检索结果-内蒙古大学图书馆

Production of Highly Polarized Positron Beams via Helicity Transfer from Polarized Electrons in a Strong Laser Field

引用

Physical Review Letters 2020年第4期125卷 044802-044802页

作者： Yan-Fei Li Yue-Yue Chen Wei-Min Wang Hua-Si Hu Department of Nuclear Science and Technology School of Energy and Power Engineering Xi’an Jiaotong University Xi’an 710049 China Department of Physics Shanghai Normal University Shanghai 200234 China Department of Physics and Beijing Key Laboratory of Opto-electronic Functional Materials and Micro-nano Devices Renmin University of China Beijing 100872 China Beijing National Laboratory for Condensed Matter Physics Institute of Physics CAS Beijing 100190 China Collaborative Innovation Center of IFSA (CICIFSA) Shanghai Jiao Tong University Shanghai 200240 China

The production of a highly polarized positron beam via nonlinear Breit-Wheeler processes during the interaction of an ultraintense circularly polarized laser pulse with a longitudinally spin-polarized ultrarelativistic electron beam is investigated theoretically. A new Monte Carlo method employing fully spin-resolved quantum probabilities is developed under the local constant field approximation to include three-dimensional polarization effects in strong laser fields. The produced positrons are longitudinally polarized through polarization transferred from the polarized electrons by the medium of high-energy photons. The polarization transfer efficiency can approach 100% for the energetic positrons moving at smaller deflection angles. This method simplifies the postselection procedure to generate high-quality positron beams in further applications. In a feasible scenario, a highly polarized (40%–65%), intense (105–106/bunch), collimated (5–70 mrad) positron beam can be obtained in a femtosecond timescale. The longitudinally polarized positron sources are desirable for applications in high-energy physics and material science.

关键词： Beam dynamics Beam polarization Electron & positron scattering Laser-cluster interaction Ponderomotive effects Relativistic multiple-particle dynamics Scattering of atoms, molecules, clusters & ions Secondary beams Ultrashort pulses

来源：评论

学校读者我要写书评

暂无评论

Highly enhanced visible-light photocatalytic NOx purification and conversion pathway on self-structurally modified g-C-3N4 nanosheets

引用

science Bulletin 2018年第10期63卷 609-620页

作者： Yuhan Li Yanjuan Sun Wingkei Ho Yuxin Zhang Hongwei Huang Qiang Cai Fan Dong Chongqing Key Laboratory of Catalysis and New Environmental Materials Engineering Research Center for Waste Oil Recovery Technology and Equipment Ministry of Education College of Environment and Resources Chongqing Technology and Business University Chongqing 400067. China Department of Science and Environmental Studies. The Center for Education in Environmental Sustainability The Education University of Hong Kong. Hong Kong China College of Materials Science and Engineering National Key Laboratory of Fundamental Science of Micro/Nano-Devices and System Technology. Chongqing University.Chongqing 400044. China School of Materials Science and Technology National Laboratory of Mineral Materials China University of Geosciences Beijing 100083 China

The unmodified graphitic carbon nitride(g-C_3N_4) suffers from low photocatalytic activity because of the unfavourable *** the present work,we reported a simple self-structural modification strategy to optimize the microstructure of g-C_3N_4 and obtained graphene-like g-C_3N_4 nanosheets with porous *** contrast to traditional thermal pyrolysis preparation of g-C_3N_4,the present thermal condensation was improved via pyrolysis of thiourea in an alumina crucible without a cover,followed by secondary heat *** popcorn-like formation and layer-by-layer thermal exfoliation of graphene-like porous g-C_3N_4 was proposed to explain the formation *** photocatalytic removal performance of both NO and NO_2 with the graphene-like porous g-C_3N_4 for was significantly enhanced by selfstructural *** experiments and in-situ diffuse reflectance infrared fourier transform spectroscopy(DRIFTS) measurement were conducted to detect the active species during photocatalysis and the conversion pathway of g-C_3N_4 photocatalysis for NO_x purification was *** photocatalytic activity of graphene-like porous g-C_3N_4 was highly enhanced due to the improved charge separation and increased oxidation capacity of the ·O_2^- radicals and *** work could not only provide a novel self-structural modification for design of highly efficient photocatalysts,but also offer new insights into the mechanistic understanding of g-C_3N_4 photocatalysis.

关键词： Self-structural modification g-C3N4 Visible light photocatalysis In-situ DRIFTS Conversion pathway

来源：评论

学校读者我要写书评

暂无评论

Quantum-stochasticity-induced asymmetry in the angular distribution of electrons in a quasiclassical regime

引用

Physical Review A 2020年第4期102卷 042218-042218页

作者： Guang Hu Wei-Qiang Sun Bing-Jun Li Yan-Fei Li Wei-Min Wang Meng Zhu Hua-Si Hu Yu-Tong Li Department of Nuclear Science and Technology Xi'an Jiaotong University Xi'an 710049 China Department of Physics and Beijing Key Laboratory of Opto-electronic Functional Materials and Micro-nano Devices Renmin University of China Beijing 100872 China Beijing National Laboratory for Condensed Matter Physics Institute of Physics CAS Beijing 100190 China Collaborative Innovation Center of IFSA (CICIFSA) Shanghai Jiao Tong University Shanghai 200240 China Northwest Institute of Nuclear Technology Xi'an 710024 China School of Physical Sciences University of Chinese Academy of Sciences Beijing 100049 China Songshan Lake Materials Laboratory Dongguan Guangdong 523808 China

Impacts of quantum stochasticity on the dynamics of an ultrarelativistic electron beam head-on colliding with a linearly polarized ultraintense laser pulse are theoretically investigated in a quasiclassical regime. Generally, the angular distribution of the electron beam keeps symmetrically in transverse directions in this regime, even under the ponderomotive force of the laser pulse. Here we show that under certain conditions an asymmetric angular distribution of the electron beam arises due to the quantum stochasticity effect, via simulations employing Landau-Lifshitz equation, quantum-modified Landau-Lifshitz equation, and quantum stochastic radiation reaction forms, to describe the radiative electron dynamics. The asymmetry is robust against a variety of laser and electron parameters, providing an experimentally detectable signature for the nature of quantum stochasticity of photon emission with laser and electron beams currently available.

关键词： Laser applications Laser driven electron acceleration Quantum algorithms Quantum description of light-matter interaction Relativistic multiple-particle dynamics Scattering theory

来源：评论

学校读者我要写书评

暂无评论

High-Q unidirectional polarization singularities

引用

Physical Review Applied 2025年第5期23卷 054020-054020页

作者： Chuanlin Li Wenhao Wang Jianfeng Chen Mengqi Liu Aobo Ren Cheng-Wei Qiu Hongxing Xu Zhiming Wang Jiang Wu Institute of Fundamental and Frontier Sciences University of Electronic Science and Technology of China Chengdu 610054 China Division of Physics and Applied Physics School of Physical and Mathematical Sciences Nanyang Technological University Singapore 637371 Singapore Centre for Disruptive Photonic Technologies The Photonics Institute Nanyang Technological University Singapore 637371 Singapore Department of Electrical and Computer Engineering National University of Singapore Singapore 117583 Singapore Institute of Engineering Thermophysics School of Mechanical Engineering Shanghai Jiao Tong University Shanghai 200240 China School of Physics and Technology Center for Nanoscience and Nanotechnology and Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education Wuhan University Wuhan 430072 China

Unidirectional guided resonances (UGRs), which are eigenstates that radiate exclusively in a single channel, are promising for advancing diverse photonic devices. However, existing approaches face an inherent trade-off between achieving high-Q factors and maximizing the radiation-asymmetry ratios. To address this challenge, we propose a scheme that exploits both out-of-plane and in-plane couplings to generate bound states in the continuum with precise radial and rotational control in momentum space. This approach effectively decouples the Q factors of UGRs from their radiation-asymmetry ratios. As a result, we achieve UGRs with Q factors exceeding 104, which is 1–2 orders of magnitude higher than traditional UGRs. Furthermore, we demonstrate the ability to reverse the emission direction of these UGRs, leading to a broad range of radiation-asymmetry ratios from −53 to 55 dB. We further validate the practical realization of high-Q UGRs using a silicon-on-silica system. Our findings provide a versatile method for generating high-Q UGRs, offering alternative pathways for innovations in nonlinear optics, light-matter interactions, and advanced optoelectronic applications.

关键词： Nonlinear optics

来源：评论

学校读者我要写书评

暂无评论

Rare-Earth Chalcogenides:A Large Family of Triangular Lattice Spin Liquid Candidates

引用

Chinese Physics Letters 2018年第11期35卷 74-79页

作者： Weiwei Liu Zheng Zhang Jianting Ji Yixuan Liu Jianshu Li Xiaoqun Wang Hechang Lei Gang Chen Qingming Zhang National Laboratory for Condensed Matter Physics and Institute of Physics Chinese Academy of Sciences Beijing 100190 Department of Physics and Beijing Key Laboratory of Opto-electronic Functional Materials & Micro-nano Devices Renmin University of China Beijing 100872 Department of Physics and Astronomy Shanghai Jiao Tong University Shanghai 200240 State Key Laboratory of Surface Physics and Department of Physics Fudan University Shanghai 200433 School of Physical Science and Technology Lanzhou University Lanzhou 730000

Frustrated quantum magnets are expected to host many exotic quantum spin states like quantum spin liquid（QSL）, and have attracted numerous interest in modern condensed matter physics. The discovery of the triangular lattice spin liquid candidate YbMgGaO_4 stimulated an increasing attention on the rare-earth-based frustrated magnets with strong spin-orbit coupling. Here we report the synthesis and characterization of a large family of rare-earth chalcogenides AReCh_2（A = alkali or monovalent ions, Re = rare earth, Ch = O,S,Se）. The family compounds share the same structure（R3 m） as YbMgGaO_4,and antiferromagnetically coupled rare-earth ions form perfect triangular layers that are well separated along the c-axis. Specific heat and magnetic susceptibility measurements on NaYbO_2,NaYbS_2 and NaYbSe_2 single crystals and polycrystals, reveal no structural or magnetic transition down to 50 mK. The family, having the simplest structure and chemical formula among the known QSL candidates, removes the issue on possible exchange disorders in YbMgGaO_4. More excitingly, the rich diversity of the family members allows tunable charge gaps, variable exchange coupling, and many other *** makes the family an ideal platform for fundamental research of QSLs and its promising applications.

关键词： Basic La A Large Family of Triangular Lattice Spin Liquid Candidates Rare-Earth Chalcogenides

来源：评论

学校读者我要写书评

暂无评论

Time-Reversal Symmetry Breaking Driven Topological Phase Transition in EuB6

引用

Physical Review X 2021年第2期11卷 021016-021016页

作者： Shun-Ye Gao Sheng Xu Hang Li Chang-Jiang Yi Si-Min Nie Zhi-Cheng Rao Huan Wang Quan-Xin Hu Xue-Zhi Chen Wen-Hui Fan Jie-Rui Huang Yao-Bo Huang Nini Pryds Ming Shi Zhi-Jun Wang You-Guo Shi Tian-Long Xia Tian Qian Hong Ding Beijing National Laboratory for Condensed Matter Physics and Institute of Physics Chinese Academy of Sciences Beijing 100190 China University of Chinese Academy of Sciences Beijing 100049 China Department of physics Renmin University of China Beijing 100872 China Beijing Key Laboratory of Opto-electronic Functional Materials & Micro-nano Devices Renmin University of China Beijing 100872 China Department of Energy Conversion and Storage Technical University of Denmark Fysikvej Building 310 DK-2800 Kgs. Lyngby Denmark Swiss Light Source Paul Scherrer Institut CH-5232 Villigen Switzerland Department of Materials Science and Engineering Stanford University Stanford California 94305 USA Shanghai Institute of Applied Physics Chinese Academy of Sciences Shanghai 201800 China Shanghai Synchrotron Radiation Facility Shanghai Advanced Research Institute Chinese Academy of Sciences Shanghai 201204 China Songshan Lake Materials Laboratory Dongguan Guangdong 523808 China CAS Center for Excellence in Topological Quantum Computation University of Chinese Academy of Sciences Beijing 100049 China

The interplay between time-reversal symmetry (TRS) and band topology plays a crucial role in topological states of quantum matter. In time-reversal-invariant (TRI) systems, the inversion of spin-degenerate bands with opposite parity leads to nontrivial topological states, such as topological insulators and Dirac semimetals. When the TRS is broken, the exchange field induces spin splitting of the bands. The inversion of a pair of spin-splitting subbands can generate more exotic topological states, such as quantum anomalous Hall insulators and magnetic Weyl semimetals. So far, such topological phase transitions driven by the TRS breaking have not been visualized. In this work, using angle-resolved photoemission spectroscopy, we have demonstrated that the TRS breaking induces a band inversion of a pair of spin-splitting subbands at the TRI points of Brillouin zone in EuB6, when a long-range ferromagnetic order is developed. The dramatic changes in the electronic structure result in a topological phase transition from a TRI ordinary insulator state to a TRS-broken topological semimetal (TSM) state. Remarkably, the magnetic TSM state has an ideal electronic structure, in which the band crossings are located at the Fermi level without any interference from other bands. Our findings not only reveal the topological phase transition driven by the TRS breaking, but also provide an excellent platform to explore novel physical behavior in the magnetic topological states of quantum matter.

关键词： Electronic structure Magnetic phase transitions Topological materials

来源：评论

学校读者我要写书评

暂无评论

Floquet engineering of exotic topological phases in systems of cold atoms

引用

Physical Review A 2019年第2期100卷 023622-023622页

作者： Hui Liu Tian-Shi Xiong Wei Zhang Jun-Hong An School of Physical Science and Technology Lanzhou University Lanzhou 730000 China Department of Physics National University of Singapore Singapore 117542 Department of Physics Renmin University of China Beijing 100872 China Beijing Key Laboratory of Opto-Electronic Functional Materials and Micro-Nano Devices Renmin University of China Beijing 100872 China

Topological phases with a widely tunable number of edge modes have been extensively studied as a typical class of exotic states of matter with potentially important applications. Although several models have been shown to support such phases, they are not easy to realize in solid-state systems due to the complexity of various intervening factors. Inspired by the realization of synthetic spin-orbit coupling in a cold-atom system [Z. Wu et al., science 354, 83 (2016)], we propose a periodic quenching scheme to realize large-topological-number phases with multiple edge modes in optical lattices. Via introducing the periodic quenching to the Raman lattice, it is found that a large number of edge modes can be induced in a controllable manner from the static topologically trivial system. Our result provides an experimentally accessible method to artificially synthesize and manipulate exotic topological phases with large topological numbers and multiple edge modes.

关键词： Cold gases in optical lattices Exotic phases of matter Spin-orbit coupling Topological insulators Ultracold gases Bloch-Floquet theorem

来源：评论

学校读者我要写书评

暂无评论

Multiple fermion scattering in the weakly coupled spin-chain compound YbAlO3 (vol 12, 3599, 2021)

引用

NATURE COMMUNICATIONS 2021年第1期12卷 3599-3599页

作者： Nikitin, S. E. Nishimoto, S. Fan, Y. Wu, J. Wu, L. S. Sukhanov, A. S. Brando, M. Pavlovskii, N. S. Xu, J. Vasylechko, L. Yu, R. Podlesnyak, A. Max Planck Institute for Chemical Physics of Solids Dresden Germany Institut für Festkörper- und Materialphysik Technische Universität Dresden Dresden Germany Department of Physics Technical University Dresden Dresden Germany Institute for Theoretical Solid State Physics IFW Dresden Dresden Germany Department of Physics and Beijing Key Laboratory of Opto-Electronic Functional Materials and Micro-Nano Devices Renmin University of China Beijing China Tsung-Dao Lee Institute and School of Physics and Astronomy Shanghai Jiao Tong University Shanghai China Neutron Scattering Division Oak Ridge National Laboratory Oak Ridge TN USA Department of Physics Southern University of Science and Technology Shenzhen China Kirensky Institute of Physics Federal Research Center Krasnoyarsk Russia Helmholtz-Zentrum Berlin für Materialien und Energie Berlin Germany Lviv Polytechnic National University Lviv Ukraine Present Address: Paul Scherrer Institute Villigen PSI Villigen Switzerland Present Address: Beijing National Laboratory for Condensed Matter Physics and Institute of Physics Chinese Academy of Sciences Beijing China Present Address: Heinz Maier-Leibnitz Zentrum Technische Universität München Garching Germany

The Heisenberg antiferromagnetic spin-1/2 chain, originally introduced almost a century ago, is one of the best studied models in quantum mechanics due to its exact solution, but nevertheless it continues to present new discoveries. Its low-energy physics is described by the Tomonaga-Luttinger liquid of spinless fermions, similar to the conduction electrons in one-dimensional metals. In this work we investigate the Heisenberg spin-chain compound YbAlO3 and show that the weak interchain coupling causes Umklapp scattering between the left- and right-moving fermions and stabilizes an incommensurate spin-density wave order at q = 2k F under finite magnetic fields. These Umklapp processes open a route to multiple coherent scattering of fermions, which results in the formation of satellites at integer multiples of the incommensurate fundamental wavevector Q = n q. Our work provides surprising and profound insight into bandstructure control for emergent fermions in quantum materials, and shows how neutron diffraction can be applied to investigate the phenomenon of coherent multiple scattering in metals through the proxy of quantum magnetic systems. A field-induced incommensurate spin density wave order was observed in the spin-chain material YbAlO3; however, its mechanism is not fully understood. Here, using neutron scattering and numerical calculations, the authors propose a mechanism based on multiple fermion scattering caused by weak inter-chain coupling.

关键词： Electronic properties and materials Magnetic properties and materials

来源：评论

学校读者我要写书评

暂无评论

Magnetic topological insulator MnBi6Te10 with a zero-field ferromagnetic state and gapped Dirac surface states

引用

Physical Review B 2020年第3期102卷 035144-035144页

作者： Shangjie Tian (田尚杰) Shunye Gao (高顺业) Simin Nie (聂思敏) Yuting Qian (钱玉婷) Chunsheng Gong (龚春生) Yang Fu (付阳) Hang Li (李航) Wenhui Fan (樊文辉) Peng Zhang (张鹏) Takesh Kondo Shik Shin Johan Adell Hanna Fedderwitz Hong Ding (丁洪) Zhijun Wang (王志俊) Tian Qian (钱天) Hechang Lei (雷和畅) Department of Physics and Beijing Key Laboratory of Opto-electronic Functional Materials & Micro-nano Devices Renmin University of China Beijing 100872 China Beijing National Laboratory for Condensed Matter Physics and Institute of Physics Chinese Academy of Sciences Beijing 100190 China University of Chinese Academy of Sciences Beijing 100049 China Department of Materials Science and Engineering Stanford University Stanford California 94305 USA Institute for Solid State Physics University of Tokyo Kashiwa Chiba 277-8581 Japan AIST-UTokyo Advanced Operando-Measurement Technology Open Innovation Laboratory (OPERANDO-OIL) Kashiwa Chiba 277-8581 Japan MAX IV Laboratory Lund University P.O. Box 118 221 00 Lund Sweden Songshan Lake Materials Laboratory Dongguan Guangdong 523808 China CAS Center for Excellence in Topological Quantum Computation University of Chinese Academy of Sciences Beijing 100049 China

Magnetic topological insulators (TIs) with nontrivial topological electronic structure and broken time-reversal symmetry exhibit various exotic topological quantum phenomena. The realization of such exotic phenomena at high temperature is one of the central topics in this area. We reveal that MnBi6Te10 is a magnetic TI with an antiferromagnetic ground state below 10.8 K whose nontrivial topology is manifested by Dirac-like surface states. The ferromagnetic axion insulator state with Z4=2 emerges once spins are polarized at a field as low as 0.1 T, accompanied with saturated anomalous Hall resistivity up to 10 K. Such a ferromagnetic state is preserved even with an external field down to zero at 2 K. Theoretical calculations indicate that the few-layer ferromagnetic MnBi6Te10 is also topologically nontrivial with a nonzero Chern number. Angle-resolved photoemission spectroscopy experiments further reveal three types of Dirac surface states arising from different terminations on the cleavage surfaces, one of which has insulating behavior with an energy gap of ∼28 meV at the Dirac point. These outstanding features suggest that MnBi6Te10 is a promising system to realize various topological quantum effects at zero field and high temperature.

关键词： Antiferromagnets Chern insulators Electronic structure Ferromagnets Single crystal materials Topological insulators Angle-resolved photoemission spectroscopy Crystal growth First-principles calculations Magnetization measurements Resistivity measurements

来源：评论

学校读者我要写书评

暂无评论

Magnetic-Field Control of Topological Electronic Response near Room Temperature in Correlated Kagome Magnets

引用

Physical Review Letters 2019年第19期123卷 196604-196604页

作者： Yangmu Li Qi Wang Lisa DeBeer-Schmitt Zurab Guguchia Ryan D. Desautels Jia-Xin Yin Qianheng Du Weijun Ren Xinguo Zhao Zhidong Zhang Igor A. Zaliznyak Cedomir Petrovic Weiguo Yin M. Zahid Hasan Hechang Lei John M. Tranquada Condensed Matter Physics and Materials Science Division Brookhaven National Laboratory Upton New York 11973 USA Department of Physics and Beijing Key Laboratory of Opto-electronic Functional Materials & Micro-nano Devices Renmin University of China Beijing 100872 China Neutron Scattering Division Oak Ridge National Laboratory Oak Ridge Tennessee 37831 USA Laboratory for Topological Quantum Matter and Advanced Spectroscopy Department of Physics Princeton University Princeton New Jersey 08544 USA Laboratory for Muon Spin Spectroscopy Paul Scherrer Institute CH-5232 Villigen PSI Switzerland Materials Science and Chemical Engineering Department Stony Brook University Stony Brook New York 11790 USA Shenyang National Laboratory for Materials Science Institute of Metal Research Chinese Academy of Sciences Shenyang 110016 China Materials Sciences Division Lawrence Berkeley National Laboratory Berkeley California 94720 USA

Strongly correlated kagome magnets are promising candidates for achieving controllable topological devices owing to the rich interplay between inherent Dirac fermions and correlation-driven magnetism. Here we report tunable local magnetism and its intriguing control of topological electronic response near room temperature in the kagome magnet Fe3Sn2 using small angle neutron scattering, muon spin rotation, and magnetoresistivity measurement techniques. The average bulk spin direction and magnetic domain texture can be tuned effectively by small magnetic fields. Magnetoresistivity, in response, exhibits a measurable degree of anisotropic weak localization behavior, which allows the direct control of Dirac fermions with strong electron correlations. Our work points to a novel platform for manipulating emergent phenomena in strongly correlated topological materials relevant to future applications.

关键词： Dirac fermions Electrical properties Magnetism Kagome lattice Strongly correlated systems Small angle neutron scattering

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：