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)
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
Materials Science, Multidisciplinary
Peter A. Schultz, Harold P. Hjalmarson
Summary: The E3 transition in irradiated GaAs has been observed to have three distinct components in deep level transient spectroscopy (DLTS). The component designated E3c is found to be metastable, reversible bleaching under minority carrier injection, with an introduction rate depending on Si doping density. First-principles modeling reveals that E3c must be the intimate Sivacancy pair, best described as a Si sitting in a divacancy Sivv. The bleached metastable state is enabled by a doubly site-shifting mechanism, where the defect undergoes a second site shift upon recharging rather than returning to its original E3c-active configuration by reversing the first site shift. Identifying this defect provides insights into short-time annealing kinetics in irradiated GaAs.
Article
Materials Science, Multidisciplinary
Yadong Jiang, Zhaochen Liu, Jing Wang
Summary: The unoccupied part of the band structure in the magnetic topological insulator MnBi2Te4 has been studied using first-principles calculations. A possible second, unoccupied topological surface state is proposed, which has a similar electronic structure to the occupied topological surface state. Two optical effects are proposed to detect the unoccupied surface state if it exists.
Article
Physics, Condensed Matter
A. M. Shikin, T. P. Makarova, A. V. Eryzhenkov, D. Yu. Usachov, D. A. Estyunin, D. A. Glazkova, I. I. Klimovskikh, A. G. Rybkin, A. V. Tarasov
Summary: We have studied various factors affecting the changes in the Dirac gap in MnBi2Te4 and determined the routes for intentional gap modulation. It was found that by adjusting the surface van der Waals interval and surface spin-orbit coupling strength, the localization of topological surface states shifts between surface septuple layers with opposite magnetizations, resulting in a nonmonotonic change in the Dirac gap size. The Dirac gap can be effectively modulated by replacing magnetic atoms with nonmagnetic ones or by replacing Bi and Te atoms with elements with lower spin-orbit coupling, allowing for the creation of synthetic layered topological systems with purposeful modification of surface properties.
PHYSICA B-CONDENSED MATTER
(2023)
Article
Physics, Applied
Zhihao Zhong, Enkui Yi, Nannan Tang, Yue Zhao, Donghui Guo, Bing Shen, Dingyong Zhong, Huichao Wang
Summary: We report a Fermi-level-sensitive linear magnetoresistance (LMR) phenomenon by doping Sb into antiferromagnetic topological insulator (TI) MnBi2Te4 crystals. LMR is most remarkable when the Fermi level is close to the charge neutral point and the bulk carriers are largely suppressed. Our analyses show a linear dependence of the LMR slope on the inverse of carrier density, consistent with the quantum LMR model based on the TI surface state.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2023)
Article
Nanoscience & Nanotechnology
Haiqin Deng, Yan Zhang, Xiaoxin Yang, Qiang Yu, Pengdong Wang, Zixin Yang, Yongping Dai, Xiuyang Pang, Xiao Wang, Jian Wu, Pu Zhou
Summary: In this study, high-quality MnBi2Te4 nanosheets were successfully synthesized and their morphology, chemical composition, magnetic properties, and nonlinear optical characteristics were systematically investigated. The results confirmed the magnetic transition of MnBi2Te4 and showed its saturable absorption property. A mode-locking laser operating at 1558.8 nm with a pulse duration of 331 fs was achieved by inserting the MnBi2Te4-based saturable absorber.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Chemistry, Multidisciplinary
Dmitry Ovchinnikov, Xiong Huang, Zhong Lin, Zaiyao Fei, Jiaqi Cai, Tiancheng Song, Minhao He, Qianni Jiang, Chong Wang, Hao Li, Yayu Wang, Yang Wu, Di Xiao, Jiun-Haw Chu, Jiaqiang Yan, Cui-Zu Chang, Yong-Tao Cui, Xiaodong Xu
Summary: MnBi2Te4 is a van der Waals magnet that can form a Chern insulator when all spins are aligned by an applied magnetic field. Through in-depth investigation, it is found that the bulk electronic structure evolves as the magnetic state is tuned, with a one-to-one correspondence with layer thickness, topological order, and magnetic state. Additionally, band topology and magnetic order in this newly discovered topological magnet exhibit an interplay during the continuous tuning of the magnetic state.
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
Engineering, Environmental
Jie Li, Cheng Wang, Hongyuan Shang, Yuan Wang, Huaming You, Hui Xu, Yukou Du
Summary: Utilizing alkali etching to drive structure reconstruction, a class of Co-modified PtTe2 nanorods with surface defects were designed for efficient methanol oxidation reaction. The enhanced performance is attributed to the abundant surface defects and optimized electronic structure, boosting the oxidation of CO-like intermediates. This alkali etching strategy can be universally applied to fabricate other metal-modified PtTe2 nanorods with surface defects, achieving a class of high-performance nanorods.
CHEMICAL ENGINEERING JOURNAL
(2021)
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)
Article
Physics, Multidisciplinary
Hengxin Tan, Binghai Yan
Summary: This letter investigates the electrical and magnetic properties of MnBi2Te4 thin films under different magnetic fields. A mechanism related to surface defects is proposed to explain the contradictory observations in previous experiments. It is found that co-antisites can strongly suppress the magnetic gap in the antiferromagnetic phase without violating the magnetic order, while preserving the magnetic gap in the ferromagnetic phase. This study is of great importance for future surface spectroscopy measurements.
PHYSICAL REVIEW LETTERS
(2023)
Article
Nanoscience & Nanotechnology
Mihovil Bosnar, Alexandra Yu. Vyazovskaya, Evgeniy K. K. Petrov, Evgueni V. V. Chulkov, Mikhail M. M. Otrokov
Summary: Chern insulators are two-dimensional magnetic topological materials that conduct electricity along their edges via one-dimensional chiral modes. We propose an efficient approach for achieving high Chern number states in MnBi2Te4/hBN van der Waals multilayer heterostructures. Our results show that a stack of n MnBi2Te4 films intercalated by hBN monolayers can give rise to a high Chern number state with n chiral edge modes. This state can be achieved both with and without an external magnetic field, resulting in quantized Hall conductance. Our findings pave the way for practical high Chern number quantized Hall systems.
NPJ 2D MATERIALS AND APPLICATIONS
(2023)
Article
Chemistry, Multidisciplinary
Jifeng Shao, Yuntian Liu, Meng Zeng, Jingyuan Li, Xuefeng Wu, Xiao-Ming Ma, Feng Jin, Ruie Lu, Yichen Sun, Mingqiang Gu, Kedong Wang, Wenbin Wu, Liusuo Wu, Chang Liu, Qihang Liu, Yue Zhao
Summary: The magnetic properties of MnBi2Te4(Bi2Te3)(n) can be manipulated by tuning the number of Bi2Te3 spacer layers n, with opposite responses observed for n = 1 and 2 under hydrostatic pressure. This is due to the essential role of intralayer exchange coupling from lattice compression in determining the magnetic properties, leading to a phase transition from A-type antiferromagnetic to quasi-two-dimensional ferromagnetic state. Such magnetic phase transition is also observed in 20% Sb-doped MnBi6Te10 due to in-plane lattice compression.
Article
Materials Science, Multidisciplinary
Felix Lupke, Anh D. Pham, Yi-Fan Zhao, Ling-Jie Zhou, Wenchang Lu, Emil Briggs, Jerzy Bernholc, Marek Kolmer, Jacob Teeter, Wonhee Ko, Cui-Zu Chang, Panchapakesan Ganesh, An-Ping Li
Summary: The study investigates the local signatures of thickness-dependent topology in MnBi2Te4 thin films using scanning tunneling microscopy and spectroscopy. Theoretical calculations reveal a topological quantum phase transition beyond a film thickness of one monolayer, with alternating quantum anomalous Hall effect and axion insulating states, and localized electronic states at step edges.
Article
Chemistry, Multidisciplinary
Kangdi Niu, Guotao Qiu, Chuanshou Wang, Daiyue Li, Yutao Niu, Songge Li, Lixing Kang, Yongqing Cai, Mengjiao Han, Junhao Lin
Summary: This study focuses on 2D magnetic heterojunctions which have attracted considerable interest due to their potential applications in spintronics. By using CrTe2 as the backbone framework and self-intercalated 2D chromium telluride (CrxTey), the researchers obtained various lateral and vertical magnetic heterojunctions. They demonstrated a Cr2Te3-Cr5Te8 lateral heterojunction prototype that can manipulate magnetic moments under different magnitudes of magnetic excitation, showing a sharply stepped hysteresis loop with a dual spin-flip transition at high Curie temperatures up to 150 and 210 K by magneto-optical Kerr measurement. The overall structural rigidity of chromium-telluride heterostructure with magnetic phase decoupled behaviors is promising for 2D spintronic devices.
ADVANCED FUNCTIONAL MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Shaolong Jiang, Gang Wang, Hanbing Deng, Kai Liu, Qishuo Yang, Erding Zhao, Liang Zhu, Weiteng Guo, Jing Yang, Cheng Zhang, Heshen Wang, Xi Zhang, Jun-Feng Dai, Guangfu Luo, Yue Zhao, Junhao Lin
Summary: Two-dimensional transition metal dihalides (TMDHs) have attracted extensive attention for their diverse magnetic properties and potential applications in spintronics. However, the controlled growth of 2D TMDHs is challenging due to their sensitivity to atmospheric moisture. In this study, a universal chemical vapor deposition synthesis route for high-quality 2D TMDH flakes (1T-FeCl2, FeBr2, VCl2, and VBr2) is developed using a nitrogen-filled glovebox system. The synthesized FeCl2 flakes exhibit interlayer antiferromagnetic ordering with a Neel temperature of approximately 17 K.
Article
Chemistry, Physical
Weiyuan Huang, Mingjian Zhang, Mingyuan Ge, Shunning Li, Lin Xie, Zhefeng Chen, Gang Wang, Junhao Lin, Jimin Qiu, Lei Yu, Jianguo Wen, Guo-Xi Ren, Cong Lin, Wenguang Zhao, Haibiao Chen, Feng Pan
Summary: A new Li-Mn-O nanohybrid cathode was developed using phase complex engineering, which integrated layered nanodomains and spinel nanodomains to effectively suppress the irreversible lattice oxygen loss at high potentials and enhance cycling stability. This strategy offers a new path for developing stable high-energy-density cathode materials.
ACS ENERGY LETTERS
(2023)
Article
Chemistry, Physical
Zhen Su, Huihui Yang, Gang Wang, Yilei Zhang, Jia Zhang, Junhao Lin, Dechang Jia, Heyan Wang, Zhengang Lu, PingAn Hu
Summary: This study successfully prepares transparent EMI shielding films with weak secondary reflection, nanoscale ultra-thin thickness, and long-term stability by using high-quality SCG/h-BN heterostructure. The shielding film, adopting SCG as the absorption layer and silver nanowires film as the reflection layer, achieves the dual coupling effect and enhances the absorption loss of electromagnetic waves. This research provides an outstanding EMI shielding material with great potential for practical applications in electronic devices protection.
JOURNAL OF COLLOID AND INTERFACE SCIENCE
(2023)
Article
Chemistry, Multidisciplinary
Songge Li, Yun-Peng Wang, Shoucong Ning, Kai Xu, Sokrates T. Pantelides, Wu Zhou, Junhao Lin
Summary: A single-frame scanning transmission electron microscopy (STEM) image can be used to reconstruct the ripple structure in monolayer MoSe2, allowing for direct visualization of the dynamics of three-dimensional ripple deformation at the atomic scale. Furthermore, the reconstructed images provide an opportunity to test the validity of the classical theory of thermal fluctuations.
Article
Chemistry, Multidisciplinary
Gang Wang, Xixi Yu, Erding Zhao, Daiyue Li, Le Wang, Junhao Lin
Summary: In this study, aberration-corrected cryogenic transmission electron microscopy (cryo-TEM) was used to investigate the in-and out-of-plane ordering of the commensurate charge density wave (CDW) superstructure in a 1T-TaS2 thin flake. By analyzing the phase intensity variation of modulated Ta atoms, a penetrative 3D CDW stacking structure with an intertwining multidomain structure was visualized, revealing three types of vertical CDW stacking configurations. This research provides microstructural evidence for the coexistence of local Mott insulation and metal phases and offers a paradigm for studying CDW structure and correlation order in condensed-matter physics using cryo-TEM.
Article
Chemistry, Multidisciplinary
Qing Zhang, Chuan Zhou, Menghao Li, Yuanmin Zhu, Xianbin Wei, Shaocheng Shen, Zongwei Ji, Guangfu Luo, Yifeng Cheng, Xuming Yang, Zhijie Wang, Lingfeng Zou, Lin Zeng, Junhao Lin, Lei Li, Joseph S. Francisco, Meng Gu
Summary: High-concentrated non-flammable electrolytes (HCNFE) in lithium metal batteries can prevent thermal runaway accidents, and the microstructure of their solid electrolyte interphase (SEI) has been explored using cryo-HRTEM. The SEI in HCNFE exhibits a uniform laminated crystalline-amorphous structure that prevents further reaction between the electrolyte and lithium. Li2S2O7, the inorganic SEI component, is precisely identified using cryo-HRTEM. Density functional theory (DFT) calculations show that the final Li2S2O7 phase has suitable natural transmission channels for Li-ion diffusion and excellent ionic conductivity of 1.2 x 10(-5) S cm(-1).
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
Nanoscience & Nanotechnology
Yongqing Cai, Jianfeng Wang, Yuan Wang, Zhanyang Hao, Yixuan Liu, Liang Zhou, Xuelei Sui, Zhicheng Jiang, Shengjie Xu, Han Ge, Xiao-Ming Ma, Chengcheng Zhang, Zecheng Shen, Yichen Yang, Qi Jiang, Zhengtai Liu, Mao Ye, Dawei Shen, Yi Liu, Shengtao Cui, Le Wang, Cai Liu, Junhao Lin, Bing Huang, Liusuo Wu, Jincheng Zhuang, Hongtao He, Wenqing Zhang, Jia-Wei Mei, Chaoyu Chen
Summary: This study identifies a rare two-dimensional neutral line semimetal material protected by mirror symmetry and observes multiple type-II Dirac nodal lines close to the Fermi level through angle-resolved photoemission spectroscopy (ARPES), providing an electronic explanation for the nonsaturating magnetoresistance effect. These findings suggest CsV8Sb12 as an ideal platform for exploring novel transport properties.
ADVANCED ELECTRONIC MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
Hongtao Rong, Zhenqiao Huang, Xin Zhang, Shiv Kumar, Fayuang Zhang, Chengcheng Zhang, Yuan Wang, Zhanyang Hao, Yongqing Cai, Le Wang, Cai Liu, Xiaoming Ma, Shu Guo, Bing Shen, Yi Liu, Shengtao Cui, Kenya Shimada, Quansheng Wu, Junhao Lin, Yugui Yao, Zhiwei Wang, Hu Xu, Chaoyu Chen
Summary: In this study, we investigate the band degeneracies in TaCo2Te2 crystals and demonstrate the realization of eightfold fermions and fourfold van Hove singularity through experimental and theoretical analyses. TaCo2Te2 serves as a topological quantum critical platform, which can be tuned into different phases by adding strain, magnetic field, or spin-orbit coupling. Our findings establish TaCo2Te2 as a platform to explore the interplay between symmetry and band topology.
NPJ QUANTUM MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Haining Zheng, Arup Ghosh, M. J. Swamynadhan, Gang Wang, Qihan Zhang, Xiao Wu, Ibrahim Abdelwahab, Walter P. D. Wong, Qing-Hua Xu, Saurabh Ghosh, Jingsheng Chen, Branton J. Campbell, Alessandro Stroppa, Junhao Lin, Ramanathan Mahendiran, Kian Ping Loh
Summary: Organic-inorganic metal hybrids are interesting materials for spintronic applications due to their tailorable latticedimensionality and intrinsic spin-splitting properties. In this study, magnetic manganese hybrid single crystals with different lattice dimensionality were synthesized and their spin decoherence processes were studied. The spin decoherence time τ(2) in these hybrids were much longer than lead- and tin-based hybrids, and were influenced by the symmetry-directed spin exchange interaction strengths of Mn2+-Mn2+ pairs. The spin decoherence in these hybrids was found to be strongly correlated with the lattice rigidity of the inorganic framework.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Multidisciplinary Sciences
Zhenjia Zhou, Fuchen Hou, Xianlei Huang, Gang Wang, Zihao Fu, Weilin Liu, Guowen Yuan, Xiaoxiang Xi, Jie Xu, Junhao Lin, Libo Gao
Summary: This study reports a high-to-low temperature strategy for the controlled growth of multiple-layered vdW superconductor heterostructure films on a wafer scale. The presence of parallel, clean, and atomically sharp vdW interfaces on a large scale, with very little contamination between neighboring layers, has been revealed. The method can be easily applied to other situations involving 2D materials, potentially accelerating the design of next-generation functional devices and applications.
Article
Engineering, Chemical
Zhen Tian, Juan Luo, Shichang Sun, Xi Zhang, Rui Ma, Junhao Lin, Yi Chen
Summary: This study prepared high-performance Fe SACs (Fe-NC) by microwave heating using Enteromorpha rich in iron and nitrogen as the precursor. The as-prepared catalysts showed hierarchical porous structures with abundant surface functional groups, defective structures, and large specific surface area. The Fe-NC catalyst prepared by microwave heating exhibited better performance in peroxymonosulfate activation and chloroquine phosphate degradation than the catalyst prepared by conventional heating.
SEPARATION AND PURIFICATION TECHNOLOGY
(2023)
Article
Chemistry, Multidisciplinary
Fangzheng Chen, Kun Zhang, Yijia Yuan, Walter Peide Wong, Gang Wang, Xing Li, Lu Wang, Runlai Li, Zhitan Wu, Junhao Lin, Hai-Sen Xu, Kian Ping Loh
Summary: Metallo-covalent organic frameworks (metallo-COFs) with configurable topology and pore structure can be synthesized using the metal-templated approach. In this study, metallo-COFs with square-like and honeycomb lattices were successfully synthesized by incorporating Zn2+ ions and in situ-generated ligands.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
