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Anomalous Hall effect from nonlinear magnetoelectric coupling

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arXiv 2024年

作者： Yu, Longju Zhao, Hong Jian Yang, Yurong Bellaiche, Laurent Ma, Yanming Key Laboratory of Material Simulation Methods and Software of Ministry of Education College of Physics Jilin University Changchun130012 China College of Physics Jilin University Changchun130012 China State Key Laboratory of Superhard Materials College of Physics Jilin University Changchun130012 China International Center of Future Science Jilin University Changchun130012 China National Laboratory of Solid State Microstructures Nanjing University Nanjing210093 China Jiangsu Key Laboratory of Artificial Functional Materials Department of Materials Science and Engineering Nanjing University Nanjing210093 China Smart Ferroic Materials Center Physics Department Institute for Nanoscience and Engineering University of Arkansas FayettevilleAR72701 United States Department of Materials Science and Engineering Tel Aviv University Ramat Aviv Tel Aviv6997801 Israel

The anomalous Hall effect (AHE) is a topology-related transport phenomenon being of potential interest in spintronics, because this effect enables the efficient probe of magnetic orders (i.e., data readout in memory devices). It is well known that AHE spontaneously occurs in ferromagnets or antiferromagnets with magnetization. While recent studies reveal electric-field induced AHE (via linear magnetoelectric coupling), an AHE originating from nonlinear magnetoelectric coupling remains largely unexplored. Here, by symmetry analysis, we establish the phenomenological theory regarding the spontaneous and electric-field driven AHE in magnets. We show that a large variety of magnetic point groups host an AHE that is driven by uni-axial, bi-axial, or tri-axial electric field and that comes from nonlinear magnetoelectric coupling. Such electric-field driven anomalous Hall conductivities are reversible by reversing the magnetic orders. Furthermore, our first-principles calculations suggest Cr2O3 and CoF2 as candidates hosting the aforementioned AHE. Our work emphasizes the important role of nonlinear magnetoelectric coupling in creating exotic transport phenomena, and offers alternative avenues for the probe of magnetic orders. Copyright © 2024, The Authors. All rights reserved.

关键词： Hall effect

Crystal Structure and Phonon Density of States of FeSi up to 120 GPa

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arXiv 2023年

作者： Kumar, Ravhi S. Liu, Han Li, Quan Xiao, Yuming Chow, Paul Meng, Yue Hu, Michael Y. Alp, Ercan Hemley, Russell Chen, Changfeng Cornelius, Andrew L. Fisk, Zachary Department of Physics University of Illinois at Chicago ChicagoIL60607 United States International Center for Computational Method Key Laboratory of Material Simulation Methods & Software Ministry of Education International Center of Future Science Jilin University Changchun130012 China HPCAT X-ray Science Division Argonne National Laboratory LemontIL60439 United States Advanced Photon Source Argonne National Laboratory ArgonneIL60439 United States Department of Physics Chemistry and Earth & Environmental Sciences University of Illinois Chicago ChicagoIL60607 United States Department of Physics and Astronomy University of Nevada Las VegasNV89154 United States Department of Physics and Astronomy University of California IrvineCA92697 United States

The strongly correlated material FeSi exhibits several unusual thermal, magnetic, and structural properties under varying pressure-temperature (P-T) conditions. It is a potential thermoelectric alloy and a material of several geological implications as a possible constituent at the Earth’s core-mantle boundary (CMB). The phase transition behavior and lattice dynamics of FeSi under different P-T conditions remain elusive. A previous theoretical work predicted a pressure-induced B20-B2 transition at ambient temperature, yet the transition is only observed at high P-T conditions in the experiments. Furthermore, the closing of the electronic gap due to a dramatic renormalization of the electronic structure and phonon anomalies has been reported based on the density function calculations. In this study, we have performed high pressure powder x-ray diffraction and Nuclear Resonant Inelastic X-ray Scattering (NRIXS) measurements up to 120 GPa to understand the phase stability and the lattice dynamics. Our study shows evidence for a nonhydrostatic stress induced B20-B2 transition in FeSi around 36 GPa for the first time. The Fe partial phonon density of states (PDOS) and thermal parameters were derived from NRIXS measurements up to 120 GPa with the density function theoretical (DFT) calculations. These calculations further predict and are consistent with pressure-induced metallization and band gap closing around 12 GPa. Copyright © 2023, The Authors. All rights reserved.

关键词： Lattice vibrations

Enhanced polarization switching characteristics of HfO2 ultrathin films via acceptor-donor co-doping

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arXiv 2024年

作者： Zhou, Chao Ma, Liyang Feng, Yanpeng Kuo, Chang-Yang Ku, Yu-Chieh Liu, Cheng-En Cheng, Xianlong Li, Jingxuan Si, Yangyang Huang, Haoliang Huang, Yan Zhao, Hongjian Chang, Chun-Fu Das, Sujit Liu, Shi Chen, Zuhuang School of Materials Science and Engineering Harbin Institute of Technology Shenzhen518055 China Fudan University Shanghai200433 China Key Laboratory for Quantum Materials of Zhejiang Province Department of Physics School of Science Westlake University Zhejiang Hangzhou310024 China Shenyang National Laboratory for Materials Science Institute of Metal Research Chinese Academy of Sciences Wenhua Road 72 Shenyang110016 China Department of Electrophysics National Yang Ming Chiao Tung University Hsinchu30010 Taiwan Department of Physics Southern University of Science and Technology Shenzhen518055 China Key Laboratory of Material Simulation Methods and Software Ministry of Education College of Physics Jilin University Changchun130012 China Max-Planck Institute for Chemical Physics of Solids Nöthnitzer Str. 40 Dresden01187 Germany Materials Research Centre Indian Institute of Science Bangalore560012 India Flexible Printed Electronics Technology Center Harbin Institute of Technology Shenzhen518055 China

In the realm of ferroelectric memories, HfO2-based ferroelectrics stand out because of their exceptional CMOS compatibility and scalability. Nevertheless, their switchable polarization and switching speed are not on par with those of perovskite ferroelectrics. It is widely acknowledged that defects play a crucial role in stabilizing the metastable polar phase of HfO2. Simultaneously, defects also pin the domain walls and impede the switching process, ultimately rendering the sluggish switching of HfO2. Herein, we present an effective strategy involving acceptor-donor co-doping to effectively tackle this dilemma. Remarkably enhanced ferroelectricity and the fastest switching process ever reported among HfO2 polar devices are observed in La3+-Ta5+ co-doped HfO2 ultrathin films. Moreover, robust macro-electrical characteristics of co-doped films persist even at a thickness as low as 3 nm, expanding potential applications of HfO2 in ultrathin devices. Our systematic investigations further demonstrate that synergistic effects of uniform microstructure and smaller switching barrier introduced by co-doping ensure the enhanced ferroelectricity and shortened switching time. The co-doping strategy offers an effective avenue to control the defect state and improve the ferroelectric properties of HfO2 films. Emerging demands for high-speed computing and high-density memory render the Von Neumann architecture less competent for future challenges. To address these issues, neuromorphic devices that mimic human synapses behaviors1,2 along with in-memory computing technologies3,4, have garnered significant attention. Ferroelectric memory devices, with stable memory state, low energy consumption, fast switching speed, and reliable endurance, emerge as promising candidates for these evolving technologies. Nevertheless, hindered by the size effect5 and incompatibility with standard complementary metal oxide semiconductor (CMOS) processing, the development of ferroelectric memory device

关键词： Ferroelectricity

The Critical Metallization of Hydrogen in Pressurized LaBeH8 Hydride

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arXiv 2024年

作者： Zhang, Zihan Cui, Tian Yao, Yansun Ma, Tianchen Jiang, Qiwen Jia, Haojun Monserrat, Bartomeu Pickard, Chris J. Duan, Defang State Key Laboratory of Superhard Materials Key Laboratory of Material Simulation Methods & Software of Ministry of Education College of Physics Jilin University Changchun130012 China Institute of High Pressure Physics School of Physical Science and Technology Ningbo University Ningbo315211 China Department of Physics and Engineering Physics University of Saskatchewan SaskatoonSKS7N 5E2 Canada Department of Chemistry Massachusetts Institute of Technology CambridgeMA02139 United States Department of Materials Science & Metallurgy University of Cambridge 27 Charles Babbage Road CambridgeCB3 0FS United Kingdom Cavendish Laboratory University of Cambridge J. J. Thomson Avenue CambridgeCB3 0HE United Kingdom Advanced Institute for Materials Research Tohoku University 2-1-1 Katahira Aoba Sendai980-8577 Japan

Behaviours of hydrogen, such as fluidity and metallicity, are crucial for our understanding of planetary interiors and the emerging field of high-temperature superconducting hydrides. These behaviours were discovered in complex phase diagrams of hydrogen and hydrides, however, the transition mechanism of behaviours driven by temperature, pressure and chemical compression remain unclear, particularly in the processes of metallization. Until now, a comprehensive theoretical framework to quantify atomization and metallization of hydrogen in phase diagram of hydrides has been lacking. In this study, we address this gap by combining molecular dynamics and electronic structure analysis to propose a theoretical framework, which clarify the content and properties of atomic hydrogen under various temperature and pressure conditions and chemical compression exerted by non-hydrogen elements in hydrides. Applying this framework to the superconducting hydride LaBeH8, we identify three general hydrogen orderings within its phase diagram: molecular, sublattice and warm hydrogens. During the phase transition from molecule to sublattice, hydrogen exhibits different properties from three general hydrogen orderings, such as fast superionicity, metallicity and unusual atomic content response to temperature. These abnormal behaviours were defined as the critical metallization of hydrogen, which not only suggests a potential synthesis route for the metastable phase but also provides valuable insights into the complex synthetic products of superconducting hydrides. Copyright © 2024, The Authors. All rights reserved.

关键词： Molecular dynamics

DPA-2: a large atomic model as a multi-task learner

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arXiv 2023年

作者： Zhang, Duo Liu, Xinzijian Zhang, Xiangyu Zhang, Chengqian Cai, Chun Bi, Hangrui Du, Yiming Qin, Xuejian Peng, Anyang Huang, Jiameng Li, Bowen Shan, Yifan Zeng, Jinzhe Zhang, Yuzhi Liu, Siyuan Li, Yifan Chang, Junhan Wang, Xinyan Zhou, Shuo Liu, Jianchuan Luo, Xiaoshan Wang, Zhenyu Jiang, Wanrun Wu, Jing Yang, Yudi Yang, Jiyuan Yang, Manyi Gong, Fu-Qiang Zhang, Linshuang Shi, Mengchao Dai, Fu-Zhi York, Darrin M. Liu, Shi Zhu, Tong Zhong, Zhicheng Lv, Jian Cheng, Jun Jia, Weile Chen, Mohan Ke, Guolin Weinan, E. Zhang, Linfeng Wang, Han AI for Science Institute Beijing100080 China DP Technology Beijing100080 China Academy for Advanced Interdisciplinary Studies Peking University Beijing100871 China State Key Lab of Processors Institute of Computing Technology Chinese Academy of Sciences Beijing100871 China University of Chinese Academy of Sciences Beijing100871 China HEDPS CAPT College of Engineering Peking University Beijing100871 China Ningbo Institute of Materials Technology and Engineering Chinese Academy of Sciences Ningbo315201 China CAS Key Laboratory of Magnetic Materials and Devices Zhejiang Province Key Laboratory of Magnetic Materials and Application Technology Chinese Academy of Sciences Ningbo315201 China School of Electronics Engineering and Computer Science Peking University Beijing100871 China Shanghai Engineering Research Center of Molecular Therapeutics & New Drug Development School of Chemistry and Molecular Engineering East China Normal University Shanghai200062 China Laboratory for Biomolecular Simulation Research Institute for Quantitative Biomedicine Department of Chemistry and Chemical Biology Rutgers University PiscatawayNJ08854 United States Department of Chemistry Princeton University PrincetonNJ08540 United States College of Chemistry and Molecular Engineering Peking University Beijing100871 China Yuanpei College Peking University Beijing100871 China School of Electrical Engineering and Electronic Information Xihua University Chengdu610039 China State Key Laboratory of Superhard Materials College of Physics Jilin University Changchun130012 China Key Laboratory of Material Simulation Methods & Software of Ministry of Education College of Physics Jilin University Changchun130012 China International Center of Future Science Jilin University Changchun130012 China Key Laboratory for Quantum Materials of Zhejiang Province Department of Physics School of Science Westlake University Zhejiang Hangzhou310030 China Atomistic Simulations Italia

The rapid advancements in artificial intelligence (AI) are catalyzing transformative changes in atomic modeling, simulation, and design. AI-driven potential energy models have demonstrated the capability to conduct large-scale, long-duration simulations with the accuracy of ab initio electronic structure methods. However, the model generation process remains a bottleneck for large-scale applications. We propose a shift towards a model-centric ecosystem, wherein a large atomic model (LAM), pre-trained across multiple disciplines, can be efficiently fine-tuned and distilled for various downstream tasks, thereby establishing a new framework for molecular modeling. In this study, we introduce the DPA-2 architecture as a prototype for LAMs. Pre-trained on a diverse array of chemical and materials systems using a multi-task approach, DPA-2 demonstrates superior generalization capabilities across multiple downstream tasks compared to the traditional single-task pre-training and fine-tuning methodologies. Our approach sets the stage for the development and broad application of LAMs in molecular and materials simulation research. Copyright © 2023, The Authors. All rights reserved.

关键词： Multi-task learning

Enhanced polarization switching characteristics of HfO2 ultrathin films via acceptor-donor co-doping

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Nature Communications 2024年第1期15卷 1-10页

作者： Chao Zhou Xianlong Cheng Jingxuan Li Yangyang Si Yan Huang Zuhuang Chen Liyang Ma Shi Liu Yanpeng Feng Chang-Yang Kuo Yu-Chieh Ku Cheng-En Liu Haoliang Huang Hongjian Zhao Chun-Fu Chang Sujit Das School of Materials Science and Engineering Harbin Institute of Technology Shenzhen 518055 China Flexible Printed Electronics Technology Center Harbin Institute of Technology Shenzhen 518055 China Key Laboratory for Quantum Materials of Zhejiang Province Department of Physics School of Science Westlake University Hangzhou Zhejiang 310024 China Shenyang National Laboratory for Materials Science Institute of Metal Research Chinese Academy of Sciences Wenhua Road 72 Shenyang 110016 China Department of Electrophysics National Yang Ming Chiao Tung University Hsinchu 30010 Taiwan National Synchrotron Radiation Research Center Hsinchu Taiwan Department of Physics Southern University of Science and Technology Shenzhen 518055 China Key Laboratory of Material Simulation Methods and Software of Ministry of Education College of Physics Jilin University Changchun 130012 China Max-Planck Institute for Chemical Physics of Solids Nöthnitzer Str. 40 01187 Dresden Germany Materials Research Centre Indian Institute of Science Bangalore 560012 India

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