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
Chemistry, Physical
S. Jena, A. Kumari, R. Dawn, A. Hussain, V. K. Verma, H. J. Gardner, Z. Aabdin, K. Amemiya, V. R. Singh
Summary: Depending on epitaxial strain, the ferromagnetic thin film SrRuO3 (SRO) exhibits varying easy magnetization axes and undergoes a metal-insulator transition as the film thickness decreases. In this study, soft x-ray magnetic circular dichroism was used to investigate the magnetic properties of SRO thin films grown on SrTiO3 (001) substrates with different thicknesses. The results show that when the film thickness reduces to around five monolayers, the film transitions from ferromagnetic to nonmagnetic, in line with magnetization measurements. The spin magnetic moment also decreases with decreasing film thickness. The article also discusses a method to obtain the orbital magnetic moment using the electronic structure of the strained SRO thin film.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Chemistry, Multidisciplinary
Mariia Stepanova, Jan Masell, Erik Lysne, Peggy Schoenherr, Laura Koehler, Michael Paulsen, Alireza Qaiumzadeh, Naoya Kanazawa, Achim Rosch, Yoshinori Tokura, Arne Brataas, Markus Garst, Dennis Meier
Summary: Research on magnetic disclinations, dislocations, and domain walls in FeGe reveals unique responses that distinguish them from the helimagnetic background, proposing a new detection scheme using superconducting microcoils for topological spin textures and domain walls in device-relevant geometries.
Article
Materials Science, Multidisciplinary
T. Nathan Nunley, Side Guo, Liang-Juan Chang, David Lujan, Jeongheon Choe, Shang-Fan Lee, Fengyuan Yang, Xiaoqin Li
Summary: Recent research has found that thulium iron garnet (TmIG) based bilayers show promise in realizing small skyrmions at room temperature. By directly measuring the magnetic hysteresis loops, researchers have determined that the spin Hall topological Hall resistivity is considerably larger than previously estimated values. This finding further confirms the existence of skyrmions at room temperature and near-zero applied magnetic fields.
Article
Physics, Multidisciplinary
Jongjun M. Lee, Myung-Joong Hwang, Hyun-Woo Lee
Summary: The study investigates the possibility of combining cavity magnonics and topological insulators by exploring hybrid cavity systems incorporating a ferromagnet and a topological insulator. The researchers find that the topological surface state efficiently mediates the coupling between the spin of the ferromagnet and the electric field of the cavity, which is different from the conventional magnetic dipole coupling. They refer to this coupling as topological magnon-photon interaction and show that it is significantly stronger than the conventional magnon-photon coupling. The proposed device has the potential to scale down and control the cavity system using electronics.
COMMUNICATIONS PHYSICS
(2023)
Article
Physics, Multidisciplinary
Chao Chen, Xing Ding, Jian Qin, Jizhou Wu, Yu He, Chao-Yang Lu, Li Li, Xiong-Jun Liu, Barry C. Sanders, Jian-Wei Pan
Summary: The dissipationless chiral edge states in spin-orbit coupled anomalous Floquet topological phase exhibit nontrivial topological spin texture on boundaries, which can inspire novel topology-based spintronic phenomena and devices.
PHYSICAL REVIEW LETTERS
(2022)
Article
Chemistry, Multidisciplinary
Sanjeev, Mukhtiyar Singh, Ramesh Kumar, Sunita Srivastava, Tankeshwar Kumar
Summary: Topological insulators NaCaBi and KBaBi exhibit topologically protected dissipationless surface states, forming a nodal loop and showing band inversion with strong spin-orbit coupling. The presence of spin-orbit coupling induces a band gap and the compounds are classified as strong topological insulators with Z2 indices of (1; 000). Additionally, the calculated topological surface states reveal a single Dirac cone at the Gamma-point below the Fermi level.
JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS
(2022)
Article
Materials Science, Multidisciplinary
Na Li, Yun-bin Sun, Rui Sun, Xu Yang, Wei Zhang, Zong-kai Xie, Jia-nan Liu, Yan Li, Yang Li, Zi-zhao Gong, Xiang-qun Zhang, Wei He, Zhao-hua Cheng
Summary: Topological insulators with distinct topological surface states have been widely investigated for spintronics and quantum information devices. This study reveals that the topological surface states can significantly accelerate ultrafast demagnetization and enhance the damping factor of heterostructures. These findings have implications for future topological spintronic devices or quantum information processing.
Article
Chemistry, Multidisciplinary
Kazuyuki Sakamoto, Hirotaka Ishikawa, Takashi Wake, Chie Ishimoto, Jun Fujii, Hendrik Bentmann, Minoru Ohtaka, Kenta Kuroda, Natsu Inoue, Takuma Hattori, Toshio Miyamachi, Fumio Komori, Isamu Yamamoto, Cheng Fan, Peter Kruger, Hiroshi Ota, Fumihiko Matsui, Friedrich Reinert, Jose Avila, Maria C. Asensio
Summary: The study demonstrates a novel method for doping a hole into n-type topological insulators Bi2X3 by adsorbing H2O on Bi2X3 decorated with carbon and triggering it with photon irradiation. This method allows for controlling the doping amount through irradiation time and can act as photolithography, offering a promising avenue for the development of spintronics devices based on topological insulators at the nanometer scale.
Article
Multidisciplinary Sciences
Minkyung Kim, Zihao Wang, Yihao Yang, Hau Tian Teo, Junsuk Rho, Baile Zhang
Summary: Researchers have designed and demonstrated a 3D photonic topological insulator (PTI) that exhibits self-guided topological surface states without the need for additional confinement. By removing spin-orbit coupling, this PTI opens new possibilities for manipulating photons at the outer surface of photonic bandgap materials.
NATURE COMMUNICATIONS
(2022)
Article
Chemistry, Physical
Can Liu, Huai Zhang, Zefang Li, Yuan Yan, Yajiu Zhang, Zhipeng Hou, Xuewen Fu
Summary: We report the magnetometry and magnetoelectric transport properties of TmMn6Sn6 single crystal, which coexists with Tm and Mn magnetic sublattices. We reveal that this compound displays multiple magnetic structures with the increase of in-plane magnetic field. The combination of non-collinear magnetic structure and real-space Berry curvature leads to a remarkable topological Hall effect over an extensive temperature range.
SURFACES AND INTERFACES
(2023)
Article
Physics, Multidisciplinary
C. H. Fuentevilla, J. D. Lejarreta, F. Dominguez-Adame, E. Diez
Summary: Proximity exchange interaction between graphene electrons and nearby magnetic insulators leads to the creation of spin-polarised currents for spintronics applications. Various types of magnetic insulators can induce magnetic correlations in graphene. Theoretical studies show that heterostructures based on europium chalcogenides are ideal candidates for achieving high polarization in low-temperature conditions.
NEW JOURNAL OF PHYSICS
(2021)
Article
Physics, Applied
Lalit Pandey, Rahul Gupta, Amir Khan, Nanhe Kumar Gupta, Soumyarup Hait, Nakul Kumar, Vireshwar Mishra, Nikita Sharma, Peter Svedlindh, Sujeet Chaudhary
Summary: In this study, magnetic heterostructures consisting of Bi2Te3 (BT) and Co60Fe20B20 (CFB) were fabricated using the DC magnetron sputtering technique to investigate the temperature-dependent spin pumping. The results revealed that the effective spin-mixing conductance is significantly affected by the contribution of two-magnon scattering (TMS) and it increases with decreasing temperature when TMS is absent. Furthermore, magneto-transport measurements indicated that the surface coherence length of BT is consistent with the temperature-dependent effective spin-mixing conductance. The enhancement of effective mixing conductance was found to be correlated with the increased contribution of the topological surface states (TSSs) as evaluated using the weak-anti-localization effect. This study provides insights into the temperature-dependent spin dynamics in sputtered BT/CFB heterostructures and serves as a guide for further exploration of such bilayers for topological-based spintronic applications.
JOURNAL OF APPLIED PHYSICS
(2023)
Article
Materials Science, Multidisciplinary
Raditya Weda Bomantara, Sen Mu, Jiangbin Gong
Summary: Studies of periodically driven spin ladders reveal subharmonic magnetization dynamics resembling discrete time crystals, attributed to corner Majorana p modes and preserved quasienergy spacing of Floquet eigenstates despite imperfections in the system's parameters. The coupling in the rung direction prevents degeneracy between states differing by a single spin excitation, a feature absent in strict one-dimensional counterparts, which may have intriguing implications for future studies of higher dimensional Floquet many-body systems.
Article
Engineering, Electrical & Electronic
Xianzhe Chen, Hua Bai, Yuchen Ji, Yongjian Zhou, Liyang Liao, Yunfeng You, Wenxuan Zhu, Qian Wang, Lei Han, Xiaoyang Liu, Ang Li, Xiaodong Han, Jia Yin, Xufeng Kou, Feng Pan, Cheng Song
Summary: The antiferromagnetic moments in the topological insulator/antiferromagnetic insulator bilayer can be reversibly switched using electrical currents at room temperature, with a critical current density that is one order of magnitude smaller than that in heavy-metal/magnetic insulator systems. This finding has potential applications in building low-power, high-speed memory devices.
NATURE ELECTRONICS
(2022)
Article
Chemistry, Physical
Rafael Besse, Han Wang, Damien West, Juarez L. F. De Silva, Shengbai Zhang
Summary: Understanding the dynamics of charge transfer at vertical heterostructures of transition metal dichalcogenide monolayers is crucial for future technological applications. In this study, a different mechanism from type-II is found in the MoS2/PtSe2 van der Waals heterobilayer, where the phonon bottleneck effectively separates photoelectrons from photoholes, providing a new direction for effective charge separation at interfaces.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2022)
Article
Physics, Condensed Matter
Eleanor Lawrence Bright, Lei Xu, Lottie M. Harding, Ross Springell, Andrew C. Walters, Martin Sundermann, Mirian Garcia-Fernandez, Stefano Agrestini, Roberto Caciuffo, Gerrit van der Laan, Gerard H. Lander
Summary: Resonant inelastic x-ray scattering (RIXS) was used to study epitaxial films of alpha-U3O8 and UN, with an incident energy tuned to the uranium N-4,N-5 absorption edges. The multiplets associated with a 5f(1) configuration were observed for U3O8, but the predicted strong transition at a transfer energy of 1.67 eV was not observed. For the 5f-itinerant system UN, no sharp transitions were observed, indicating a predominantly 5f(3) configuration in this band-like semi-metallic system. These findings provide important information on these materials and the potential of RIXS at the uranium N edge for actinide research.
JOURNAL OF PHYSICS-CONDENSED MATTER
(2023)
Article
Chemistry, Multidisciplinary
Haonan Jin, Wancong Tan, Yizhou Liu, Kejing Ran, Raymond Fan, Yanyan Shangguan, Yao Guang, Gerrit van der Laan, Thorsten Hesjedal, Jinsheng Wen, Guoqiang Yu, Shilei Zhang
Summary: In this study, we introduce a novel mechanism for the controlled stabilization of emergent monopoles and demonstrate that magnetic skyrmion strings can be folded into monopoles. Conversely, monopoles can act as seeds out of which the entire string structure can unfold. Resonant elastic X-ray scattering is used to observe the reversible evolution from monopole to string, resulting in the emergence of a pure monopole lattice on the surface. This provides new insight into topological defects and establishes the emergent monopole lattice as a new 3D topological phase.
Article
Nanoscience & Nanotechnology
David M. Burn, Jheng-Cyuan Lin, Ryuji Fujita, Barat Achinuq, Joshua Bibby, Angadjit Singh, Andreas Frisk, Gerrit van der Laan, Thorsten Hesjedal
Summary: The TSSs in TIs provide exciting possibilities for dissipationless spin transport. However, using high-quality single-crystalline TI films limits the amount of spin current that can be pumped due to a single pair of spin-momentum locked channels. On the other hand, using nanocrystalline TI films can effectively increase the number of spin channels available for spin pumping. This study demonstrates spin pumping from a FM layer through a TI layer and into a FM spin sink using x-ray based ferromagnetic resonance technique.
Article
Materials Science, Multidisciplinary
Andreas Frisk, Barat Achinuq, David G. Newman, Emily Heppell, Maciej Dabrowski, Robert J. Hicken, Gerrit van der Laan, Thorsten Hesjedal
Summary: The ability to control the in-plane magnetic anisotropy of thin films is crucial for magnetic device applications. In this study, thin layers of Co were deposited using glancing angle deposition (GLAD) magnetron sputtering on MgO(001) and MgO(110) substrates. The in-plane anisotropy direction in Co films on MgO(001) can be controlled by adjusting the deposition angle. However, in Co films on MgO(110), the anisotropy induced by the deposition angle competes with the anisotropy induced by the substrate, and the dominant contribution is determined by the growth parameters. Additionally, while the deposition angle and film thickness affect the strength of Co in-plane anisotropy on MgO(001), no influence of these parameters on the magnetic properties is observed for films on MgO(110).
PHYSICA STATUS SOLIDI A-APPLICATIONS AND MATERIALS SCIENCE
(2023)
Review
Physics, Multidisciplinary
R. Caciuffo, G. H. Lander, G. van der Laan
Summary: Research on actinide materials has been greatly advanced by the general techniques available from high-intensity photon beams from x-ray synchrotron sources, which can work with minute samples and reduce the radioactive hazards. The article discusses the form and encapsulation procedures used for different techniques and presents the basic theory for interpreting the results. It also reviews a selection of experiments to demonstrate the potential of synchrotron radiation techniques for studying actinide materials.
REVIEWS OF MODERN PHYSICS
(2023)
Article
Chemistry, Physical
Amir A. Haghighirad, Matthew T. Klug, Liam Duffy, Junjie Liu, Arzhang Ardavan, Gerrit van der Laan, Thorsten Hesjedal, Henry J. Snaith
Summary: Substitution of Co2+ into methylammonium lead triiodide lattice imparts magnetic behavior while maintaining photovoltaic performance. Co2+ ions are used as probes to sense the local electronic environment of Pb, revealing their incorporation into the perovskite. This work provides a comprehensive understanding of transition metal incorporation, opening the gateway for developing novel perovskite materials and devices.
Article
Physics, Condensed Matter
R. Sant, A. De Vita, V Polewczyk, G. M. Pierantozzi, F. Mazzola, G. Vinai, G. van der Laan, G. Panaccione, N. B. Brookes
Summary: Polarization dependent x-ray absorption spectroscopy was used to study the magnetic ground state and orbital occupation in VI3 van der Waals crystals. The effects of symmetry reduction and hybridization between vanadium and ligand states were evaluated. The results suggest that the insulating ground state is stabilized by Mott correlation effects rather than a Jahn-Teller mechanism, and provide insights for studying the spectroscopic properties of other van der Waals halides.
JOURNAL OF PHYSICS-CONDENSED MATTER
(2023)
Article
Instruments & Instrumentation
Gerrit van der Laan, Thorsten Hesjedal
Summary: Element-specific spectroscopies using synchrotron-radiation provide unique insights into materials properties. X-ray detected ferromagnetic resonance (XFMR) allows studying the magnetization dynamics of magnetic spin structures. Recent developments in X-ray scattering techniques reveal the precessional magnetization dynamics of ordered spin structures, providing valuable information for the engineering of high-density and low-energy consumption data processing solutions.
NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS
(2023)
Article
Materials Science, Multidisciplinary
C. Love, J. E. Beevers, B. Achinuq, R. Fan, T. Susaki, K. Matsuzaki, V. K. Lazarov, S. S. Dhesi, G. van der Laan, S. A. Cavill
Summary: The size of the orbital moment in bulklike epitaxial Fe3O4 films on yttria-stabilized zirconia (111) substrates has been determined using ferromagnetic resonance (FMR) spectroscopy and x-ray magnetic circular dichroism (XMCD). Annealing the films improves their stoichiometry and microstructure, allowing for the recovery of bulklike properties. Both FMR and XMCD techniques provide evidence for the presence of a finite orbital moment in Fe3O4, with a spectroscopic splitting factor g approximately 2.18.
Article
Materials Science, Multidisciplinary
Marisel Di Pietro Martinez, Alexis Wartelle, Carlos Herrero Martinez, Farid Fettar, Florent Blondelle, Jean-Francois Motte, Claire Donnelly, Luke Turnbull, Feodor Ogrin, Gerrit van der Laan, Horia Popescu, Nicolas Jaouen, Flora Yakhou-Harris, Guillaume Beutier
Summary: In recent years, there has been increased interest in expanding from 2D to 3D systems in the magnetism community. This has led to the need for new characterization techniques, including tomographic imaging, to explore new geometries and broaden knowledge on magnetic textures in thick samples. This study presents a new tomographic technique based on Fourier transform holography, which overcomes the phase problem inherent to reciprocal-space-based techniques and allows for investigation of thicker samples.
Article
Materials Science, Multidisciplinary
Xiaodong Xie, Kejing Ran, Yizhou Liu, Raymond Fan, Wancong Tan, Haonan Jin, Manuel Valvidares, Nicolas Jaouen, Haifeng Du, Gerrit van der Laan, Thorsten Hesjedal, Shilei Zhang
Summary: We have identified a three-dimensional skyrmion side-face state in chiral magnets, which is composed of a thin layer of modulated surface spirals and an array of phase-locked skyrmion screws. Using resonant elastic x-ray scattering, we observed a characteristic X-shaped magnetic diffraction pattern that resembles Photo 51 of the DNA double-helix diffraction. By measuring both thin plates and bulk Cu2OSeO3 crystals in the field-in-plane geometry, we were able to unambiguously identify the modulated skyrmion strings and retrieve their chirality and helix angle. The breaking of translational symmetry along the side faces suppresses the bulk-favored conical state and provides a previously overlooked stabilization mechanism for the skyrmion lattice phase.
Article
Materials Science, Multidisciplinary
R. Brearton, D. M. Burn, A. A. Haghighirad, G. van der Laan, T. Hesjedal
Summary: This study investigates the symmetry of the micromagnetic free energy of magnetic skyrmions and their three-dimensional characteristics. The study shows that complex modulation and bending along the surfaces are necessary requirements for skyrmions to coexist with other magnetization configurations.
Article
Materials Science, Multidisciplinary
D. M. Burn, S. L. Zhang, G. van der Laan, T. Hesjedal
Summary: Magnetic diffraction combined with x-ray detected ferromagnetic resonance (DFMR) is used to study the FMR modes in chiral magnet Cu2OSeO3. The DFMR technique allows for time-resolved measurements of the spin configurations and dynamics of different FMR modes. Continuous phase advance in the conical mode and phase lag in the field-polarized mode are observed, and the dynamics along the conical axis show inversion upon reversing the applied field direction.
Article
Materials Science, Multidisciplinary
Kook Tae Kim, Jung Yun Kee, Margaret R. McCarter, Gerrit van der Laan, Vladimir A. Stoica, John W. Freeland, Ramamoorthy Ramesh, Se Young Park, Dong Ryeol Lee
Summary: This paper presents a detailed analytical formulation of CD-REXS for one-dimensional helices composed of magnetic moments and electric polarization vectors. The results show that CD-REXS can discriminate between different types of helices and that the x-ray polarization factor is a significant factor in determining the characteristics of CD-REXS for chiral structures.
