Article
Materials Science, Multidisciplinary
Hiroaki Ishizuka, Naoto Nagaosa
Summary: This study investigates the skew scattering mechanism in three-spin clusters, revealing that three spins are necessary for skew scattering in the absence of spin-orbit interaction. The research shows that the skew angle produced by the three-spin cluster is on the order of 0.1 pi rad (approximately 18 degrees) when the electron-spin coupling is comparable to the bandwidth. Additionally, the study explores the relationship between anomalous/spin Hall effects and spin chiralities, suggesting that the skew angle is approximately proportional to the scalar (net vector) spin chirality even in strong-coupling cases.
Article
Nanoscience & Nanotechnology
Sara Catalano, Juan M. Gomez-Perez, M. Xochitl Aguilar-Pujol, Andrey Chuvilin, Marco Gobbi, Luis E. Hueso, Felix Casanova
Summary: Spin Hall magnetoresistance (SMR) is a reference tool used to investigate the magnetic properties of materials, but realistic surfaces may lead to unexpected artifacts in SMR due to defects and disorder. This study discovers that the SMR-like signal in heterostructures is generated by strong interfacial disorder, challenging the widespread assumption on the role of disorder in SMR measurements.
ACS APPLIED MATERIALS & INTERFACES
(2022)
Article
Physics, Applied
M. K. Zhao, C. H. Wan, X. M. Luo, Y. Z. Wang, T. Y. Ma, W. L. Yang, Y. Zhang, L. Yin, G. Q. Yu, X. F. Han
Summary: Spin logics offer a shortcut to logic-in-memory architectures by independently controlling magnetization of in-plane and perpendicular layers without an external magnetic field. Experimental construction of five Boolean logic gates in a single device in a field-free condition marks progress towards practical spin-orbit torque logics.
APPLIED PHYSICS LETTERS
(2021)
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
Materials Science, Multidisciplinary
Oliver Busch, Boerge Goebel, Ingrid Mertig
Summary: The spin Hall effect is typically associated with spin-orbit interaction, but it can also occur in specific materials even in absence of spin-orbit coupling. Coplanar kagome antiferromagnets Mn3X are interesting candidates for applications involving spin currents. The main contribution to the intrinsic spin Hall signal in these materials comes from noncollinear magnetic texture and is most significant in coplanar systems. Furthermore, spin-orbit coupling or out-of-plane tilting of magnetic moments can effectively reduce the spin Hall effect.
Article
Materials Science, Multidisciplinary
M. Creff, J. -E. Wegrowe, E. Olive
Summary: This study investigates the stationary state of a spin Hall bar using a variational approach that considers the nonequilibrium screening effects at the edges. The calculation takes into account the spin-flip relaxation and global constraints due to the electric generator and global charge conservation. It derives simple analytical expressions for the spin accumulation and longitudinal and transverse pure spin currents under the approximations of negligible and strong spin-flip scattering. In typical conditions, the maximum amplitude of the spin accumulation is expected to be around 1% of the equilibrium density of carriers.
Article
Quantum Science & Technology
Biswajit Sahoo, Koustuv Roy, Pushpendra Gupta, Abhisek Mishra, Biswarup Satpati, Braj Bhusan Singh, Subhankar Bedanta
Summary: The study focuses on spin pumping and inverse spin Hall effect in an IrO2/CoFeB system. By analyzing the angular dependence of ISHE voltage, it identifies the significant contribution of spin pumping to the ISHE signal. The research shows that polycrystalline IrO2 thin film exhibits high spin Hall conductivity and spin Hall angle comparable to Pt.
ADVANCED QUANTUM TECHNOLOGIES
(2021)
Article
Chemistry, Physical
Liwen Zhang, Jun Chen, Lei Zhang, Fuming Xu, Liantuan Xiao, Suotang Jia
Summary: Graphene with micrometer spin relaxation length presents promising potential in spintronics, but efficient spin injection remains a challenge. Generating spin current in ZGNR via photogalvanic effect provides a novel approach to achieve spin injection without accompanying charge current, and the spin current generation and polarization can be controlled through a dual gate system.
Article
Multidisciplinary Sciences
Yukako Fujishiro, Naoya Kanazawa, Ryosuke Kurihara, Hiroaki Ishizuka, Tomohiro Hori, Fehmi Sami Yasin, Xiuzhen Yu, Atsushi Tsukazaki, Masakazu Ichikawa, Masashi Kawasaki, Naoto Nagaosa, Masashi Tokunaga, Yoshinori Tokura
Summary: The electrical Hall effect, known as the anomalous Hall effect (AHE), can be significantly enhanced through the interaction of conduction electrons with magnetism. In a study on a chiral magnet MnGe thin film, giant AHE of electron-scattering origin was observed, attributed to a new type of skew-scattering mechanism involving thermally excited spin-clusters with scalar spin chirality.
NATURE COMMUNICATIONS
(2021)
Article
Materials Science, Multidisciplinary
Haoshen Ye, Lisha Liu, Dongmei Bai, G. P. Zhang, Junting Zhang, Jianli Wang
Summary: In this study, the spin valve effect in the TiCr2N4 monolayer was investigated using density functional theory and Boltzmann transport theory. The results showed that the TiCr2N4 monolayer retains a ferromagnetic ground state above room temperature, and its electrical transport property is strongly dependent on the angle of magnetization direction. The large difference in conductivity between the TiCr2N4 monolayers with parallel and anti-parallel magnetization leads to giant magnetoresistance.
JOURNAL OF MATERIALS CHEMISTRY C
(2022)
Article
Chemistry, Physical
Seif Alwan, Subhajit Sarkar, Amos Sharoni, Yonatan Dubi
Summary: This article investigates the temperature-dependence of the chirality-induced spin selectivity (CISS) effect and provides experimental evidence for different theoretical explanations of the CISS mechanism. The recently proposed spinterface model and its temperature effects are discussed, and recent experimental results presented in Qian et al.'s work are analyzed in detail. The findings demonstrate that the CISS effect increases with decreasing temperature, contrary to the original interpretation by the authors, and show the accuracy of the spinterface model in reproducing these experimental results.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Physics, Applied
Xin Chen, Duo Wang, Linyang Li, Biplab Sanyal
Summary: In this study, we propose the theoretical predictions of a two-dimensional collinear antiferromagnetic semimetal, CrO, which exhibits remarkable spin-split band structure, spin-momentum locked transport properties, and high Neel temperature. By manipulating the position of spin-polarized anisotropic Weyl points with strain, we demonstrate the possibility of achieving four different antiferromagnetic spintronic states with zero net magnetic moments. These findings provide a new avenue in spintronics without net magnetic moment or strong spin-orbit coupling and have the potential for spintronic applications in antiferromagnetic materials.
APPLIED PHYSICS LETTERS
(2023)
Article
Materials Science, Multidisciplinary
Jingu Qin, Dazhi Hou, Yao Chen, Eiji Saitoh, Xiaofeng Jin
Summary: The temperature dependence of spin Hall magnetoresistance (SMR) was investigated in Pt/Cr2O3/Y3Fe5O12 structure. The SMR was not observed well below the Neel temperature of Cr2O3, and only a positive SMR was seen near the Neel temperature, tracking the YIG magnetic switching process. The high field magnetoresistance observed up to an external magnetic field of 20000 Oe is attributed to the Hanle magnetoresistance in Pt.
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
(2021)
Article
Chemistry, Physical
Yun Ni, Jia Li, Wei Tao, Hao Ding, Rui-Xue Li
Summary: This paper studied the transport properties of defected ZGNR with a graphene nanobubble through first-principles quantum transport calculations. When the nanobubble is intact and located at the center, the spin polarization and magnetoresistance tend to decrease at low bias voltages, while when the nanobubble is split and located at the edge, all transport properties are significantly affected and altered. New results obtained from the device include the negative differential resistance effect and the pure thermal-induced spin-current.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2021)
Article
Materials Science, Multidisciplinary
M. Mehraeen, Steven S. -L. Zhang
Summary: This study predicts the existence of spin anomalous-Hall unidirectional magnetoresistance (AH-UMR) in conducting bilayers composed of a ferromagnetic layer and a nonmagnetic layer, which is different from the well-studied unidirectional spin-Hall magnetoresistance and is mainly derived from the spin anomalous Hall effect in the ferromagnetic layer. It is found that the charge-spin conversion induced by the spin anomalous Hall effect and the structural inversion asymmetry generate a net nonequilibrium spin density in the ferromagnetic layer, which modulates the resistance of the bilayer when the direction of the applied current or the magnetization is reversed.
Article
Chemistry, Physical
Yujing Du, Shiping Wang, Lei Wang, Shengye Jin, Yifan Zhao, Tai Min, Zhuangde Jiang, Ziyao Zhou, Ming Liu
Summary: The development of solar control of magnetism enables the manipulation of magnetic moments by sunlight instead of traditional methods. Using ternary systems in photovoltaic/magnetic heterostructures allows for greater magnetic changes, which could be applied in solar-driven magneto-optical memory applications.
Article
Chemistry, Multidisciplinary
Su Kong Chong, Peng Zhang, Jie Li, Yinong Zhou, Jingyuan Wang, Huairuo Zhang, Albert. V. V. Davydov, Christopher Eckberg, Peng Deng, Lixuan Tai, Jing Xia, Ruqian Wu, Kang. L. L. Wang
Summary: A novel procedure combining thin-film deposition and 2D material stacking techniques is demonstrated to create dual-gated devices of magnetically doped topological insulators. The orthogonal control over the charge density and electric displacement field is achieved in these devices. Through electrical manipulation of the surface exchange gap, the capabilities to strengthen or suppress the quantum anomalous Hall state and drive a topological phase transition to a trivial state are demonstrated. The experimental results are explained using first principle theoretical calculations, providing a practical route for in situ control of quantum anomalous Hall states and topology.
ADVANCED MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
Yipeng An, Juncai Chen, Zhengxuan Wang, Jie Li, Shijing Gong, Chunlan Ma, Tianxing Wang, Zhaoyong Jiao, Ruqian Wu, Jiangping Hu, Wuming Liu
Summary: In this study, a new kagome magnesium triboride (MgB3) superconductor is predicted, with a calculated critical temperature of about 12.2 K and 15.4 K under external stress, which is potentially the highest among the reported diverse kagome-type superconductors. Various exotic physical properties of the system, including van Hove singularity, flat-band, multiple Dirac points, and nontrivial topology, are revealed. The topological and nodal superconducting nature of MgB3 is unveiled using a recently developed symmetry indicators method. This study suggests that MgB3 can serve as a new platform to explore exotic physics in the kagome structure and search for more superconductors and topological materials with XY3-type kagome lattice.
PHYSICAL REVIEW MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Jie Li, Ruqian Wu
Summary: In this study, a van der Waals (vdW) heterostructure of ultrathin MnBi2Se4 and Bi2Se3 layers is proposed as an excellent tunable platform for the quantum anomalous Hall (QAH) effect. The band gap of this heterostructure closes and reopens as the applied electric field increases, exhibiting a novel topological phase transition. It also has other advantageous properties such as a large topological band gap, perpendicular magnetization, and strong ferromagnetic ordering.
Article
Chemistry, Multidisciplinary
Huaixun Huyan, Zhe Wang, Linze Li, Xingxu Yan, Yi Zhang, Colin Heikes, Darrell G. Schlom, Ruqian Wu, Xiaoqing Pan
Summary: Defect engineering in perovskite thin films has received extensive attention due to their atomic-level modification and the design of novel nanostructures. However, three-dimensional defect-assisted nanostructures in thin film matrices usually have large misfit strains and unstable structures. In contrast, one- or two-dimensional defect-assisted nanostructures embedded in thin films can sustain large misfit strains without relaxation, making them suitable for defect engineering in perovskite thin films.
Article
Chemistry, Multidisciplinary
Meng Zhao, Lei Wang, Yifan Zhao, Yujing Du, Zhexi He, Kai Chen, Zhenlin Luo, Wensheng Yan, Qian Li, Chenying Wang, Zhuangde Jiang, Ming Liu, Ziyao Zhou
Summary: Researchers propose an energy-efficient method for switching magnetization in spintronic devices using sunlight control. By inducing photoelectron-induced redistribution of the orbital and spin moment, the in-plane Rashba field is enhanced, leading to a weakened perpendicular magnetic anisotropy and magnetization switching. This sunlight control of PMA could offer an alternative way for energy-efficient magnetic recording.
Article
Multidisciplinary Sciences
Zhizhong Zhang, Kelian Lin, Yue Zhang, Arnaud Bournel, Ke Xia, Mathias Klaeui, Weisheng Zhao
Summary: This study proposes a neural network based on magnon scattering modulated by an omnidirectional mobile hopfion in antiferromagnets. The states of neurons are encoded in the frequency distribution of magnons, and the connections between them are related to the frequency dependence of magnon scattering. By controlling the hopfion's state, hyperparameters in the network can be modulated, realizing the first verified well-functioning meta-learning device. This research not only breaks the connection density bottleneck but also provides a guideline for future designs of neuromorphic devices.
Article
Chemistry, Multidisciplinary
Yujing Du, Yifan Zhao, Lei Wang, Zhexi He, Yangyang Wu, Chenying Wang, Libo Zhao, Zhuangde Jiang, Ming Liu, Ziyao Zhou
Summary: This study demonstrates visible light tuning of interfacial exchange interaction in synthetic antiferromagnetic heterostructure, enabling reversible magnetism switching and deterministic magnetization control. Photoelectron doping is found to enhance the exchange interaction by increasing the Fermi energy. A prototype device with visible light control of magnetoresistance ratio change is fabricated, paving the way for fast, compact, and energy-efficient solar-driven memories.
Article
Materials Science, Multidisciplinary
Lei Wang, Tai Min, Ke Xia
Summary: The abnormal scaling law of the anomalous Hall effect in L12-type Mn3X (X = Ir, Pt, Rh) is found to originate from a two-center scattering (TCS) contribution using a first-principles-based scattering wave-function approach in this study. The TCS contribution dominates the anomalous Hall effect in noncollinear antiferromagnetic metals, with the anomalous Hall conductivity being as large as & sigma;H <^> 5 x 104 (0 cm)-1 in L12-type Mn3Ir at low temperature, which is two orders of magnitude larger than the current Berry curvature calculations.
Article
Materials Science, Multidisciplinary
S. B. Song, Z. Wang, R. Q. Wu
Summary: In this study, we used density functional theory calculations to investigate the magnetic properties of 5d transition metal monolayers on a ferroelectric substrate. Our results showed that the easy magnetization axis of iridium and platinum monolayers can be rotated by 90 degrees by reversing the electric polarization of the substrate, while the magnetocrystalline anisotropy energy of the osmium monolayer is significantly enhanced in the upward polarization state. These findings provide valuable insights for controlling the magnetization direction of monoatomic layers and developing low-energy spintronics devices.
Article
Materials Science, Multidisciplinary
Y. D. Sun, Lei Wang, Lili Lang, Ke Xia, S. M. Zhou
Summary: We investigated the hysteresis and training effect of spin current in Pt/Y3Fe5O12 heterostructures under successive cycles of ionic liquid gate voltage Vg. The diode-like behaviors of inverse spin Hall effect voltage and spin Hall magnetoresistance in spin pumping during the first half cycle of Vg, as well as the hysteresis in the first cycle of Vg, become weak and disappear in the second cycle due to the training effect. This study provides valuable insights into enhancing the functional performance of electrically controlled spin current devices.
Article
Chemistry, Physical
Ao Lou, Hua-Hua Fu, Ruqian Wu
Summary: Using density functional theory and the Boltzmann transport equation, we have discovered a new class of high-performance thermoelectric materials, called supertetrahedral Ga4C-family materials, which exhibit an ultrahigh thermoelectric figure of merit (ZT) due to a large power factor and ultralow lattice thermal conductivity. The power factor is influenced by multiple electronic band degeneracies, flat bands, and valley anisotropy, while the low lattice thermal conductivity is attributed to strong phonon scattering and low phonon group velocity. Moreover, we found that tensile strain engineering can further decrease lattice thermal conductivity while maintaining the multi-band degeneracies, valley anisotropy, and flat bands. In addition to band degeneracy, the scattering mechanism can also greatly affect the power factor during strain implementation. As a result, we observed a novel thermoelectric phenomenon, with Ca4C exhibiting a ZT value larger than 4.4 under a small strain ratio (0.75%). Our theoretical studies not only reveal a new class of high-performance thermoelectric materials with multiple effective mechanisms but also provide a realistic platform for investigating the competitive effects of different factors on enhancing the thermoelectric figure of merit.
JOURNAL OF MATERIALS CHEMISTRY A
(2023)
Article
Materials Science, Multidisciplinary
Yinong Zhou, Ruqian Wu
Summary: In this study, the possibility of direct control of topological corner states is demonstrated by introducing spin degrees of freedom and local magnetization and electric potential in a rhombus-shaped Kekule nanostructure. By applying local magnetization on one corner, strong spin polarization can be achieved in both corners. Reversal of spin polarization at both corners is achieved by applying local electric potential at the same corner. The robustness of spin polarization control under disorder is also proven, and material realization is demonstrated in a gamma-graphyne nanostructure. Other higher-order lattices and nanostructure shapes are discussed as well. These studies provide a showcase of the remote correlation of quantum states in higher-order topological materials for spintronic and quantum applications.
