检索结果-内蒙古大学图书馆

Extraordinary Quality Factors in Dual-Band Polarization-Insensitive QuasiBound States in the Continuum

学校读者我要写书评

暂无评论

arXiv 2024年

作者： Ghahremani, Maryam Zapata-Rodríguez, Carlos J. Photonics Research Laboratory Center of Excellence on Applied Electromagnetic Systems School of Electrical and Computer Engineering College of Engineering University of Tehran Tehran Iran Department of Optics and Optometry and Vision Sciences Faculty of Physics University of Valencia Dr. Moliner 50 Burjassot46100 Spain

In this study, we investigate a novel "dimerized" dielectric metasurface featuring dual-mode resonances governed by symmetry-protected bound states in the continuum (BICs). The metasurface design offers advantages such as insensitivity to incident light polarization and exceptionally high quality factors exceeding 105 for low and moderate structural deviations from the monoatomic array. By introducing mastered perturbations in the metasurface via the Brillouin zone folding method, without reducing symmetry, we explore the behavior of symmetry-protected BIC states and their polarization-independent responses. Through numerical simulations and analysis, we demonstrate the superiority of Q factors for specific BIC-based resonances, leading to precise control over interaction behaviors and light engineering in both near and far fields. Our findings contribute to the understanding of BIC resonance interactions and offer insights into the design of high-performance sensing applications and meta-devices with enhanced functionalities. © 2024, CC BY-NC-ND.

关键词： Incident light

Characterization of Solar Cell Busbar Grid for Different Technologies by Time Domain Reflectometry Simulation: Transmission Line Approach

学校读者我要写书评

暂无评论

Characterization of Solar Cell Busbar Grid for Different Tec...

IEEE Conference Photovoltaic Specialists (PVSC)

作者： A.M.C. Silveira M.R.M. Neves R. Garcia H. Alvarez M.G. Villalva F.C. Marques L.C. Kretly Communications Department - DECOM School of Electrical and Computer Engineering Campinas Brazil Dept. of Systems and Energy - DSE School of Electrical and Computer Engineering Campinas Brazil Dept. Research and Development - R&D Build Your Dreams Company - BYD Campinas Brazil Dept. of Applied Physics - DFA Institute of Physics Gleb Wataghin Campinas Brazil

This work electromagnetically simulates the design of metallic grids for different Busbar technologies in standard solar cells existing in the photovoltaic market in order to characterize their grid impedance using a signal integrity technique known as Time Domain Reflectometry - TDR and addressing the design of metallized grid of solar cells within the foundations of transmission lines. The objective of the investigation is to parameterize the results obtained so that they can serve as a reference in studies of micro-resistance in series of solar cells and their effects on energy efficiency.

关键词：

Calculating radio emissions of positive streamer phenomena using 3D simulations

学校读者我要写书评

暂无评论

arXiv 2024年

作者： Malla, Hemaditya Hare, Brian M. Cummer, Steven Guo, Yihao Malagón-Romero, Alejandro Nijdam, Sander Ebert, Ute Teunissen, Jannis Amsterdam Netherlands Department of Applied Physics Eindhoven University of Technology Netherlands ASTRON Dutch Institute for radio astronomy Dwingeloo Netherlands Kapteyn Astronomical Institute University of Groningen Groningen Netherlands Electrical and Computer Engineering Department Duke University DurhamNC United States

We study radio emissions from positive streamers in air using 3D simulations, from which the radiated electric field is computed by solving Jefimenko’s equations. The simulations are performed at 0.5 bar using two photoionization methods: the Helmholtz approximation for a photon density and a Monte Carlo method using discrete photons, with the latter being the most realistic. We consider cases with single streamers, streamer branching, streamers interacting with preionization and streamer-streamer encounters. We do not observe a strong VHF radio signal during or after branching, which is confirmed by lab experiments. This indicates that the current inside a streamer discharge evolves approximately continuously during branching. On the other hand, stochastic fluctuations in streamer propagation due to Monte Carlo photoionization lead to more radio emission being emitted at frequencies of 100 MHz and above. Another process that leads to such high-frequency emission is the interaction of a streamer with a weakly preionized region, which can be present due to a previous discharge. In agreement with previous work, we observe the strongest and highest-frequency emission from streamer encounters. The amount of total energy that is radiated seems to depend primarily on the background electric field, and less on the particular streamer evolution. Finally, we present approximations for the maximal current along a streamer channel and a fit formula for a streamer’s current moment. Copyright © 2024, The Authors. All rights reserved.

关键词： Stochastic systems

Metamaterial-induced-transparency engineering through quasi-bound states in the continuum by using dielectric cross-shaped trimers

学校读者我要写书评

暂无评论

arXiv 2024年

This study presents a novel approach to activate a narrowband transparency line within a reflecting broadband window in all-dielectric metasurfaces, in analogy to the electromagnetically-induced transparency effect, by means of a quasi-bound state in the continuum (qBIC). We demonstrate that the resonance overlapping of a bright mode and a qBIC-based nearly-dark mode with distinct Q-factor can be fully governed by a silicon trimer-based unit cell with broken-inversion-symmetry cross shape, thus providing the required response under normal incidence of a linearly-polarized light. Our analysis that is derived from the far-field multipolar decomposition and near-field electromagnetic distributions uncovers the main contributions of different multipoles on the qBIC resonance, with governing magnetic dipole and electric quadrupole terms supplied by distinct parts of the dielectric "molecule." The findings extracted from this research open up new avenues for the development of polarization-dependent technologies, with particular interest in its capabilities for sensing and biosensing. © 2024, CC BY-NC-ND.

关键词： Transparency

Design of Miniaturized Metamaterial Reflector with Doubly Interdigital Structure for 5G Use Cases

学校读者我要写书评

暂无评论

Design of Miniaturized Metamaterial Reflector with Doubly In...

International electrical engineering Congress (iEECON)

作者： Tanee Somwong Pongsathorn Chomtong Jirayut Khamsuthat Nonchanutt Chudpooti Prayoot Akkaraekthalin Department of Electronic and Telecommunications Engineering Faculty of Engineering and Architecture Rajamangala University of Technology Suvarnabhumi Nonthaburi Thailand Department of Teacher Training in Electrical Engineering Faculty of Technical Education King Mongkut’s University of Technology North Bangkok Bangkok Thailand Department of Industrial Physics and Medical Instrumentation Faculty of Applied Science King Mongkut’s University of Technology North Bangkok Bangkok Thailand Department of Electrical and Computer Engineering Faculty of Engineering King Mongkut’s University of Technology North Bangkok Bangkok Thailand

ISBN: (数字)9798331543952

ISBN: (纸本)9798331543969

This paper presents the design of a miniaturized metamaterial reflector composing of an open-loop transmission line unit cell structure. The transmission line ends are connected by using a double interdigital technique, resulting in a large capacitive value compared to the conventional methods. When combined with the open-loop line employing the trisection step-impedance structure with adjusting of the capacitive value, its second and third resonant frequencies will be controllable. As a result, this approach can reduce the unit cell size from a typical value of λ/2 to an approximate value of λ/16, therefore overall size of the reflector is significantly decreased. The designed unit cell is measured to be 1.05 cm × 1.0 cm. We implemented the proposed reflector on an FR-4 PCB with a relative permittivity of about 4.4, a substrate height (h) of 1.6 mm, and a loss tangent of about 0.02. The operating frequency range targets of 5G use cases were set to be at 1.8 GHz, 2.6 GHz and 3.5 GHz, respectively. When used with a dipole antenna, the bandwidths of 390 MHz, 604 MHz, and 1.1 GHz and the antenna gains of about 8.23 dB, 8.14 dB, and 8.19 dB were obtained at the operating frequencies, respectively.

关键词： Wireless communication 5G mobile communication Dipole antennas Simulation Resonant frequency Reflector antennas Transmission line measurements Metamaterials Gain Substrates

Design of Miniaturized Metamaterial Reflector with Doubly Interdigital Structure for 5G Use Cases

学校读者我要写书评

暂无评论

Design of Miniaturized Metamaterial Reflector with Doubly In...

13th International electrical engineering Congress, iEECON 2025

作者： Somwong, Tanee Chomtong, Pongsathorn Khamsuthat, Jirayut Chudpooti, Nonchanutt Akkaraekthalin, Prayoot Rajamangala University of Technology Suvarnabhumi Faculty of Engineering and Architecture Department of Electronic and Telecommunications Engineering Nonthaburi Thailand King Mongkut's University of Technology North Bangkok Faculty of Technical Education Department of Teacher Training in Electrical Engineering Bangkok Thailand King Mongkut's University of Technology North Bangkok Faculty of Applied Science Department of Industrial Physics and Medical Instrumentation Bangkok Thailand King Mongkut's University of Technology North Bangkok Faculty of Engineering Department of Electrical and Computer Engineering Bangkok Thailand

ISBN: (纸本)9798331543952

关键词： Antenna reflectors

Evolution of Metallic Connection Technologies of Busbar in Silicon Solar Cells: Brief Review

学校读者我要写书评

暂无评论

Evolution of Metallic Connection Technologies of Busbar in S...

IEEE/IAS International Conference on Industry Applications (INDUSCON)

作者： A.M.C. Silveira M.R.M. Neves R. Garcia H. Alvarez M.G. Villalva F.C. Marques L.C. Kretly Communications Department DECOM School of Electrical and Computer Engineering Campinas Brazil Dept. of Systems and Energy DSE School of Electrical and Computer Engineering Campinas Brazil Dept. Research and Development - R&D Build Your Dreams Company - BYD Campinas Brazil Dept. of Applied Physics DFA Institute of Physics Gleb Wataghin Campinas Brazil

This work consists of presenting a brief review of the evolution of metallic connection technologies in busbars applied to the front and rear of solar cells, thus demonstrating their fundamentals, materials and essential manufacturing processes that impact on improving the energy efficiency of solar modules. In this brief review, one can follow the technical limitations that led to the evolution of metallic connection technologies in busbars over time and their impacts on the photovoltaic market. Contributing to a broad understanding of the resistive components of solar cells that consists of the series resistance parameter.

关键词：

Towards All-optical Cavity-based Memory for Non-Gaussian Quantum State engineering

学校读者我要写书评

暂无评论

Towards All-optical Cavity-based Memory for Non-Gaussian Qua...

CLEO: Fundamental Science, CLEO:FS 2024 - Part of Conference on Lasers and Electro-Optics, CLEO 2024

作者： Hanamura, Fumiya Takase, Kan Hirota, Kazuki Nehra, Rajveer Lang, Florian Miki, Shigehito Terai, Hirotaka Yabuno, Masahiro China, Fumihiro Kahiwazaki, Takahiro Inoue, Asuka Umeki, Takeshi Asavanant, Warit Endo, Mamoru Yoshikawa, Jun-Ichi Furusawa, Akira Department of Applied Physics School of Engineering The University of Tokyo 7-3-1 Hongo Bunkyo-ku Tokyo113-8656 Japan Optical Quantum Computing Research Team RIKEN Center for Quantum Computing 2-1 Hirosawa Saitama Wako351-0198 Japan Department of Electrical and Computer Engineering University of Massachusetts-Amherst AmherstMA01003 United States Department of Physics University of Massachusetts-Amherst AmherstMA01003 United States Department of Information Technology and Electrical Engineering ETH Zurich Zurich8092 Switzerland Advanced ICT Research Institute National Institute of Information and Communications Technology 588-2 Iwaoka Nishi-ku Hyogo Kobe651-2492 Japan Graduate School of Engineering Kobe University 1-1 Rokkodai-cho Nada-ku Hyogo Kobe657-0013 Japan NTT Device Technology Labs NTT Corporation 3-1 Morinosato Wakamiya Kanagawa Atsugi243-0198 Japan

We present our experimental results on all-optical memory to store and manipulate quantum states, and propose resource-efficient time-domain-multiplexed state engineering using the memory. This paves a path to scalabl... 详细信息

ISBN: (纸本)9781957171395

关键词： Optical recording

Quantum dichotomies and coherent thermodynamics beyond first-order asymptotics

学校读者我要写书评

暂无评论

arXiv 2023年

作者： Lipka-Bartosik, Patryk Chubb, Christopher T. Renes, Joseph M. Tomamichel, Marco Korzekwa, Kamil Department of Applied Physics University of Geneva Geneva1211 Switzerland Institute for Theoretical Physics ETH Zurich Zürich8093 Switzerland Department of Electrical and Computer Engineering National University of Singapore Singapore117583 Singapore Centre for Quantum Technologies National University of Singapore Singapore117543 Singapore Faculty of Physics Astronomy and Applied Computer Science Jagiellonian University Kraków30-348 Poland

We address the problem of exact and approximate transformation of quantum dichotomies in the asymptotic regime, i.e., the existence of a quantum channel E mapping (Equation presented) into (Equation presented) with an error ϵn (measured by trace distance) and (Equation presented) into (Equation presented) exactly, for a large number n. We derive second-order asymptotic expressions for the optimal transformation rate Rn in the small, moderate, and large deviation error regimes, as well as the zero-error regime, for an arbitrary pair (ρ1,σ1) of initial states and a commuting pair (ρ2,σ2) of final states. We also prove that for σ1 and σ2 given by thermal Gibbs states, the derived optimal transformation rates in the first three regimes can be attained by thermal operations. This allows us, for the first time, to study the second-order asymptotics of thermodynamic state interconversion with fully general initial states that may have coherence between different energy eigenspaces. Thus, we discuss the optimal performance of thermodynamic protocols with coherent inputs and describe three novel resonance phenomena allowing one to significantly reduce transformation errors induced by finite-size effects. What is more, our result on quantum dichotomies can also be used to obtain, up to second-order asymptotic terms, optimal conversion rates between pure bipartite entangled states under local operations and classical communication. Copyright © 2023, The Authors. All rights reserved.

关键词： Thermodynamics