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Highly spin-polarized carriers and strong ferromagnetism in doped perovskite antiferromagnetic semiconductors

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arXiv 2023年

作者： Zhao, Hong Jian Yu, Longju Wang, Yanchao 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 Physics Department Institute for Nanoscience and Engineering University of Arkansas FayettevilleAR72701 United States

In semiconductor spintronics, the generation of highly spin-polarized carriers and the efficient probe of spin order (due to strong ferromagnetism) - at or above room temperature - are crucial because it allows for the design of spin-based semiconductor devices. Usually, such goals were fulfilled in room-temperature ferromagnetic semiconductors, being rare materials in nature. While room-temperature antiferromagnetic semiconductors are plentiful, the possibility for creating highly spin-polarized carriers and strong ferromagnetism in these materials remain to be unraveled. Here, we explore such a possibility by first-principles simulations, working with CaTcO3 and NaOsO3 perovskites - being room-temperature antiferromagnetic semiconductors. We find that doping them by electrons or holes results in these materials to be highly spin-polarized, carrying enormous ferromagnetic moments. Doping electrons with moderate carrier density can yield strong ferromagnetism in them, with the ferromagnetic moments being comparable to that in typical ferromagnetic semiconductors. Our work thus indicates the merit of perovskite antiferromagnetic semiconductors in spintronics - for a possible replacement of ferromagnetic semiconductors. Copyright © 2023, The Authors. All rights reserved.

关键词： Ferromagnetism

Nonlocal vs Local Pseudopotentials Affect Kinetic Energy Kernels in Orbital-Free DFT

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arXiv 2024年

作者： Moldabekov, Zhandos A. Shao, Xuecheng Pavanello, Michele Vorberger, Jan Dornheim, Tobias Görlitz03581 Germany Dresden01328 Germany Key Laboratory of Material Simulation Methods & Software Ministry of Education College of Physics Jilin University Changchun130012 China Department of Chemistry Rutgers University 73 Warren St. NewarkNJ07102 United States Department of Physics Rutgers University 101 Warren St. NewarkNJ07102 United States

The kinetic energy (KE) kernel, which is defined as the second order functional derivative of the KE functional with respect to density, is the key ingredient to the construction of KE models for orbital free density functional theory (OFDFT) applications. For solids, the KE kernel is usually approximated using the uniform electron gas (UEG) model or the UEG-with-gap model. These kernels do not have information about the effects from the core electrons since there are no orbitals for the projection on nonlocal pseudopotentials. To illuminate this aspect, we provide a methodology for computing the KE kernel from Kohn-Sham DFT and apply it to the valence electrons in bulk aluminum (Al) with a face-centered cubic lattice and in bulk silicon (Si) in a semiconducting crystal diamond state. We find that bulk-derived local pseudopotentials provide accurate results for the KE kernel in the interstitial region. The effect of using nonlocal pseudopotentials manifests at short wavelengths, defined by the diameter of an ion surrounded by its core electrons. Specifically, we find that the utilization of nonlocal pseudopotentials leads to significant deviations in the KE kernel from the von Weizsäcker result in this region, which is, as a rule, explicitly enforced in most widely used KE functional approximations for OFDFT simulations. Copyright © 2024, The Authors. All rights reserved.

关键词： Kinetic energy

General theory for longitudinal nonreciprocal charge transport

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arXiv 2024年

作者： Zhao, Hong Jian Tao, Lingling Fu, Yuhao Bellaiche, Laurent Ma, Yanming Key Laboratory of Material Simulation Methods and Software of Ministry of Education College of Physics Jilin University Changchun130012 China School of Physics Harbin Institute of Technology Harbin150001 China Physics Department Institute for Nanoscience and Engineering University of Arkansas FayettevilleAR72701 United States International Center of Future Science Jilin University Changchun130012 China State Key Laboratory of Superhard Materials College of Physics Jilin University Changchun130012 China

The longitudinal nonreciprocal charge transport (NCT) in crystalline materials is a highly nontrivial phenomenon, motivating the design of next generation two-terminal rectification devices (e.g., semiconductor diodes beyond PN junctions). The practical application of such devices is built upon crystalline materials whose longitudinal NCT occurs at room temperature and under low magnetic field. However, materials of this type are rather rare and elusive, and theory guiding the discovery of these materials is lacking. Here, we develop such a theory within the framework of semiclassical Boltzmann transport theory. By symmetry analysis, we classify the complete 122 magnetic point groups with respect to the longitudinal NCT phenomenon. The symmetry-adapted Hamiltonian analysis further uncovers a previously overlooked mechanism for this phenomenon. Our theory guides the first-principles prediction of longitudinal NCT in multiferroic Ε-Fe2O3 semiconductor that possibly occurs at room temperature, without the application of external magnetic field. These findings advance our fundamental understandings of longitudinal NCT in crystalline materials, and aid the corresponding materials discoveries. Copyright © 2024, The Authors. All rights reserved.

关键词： Statistical mechanics

Prediction of Room-Temperature Superconductivity in Quasi-atomic H2-Type Hydrides at High Pressure

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arXiv 2023年

作者： Jiang, Qiwen Duan, Defang Song, Hao Zhang, Zihan Huo, Zihao Jiang, Shuqing Cui, Tian Yao, Yansun Key Laboratory of Material Simulation Methods & Software Ministry of Education State Key Laboratory of Superhard Materials College of Physics Jilin University Changchun130012 China Institute of High Pressure Physics School of Physical Science and Technology Ningbo University Ningbo315211 China Synergetic Extreme Condition User Facility College of Physics Jilin University Jilin Changchun130012 China Department of Physics and Engineering Physics University of Saskatchewan SaskatoonSKS7N 5E2 Canada

Achieving superconductivity at room temperature (RT) is a holy grail in physics. Recent discoveries on high-Tc superconductivity in binary hydrides H3S and LaH10 at high pressure have directed the search for RT superconductors to compress hydrides with conventional electron-phonon mechanisms. Here, we predict an exceptional family of superhydrides under high pressures, MH12 (M = Mg, Sc, Zr, Hf, Lu), all exhibiting RT superconductivity with calculated Tcs ranging from 313 to 398 K. In contrast to H3S and LaH10, the hydrogen sublattice in MH12 is arranged as quasi-atomic H2 units. This unique configuration is closely associated with high Tc, attributed to the high electronic density of states derived from H2 antibonding states at the Fermi level and the strong electron-phonon coupling related to the bending vibration of H2 and HM-H. Notably, MgH12 and ScH12 remain dynamically stable even at pressure below 100 GPa. Our findings offer crucial insights into achieving RT superconductivity and pave the way for innovative directions in experimental research. Copyright © 2023, The Authors. All rights reserved.

关键词： Hydrides

Theory of polarization-switchable electrical conductivity anisotropy in nonpolar semiconductors

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arXiv 2024年

作者： Zhao, Hong Jian Wang, Yanchao Bellaiche, Laurent Ma, Yanming Key Laboratory of Material Simulation Methods and Software Ministry of Education College of Physics Jilin University Changchun130012 China Key Laboratory of Physics and Technology for Advanced Batteries Ministry of Education College of Physics Jilin University Changchun130012 China International Center of Future Science Jilin University Changchun130012 China State Key Laboratory of Superhard Materials College of Physics Jilin University Changchun130012 China Smart Functional 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 anisotropic propagation of particles is a fundamental transport phenomenon in solid state physics. As for crystalline semiconductors, the anisotropic charge transport opens novel designing routes for electronic devices, where the electrical manipulation of anisotropic resistance provides essential guarantees. Motivated by the concept of anisotropic magnetoresistance, we develop an original theory on the electrically manipulatable anisotropic electroresistance. We show that when gaining electric polarization, nonpolar semiconductors can showcase anisotropic electrical conductivities between two perpendicular directions and the electrical conductivity anisotropy (ECA) is switchable by flipping the polarization. By symmetry analysis, we identify several point groups hosting the polarization-switchable ECA. These point groups simultaneously enable polarization-reversal induced conductivity change along specific directions, akin to the tunnelling electroresistance in ferroelectric tunnel junctions. First-principles-based conductivity calculations predict that AlP and NaSrP are two good materials having such exotic charge transport. Our theory can motivate the design of intriguing anisotropic electronic devices (e.g., anisotropic memristor and field effect transistor). Copyright © 2024, The Authors. All rights reserved.

关键词： Polarization

Modulation of the Octahedral Structure and Potential Superconductivity of La3Ni2O7 through Strain Engineering

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arXiv 2024年

作者： Huo, Zihao Luo, Zhihui Zhang, Peng Yang, Aiqin Liu, Zhengtao Tao, Xiangru Zhang, Zihan Guo, Shumin Jiang, Qiwen Chen, Wenxuan Yao, Dao-Xin Duan, Defang Cui, Tian Key Laboratory of Material Simulation Methods & Software of Ministry of Education State Key Laboratory of Superhard Materials College of Physics Jilin University Changchun130012 China MOE Key Laboratory for Non-equilibrium Synthesis and Modulation of Condensed Matter Shaanxi Province Key Laboratory of Advanced Functional Materials and Mesoscopic Physics School of Physics Xi’an Jiaotong University Xi’an710049 China Center for Neutron Science and Technology Guangdong Provincial Key Laboratory of Magnetoelectric Physics and Devices State Key Laboratory of Optoelectronic Materials and Technologies School of Physics Sun Yat-Sen University Guangzhou510275 China Institute of High Pressure Physics School of Physical Science and Technology Ningbo University Ningbo315211 China

The recent transport measurement of La3Ni2O7 uncover a "right-triangle" shape of the superconducting dome in the pressure-temperature (P-T) phase diagram. Motivated by this, we perform theoretical first-principles studies of La3Ni2O7 with the pressure ranging from 0 to 100 GPa. Notably, we reveal a pressure dependence of the Ni-dz2 electron density at the Fermi energy (nzEF) that highly coincides with such shape. On this basis, we further explore the electronic structure under uniaxial stress. By tracking the stress response of nzEF , we propose that superconductivity can be achieved by applying only ~ 2 GPa of compression along the c axis. The idea is further exemplified from the perspectives of lattice distortion, band structure, Fermi surface and superconducting phase coherence. We also discuss the possible charge modulation under the stress and provide an insight to the relation between nzEF and the superconducting Tc in La3Ni2O7 system. Our study provides a helpful guide to the future experiment. © 2024, CC BY.

关键词： Band structure

Engineering ferroelectricity in monoclinic hafnia

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arXiv 2023年

作者： Zhao, Hong Jian Fu, Yuhao Yu, Longju Wang, Yanchao 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 International Center of Future Science Jilin University Changchun130012 China State Key Laboratory of Superhard Materials College of Physics Jilin University Changchun130012 China National Laboratory of Solid State Microstructures Jiangsu Key Laboratory of Artificial Functional Materials Department of Materials Science and Engineering Nanjing University Nanjing210093 China Physics Department Institute for Nanoscience and Engineering University of Arkansas FayettevilleAR72701 United States

Ferroelectricity in the complementary metal–oxide semiconductor (CMOS)-compatible hafnia (HfO2) is crucial for the fabrication of high-integration nonvolatile memory devices. However, the capture of ferroelectricity in HfO2 requires the stabilization of thermodynamically-metastable orthorhombic or rhombohedral phases, which entails the introduction of defects (e.g., dopants and vacancies) and pays the price of crystal imperfections, causing unpleasant wake-up and fatigue effects. Here, we report a theoretical strategy on the realization of robust ferroelectricity in HfO2-based ferroelectrics by designing a series of epitaxial (HfO2)1/(CeO2)1 superlattices. The advantages of the designated ferroelectric superlattices are defects free, and most importantly, on the base of the thermodynamically stable monoclinic phase of HfO2. Consequently, this allows the creation of superior ferroelectric properties with an electric polarization >25 µC/cm2 and an ultralow polarization-switching energy barrier at ∼2.5 meV/atom. Our work may open an entirely new route towards the fabrication of high-performance HfO2 based ferroelectric devices. Copyright © 2023, The Authors. All rights reserved.

关键词： Ferroelectricity

DPA-2:a large atomic model as a multitask learner

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npj Computational materials 2024年第1期10卷 185-199页

作者： Duo Zhang Xinzijian Liu Xiangyu Zhang Chengqian Zhang Chun Cai Hangrui Bi Yiming Du Xuejian Qin Anyang Peng Jiameng Huang Bowen Li Yifan Shan Jinzhe Zeng Yuzhi Zhang Siyuan Liu Yifan Li Junhan Chang Xinyan Wang Shuo Zhou Jianchuan Liu Xiaoshan Luo Zhenyu Wang Wanrun Jiang Jing Wu Yudi Yang Jiyuan Yang Manyi Yang Fu-Qiang Gong Linshuang Zhang Mengchao Shi Fu-Zhi Dai Darrin M.York Shi Liu Tong Zhu Zhicheng Zhong Jian Lv Jun Cheng Weile Jia Mohan Chen Guolin Ke Weinan E Linfeng Zhang Han Wang AI for Science Institute BeijingP.R.China DP Technology BeijingP.R.China Academy for Advanced Interdisciplinary Studies Peking UniversityBeijingP.R.China State Key Lab of Processors Institute of Computing TechnologyChinese Academy of SciencesBeijingP.R.China University of Chinese Academy of Sciences BeijingP.R.China HEDPS CAPTCollege of EngineeringPeking UniversityBeijingP.R.China Ningbo Institute of Materials Technology and Engineering Chinese Academy of SciencesNingboP.R.China CAS Key Laboratory of Magnetic Materials and Devices and Zhejiang Province Key Laboratory of Magnetic Materials and Application Technology Chinese Academy of SciencesNingboP.R.China School of Electronics Engineering and Computer Science Peking UniversityBeijingP.R.China Shanghai Engineering Research Center of Molecular Therapeutics&New Drug Development School of Chemistry and Molecular EngineeringEast China Normal UniversityShanghaiP.R.China Laboratory for Biomolecular Simulation Research Institute for Quantitative Biomedicine and Department of Chemistry and Chemical BiologyRutgers UniversityPiscatawayNJUSA Department of Chemistry Princeton UniversityPrincetonNJUSA College of Chemistry and Molecular Engineering Peking UniversityBeijingP.R.China Yuanpei College Peking UniversityBeijingP.R.China School of Electrical Engineering and Electronic Information Xihua UniversityChengduP.R.China State Key Laboratory of Superhard Materials College of PhysicsJilin UniversityChangchunP.R.China Key Laboratory of Material Simulation Methods&Software of Ministry of Education College of PhysicsJilin UniversityChangchunP.R.China International Center of Future Science Jilin UniversityChangchunP.R.China Key Laboratory for Quantum Materialsof Zhejiang Province Department of PhysicsSchool of ScienceWestlake UniversityHangzhouP.R.China Atomistic Simulations Italian Institute of TechnologyGenovaItaly State Key Laboratory of Physical Chemistry of Solid Surface iChEMCollege of Chemistry and Chemical EngineeringXiame

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

关键词： DPA establishing thereby

Unravelling spontaneous Bloch-type skyrmion in centrosymmetric two-dimensional magnets

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arXiv 2023年

作者： Pang, Jingman Niu, Xiaohang Zhao, Hong Jian Zhang, Yun Bellaiche, Laurent College of Physics and Optoelectronic Technology Collaborative Innovation Center of Rare-Earth Functional Materials and Devices Development Baoji University of Arts and Sciences Baoji721016 China Faculty of Chemistry and Chemical Engineering Baoji University of Arts and Sciences 1 Hi-Tech Avenue Shaanxi Baoji China Key Laboratory of Material Simulation Methods and Software of Ministry of Education College of Physics Jilin University Changchun130012 China Physics Department Institute for Nanoscience and Engineering University of Arkansas FayettevilleAR72701 United States

The realization of magnetic skyrmions in two-dimensional (2D) magnets holds great promise for both fundamental research and device applications. Despite recent progress, two-dimensional skyrmions hosts are still limited, due to the fact that most 2D magnets are centrosymmetric and thus lack Dzyaloshinskii−Moriya interaction (DMI). We show here, using a general analysis based on symmetry, that Bloch-type skyrmions can, in fact, be stabilized in 2D magnets, due to the interplay between in-plane component (dx) of second nearest-neighbor DMI and magnetic anisotropy. Its validity is demonstrated in Cr2Ge2Te6 monolayer, which is also verified by recent experiments. Our work gives a clear direction for experimental studies of 2D magnetic materials to stabilize skyrmions and should greatly enrich the research on magnetic skyrmions in 2D lattices. © 2023, CC BY.

关键词： Magnetic anisotropy