Review
Multidisciplinary Sciences
Shuai Li, Tianyu Liu, Chang Liu, Yayu Wang, Hai-Zhou Lu, X. C. Xie
Summary: Topological materials with robust surface and/or edge states have become a focus of research in condensed matter physics. Magnetic topological materials, such as MnBi2Te4, have attracted considerable attention due to their potential for studying the interplay between topological and magnetic orders. This review summarizes the progress made on MnBi2Te4, including its crystal and magnetic structures, theoretical calculations, experimental probes, and possible future research directions.
NATIONAL SCIENCE REVIEW
(2023)
Review
Chemistry, Multidisciplinary
Gang Qiu, Hung-Yu Yang, Su Kong Chong, Yang Cheng, Lixuan Tai, Kang L. Wang
Summary: Magnetic topological insulators (MTIs) are materials that combine topological band structures with magnetism, offering new opportunities for technological advancements. This paper reviews the mainstream MTI material platforms and highlights recent developments in modulating topological properties in MTIs through various means. The manipulation of topological phases in MTIs provides an exciting avenue for fundamental research and practical applications.
Article
Chemistry, Multidisciplinary
Wenbo Wang, Yi-Fan Zhao, Fei Wang, Matthew W. Daniels, Cui-Zu Chang, Jiadong Zang, Di Xiao, Weida Wu
Summary: In this study, evidence of an emergent topological Hall effect from chiral bubbles in a two-dimensional ferromagnet was reported. The sign of the THE signal is determined by the net curvature of domain walls in different configurations, and the strength of the signal is correlated with the density of nucleation or pinned bubble domains. The findings not only reveal a general mechanism of THE in two-dimensional ferromagnets but also open up possibilities for the manipulation of topological spin textures for spintronic applications.
Article
Chemistry, Physical
Hongwei Xue, Wenxing Lv, Di Wu, Jialin Cai, Zhihao Ji, Yu Zhang, Zhongming Zeng, Qingyuan Jin, Zongzhi Zhang
Summary: This study investigates the temperature-dependent spin-orbit torque efficiencies in topological insulators, showing a significant enhancement at lower temperatures due to improved spin-polarized surface states. The findings provide insights into spin transport mechanisms and robust charge-spin conversion in TIs.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2021)
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
Chemistry, Multidisciplinary
Aiji Liang, Cheng Chen, Huijun Zheng, Wei Xia, Kui Huang, Liyang Wei, Haifeng Yang, Yujie Chen, Xin Zhang, Xuguang Xu, Meixiao Wang, Yanfeng Guo, Lexian Yang, Zhongkai Liu, Yulin Chen
Summary: This study demonstrates the control of topological surface state in an intrinsic magnetic topological insulator through surface modification. By using experimental methods, researchers found the hybridization of topological surface state and discovered an efficient method to remove the hybridization. This study provides new possibilities for the topological behavior in magnetic topological quantum materials.
Article
Multidisciplinary Sciences
Zhaowei Zhang, Naizhou Wang, Ning Cao, Aifeng Wang, Xiaoyuan Zhou, Kenji Watanabe, Takashi Taniguchi, Binghai Yan, Wei-bo Gao
Summary: This study reports on the controllable non-reciprocal charge transport in the magnetic topological insulator MnBi2Te4. By observing and manipulating the non-reciprocal response, the fundamental role of chirality in charge transport of this material is revealed, paving the way for the development of van der Waals spintronic devices through chirality engineering.
NATURE COMMUNICATIONS
(2022)
Article
Materials Science, Multidisciplinary
D. A. Estyunin, T. P. Makarova, K. A. Kokh, O. E. Tereshchenko, A. M. Shikin, I. I. Klimovskikh
Summary: This paper experimentally investigates the gradual growth of a Pb thin film on the surface of Mn(Bi0.7Sb0.3)2Te4 and its effects on the topological properties of the material. The study shows that the shape of the Dirac cone state remains almost unchanged with the growth of the Pb film, indicating the preservation of the topological properties. The deposition of Pb atoms leads to surface modification and disorder in the layers closest to the surface, causing a shift in the localization of the Dirac cone state towards the bulk.
Article
Multidisciplinary Sciences
Yuejie Zhang, Vijaysankar Kalappattil, Chuanpu Liu, M. Mehraeen, Steven S-L Zhang, Jinjun Ding, Uppalaiah Erugu, Zhijie Chen, Jifa Tian, Kai Liu, Jinke Tang, Mingzhong Wu
Summary: The spin-momentum locking in topological materials can generate a bilinear magnetoelectric resistance (BMER) effect, which has potential applications in information reading and field sensing. This article reports the first observation of BMER effects in topological Dirac semimetals, with significantly stronger responses measured at room temperature. The experiments were conducted using alpha-Sn thin films grown on silicon substrates, which showed BMER responses 10^6 times larger than previously measured at room temperature.
Article
Materials Science, Multidisciplinary
N. B. Devlin, T. Ferrus, C. H. W. Barnes
Summary: This study explores the emergence of spin-polarized flat bands at head-to-head domain walls in topological insulator heterostructures. By tuning the width of the domain wall, the functional form of bound states can be controlled. The number of layers in a multilayer sample affects the electronic dispersion, with odd-layer samples exhibiting particle-hole symmetry and linearly dispersing topologically nontrivial states around E=0, while even-layer samples lack such symmetry and result in a gapped system with spin-polarized flat bands.
Article
Physics, Applied
X. L. Ou, J. Wang, K. Zhao, X. S. Yang, Y. Zhao
Summary: We report the first rare-earth element doping in MnBi2Te4 crystals, which can modify the magnetism of MnBi2Te4 and lead to small-scale ferromagnetic transitions at low temperature. This study has significant importance for tuning the magnetism of MnBi2Te4 and future applications of magnetic topological insulators.
MODERN PHYSICS LETTERS B
(2023)
Article
Chemistry, Multidisciplinary
Hao-Ke Xu, Mingqiang Gu, Fucong Fei, Yi-Sheng Gu, Dang Liu, Qiao-Yan Yu, Sha-Sha Xue, Xu-Hui Ning, Bo Chen, Hangkai Xie, Zhen Zhu, Dandan Guan, Shiyong Wang, Yaoyi Li, Canhua Liu, Qihang Liu, Fengqi Song, Hao Zheng, Jinfeng Jia
Summary: Research has discovered that MnBi4Te7 is a topological insulator with quantum anomalous Hall effect and axion insulator phase. Through scanning tunneling spectroscopy, it has been observed that there is an electronic state at the edge of the magnetic MnBi2Te4 layer at 4.5 K, but not in the nonmagnetic Bi2Te3 layer. As the temperature increases, the edge state disappears, while the state induced by point defects persists.
Article
Chemistry, Multidisciplinary
Hongxiang Chen, Jiacheng Gao, Long Chen, Gang Wang, Hang Li, Yulong Wang, Juanjuan Liu, Jinchen Wang, Daiyu Geng, Qinghua Zhang, Jieming Sheng, Feng Ye, Tian Qian, Lan Chen, Hongming Weng, Jie Ma, Xiaolong Chen
Summary: This study presents the hourglass fermion surface state and exotic phases in the newly discovered ErAsS single crystals. In the paramagnetic phase, ErAsS is expected to be a TCI with hourglass fermion surface state, which is experimentally confirmed by observed band structures. Below a certain temperature, ErAsS enters a collinear antiferromagnetic state, and an intermediate incommensurate magnetic state appears in a narrow temperature range.
ADVANCED MATERIALS
(2022)
Article
Physics, Multidisciplinary
Wen-Ti Guo, Lu Huang, Yanmin Yang, Zhigao Huang, Jian-Min Zhang
Summary: This study demonstrates that pressure strain can induce a topological quantum phase transition in the magnetic topological insulator MnBi2Te4 by modulating its electronic band structure. The findings suggest that strain engineering could be a feasible approach for manipulating the electronic properties of intrinsic magnetic insulators.
NEW JOURNAL OF PHYSICS
(2021)
Review
Physics, Multidisciplinary
Yuan Wang, Fayuan Zhang, Meng Zeng, Hongyi Sun, Zhanyang Hao, Yongqing Cai, Hongtao Rong, Chengcheng Zhang, Cai Liu, Xiaoming Ma, Le Wang, Shu Guo, Junhao Lin, Qihang Liu, Chang Liu, Chaoyu Chen
Summary: Topological states of matter, especially those with intrinsic magnetic order, show promise in dissipationless spintronics, information storage, and quantum computation. In this review, we discuss recent progress in exploring intrinsic magnetic topological materials, including magnetic topological insulators, magnetic topological metals, and magnetic Weyl semimetals. We focus on their characteristic band features and the exotic transport responses resulting from these features. Furthermore, we present a brief outlook on experimental explorations of new physics or effects by incorporating other orders in intrinsic magnetic topological materials.
FRONTIERS OF PHYSICS
(2023)
Article
Mechanics
A. D. Lai, J. F. Jia, J. L. Qu, J. Y. Wang, J. B. Sun, Z. H. Zhou, X. S. Xu, C. W. Lim
Summary: This study investigates the influence of local thinning thickness defects on the buckling of cylindrical shells. A static buckling model is established based on the Hamiltonian system, and the complete symplectic eigensolutions are superimposed to derive the buckling modes of the cylindrical shell with defects. The influence of different defect shapes on the shell's buckling is analyzed by constraining the defect volume, and it is concluded that defects of exponential function are more harmful.
MECHANICS BASED DESIGN OF STRUCTURES AND MACHINES
(2023)
Article
Nanoscience & Nanotechnology
Xingyu Jiang, Yiren Liu, Yipeng Zang, Yuwei Liu, Tianyi Gao, Ningchong Zheng, Zhengbin Gu, Yurong Yang, Di Wu, Yuefeng Nie
Summary: This study investigates the bandgap evolution of freestanding BiFeO3 films under uniaxial strain using in situ ellipsometry measurements. The experimental results reveal the exotic anisotropic bandgap engineering phenomenon, and first-principles calculations unveil the underlying mechanism of O-6 octahedral rotations.
Article
Chemistry, Physical
Jin Lei, Song Sun, Yuchen Li, Ping Xu, Chang Liu, Shaozhong Chang, Genglai Yang, Shuang Chen, Wei Fa, Di Wu, Ai-Dong Li
Summary: Researchers have constructed an organic-inorganic hybrid resistive random-access memory using a nanoporous zinc-based hydroquinone (Zn-HQ) thin film. The Pt/Zn-HQ/Ag sandwich structure was used for the device. The nanoporous Zn-HQ thin film, fabricated through one-step molecular layer deposition, enables lower operation voltages, higher on/off ratio, multilevel storage capability, and excellent endurance/retention properties.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2023)
Article
Physics, Applied
Zhijie Liu, Xinyu Wang, Xingyue Ma, Yurong Yang, Di Wu
Summary: We investigate the doping effects on the ferroelectric properties of Sc-doped AlN and B-doped AlN using first-principles methods. Our results show that the energy barrier against polarization switching decreases with increasing doping concentration, leading to the emergence of ferroelectricity in doped AlN. However, when the doping concentration exceeds a critical value, the ferroelectric phase transforms into paraelectric phases, making it ineffective to reduce coercivity by increasing doping concentration. Furthermore, different nonpolar structures appear in the ferroelectric switching pathway, resulting in different switching features in doped AlN.
APPLIED PHYSICS LETTERS
(2023)
Article
Physics, Multidisciplinary
Haoying Sun, Jiahui Gu, Yongqiang Li, Tula R. Paudel, Di Liu, Jierong Wang, Yipeng Zang, Chengyi Gu, Jiangfeng Yang, Wenjie Sun, Zhengbin Gu, Evgeny Y. Tsymbal, Junming Liu, Houbing Huang, Di Wu, Yuefeng Nie
Summary: By applying uniaxial strain, we achieved pure in-plane polarized ferroelectricity in ultrathin SrTiO3 membranes, which allows for the investigation of ferroelectric size effects without the interference of the depolarization field. Our study reveals that the stability of ferroelectricity is influenced by the thickness-dependent dipole-dipole interactions within the transverse Ising model.
PHYSICAL REVIEW LETTERS
(2023)
Review
Physics, Applied
Mohammad Yazdani-Asrami, Wenjuan Song, Antonio Morandi, Giovanni De Carne, Joao Murta-Pina, Anabela Pronto, Roberto Oliveira, Francesco Grilli, Enric Pardo, Michael Parizh, Boyang Shen, Tim Coombs, Tiina Salmi, Di Wu, Eric Coatanea, Dominic A. Moseley, Rodney A. Badcock, Mengjie Zhang, Vittorio Marinozzi, Nhan Tran, Maciej Wielgosz, Andrzej Skoczen, Dimitrios Tzelepis, Sakis Meliopoulos, Nuno Vilhena, Guilherme Sotelo, Zhenan Jiang, Veit Grosse, Tommaso Bagni, Diego Mauro, Carmine Senatore, Alexey Mankevich, Vadim Amelichev, Sergey Samoilenkov, Tiem Leong Yoon, Yao Wang, Renato P. Camata, Cheng-Chien Chen, Ana Maria Madureira, Ajith Abraham
Summary: This paper presents a roadmap for applying AI techniques and big data (BD) in various aspects of superconducting applications, such as modelling, design, monitoring, manufacturing, and operation. Short articles are provided to outline potential applications and solutions, aiming to assist researchers, engineers, and manufacturers in understanding the feasibility of using AI and BD techniques to tackle challenges in superconductivity. These potential futuristic routes and their related materials/technologies are considered for a time frame of 10-20 years.
SUPERCONDUCTOR SCIENCE & TECHNOLOGY
(2023)
Article
Physics, Applied
Yajie Han, Zhijie Liu, Zhiyu Liu, Hongying Chen, Pengxiang Hou, Jiayi Li, Yuqi Wang, Yu Deng, Yurong Yang, Di Wu
Summary: We have deposited BMN-modified BFO thin films on (001)-oriented SrTiO3 substrates buffered with La2/3Sr1/3MnO3 electrodes and observed a large remanent polarization of 116.8 mu C cm-2. Experimental analyses and first-principles calculations show that the inclusion of 10 mol % BMN increases both the intrinsic and extrinsic contributions, resulting in a doubled polarization. Compared to rhombohedral BFO films, the epitaxial BFO-BMN films exhibit a more tetragonal-like structure and a unique rotated twinning-domain structure, enhancing the out-of-plane polarization.
PHYSICAL REVIEW APPLIED
(2023)
Article
Physics, Multidisciplinary
Yao Li, Pengxiang Hou, Zhongnan Xi, Yeming Xu, Yiren Liu, Hao Tian, Jiayi Li, Yurong Yang, Yu Deng, Di Wu
Summary: Charge transfer in perovskite oxide heterostructures can disrupt the delicate balance among charge, spin, orbital, and lattice order at the interface, resulting in exotic phenomena not seen in bulk materials. The authors observed opposite charge transfer directions in two 3d/5d perovskite oxide heterostructures (SrIrO3/LaNiO3 and SrIrO3/NdNiO3), investigated the resulting interfacial orbital and lattice reconstructions, and discussed their effects on transport and magnetic characteristics.
COMMUNICATIONS PHYSICS
(2023)
Article
Physics, Applied
Zhongnan Xi, Yuqi Wang, Yang Wu, Pengxiang Hou, Peijie Jiao, Yu Deng, Yurong Yang, Di Wu
Summary: We reported an unusual thickness dependence of perpendicular magnetic anisotropy (PMA) in epitaxially deposited spinel NiCo2O4 (NCO) films on MgAl2O4 (001) single crystalline substrates, which is stronger in thinner films. The effective PMA field increases from about 3 T in 23.0 nm-thick films to about 7 T in 4.5 nm-thick films. X-ray absorption spectra reveal an inhomogeneous distribution of Co2+ cations along the film's normal, with a higher concentration near the film/substrate interface. X-ray linear dichroism spectra indicate that the PMA in NCO films is associated with the x(2)-y(2) orbital of Co cations at the tetrahedral sites. This work demonstrates the potential of ultrathin NCO films in all-oxide spintronic devices.
APPLIED PHYSICS LETTERS
(2023)
Article
Chemistry, Physical
Xin-Yue Zhang, Qiang Ren, Chen Wang, Lin Zhu, Wen-Juan Ding, Yan-Qiang Cao, Wei-Ming Li, Di Wu, Ai-Dong Li
Summary: In this study, SnO2, ZnO thin film, and SnO2/ZnO composite thin film hydrogen sensors were fabricated using atomic layer deposition (ALD). The effects of ALD cycles and heat treatment temperatures on the sensing properties were investigated. The SnO2/ZnO composite film sensor exhibited the best hydrogen-sensing performance, attributed to the synergistic effect of the SnO2-ZnO heterojunction and oxygen vacancies in the SnO2 film. ALD may be a feasible strategy for constructing highly sensitive hydrogen sensors based on Si for micro-electromechanical system applications.
APPLIED SURFACE SCIENCE
(2023)
Article
Chemistry, Physical
Jin Lei, Song Sun, Yuchen Li, Ping Xu, Chang Liu, Shaozhong Chang, Genglai Yang, Shuang Chen, Wei Fa, Di Wu, Ai-Dong Li
Summary: A resistive random-access memory based on a nanoporous zinc-based hydroquinone thin film was created with a Pt/ZnHQ/Ag sandwich structure. These devices exhibit electroforming-free bipolar resistive switching characteristic with lower operation voltages and higher on/off ratio above 10(2). The nanoporous hybrid devices also show multilevel storage capability and excellent endurance/retention properties. The connection and disconnection of Ag conductive filaments in the nanoporous Zn-HQ thin film follow the electrochemical metallization mechanism, which is facilitated by the existence of nanopores.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2023)
Article
Nanoscience & Nanotechnology
Kai Liu, Jian Zheng, Yating Sha, Bosai Lyu, Fengping Li, Youngju Park, Yulu Ren, Kenji Watanabe, Takashi Taniguchi, Jinfeng Jia, Weidong Luo, Zhiwen Shi, Jeil Jung, Guorui Chen
Summary: Interactions among charge carriers in graphene can lead to the spontaneous breaking of multiple degeneracies. In this study, the stacking orders of tetralayer graphene devices were determined using near-field infrared imaging. Through quantum transport measurements, a range of spontaneous broken-symmetry states and their transitions were observed, which could be finely tuned by carrier density and electric displacement field. These findings highlight the potential of multilayer graphene as a platform for investigating broken symmetries.
NATURE NANOTECHNOLOGY
(2023)
Article
Materials Science, Multidisciplinary
Xu Li, Hao Tian, Hong Jian Zhao, Changsong Xu, Meng Ye, Lan Chen, Hongjun Xiang, Di Wu, Yurong Yang, Jun-Ming Liu, L. Bellaiche
Summary: The Rashba-type and Zeeman effects in the two-dimensional three-atom-layer structures XTe/MnTe/X Te are found to cooperate and improve each other, which is crucial for the realization of stable Majorana fermions and topological superconductivity.
Article
Materials Science, Multidisciplinary
Yaorong Luo, Hao Tian, Xu Li, Lan Chen, Yurong Yang, Di Wu
Summary: Using first-principles and particle swarm optimization methods, this study systematically investigated the crystal structural stability and electrical properties of AGeX(3) compounds (A = Li, Na, K, Rb, Cs; X = F, Cl, Br, I). Various new structural phases and their corresponding electrical properties were discovered, such as the P2(1)2(1)2(1) perovskite phase with intrinsic small polar vortices and antivortices in KGeCl3 and KGeBr3, which may lead to a gyrotropic phase transition. Additionally, ferroelectric phases were found in R3c (LiGeX3, NaGeX3), R3m (CsGeX3) and Pna2(1) (KGeX3, RbGeX3), including the new Pna2(1) phase with both proper and hybrid improper polarization. These findings highlight the promising applications of Ge-based halide compounds in ferroics and piezoelectrics.
Article
Materials Science, Multidisciplinary
Xingyue Ma, Yurong Yang, L. Bellaiche, Di Wu
Summary: The study found that for ferroelectric PST, the electrocaloric coefficient reaches its maximum at a critical electric field for any specific temperature above the Curie temperature, which is exactly the threshold for polar nanoregions to propagate throughout the sample through percolation. This percolation-induced maximal ECE occurs for all degrees of chemical ordering, suggesting a novel mechanism for improving ECE.
