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Spin-order dependent anomalous Hall effect and magneto-optical effect in the noncollinear antiferromagnets Mn3XN with X=Ga, Zn, Ag, or Ni

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Physical Review B 2019年第10期99卷 104428-104428页

作者： Xiaodong Zhou Jan-Philipp Hanke Wanxiang Feng Fei Li Guang-Yu Guo Yugui Yao Stefan Blügel Yuriy Mokrousov Key Laboratory of Advanced Optoelectronic Quantum Architecture and Measurement Ministry of Education School of Physics Beijing Institute of Technology Beijing 100081 China Institute of Physics Johannes Gutenberg University Mainz 55099 Mainz Germany Peter Grünberg Institut and Institute for Advanced Simulation Forschungszentrum Jülich and JARA 52425 Jülich Germany Department of Physics and Center for Theoretical Physics National Taiwan University Taipei 10617 Taiwan Physics Division National Center for Theoretical Sciences Hsinchu 30013 Taiwan

The anomalous Hall effect (AHE) and the magneto-optical effect (MOE) are two prominent manifestations of time-reversal symmetry breaking in magnetic materials. Noncollinear antiferromagnets (AFMs) have recently attracted a lot of attention owing to the potential emergence of exotic spin orders on geometrically frustrated lattices, which can be characterized by corresponding spin chiralities. By performing first-principles density functional calculations together with group-theory analysis and tight-binding modeling, here we systematically study the spin-order dependent AHE and MOE in representative noncollinear AFMs Mn3XN(X=Ga, Zn, Ag, and Ni). The symmetry-related tensor shape of the intrinsic anomalous Hall conductivity (IAHC) for different spin orders is determined by analyzing the relevant magnetic point groups. We show that while only the xy component of the IAHC tensor is nonzero for right-handed spin chirality, all other elements—σxy,σyz, and σzx—are nonvanishing for a state with left-handed spin chirality owing to lowering of the symmetry. Our tight-binding arguments reveal that the magnitude of IAHC relies on the details of the band structure and that σxy is periodically modulated as the spin rotates in-plane. The IAHC obtained from first principles is found to be rather large, e.g., it amounts to 359 S/cm in Mn3AgN, which is comparable to other well-known noncollinear AFMs such as Mn3Ir and Mn3Ge. We evaluate also the magnetic anisotropy energy and find that the evolution of spin order is related to the number of valence electrons in the X ion. Interestingly, the left-handed spin chirality could exist in Mn3XN with some particular spin configurations. By extending our analysis to finite frequencies, we calculate the optical isotropy [σxx(ω)≈σyy(ω)≈σzz(ω)] and the magneto-optical anisotropy [σxy(ω)≠σyz(ω)≠σzx(ω)] of Mn3XN. Similar to the IAHC, the magneto-optical Kerr and Faraday spectra depend strongly on the spin order. The Kerr rotation angles in Mn3XN a

关键词： Anomalous Hall effect Magneto-optical effect Noncollinear magnets Density functional calculations Group theory Tight-binding model

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QCD θ-vacuum energy and axion properties

arXiv

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arXiv 2020年

作者： Lu, Zhen-Yan Du, Meng-Lin Guo, Feng-Kun Meißner, Ulf-G Vonk, Thomas School of Physics and Electronic Science Hunan University of Science and Technology Xiangtan411201 China CAS Key Laboratory of Theoretical Physics Institute of Theoretical Physics Chinese Academy of Sciences Beijing100190 China Helmholtz-Institut für Strahlen- und Kernphysik Bethe Center for Theoretical Physics Universität Bonn BonnD-53115 Germany School of Physical Sciences University of Chinese Academy of Sciences Beijing100049 China Institute for Advanced Simulation Institut für Kernphysik Jülich Center for Hadron Physics Forschungszentrum Jülich JülichD-52425 Germany Tbilisi State University Tbilisi0186 Georgia

At low energies, the strong interaction is governed by the Goldstone bosons associated with the spontaneous chiral symmetry breaking, which can be systematically described by chiral perturbation theory. In this paper, we apply this theory to study the θvacuum energy density and hence the QCD axion potential up to next-to-leading order with N non-degenerate quark masses. By setting N = 3, we then derive the axion mass, self-coupling, topological susceptibility and the normalized fourth cumulant both analytically and numerically, taking the strong isospin breaking effects into account. In addition, the model-independent part of the axion-photon coupling, which is important for axion search experiments, is also extracted from the chiral Lagrangian supplemented with the anomalous terms up to O(p6). Copyright © 2020, The Authors. All rights reserved.

关键词： Perturbation techniques

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Electronic structure of pristine and Ni-substituted LaFeO3 from near edge x-ray absorption fine structure experiments and first-principles simulations

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Physical Review Research 2020年第3期2卷 033265-033265页

作者： Iurii Timrov Piyush Agrawal Xinyu Zhang Selma Erat Riping Liu Artur Braun Matteo Cococcioni Matteo Calandra Nicola Marzari Daniele Passerone Theory and Simulation of Materials (THEOS) and National Centre for Computational Design and Discovery of Novel Materials (MARVEL) École Polytechnique Fédérale de Lausanne (EPFL) CH-1015 Lausanne Switzerland nanotech@surfaces Laboratory and National Centre for Computational Design and Discovery of Novel Materials (MARVEL) Empa–Swiss Federal Laboratories for Materials Science and Technology CH-8600 Dübendorf Switzerland Electron Microscopy Center Empa–Swiss Federal Laboratories for Materials Science and Technology CH-8600 Dübendorf Switzerland nanotech@surfaces Laboratory Empa–Swiss Federal Laboratories for Materials Science and Technology CH-8600 Dübendorf Switzerland State Key Laboratory of Metastable Material Science and Technology Yanshan University CN-066004 Qinhuangdao China High Performance Ceramics Laboratory Empa–Swiss Federal Laboratories for Materials Science and Technology CH-8600 Dubendorf Switzerland Department for Materials Nonmetallic Inorganic Materials ETH Zurich Swiss Federal Institute of Technology CH-8037 Zurich Switzerland Vocational School of Technical Sciences Department of Medical Services and Techniques Program of Opticianry Mersin University TR-33343 Yenisehir Mersin Turkey Advanced Technology Education Research and Application Center Mersin University TR-33343 Yenisehir Mersin Turkey Department of Physics University of Pavia Via Bassi 6 I-27100 Pavia Italy Dipartmento di Fisica Università di Trento Via Sommarive 14 38123 Povo Italy Sorbonne Université CNRS Institut des Nanosciences de Paris UMR7588 F-75252 Paris France

We present a joint theoretical and experimental study of the oxygen K-edge spectra for LaFeO3 and homovalent Ni-substituted LaFeO3 (LaFe0.75Ni0.25O3), using first-principles simulations based on density-functional theory with extended Hubbard functionals and x-ray absorption near edge structure (XANES) measurements. Ground-state and excited-state XANES calculations employ Hubbard onsite U and intersite V parameters determined from first principles and the Lanczos recursive method to obtain absorption cross sections, which allows for a reliable description of XANES spectra in transition-metal compounds in a very broad energy range, with an accuracy comparable to that of hybrid functionals but at a substantially lower cost. We show that standard gradient-corrected exchange-correlation functionals fail in capturing accurately the electronic properties of both materials. In particular, for LaFe0.75Ni0.25O3 they do not reproduce its semiconducting behavior and provide a poor description of the pre-edge features at the O K edge. The inclusion of Hubbard interactions leads to a drastic improvement, accounting for the semiconducting ground state of LaFe0.75Ni0.25O3 and for good agreement between calculated and measured XANES spectra. We show that the partial substitution of Ni for Fe affects the conduction-band bottom by generating a strongly hybridized O(2p)−Ni(3d) minority-spin empty electronic state. The present work, based on a consistent correction of self-interaction errors, outlines the crucial role of extended Hubbard functionals to describe the electronic structure of complex transition-metal oxides such as LaFeO3 and LaFe0.75Ni0.25O3 and paves the way to future studies on similar systems.

关键词： Density of states Electronic structure Transition-metal rare-earth alloys DFT+U Density functional calculations Density functional theory X-ray absorption near-edge spectroscopy

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Detection of Picric Acid by Terpy-Based Metallo- Supramolecular Fluorescent Coordination Polymers in Aqueous Media

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Chinese Journal of Chemistry 2017年第4期35卷 447-456页

作者： Zhongyu Ding Hongqing Li Wanqing Gao Yiquan Zhang Chunhua Liu Yuanyuan Zhu School of Chemistry and Chemical Engineering Hefei University of Technology and Anhui Key Laboratory of Advanced Functional Materials and Devices Hefei Anhui 230009 China Jiangsu Provincial Key Laboratory for Numerical Simulation of Large Scale Complex Systems (NSLSCS) School of Physical Science and Technology Nanjing Normal University Nanjing Jiangsu 210023 China

The synthesis of two linear terpy-based metallo-supramolecular fluorescent coordination polymers through 1 ： 1 complexation of Zn^2＋ and Cd^2＋ ions with ditopic terpyridine ligand was reported. The dispersibility of P1 and P2 was significantly improved in organic solvent and water through the introduction of hydrophilic oligo-ethyoxy side chain. Two polymers displayed yellow light emission both in solution and the solid state due to the intra-ligand charge transfer （ILCT） between the d^10 metal ions and the conjugated spacer unit. These coordination polymers were explored as fluorescent chemosensors for detecting picric acid in aqueous media, displaying high sensitivity and good selectivity. In addition, test strips were prepared from these polymers and exhibited the practical potential of detecting the NACs pollutants in the outdoor water for public safety and security.

关键词： coordination polymer fluorescent chemosensors nitroaromatic explosives picric acid aqueous media

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Bionic Optimization Design of Electronic Nose Chamber for Oil and Gas Detection

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Journal of Bionic Engineering 2018年第3期15卷 533-544页

作者： Zhiyong Chang Youhong Sun Yuchen Zhang Yanli Gao Xiaohui Weng Donghui Chen Liewe David Jun Xie Key Lab of Advanced Technologies of Materials Ministry of Education School of Materials Science and Engineering Southwest Jiaotong University Chengdu 610031 China Key Laboratory of Bionic Engineering Ministry of Education Jilin University Changchun 130022 China National-Local Joint Engineering Laboratory of In-situ Conversion Drilling and Exploitation Technology for Oil Shale Jilin University Changchun 130021 China College of Construction Engineering Jilin University Changchun 130022 China Clinical Medicine Bethune First Hospital of Jilin University Changchun 130021China College of Mechanical Science and Engineering Jilin University Changchun 130022 China School of Computing and Technology the University of Gloucestershire The Park Cheltenham GL50 2RH UK Air Combat Service Academy Air Force Aviation University Changchun 130021 China

In this paper, a miniaturized bionic electronic nose system is developed in order to solve the problems arising in oil and gas detection for large size and inflexible operation in downhole. The bionic electronic nose chamber is designed by mimicking human nasal turbinate structure, V-groove structure on shark skin surface and flow field distribution around skin surface. The sensitivity of the bionic electronic nose system is investigated through experimentation. Radial Basis Function （RBF） and Support Vector Machines （SVM） of 10-fold cross validation are used to compare the recognition performance of the bionic electronic nose system and common one. The results show that the sensitivity of the bionic electronic nose system with bionic composite chamber （chamber B） is significantly improved compared with that with common chamber （chamber A）. The recognition rate of chamber B is 4.27% higher than that of chamber A for the RBF algorithm, while for the SVM algorithm, the recognition rate of chamber B is 5.69% higher than that of chamber A. The three-dimensional simulation model of the chamber is built and verified by Computational Fluid Dynamics （CFD） simulation analysis. The number of vortices in chamber B is fewer than that in chamber A. The airflow velocity near the sensors inside chamber B is slower than that inside chamber A. The vortex intensity near the sensors in chamber B is 2.27 times as much as that in chamber A, which facilitates gas molecules to fully contact with the sensor surface and increases the intensity of sensor signal, and the contact strength and time between odorant molecules and sensor surface. Based on the theoretical investigation and test validation, it is believed that the proposed bionic electronic nose system with bionic composite chamber has potential for oil and gas detection in downhole.

关键词： electronic nose bionic chamber sensors oil gas detection

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Preliminary Study on the Magnetohydrodynamic(MHD) Angular Rate Sensor Combing Coriolis Effect at Low-frequency 3

Preliminary Study on the Magnetohydrodynamic(MHD) Angular Ra...

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2017 IEEE 第3届信息技术与机电一体化工程国际学术会议(ITOEC 2017)

作者： Yue Ji Xingfei Li Tengfei Wu Jun Wu Key Laboratory of Advanced Electrical Engineering and Energy Technology Tianjin Polytechnic University State Key Laboratory of Precision Measuring Technology and Instruments Tianjin University College of Aeronautical Automation Civil Aviation University of China

The poor performance of MHD ARS at low frequency has depressed its accuracy and application range.A preliminary study on the magnetohydrodynamic(MHD) angular rate sensor combing Coriolis effect(C-MHD

ISBN: (纸本)9781509053643;9781509053636

The poor performance of MHD ARS at low frequency has depressed its accuracy and application range.A preliminary study on the magnetohydrodynamic(MHD) angular rate sensor combing Coriolis effect(C-MHD

关键词： angular measurement error analysis magnetic field measurement magnetic sensors magnetohydrodynamics pumps magnetohydrodynamics Error analysis Angle measurement Coriolis effect Magnetic field measurement Magnetic sensors Pumps low frequencies Action Request System rate sensor ANGULAR VELOCITY combed Sensors

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Cylindrical vector beam-excited frequency-tunable second harmonic generation in a plasmonic octamer

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Photonics Research 2018年第3期6卷 157-161页

作者： FAJUN XIAO WUYUN SHANG WEIREN ZHU LEI HAN MALIN PREMARATNE TING MEI JIANLIN ZHAO MOE Key Laboratory of Material Physics and Chemistry under Extraordinary Conditions and Shaanxi Key Laboratory of Optical Information TechnologySchool of ScienceNorthwestern Polytechnical UniversityXi'an 710129China Department of Electronic Engineering Shanghai Jiao Tong UniversityShanghai 200240China Advanced Computing and Simulation Laboratory(AχL) Department of Electrical and Computer Systems Monash UniversityClaytonVlC 3800Australia

We report a method to tune the second harmonic generation(SHG) frequency of a metallic octamer by employing cylindrical vector beams as the excitation. Our method exploits the ability to spatially match the polarization state of excitations with the fundamental target plasmonic modes, enabling flexible control of the SHG resonant *** is found that SHG of the octamer is enhanced over a broad band(400 nm) by changing the excitation from the linearly polarized Gaussian beam to radially and azimuthally polarized beams. More strikingly, when subjected to an azimuthally polarized beam, the SHG intensity of the octamer becomes 30 times stronger than that for the linearly polarized beam even in the presence of Fano resonance.

关键词： SHG Cylindrical vector beam-excited frequency-tunable second harmonic generation in a plasmonic octamer

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Static quadrupole moments of nuclear chiral doublet bands

arXiv

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arXiv 2020年

作者： Chen, Q.B. Kaiser, N. Meißner, Ulf G. Meng, J. Physik-Department Technische Universität München GarchingD-85747 Germany Helmholtz-Institut für Strahlen- und Kernphysik and Bethe Center for Theoretical Physics Universität Bonn BonnD-53115 Germany Institute for Advanced Simulation Institut für Kernphysik Jülich Center for Hadron Physics Forschungszentrum Jülich JülichD-52425 Germany Ivane Javakhishvili Tbilisi State University Tbilisi0186 Georgia State Key Laboratory of Nuclear Physics and Technology School of Physics Peking University Beijing100871 China Yukawa Institute for Theoretical Physics Kyoto University Kyoto606-8502 Japan

The static quadrupole moments (SQMs) of nuclear chiral doublet bands are investigated for the first time taking the particle-hole configuration π(1h11/2) ⊗ ν(1h11/2)−1 with triaxial deformation parameters in the range 260◦ ≤ γ ≤ 270◦ as examples. The behavior of the SQM as a function of spin I is illustrated by analyzing the components of the total angular momentum. It is found that in the region of chiral vibrations the SQMs of doublet bands are strongly varying with I, whereas in the region of static chirality the SQMs of doublet bands are almost constant. Hence, the measurement of SQMs provides a new criterion for distinguishing the modes of nuclear chirality. Moreover, in the high-spin region the SQMs can be approximated by an analytic formula with a proportionality to cos γ for both doublet bands. This provides a way to extract experimentally the triaxial deformation parameter γ for chiral bands from the measured SQMs. Copyright © 2020, The Authors. All rights reserved.

关键词： Chirality

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Design and simulation of a Micromechanical Silicon Resonant Accelerometer with Low Temperature Sensitivity

Design and Simulation of a Micromechanical Silicon Resonant ...

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International Conference on Instrumentation, Measurement, Computer, Communication and Control (IMCCC)

作者： Yang Gao Hongsheng Li Libin Huang Songli Wang School of Instrument Science and Engineering Southeast University Nanjing China Key Laboratory of Micro-Inertial Instrument and Advanced Navigation Technology Southeast University Ministry of Education Nanjing China Aviation Key Laboratory of Science and Technology on Inertia FACRI Xi'an China

ISBN: (数字)9781538682463

ISBN: (纸本)9781538682470

Because of the mismatch of material properties between silicon and glass, especially the mismatching thermal expansion coefficients, the Micromechanical Silicon Resonant Accelerometer based on the Deep Dry Silicon On Glass (DDSOG) technique is seriously affected by the temperature during the fabrication, packaging and use processes. Based on the working principle and temperature characteristics of Micromechanical Silicon Resonant Accelerometer, the effect of the mismatching thermal expansion coefficients of silicon and glass is analyzed, and a Single-Anchor-Supported accelerometer structure with low temperature sensitivity is designed. simulation results show that the structure can effectively reduce the effect of mismatching thermal expansion coefficients of silicon and glass.

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Effective field theory for triaxially deformed odd-mass nuclei

arXiv

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arXiv 2020年

作者： Chen, Q.B. Kaiser, N. Meißner, Ulf-G. Meng, J. Physik-Department Technische Universität München GarchingD-85747 Germany Helmholtz-Institut für Strahlen- und Kernphysik Bethe Center for Theoretical Physics Universität Bonn BonnD-53115 Germany Institute for Advanced Simulation Institut für Kernphysik and Jülich Center for Hadron Physics Forschungszentrum Jülich JülichD-52425 Germany Ivane Javakhishvili Tbilisi State University Tbilisi0186 Georgia State Key Laboratory of Nuclear Physics and Technology School of Physics Peking University Beijing100871 China Yukawa Institute for Theoretical Physics Kyoto University Kyoto606-8502 Japan

The effective field theory for collective rotations of triaxially deformed nuclei is generalized to odd-mass nuclei by including the angular momentum of the valence nucleon as an additional degree of freedom. The Hamiltonian is constructed up to next-to-leading order within the effective field theory formalism. The applicability of this Hamiltonian is examined by describing the wobbling bands observed in the lutetium isotopes 161,163,165,167Lu. It is found that by taking into account the next-to-leading order corrections, quartic in the rotor angular momentum, the wobbling energies Ewob and spin-rotational frequency relations ω(I) are better described than with the leading order Hamiltonian. Copyright © 2020, The Authors. All rights reserved.

关键词： Hamiltonians

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