检索结果-内蒙古大学图书馆

arXiv 2021年

作者： Zhang, Li Yang, Yihao Ge, Yong Guan, Yi-Jun Chen, Qiaolu Yan, Qinghui Chen, Fujia Xi, Rui Li, Yuanzhen Jia, Ding Yuan, Shou-Qi Sun, Hong-Xiang Chen, Hongsheng Zhang, Baile Interdisciplinary Center for Quantum Information State Key Laboratory of Modern Optical Instrumentation College of Information Science and Electronic Engineering Zhejiang University Hangzhou310027 China ZJU-Hangzhou Global Science and Technology Innovation Center Key Lab. of Advanced Micro/Nano Electronic Devices & Smart Systems of Zhejiang ZJU-UIUC Institute Zhejiang University Hangzhou310027 China Research Center of Fluid Machinery Engineering and Technology School of Physics and Electronic Engineering Jiangsu University Zhenjiang212013 China Division of Physics and Applied Physics School of Physical and Mathematical Sciences Nanyang Technological University 21 Nanyang Link Singapore637371 Singapore Centre for Disruptive Photonic Technologies The Photonics Institute Nanyang Technological University 50 Nanyang Avenue Singapore639798 Singapore

The recently discovered non-Hermitian skin effect (NHSE) manifests the breakdown of current classification of topological phases in energy-nonconservative systems, and necessitates the introduction of non-Hermitian band topology. So far, all NHSE observations are based on one type of non-Hermitian band topology, in which the complex energy spectrum winds along a closed loop. As recently characterized along a synthetic dimension on a photonic platform, non-Hermitian band topology can exhibit almost arbitrary windings in momentum space, but their actual phenomena in real physical systems remain unclear. Here, we report the experimental realization of NHSE in a one-dimensional (1D) non-reciprocal acoustic crystal. With direct acoustic measurement, we demonstrate that a twisted winding, whose topology consists of two oppositely oriented loops in contact rather than a single loop, will dramatically change the NHSE, following previous predictions of unique features such as the bipolar localization and the Bloch point for a Bloch-wave-like extended state. This work reveals previously unnoticed features of NHSE, and provides the observation of physical phenomena originating from complex non-Hermitian winding topology. Copyright © 2021, The Authors. All rights reserved.

关键词： Topology

来源：评论

学校读者我要写书评

暂无评论

Corrigendum to “The metallurgical bonding and high temperature tensile behaviors of 9Cr-1W steel and 316L steel dissimilar joint by friction stir welding” [J. Manuf. Process. 44 (2019) 241–251]

引用

Journal of Manufacturing Processes 2021年 65卷 354-354页

作者： Bin He Lei Cui Dongpo Wang Yongchang Liu Chenxi Liu Huijun Li Tianjin Key Laboratory of Advanced Joining Technology School of Materials Science and Engineering Tianjin University Tianjin 300354 PR China State Key Lab. of Hydraulic Engineering Simulation and Safety School of Materials Science & Engineering Tianjin University Tianjin 300354 PR China

来源：评论

学校读者我要写书评

暂无评论

A Broadband Metasurface-Based Terahertz Flat-Lens Array

引用

advanced Optical Materials 2015年第6期3卷 779-785页

作者： Wang, Qiu Zhang, Xueqian Xu, Yuehong Tian, Zhen Gu, Jianqiang Yue, Weisheng Zhang, Shuang Han, Jiaguang Zhang, Weili Center for Terahertz Waves and College of Precision Instrument and Optoelectronics Engineering Tianjin Univ. and the Key Lab. of Optoelectronics Inf. and Technol. Tianjin (Ministry of Education) Tianjin 300072 China Advanced Nanofabrication and Imaging Core Lab King Abdullah University of Science and Technology (KAUST) Thuwal 23955-6900 Saudi Arabia School of Physics and Astronomy University of Birmingham Birmingham B15 2TT United Kingdom School of Electrical and Computer Engineering Oklahoma State University Stillwater 74078 OK United States

来源：评论

学校读者我要写书评

暂无评论

Observation of vortex-string chiral modes in metamaterials

arXiv

引用

arXiv 2023年

作者： Ma, Jingwen Jia, Ding Zhang, Li Guan, Yi-Jun Ge, Yong Sun, Hong-Xiang Yuan, Shou-Qi Chen, Hongsheng Yang, Yihao Zhang, Xiang Faculties of Science and Engineering The University of Hong Kong Hong Kong Interdisciplinary Center for Quantum Information State Key Laboratory of Extreme Photonics and Instrumentation ZJU-Hangzhou Global Scientific and Technological Innovation Center Zhejiang University Hangzhou310027 China Research Center of Fluid Machinery Engineering and Technology School of Physics and Electronic Engineering Jiangsu University Zhenjiang212013 China International Joint Innovation Center The Electromagnetics Academy Zhejiang University Zhejiang University Haining314400 China Key Lab. of Advanced Micro/Nano Electronic Devices & Smart Systems of Zhejiang Jinhua Institute Zhejiang University Zhejiang University Jinhua321099 China Shaoxing Institute of Zhejiang University Zhejiang University Shaoxing312000 China State Key Laboratory of Acoustics Institute of Acoustics Chinese Academy of Sciences Beijing100190 China

As a hypothetical topological defect in the geometry of spacetime, vortex strings play a crucial role in shaping the clusters of galaxies that exist today, and their distinct features can provide observable clues about the early universe’s evolution. A key feature of vortex strings is that they can interact with Weyl fermionic modes and support topological chiral-anomaly states with massless dispersions at the core of strings. To date, despite many attempts to detect vortex strings in astrophysics or to emulate them in artificially created systems, observation of these topological vortex-string chiral modes remains experimentally elusive. Here we report the experimental observation of such vortex-string chiral modes using a metamaterial system. This is implemented by inhomogeneous perturbation of a Yang-monopole phononic metamaterial. The measured linear dispersion and modal profiles confirm the existence of topological modes bound to and propagating along the vortex string with the chiral anomaly. Our work not only provides a platform for studying diverse cosmic topological defects in astrophysics but also offers intriguing device applications as topological fibres in signal processing and communication *** Codes No © 2023, CC BY.

关键词： Vortex flow

来源：评论

学校读者我要写书评

暂无评论

Effects of Back-Reflectors on a-Si: H Solar Cells

引用

Journal of Physics: Conference Series 2021年第1期1965卷

作者： Zhihua Hu Abuduwayiti Aierken Hongwei Diao Key Lab. of Advanced Technology & Preparation for Renewable Energy Materials State Ministry of Education Yunnan Key Lab. of Rural Energy Engineering School of Energy and Environmental Sciences Yunnan Normal University Kunming Yunnan P.R. China Institute of Electrical Engineering Chinese Academic of Sciences Beijing P.R. China

ZAO (ZnO: Al)/Al and ITO/Ag complex back-reflectors were successfully applied to substrate nip and superstrate pin amorphous silicon solar cells respectively. As a result, the short circuit current (Isc) for a cell with a complex back-reflector increases significantly as compared with a cell without a complex back-reflector. For a superstrate pin cell prepared on SnO2 coated glass, the short-circuit current even increases up to 30%.

关键词：

来源：评论

学校读者我要写书评

暂无评论

Spinful Topological Phases in Acoustic Crystals with Projective PT Symmetry

引用

Physical Review Letters 2023年第2期130卷 026101-026101页

作者： Yan Meng Shuxin Lin Bin-jie Shi Bin Wei Linyun Yang Bei Yan Zhenxiao Zhu Xiang Xi Yin Wang Yong Ge Shou-qi Yuan Jingming Chen Gui-Geng Liu Hong-xiang Sun Hongsheng Chen Yihao Yang Zhen Gao Department of Electrical and Electronic Engineering Southern University of Science and Technology Shenzhen 518055 China Research Center of Fluid Machinery Engineering and Technology School of Physics and Electronics Engineering Jiangsu University Zhenjiang 212013 China SKLSM Institute of Semiconductors Chinese Academy of Sciences Beijing 100083 China Center for Excellence in Topological Quantum Computation University of Chinese Academy of Sciences Beijing 100190 China Division of Physics and Applied Physics School of Physical and Mathematical Sciences Nanyang Technological University 21 Nanyang Link Singapore 637371 Singapore State Key Laboratory of Acoustics Institute of Acoustics Chinese Academy of Sciences Beijing 100190 China Interdisciplinary Center for Quantum Information State Key Laboratory of Extreme Photonics and Instrumentation ZJU-Hangzhou Global Scientific and Technological Innovation Center Zhejiang University Hangzhou 310027 China International Joint Innovation Center The Electromagnetics Academy at Zhejiang University Zhejiang University Haining 314400 China Key Lab. of Advanced Micro/Nano Electronic Devices & Smart Systems of Zhejiang Jinhua Institute of Zhejiang University Zhejiang University Jinhua 321099 China Shaoxing Institute of Zhejiang University Zhejiang University Shaoxing 312000 China

For the classification of topological phases of matter, an important consideration is whether a system is spinless or spinful, as these two classes have distinct symmetry algebra that gives rise to fundamentally different topological phases. However, only recently has it been realized theoretically that in the presence of gauge symmetry, the algebraic structure of symmetries can be projectively represented, which possibly enables the switch between spinless and spinful topological phases. Here, we report the experimental demonstration of this idea by realizing spinful topological phases in “spinless” acoustic crystals with projective space-time inversion symmetry. In particular, we realize a one-dimensional topologically gapped phase characterized by a 2Z winding number, which features double-degenerate bands in the entire Brillouin zone and two pairs of degenerate topological boundary modes. Our Letter thus overcomes a fundamental constraint on topological phases by spin classes.

关键词： Acoustics Edge states Topological insulators 1-dimensional systems Finite-element method Gauge symmetries Projective symmetries Tight-binding model

来源：评论

学校读者我要写书评

暂无评论

Commensurate stacking phase transitions in an intercalated transition metal dichalcogenide

arXiv

引用

arXiv 2021年

作者： Yang, Xiaohui Bao, Jin-Ke Lou, Zhefeng Li, Peng Jiang, Chenxi Wang, Jialu Sun, Tulai Liu, Yabin Guo, Wei Ramakrishnan, Sitaram Kotla, Surya Rohith Tolkiehn, Martin Paulmann, Carsten Cao, Guang-Han Nie, Yuefeng Li, Wenbin Liu, Yang van Smaalen, Sander Lin, Xiao Xu, Zhu-An Zhejiang Province Key Laboratory of Quantum Technology and Device Department of Physics Zhejiang University Hangzhou310027 China Key Laboratory for Quantum Materials of Zhejiang Province School of Science Westlake University Hangzhou310024 China Institute of Natural Sciences Westlake Institute for Advanced Study Hangzhou310024 China Laboratory of Crystallography University of Bayreuth Bayreuth95447 Germany Department of Physics Materials Genome Institute International Center for Quantum and Molecular Structures Shanghai University Shanghai200444 China Center for Correlated Matter Zhejiang University Hangzhou310058 China Center for Electron Microscopy State Key Laboratory Breeding Base of Green Chemistry Synthesis Technology College of Chemical Engineering Zhejiang University of Technology Hangzhou310014 China School of Materials Science and Engineering Zhejiang University Hangzhou310027 China National Laboratory of Solid State Microstructures College of Engineering and Applied Sciences Collaborative Innovation Center of Advanced Microstructures Nanjing University Nanjing210093 China Department of Quantum Matter AdSM Hiroshima University Higashi-Hiroshima739-8530 Japan P24 PETRA III DESY Hamburg22607 Germany Mineralogisch-Petrographisches Institute Universität Hamburg Hamburg20146 Germany State Key Lab. of Silicon Materials Zhejiang University Hangzhou310027 China Key Laboratory of 3D Micro/Nano Fabrication and Characterization of Zhejiang Province School of Engineering Westlake University Zhejiang Province Hangzhou310024 China

Intercalation and stacking order modulation are two active ways in manipulating the interlayer interaction of transition metal dichalcogenides (TMDCs), which lead to a variety of emergent phases and allow for engineering material properties. Herein, the growth of Pb intercalated TMDCs–Pb(Ta1+xSe2)2, the first 124-phase, is reported. Pb(Ta1+xSe2)2 exhibits a unique two-step first-order structural phase transition at around 230 K. The transitions are solely associated with the stacking degree of freedom, evolving from a high temperature phase with ABC stacking and symmetry R3m to an intermediate phase with AB stacking and P3m1, and finally to a low temperature phase with again symmetry R3m, but with ACB stacking. Each step involves a rigid slide of building blocks by a vector [1/3, 2/3, 0]. Intriguingly, gigantic lattice contractions occur at the transitions on warming. At low temperature, bulk superconductivity with Tc ≈ 1.8 K is observed. The underlying physics of the structural phase transitions are discussed from first-principle calculations. The symmetry analysis reveals topological nodal lines in the band structure. Our results demonstrate the possibility to realize higher order metal intercalated phases of TMDCs, advance our knowledge of polymorphic transitions and may inspire stacking order engineering in TMDCs and beyond. Copyright © 2021, The Authors. All rights reserved.

关键词： Transition metals

来源：评论

学校读者我要写书评

暂无评论

Polarization-Orthogonal Nondegenerate Plasmonic Higher-Order Topological states

arXiv

引用

arXiv 2021年

作者： Li, Yuanzhen Xu, Su Zhang, Zijian Yang, Yumeng Xie, Xinrong Ye, Wenzheng Liu, Feng Xue, Haoran Jing, Liqiao Wang, Zuojia Chen, Qi-Dai Sun, Hong-Bo Li, Erping Chen, Hongsheng Gao, Fei Interdisciplinary Center for Quantum Information State Key Laboratory of Extreme Photonics and Instrumentation ZJU-Hangzhou Global Scientific and Technological Innovation Center Zhejiang University Hangzhou310027 China International Joint Innovation Center The Electromagnetics Academy Zhejiang University Zhejiang University Haining314400 China State Key Laboratory of Integrated Optoelectronics College of Electronic Science and Engineering Jilin University 2699 Qianjin Street Changchun130012 China Division of Physics and Applied Physics School of Physical and Mathematical Sciences Nanyang Technological University Singapore637371 Singapore State Key Laboratory of Precision Measurement Technology and Instruments Department of Precision Instrument Tsinghua University Haidian Beijing100084 China Key Lab. of Advanced Micro/Nano Electronic Devices & Smart Systems of Zhejiang Jinhua Institute of Zhejiang University Zhejiang University Jinhua321099 China Shaoxing Institute of Zhejiang University Zhejiang University Shaoxing312000 China

Photonic topological states, providing light-manipulation approaches in robust manners, have attracted intense attention. Connecting photonic topological states with far-field degrees of freedom (DoFs) has given rise to fruitful phenomena. Recently emerged higher-order topological insulators (HOTIs), hosting boundary states two or more dimensions lower than those of bulk, offer new paradigms to localize/transport light topologically in extended dimensionalities. However, photonic HOTIs have not been related to DoFs of radiation fields yet. Here, we report the observation of polarization-orthogonal second-order topological corner states at different frequencies on a designer-plasmonic Kagome metasurface in the far field. Such phenomenon stands on two mechanisms, i.e., projecting the far-field polarizations to the intrinsic parity DoFs of lattice modes and the parity splitting of the plasmonic corner states in spectra. We theoretically and numerically show that the parity splitting originates from the underlying inter-orbital coupling. Both near-field and far-field experiments verify the polarization-orthogonal nondegenerate second-order topological corner states. These results promise applications in robust optical single photon emitters and multiplexed photonic devices. Copyright © 2021, The Authors. All rights reserved.

关键词： Polarization

来源：评论

学校读者我要写书评

暂无评论

Manipulation of valley-polarized topological kink states in ultrathin substrate-integrated photonic circuitry

arXiv

引用

arXiv 2018年

作者： Zhang, Li Yang, Yihao He, Mengjia Wang, Hai-Xiao Yang, Zhaoju Li, Erping Gao, Fei Zhang, Baile Singh, Ranjan Jiang, Jian-Hua Chen, Hongsheng State Key Laboratory of Modern Optical Instrumentation Electromagnetics Academy at Zhejiang University Zhejiang University Hangzhou310027 China Key Lab. of Advanced Micro/Nano Electronic Devices & Smart Systems of Zhejiang College of Information Science and Electronic Engineering Zhejiang University Hangzhou310027 China Division of Physics and Applied Physics School of Physical and Mathematical Sciences Nanyang Technological University 21 Nanyang Link Singapore637371 Singapore Centre for Disruptive Photonic Technologies Photonics Institute Nanyang Technological University 50 Nanyang Avenue Singapore639798 Singapore Shool of Physical Science and Technology Collaborative Innovation Center of Suzhou Nano Science and Technology Soochow University Suzhou215006 China

Valley degrees of freedom, providing a novel way to increase the capacity and efficiency of information storage and processing, has become an important instrument for photonics. However, at present stage, valley photonics is restricted to unprotected valley transport and valley Hall effects at zigzag interfaces, limiting its development and applications. Here, we demonstrate realization, engineering, and manipulation of valley-polarized topological kink states at generic interfaces in ultrathin substrate-integrated photonic circuitry experimentally. The robustness of the valley-polarized topological kink states at generic interfaces is verified by the robust in-gap transmission though sharply bending interface channels and disordered domain wall channels, respectively. With the ultrathin substrate-integrated photonic architecture, we realize geometry-dependent topological channel intersections. This platform has ultrathin thicknesses and excellent self-consistent electrical shielding, which is perfectly compatible with the conventional substrate-integrated photonic circuits. Our study thus provides a novel pathway for controlling valley degrees of freedom in photonics and may work as a novel integration platform for information processing that has disorder-insensitivity, easy access, and lightweight. Copyright © 2018, The Authors. All rights reserved.

关键词： Substrates

来源：评论

学校读者我要写书评

暂无评论

Reciprocity of thermal diffusion in time-modulated systems

arXiv

引用

arXiv 2021年

作者： Li, Jiaxin Li, Ying Cao, Pei-Chao Zheng, Xu Peng, Yu-Gui Li, Baowen Zhu, Xue-Feng Alù, Andrea Qiu, Cheng-Wei Department of Electrical and Computer Engineering National University of Singapore Singapore117583 Singapore School of Mechatronics Engineering Harbin Institute of Technology Harbin150001 China Interdisciplinary Center for Quantum Information State Key Laboratory of Modern Optical Instrumentation College of Information Science and Electronic Engineering Zhejiang University Hangzhou310027 China ZJU-Hangzhou Global Science and Technology Innovation Center Key Lab. of Advanced Micro Nano Electronic Devices & Smart Systems of Zhejiang Zhejiang University Hangzhou310027 China International Joint Innovation Center ZJU-UIUC Institute Electromagnetics Academy at Zhejiang University Zhejiang University Haining314400 China School of Physics and Innovation Institute Huazhong University of Science and Technology Wuhan430074 China Department of Physics University of Colorado BoulderCO80309 United States Department of Electrical Engineering City University of New York New YorkNY10031 United States Department of Mechanical Engineering University of Colorado BoulderCO80309 United States

The reciprocity principle governs the symmetry in transmission of electromagnetic and acoustic waves, as well as the diffusion of heat between two points in space, with important consequences for thermal management and energy harvesting. There has been significant recent interest in materials with time-modulated properties, which have been shown to efficiently break reciprocity for light, sound, and even charge diffusion. Quite surprisingly, here we show that, from a practical point of view, time modulation cannot generally be used to break reciprocity for thermal diffusion. We establish a theoretical framework to accurately describe the behavior of diffusive processes under time modulation, and prove that thermal reciprocity in dynamic materials is generally preserved by the continuity equation, unless some external bias or special material is considered. We then experimentally demonstrate reciprocal heat transfer in a time-modulated device. Our findings correct previous misconceptions regarding reciprocity breaking for thermal diffusion, revealing the generality of symmetry constraints in heat transfer, and clarifying its differences from other transport processes in what concerns the principles of reciprocity and microscopic reversibility. © 2021, CC BY.

关键词： Energy harvesting

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：