EPJ Applied Metamaterials最新文献_第2页

On negative effective mass and negative group velocity in anharmonic seismic metamaterials 非调和地震超材料的负有效质量和负群速度

IF 1.6

EPJ Applied Metamaterials Pub Date : 2022-01-01 DOI: 10.1051/epjam/2022008

R. Zivieri

引用次数: 1

The role of nonlocal response in second harmonic generation at metasurfaces with triangular metaatoms 非局域响应在具有三角元原子的超表面上二次谐波产生中的作用

IF 1.6

EPJ Applied Metamaterials Pub Date : 2022-01-01 DOI: 10.1051/epjam/2022013

Y. B. Habibullah, T. Ishihara

{"title":"The role of nonlocal response in second harmonic generation at metasurfaces with triangular metaatoms","authors":"Y. B. Habibullah, T. Ishihara","doi":"10.1051/epjam/2022013","DOIUrl":"https://doi.org/10.1051/epjam/2022013","url":null,"abstract":"Metasurface consisting of square array of obtuse isosceles triangle metaatoms is found to exhibit much more efficient second harmonic generation (SHG) compared to that of split ring resonators and its heptagonal modification, experimentally as well as numerically. All of them are designed to lack inversion symmetry in horizontal direction but to have vertical symmetry, and to meet the double resonance condition for vertically-polarized fundamental and horizontally-polarized SHG waves. SHG efficiencies were estimated numerically for each structure by evaluating an overlap integral of second order nonlinear polarization and field distribution at the SHG wavelength. The large overlap integral for the triangle metasurface is ascribed to the nonlocal response at the SHG wavelength. Current induced at the center of the triangle near the obtuse angle by horizontally polarized light at SHG wavelength flows toward two corners of acute angles. As a result, polarization charges oscillate in time at the surfaces of two acute corners, which results in strong field oscillation away from the center where the electric field is applied to majority of free electrons. Experimentally observed wavelength dependence of SHG efficiencies for the three metasurfaces are reasonably reproduced by a numerical estimation.","PeriodicalId":43689,"journal":{"name":"EPJ Applied Metamaterials","volume":"1 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"57823745","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Dynamic transmission-reflection dichroism based on humidity-responsive metal-hydrogel-metal nanocavities 基于湿度响应金属-水凝胶-金属纳米腔的动态透射-反射二色性

IF 1.6

EPJ Applied Metamaterials Pub Date : 2022-01-01 DOI: 10.1051/epjam/2022016

Dandan Wang, Qiang Li, Yunbin Ying, Runhu Li, Minglian Cheng, Yingxin Chen, Jian Zhang, Xuefeng Zhang

{"title":"Dynamic transmission-reflection dichroism based on humidity-responsive metal-hydrogel-metal nanocavities","authors":"Dandan Wang, Qiang Li, Yunbin Ying, Runhu Li, Minglian Cheng, Yingxin Chen, Jian Zhang, Xuefeng Zhang","doi":"10.1051/epjam/2022016","DOIUrl":"https://doi.org/10.1051/epjam/2022016","url":null,"abstract":"“Lycurgus cup” effect, referring dichroism between reflection and transmission modes of the same structures, is a peculiar phenomenon of multi-faceted display in structural color. Beyond the static dichrotic display, the realization of dynamic dichroism desires active materials and tunable structures, and owns the great demand from smart display, anti-counterfeiting and environmental sensing. We hereby propose a metal-hydrogel-metal (MHM) nanocavity for dynamic dichrotic display. This structure includes thin silver layers to induce the partial transmission with the existing reflection, and a polyvinyl alcohol (PVA) hydrogel layer owning the swelling/deswelling deformability to humidity change. The following experimental measurements and theoretical analysis prove that the reflection and transmission modes exist at distinct wavelengths, and the swelling hydrogel layer by humidity change between 10 and 90% RH can dynamically modulate the dichrotic resonance with the wavelength shift over 100 nm. Such environmental-sensitive and real-time tunable dichroism with hydrogel-based structural color is then verified for multi-color printing, resolution test, and cycling test.","PeriodicalId":43689,"journal":{"name":"EPJ Applied Metamaterials","volume":"1 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"57823819","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Numerical methods for design of metamaterial photonic crystals and random metamaterials 超材料光子晶体和随机超材料设计的数值方法

IF 1.6

EPJ Applied Metamaterials Pub Date : 2022-01-01 DOI: 10.1051/epjam/2021012

T. Terao

引用次数: 1

Morphing for faster computations with finite difference time domain algorithms 变形为更快的计算与有限差分时域算法

IF 1.6

EPJ Applied Metamaterials Pub Date : 2022-01-01 DOI: 10.1051/epjam/2021011

Ronald Aznavourian, S. Guenneau, B. Ungureanu, J. Marot

{"title":"Morphing for faster computations with finite difference time domain algorithms","authors":"Ronald Aznavourian, S. Guenneau, B. Ungureanu, J. Marot","doi":"10.1051/epjam/2021011","DOIUrl":"https://doi.org/10.1051/epjam/2021011","url":null,"abstract":"In the framework of wave propagation, finite difference time domain (FDTD) algorithms, yield high computational time. We propose to use morphing algorithms to deduce some approximate wave pictures of their interactions with fluid-solid structures of various shapes and different sizes deduced from FDTD computations of scattering by solids of three given shapes: triangular, circular and elliptic ones. The error in the L2 norm between the FDTD solution and approximate solution deduced via morphing from the source and destination images are typically less than 1% if control points are judiciously chosen. We thus propose to use a morphing algorithm to deduce approximate wave pictures: at intermediate time steps from the FDTD computation of wave pictures at a time step before and after this event, and at the same time step, but for an average frequency signal between FDTD computation of wave pictures with two different signal frequencies. We stress that our approach might greatly accelerate FDTD computations as discretizations in space and time are inherently linked via the Courant–Friedrichs–Lewy stability condition. Our approach requires some human intervention since the accuracy of morphing highly depends upon control points, but compared to the direct computational method our approach is much faster and requires fewer resources. We also compared our approach to some neural style transfer (NST) algorithm, which is an image transformation method based on a neural network. Our approach outperforms NST in terms of the L2 norm, Mean Structural SIMilarity, expected signal to error ratio.","PeriodicalId":43689,"journal":{"name":"EPJ Applied Metamaterials","volume":"1 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"57823912","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Graded elastic meta-waveguides for rainbow reflection, trapping and mode conversion 用于彩虹反射、捕获和模式转换的梯度弹性元波导

IF 1.6

EPJ Applied Metamaterials Pub Date : 2022-01-01 DOI: 10.1051/epjam/2022004

J. D. De Ponti, L. Iorio, R. Ardito

引用次数: 3

High-sensitivity in various gyrator-based circuits with exceptional points of degeneracy 具有特殊简并点的各种陀螺电路的高灵敏度

IF 1.6

EPJ Applied Metamaterials Pub Date : 2022-01-01 DOI: 10.1051/epjam/2022005

K. Rouhi, A. Nikzamir, A. Figotin, F. Capolino

引用次数: 1

Morphology dependence of nanoparticle-on-mirror geometries: A quasinormal mode analysis 纳米粒子对镜面几何形状的形态学依赖性:准正态模态分析

IF 1.6

EPJ Applied Metamaterials Pub Date : 2022-01-01 DOI: 10.1051/epjam/2022002

K. Bedingfield, E. Elliott, N. Kongsuwan, J. Baumberg, A. Demetriadou

{"title":"Morphology dependence of nanoparticle-on-mirror geometries: A quasinormal mode analysis","authors":"K. Bedingfield, E. Elliott, N. Kongsuwan, J. Baumberg, A. Demetriadou","doi":"10.1051/epjam/2022002","DOIUrl":"https://doi.org/10.1051/epjam/2022002","url":null,"abstract":"Plasmonic nanoantennas are able to produce extreme enhancements by concentrating electromagnetic fields into sub-wavelength volumes. Recently, one of the most commonly used nanoantennas is the nanoparticle-on-mirror geometry, which allowed for the room temperature strong coupling of a single molecule. Very few studies offer analysis of near-field mode decompositions, and they mainly focus on spherical and/or cylindrically-faceted nanoparticle-on-mirror geometries. Perfectly spherical nanoparticles are not easy to fabricate, with recent publications revealing that a rhombicuboctahedron is a commonly occurring nanoparticle shape – due to the crystalline nature of metallic nanoparticles. In this paper, we perform a quasi-normal mode analysis for the rhombicuboctahedron-on-mirror nanoantenna and map the field distributions of each mode. We examine how the geometry of the cavity defines the near-field distribution and energies of the modes, and we show that in some cases the mode degeneracies break. This has a significant impact on the radiative emission and far-field profile of each mode, which are measured experimentally. Understanding how realistic nanoantenna geometries behave in the near-field and far-field helps us design antennas with specific properties for controlling and sensing quantum emitters in plasmonic systems.","PeriodicalId":43689,"journal":{"name":"EPJ Applied Metamaterials","volume":"1 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"57823468","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 4

How to achieve exceptional points in coupled resonators using a gyrator or PT-symmetry, and in a time-modulated single resonator: high sensitivity to perturbations 如何在使用旋转器或pt对称的耦合谐振器中实现特殊点，以及在时间调制的单谐振器中:对扰动的高灵敏度

IF 1.6

EPJ Applied Metamaterials Pub Date : 2022-01-01 DOI: 10.1051/epjam/2022006

A. Nikzamir, K. Rouhi, A. Figotin, F. Capolino

{"title":"How to achieve exceptional points in coupled resonators using a gyrator or PT-symmetry, and in a time-modulated single resonator: high sensitivity to perturbations","authors":"A. Nikzamir, K. Rouhi, A. Figotin, F. Capolino","doi":"10.1051/epjam/2022006","DOIUrl":"https://doi.org/10.1051/epjam/2022006","url":null,"abstract":"We study the rise of exceptional points of degeneracy (EPD) in various distinct circuit configurations such as gyrator-based coupled resonators, coupled resonators with PT-symmetry, and in a single resonator with a time-varying component. In particular, we analyze their high sensitivity to changes in resistance, capacitance, and inductance and show the high sensitivity of the resonance frequency to perturbations. We also investigate stability and instability conditions for these configurations; for example, the effect of losses in the gyrator-based circuit leads to instability, and it may break the symmetry in the PT-symmetry-based circuit, also resulting in instabilities. Instability in the PT-symmetry circuit is also generated by breaking PT-symmetry when one element (e.g., a capacitor) is perturbed due to sensing. We have turned this instability “inconvenience” to an advantage, and we investigate the effect of nonlinear gain in the PT-symmetry coupled-resonator circuit and how this leads to an oscillator with oscillation frequency very sensitive to perturbation. The circuits studied in this paper have the potential to lead the way for a more efficient generation of high-sensitivity sensors that can detect very small changes in chemical, biological, or physical quantities.","PeriodicalId":43689,"journal":{"name":"EPJ Applied Metamaterials","volume":"25 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"57823550","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 5

Metamaterials simulation for thermal diffusers 热扩散器的超材料模拟

IF 1.6

EPJ Applied Metamaterials Pub Date : 2022-01-01 DOI: 10.1051/epjam/2022017

Luis Alfonso Nuñez-Betancourt, J. Matutes-Aquino

引用次数: 0