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, Multidisciplinary
Soonbeom Seo, Satoru Hayami, Ying Su, Sean M. Thomas, Filip Ronning, Eric D. Bauer, Joe D. Thompson, Shi-Zeng Lin, Priscila F. S. Rosa
Summary: Unusual magnetic textures can be stabilized in f-electron materials due to competing magnetic interactions, complex Fermi surfaces, and crystalline anisotropy. Through experimental and computational studies of the antiferromagnet CeAuSb2, researchers found that the enhanced magnetoresistance in the double-Q phase is attributed to the localization of electronic wave functions. The magnetic, electronic, and structural properties in f-electron systems are intrinsically linked, showing complex characteristics.
COMMUNICATIONS PHYSICS
(2021)
Article
Chemistry, Multidisciplinary
Gerald Q. Yan, Senlei Li, Hanyi Lu, Mengqi Huang, Yuxuan Xiao, Luke Wernert, Jeffrey A. Brock, Eric E. Fullerton, Hua Chen, Hailong Wang, Chunhui Rita Du
Summary: This paper reports on the nanoscale imaging of spin-orbit-torque-induced deterministic magnetic switching and chiral spin rotation in non-collinear antiferromagnet Mn3Sn films using nitrogen-vacancy (NV) centers. Direct evidence of the off-resonance dipole-dipole coupling between the spin dynamics in Mn3Sn and proximate NV centers is also demonstrated by NV relaxometry measurements.
ADVANCED MATERIALS
(2022)
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
Chemistry, Multidisciplinary
Haodong Fan, Menghao Jin, Yongming Luo, Hongxin Yang, Birui Wu, Zhongshu Feng, Yanshan Zhuang, Ziji Shao, Changqiu Yu, Hai Li, Jiahong Wen, Ningning Wang, Bo Liu, Wenjun Li, Tiejun Zhou
Summary: An exchange field gradient is introduced into perpendicularly magnetized synthetic ferro- and antiferromagnets (SFs and SAFs) through the insertion of a slightly wedged Ru between the two layers, enabling field-free switching of perpendicular SFs and SAFs with a high switching ratio. The field-free switching and effective spin-orbit torque (SOT) field are found to depend on the exchange field gradient. The results provide a new approach for achieving field-free switching and high SOT efficiency in perpendicularly magnetized SAFs for advanced magnetic memory devices.
ADVANCED FUNCTIONAL MATERIALS
(2023)
Article
Nanoscience & Nanotechnology
Anulekha De, Sri Sai Phani Kanth Arekapudi, Leopold Koch, Fabian Samad, Surya Narayan Panda, Benny Bohm, Olav Hellwig, Anjan Barman
Summary: This study investigates the ultrafast demagnetization in synthetic antiferromagnets and finds that the spin transport of optically excited carriers plays a significant role in addition to spin-flip scattering processes. Control over the individual mechanisms is achieved through the specially designed samples and varying the external magnetic field and excitation fluence.
ACS APPLIED MATERIALS & INTERFACES
(2022)
Article
Materials Science, Multidisciplinary
Xiaodong He, Yanbin Sheng, Jijun Yun, Jianrong Zhang, Hongfei Xie, Yang Rene, Baoshan Cui, Yalu Zuo, Li Xi
Summary: In this work, the ion-irradiation method was used to engineer the interface of a perpendicularly magnetized synthetic antiferromagnet (Pt/Co/Pt/Ru/Pt/Co/Ta SAF) to achieve field-free magnetization switching via the in-plane magnetization component of the top-Co layer. With the increase of ion fluence, the critical switching current density decreases, which is consistent with the increase of spin Hall angle induced by ion irradiation. These results indicate that ion irradiation is a promising approach for field-free magnetization switching in SAFs driven by spin-orbit torques and has potential applications in spintronic devices.
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
Ping Tang, Xiufeng Han, Shufeng Zhang
Summary: A quantum approach was proposed for current driven magnetization switching, taking into account the impact of spin fluctuations on the process. It was found that spin fluctuations significantly reduce the critical spin torque at high temperatures, with a stronger effect observed in two-dimensional magnets. This suggests that 2D magnets may have advantages in electrically manipulating magnetization states for spintronic applications.
Article
Materials Science, Multidisciplinary
Iulia Cojocariu, Silvia Carlotto, Matteo Jugovac, Luca Floreano, Maurizio Casarin, Vitaliy Feyer, Claus Michael Schneider
Summary: This study demonstrates the crucial role of structural flexibility in electron-doped porphyrins in defining charge localization by tracking the evolution of spin state and charge distribution in the thermodynamically favored structure as a function of dopant dose and relaxation time.
JOURNAL OF MATERIALS CHEMISTRY C
(2022)
Article
Materials Science, Multidisciplinary
Tomohiro Taniguchi, Shinji Isogami, Yohei Shiokawa, Yugo Ishitani, Eiji Komura, Tomoyuki Sasaki, Seiji Mitani, Masamitsu Hayashi
Summary: We study magnetization switching in the dynamical regime for in-plane magnetized systems and develop a formula for the switching probability. The formula agrees well with numerical simulations and experiments. We find that the transition width of the switching probability increases with decreasing pulse width and the shape of the probability density changes with varying pulse width.
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
Nanoscience & Nanotechnology
Meiyang Ma, Zhuoyi Li, Xuezhong Ruan, Jing Wu, Ruifeng Wang, Tianyu Liu, Jun Du, Xianyang Lu, Yongbing Xu
Summary: This study reveals the significant influence of spin-polarized hot electrons generated by laser excitation on the magnetization switching in an antiferromagnet. The equivalent magnetic field produced by the hot-electron spin current dominates the lower layer's magnetization switching in the antiferromagnetic configuration at low pump fluence. The strong thermal stability of the Ruderman Kittel Kasuya Yosida exchange interaction inhibits the weakening of the switching field at high pump fluence. This research provides a viable solution for controlling the magnetization switching in spintronic applications with ultrafast information operation.
ADVANCED ELECTRONIC MATERIALS
(2023)
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
Nanoscience & Nanotechnology
Pingzhi Li, Thomas J. Kools, Bert Koopmans, Reinoud Lavrijsen
Summary: Spin-orbitronics and single pulse all-optical switching of magnetization are two significant achievements in the field of nanomagnetism, with potential for novel memory and logic platforms. This study demonstrates fast current-induced domain wall motion and energy efficient all-optical switching in a synthetic ferrimagnetic system based on multilayered [Co/Gd](2), establishing it as a unique materials platform for domain wall devices with access to ultrafast single pulse all-optical switching.
ADVANCED ELECTRONIC MATERIALS
(2023)
Review
Physics, Applied
D. Bossini, D. M. Juraschek, R. M. Geilhufe, N. Nagaosa, A. Balatsky, M. Milanovic, V. V. Srdic, P. Senjug, E. Topic, D. Barisic, M. Rubcic, D. Pajic, T. Arima, M. Savoini, S. L. Johnson, C. S. Davies, A. Kirilyuk
Summary: Solid state compounds with multiple and coupled macroscopic orders, called multiferroics, pose challenges for modern condensed matter physics. Femtosecond laser pulses can manipulate spins and electric polarisation in these materials. This interdisciplinary problem requires contributions from materials science and condensed matter physics, both theoretically and experimentally.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2023)
Article
Optics
Vladislav Bilyk, Kirill Grishunin, Paul Tinnemans, Theo Rasing, Andrey Kirilyuk, Olga Sergeeva, Natalia Sherstyuk, Elena Mishina, Sergey Lavrov, Alexander Sigov
Summary: This study demonstrates the effect of optical rectification (OR) in the terahertz range (THz rectification, TR). By applying pulsed radiation with specific frequencies and electric field strengths, a direct current voltage is generated on the surfaces of a ferroelectric triglycine sulfate (TGS) single crystal. The TR effect allows for the direct determination of the nonlinear susceptibilities of media, even under strong absorption conditions, without reference or optical channel calibration, and without the need for Fourier transform.
Article
Materials Science, Multidisciplinary
Fedor Akhmetov, Igor Milov, Sergey Semin, Fabio Formisano, Nikita Medvedev, Jacobus M. Sturm, Vasily V. Zhakhovsky, Igor A. Makhotkin, Alexey Kimel, Marcelo Ackermann
Summary: We conducted experimental and theoretical studies on the heating and damaging of ruthenium thin films caused by femtosecond laser irradiation. By conducting an optical pump-probe thermoreflectance experiment with a rotating sample, we were able to reduce heat accumulation in the irradiated spot. We observed the evolution of surface morphology from the growth of a heat-induced oxide layer at low and intermediate laser fluences to cracking and grooving at high fluences. Theoretical analysis and simulation allowed us to understand the behavior of hot electrons in ruthenium and led to the conclusion that more research is needed on the Fermi smearing mechanism in transition metals. The calculated melting threshold was found to be higher than the experimental damage threshold, indicating that heat-induced stress is the main cause of Ru film damage, which accumulates with repetitive exposure to light.
Editorial Material
Physics, Applied
Tobias Kampfrath, Andrei Kirilyuk, Stephane Mangin, Sangeeta Sharma, Martin Weinelt
Summary: Spintronics aims to extend electronic functionalities by utilizing the spin of electrons as information carrier, and its speed needs to be pushed to femtosecond time scales and terahertz frequencies to be competitive and compatible with other information carriers. Ultrafast and terahertz spintronics utilize optical and electromagnetic pulses to induce spin torque and transport, and provide new insights and applications for spintronics. This Special Topic Collection aims to present the newest developments and future trends in the field of ultrafast and terahertz spintronics.
APPLIED PHYSICS LETTERS
(2023)
Article
Physics, Applied
A. Frej, C. S. Davies, A. Kirilyuk, A. Stupakiewicz
Summary: In this study, the authors experimentally and numerically investigate the magnetization dynamics induced by laser in iron garnets. By exciting with an infrared pulse and applying an external magnetic field, spatially varying magnetization precession is observed, and the phase of magnetization precession is found to depend on the direction of the external magnetic field. Micro-magnetic simulations effectively describe the effects of laser-induced changes in the crystal's magneto-elastic energy on magnetization precession and switching.
APPLIED PHYSICS LETTERS
(2023)
Article
Physics, Applied
Thomas J. Kools, Youri L. W. van Hees, Kenneth Poissonnier, Pingzhi Li, Beatriz Barcones Campo, Marcel A. Verheijen, Bert Koopmans, Reinoud Lavrijsen
Summary: Synthetic ferrimagnets based on Co and Gd show potential for bridging the gap between volatile information in the photonic domain and nonvolatile information in the magnetic domain. This study focuses on the time-evolution of the magnetic moment and compensation temperature of Pt/Co/Gd trilayers with different capping layers. The results reveal significant changes in the magnetic moment and compensation temperature due to quenching of the Gd magnetization, primarily caused by intermixing of the capping layer and Gd.
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, 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
Instruments & Instrumentation
K. A. Grishunin, V. R. Bilyk, E. D. Mishina, A. V. Kimel, E. A. Mashkovich
Summary: In a system with multiple eigenstates (magnons and phonons), it is challenging to analyze the coupled excitation mechanism using conventional single-pulse terahertz (THz) spectroscopy. However, 2D THz spectroscopy reveals energy flows between these states, making it easier to identify the coupled dynamics. This article provides a theoretical description of this advanced technique and demonstrates its performance in antiferromagnet CoF2, where 2D THz spectroscopy shows energy transfer from the magnon mode to the Raman-active phonon mode via a nonlinear excitation pathway.
REVIEW OF SCIENTIFIC INSTRUMENTS
(2023)
Article
Nanoscience & Nanotechnology
D. Khusyainov, T. Gareev, V. Radovskaia, K. Sampathkumar, S. Acharya, M. Siskins, S. Manas-Valero, B. A. Ivanov, E. Coronado, Th. Rasing, A. V. Kimel, D. Afanasiev
Summary: Using a time-resolved magneto-optical pump-probe technique, the ultrafast laser-induced dynamics of mutually correlated spins and lattice in CoPS3 were experimentally studied. It was found that the femtosecond laser pulse acted as an ultrafast heater and melted the antiferromagnetic order. The resonant pumping of the T-4(1g) ? T-4(2g) electronic transition in Co2+ ions effectively changed their orbital momentum and generated a coherent B-g phonon mode.
Article
Physics, Multidisciplinary
K. Mishra, T. G. H. Blank, C. S. Davies, L. Aviles-Felix, D. Salomoni, L. D. Buda-Prejbeanu, R. C. Sousa, I. L. Prejbeanu, B. Koopmans, Th. Rasing, A. V. Kimel, A. Kirilyuk
Summary: Recent works have demonstrated the all-optical switching of magnetization in Tb/Co multilayers using ultrashort laser pulses, while the same process is not achievable in TbCo alloys. In this study, we provide a plausible explanation for this difference based on the angular momenta treatment and gyromagnetic ratio of rare-earth-based ferrimagnets. Furthermore, we investigate the composition-dependent dynamic behavior of the switching process in Tb/Co multilayers through single-shot time-resolved pump-probe experiments, revealing it deviates from the accepted framework applicable to Gd-based systems and Mn-containing Heusler alloys.
PHYSICAL REVIEW RESEARCH
(2023)
Article
Physics, Multidisciplinary
T. G. H. Blank, K. A. Grishunin, B. A. Ivanov, E. A. Mashkovich, D. Afanasiev, A. V. Kimel
Summary: This study demonstrates a new approach to control antiferromagnetism by utilizing the magnetization emerging from a state of coherent spin precession in antiferromagnetic iron borate FeBO3, enabling the nonlinear coupling of light to another mode of spin precession.
PHYSICAL REVIEW LETTERS
(2023)
Article
Materials Science, Multidisciplinary
T. Janssen, M. Gidding, C. S. Davies, A. V. Kimel, A. Kirilyuk
Summary: Utilizing optically induced strain to spatially modify the magnetic order parameter of an antiferromagnet could have important applications in future antiferromagnet-based data-storage technologies.
Article
Materials Science, Multidisciplinary
C. E. Zaspel, E. G. Galkina, B. A. Ivanov
Summary: By studying both analytically and numerically, researchers found that the precession frequency of magnon drop solitons in ferrimagnetic materials is strongly influenced by the angular momentum compensation parameter. The frequency significantly increases near the compensation point, and these solitons are shown to be stable.
