COMMUNICATIONS
(2023)
Article
Materials Science, Multidisciplinary
Takahiro Moriyama, Luis Sanchez-Tejerina, Kent Oda, Takuo Ohkochi, Motoi Kimata, Yoichi Shiota, Hiroyuki Nojiri, Giovanni Finocchio, Teruo Ono
Summary: In this paper, the evolutions of antiferromagnetic domains in NiO under magnetic fields are experimentally investigated and numerically simulated. A micromagnetic framework with a simulation algorithm is extended to reproduce the domain patterns and provide detailed understanding of the domain evolutions. This work offers an important theoretical methodology to predict and understand the behaviors of micromagnetic structures in antiferromagnets.
PHYSICAL REVIEW MATERIALS
(2023)
Article
Physics, Applied
Kakeru Ujimoto, Hiroki Sameshima, Kentaro Toyoki, Yoshinori Kotani, Takahiro Moriyama, Kohji Nakamura, Ryoichi Nakatani, Yu Shiratsuchi
Summary: In this paper, we studied the magnetic response of boundary magnetization in the Pt/magnetoelectric Cr2O3/Pt epitaxial trilayer using AHE and XMCD. We found that the film exhibited magnetic responsiveness when the Cr2O3 thickness was reduced to 15 nm, manifested as rectangular hysteresis in AHE's magnetic field dependence. XMCD intensity and its rectangular magnetic field dependence confirmed that the magnetic response was attributed to the interfacial Cr moment. Further investigation revealed that the reversal process of boundary magnetization was dominated by domain wall motion, directly visualized by scanning XMCD microscope.
APPLIED PHYSICS LETTERS
(2023)
Article
Engineering, Electrical & Electronic
Chanhyeong Lee, Kabjin Kim, Mincheol Shin
Summary: This work assesses the performance of Bloch line (BL) racetrack memory (RTM) through circuit-level simulations. A micromagnetics-SPICE hybrid simulation framework is proposed to guarantee both computational efficiency and micromagnetics-level accuracy. The feasibility of multibit BL memory operations is demonstrated, and some crucial considerations in designing and optimizing the BL memory are addressed.
IEEE TRANSACTIONS ON MAGNETICS
(2023)
Article
Materials Science, Multidisciplinary
Kohki Sugi, Takuto Ishikawa, Motoi Kimata, Yoichi Shiota, Teruo Ono, Takeo Kato, Takahiro Moriyama
Summary: Magnetic van der Waals materials offer a physical paradigm for studying two-dimensional magnetic systems. This study reports on spin Hall magnetoresistance in the NiPS3/Pt system, revealing the magnetic properties of NiPS3 and opening a path for 2D AFM spintronics.
