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Mechanically reprogrammable Pancharatnam-Berry metasurface for microwaves

Advanced Photonics 2022年第1期4卷 69-79页

作者： Quan Xu Xiaoqiang Su Xueqian Zhang Lijuan Dong Lifeng Liu Yunlong Shi Qiu Wang Ming Kang Andrea Alù Shuang Zhang Jiaguang Han Weili Zhang Tianjin University Center for Terahertz Waves and College of Precision Instrument and Optoelectronics EngineeringKey Laboratory of Optoelectronic Information Technology(Ministry of Education of China)TianjinChina Shanxi Datong University Institute of Solid State Physics and College of Physics and Electronic ScienceShanxi Province Key Laboratory of Microstructure Electromagnetic Functional MaterialsDatongChina Wuhan University of Technology School of Information EngineeringWuhanChina Tianjin Normal University College of Physics and Materials ScienceTianjinChina City University of New York Advanced Science Research CenterPhotonics InitiativeNew YorkUnited States City University of New York Graduate CenterPhysics ProgramNew YorkUnited States University of Hong Kong Faculty of ScienceDepartment of PhysicsHong KongChina University of Hong Kong Department of Electrical and Electronic EngineeringHong KongChina Guilin University of Electronic Technology Guangxi Key Laboratory of Optoelectronic Information ProcessingSchool of Optoelectronic EngineeringGuilinChina Oklahoma State University School of Electrical and Computer EngineeringStillwaterOklahomaUnited States

Metasurfaces have enabled the realization of several optical functionalities over an ultrathin platform,fostering the exciting field of flat *** metasurfaces are achieved by arranging a layout of static meta-atoms to imprint a desired operation on the impinging wavefront,but their functionality cannot be *** and programmability of metasurfaces are the next important step to broaden their impact,adding customized on-demand functionality in which each meta-atom can be individually *** demonstrate a mechanical metasurface platform with controllable rotation at the meta-atom level,which can implement continuous Pancharatnam–Berry phase control of circularly polarized *** the proof-of-concept experiments,we demonstrate metalensing,focused vortex beam generation,and holographic imaging in the same metasurface template,exhibiting versatility and superior *** dynamic control of electromagnetic waves using a single,low-cost metasurface paves an avenue towards practical applications,driving the field of reprogrammable intelligent metasurfaces for a variety of applications.

关键词： reprogrammable metasurfaces Pancharatnam-Berry phase mechanical metasurfaces microwaves

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Pulmonary Disease Pattern Recognition on X-Ray Radiography Image Using Artificial Neural Network (ANN) Method 3

Pulmonary Disease Pattern Recognition on X-Ray Radiography I...

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3rd Annual Scientific Meeting on Medical physics and Biophysics, PIT-FMB in conjunction with the 17th South-East Asia Congress of Medical physics, SEACOMP 2019

作者： Fitriyah, N. Kurniawati, L.D. Purwanti, E. Astuti, S.D. Department of Physics Faculty of Science and Technology Universitas Airlangga Surabaya60115 Indonesia Biomedical Engineering Study Program Faculty of Science and Technology Universitas Airlangga Surabaya60115 Indonesia Department of Biomedical Engineering Post-Graduate Program Faculty of Science and Technology Universitas Airlangga Surabaya60115 Indonesia

This research aims to recognize the pattern of pulmonary disease on x-ray radiography image using artificial neural network (ANN) method. The images, which were used such as images of healthy pulmonary, pulmonary tuberculosis, and pulmonary tumour. Pattern recognition was using an extraction feature of GLCM (Gray Level Co-occurrence Matrix) and back propagation method. Before being identified, the images were processed by median filter and adaptive histogram equalization. The GLCM features that used were homogeneity, energy, contrast, variance and correlation. The parameters were learning rate and hidden layer. Learning rate was 0.3 and hidden layer was 25. Back propagation training showed 100% accuracy, which all of 44 images were used had been successfully identified. From the result, the healthy pulmonary showed 60% accuracy, 83.3% for pulmonary tuberculosis and 100% for pulmonary tumor. Hence, the overall result showed 81.25% accuracy, which 13 of 16 images had been successfully identified. From these result, extraction feature of GLCM using back propagation method was capable to recognize the pattern of pulmonary disease. However, due to narrow range of the feature, this application may not be used optimally for comparing features in every category of images. Therefore, the further research is needed to determine the best features and parameters of training back propagation. © Published under licence by IOP Publishing Ltd.

关键词： Pattern recognition

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Search for Majorana Neutrinos with the Complete KamLAND-Zen Dataset

arXiv

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arXiv 2024年

作者： Abe, S. Araki, T. Chiba, K. Eda, T. Eizuka, M. Funahashi, Y. Furuto, A. Gando, A. Gando, Y. Goto, S. Hachiya, T. Hata, K. Ichimura, K. Ieki, S. Ikeda, H. Inoue, K. Ishidoshiro, K. Kamei, Y. Kawada, N. Kishimoto, Y. Koga, M. Marthe, A. Matsumoto, Y. Mitsui, T. Miyake, Haruhiko Morita, D. Nakamura, K. Nakamura, R. Nakamura, R. Nakane, J. Ono, T. Ozaki, H. Saito, K. Sakai, T. Shimizu, I. Shirai, J. Shiraishi, K. Suzuki, A. Tachibana, K. Tamae, K. Watanabe, H. Watanabe, K. Yoshida, S. Umehara, S. Fushimi, K. Kotera, K. Urano, Y. Berger, B.E. Fujikawa, B.K. Learned, J.G. Maricic, J. Fu, Z. Ghosh, S. Smolsky, J. Winslow, L.A. Efremenko, Y. Karwowski, H.J. Markoff, D.M. Tornow, W. Dell'Oro, S. Donnell, T.O. Detwiler, J.A. Enomoto, S. Decowski, M.P. Weerman, K.M. Grant, C. Penek, O. Song, H. Li, A. Axani, S.N. Garcia, M. Sarfraz, M. Research Center for Neutrino Science Tohoku University Sendai980-8578 Japan Department of Human Science Obihiro University of Agriculture and Veterinary Medicine Hokkaido Obihiro080-8555 Japan The University of Tokyo Institutes for Advanced Study The University of Tokyo Chiba Kashiwa277-8583 Japan Graduate Program on Physics for the Universe Tohoku University Sendai980-8578 Japan Graduate School of Science Osaka University Toyonaka Osaka560-0043 Japan Research Center for Nuclear Physics Osaka University Osaka Ibaraki567-0047 Japan Department of Physics Tokushima University Tokushima770-8506 Japan Graduate School of Integrated Arts and Sciences Tokushima University Tokushima770-8502 Japan Nuclear Science Division Lawrence Berkeley National Laboratory BerkeleyCA94720 United States Department of Physics and Astronomy University of Hawaii at Manoa HonoluluHI96822 United States Massachusetts Institute of Technology CambridgeMA02139 United States Department of Physics and Astronomy University of Tennessee KnoxvilleTN37996 United States Triangle Universities Nuclear Laboratory DurhamNC27708 United States Physics Departments Duke University DurhamNC27708 United States North Carolina Central University DurhamNC27707 United States The University of North Carolina at Chapel Hill Chapel HillNC27599 United States Center for Neutrino Physics Virginia Polytechnic Institute State University BlacksburgVA24061 United States Center for Experimental Nuclear Physics and Astrophysics University of Washington SeattleWA98195 United States Nikhef The University of Amsterdam Science Park Amsterdam Netherlands Boston University BostonMA02215 United States Halıcıoglu Data Science Institute Department of Physics University of California San Diego La Jolla CA92093 United States Department of Physics and Astronomy University of Delaware NewarkDE19716 United States

We present a search for neutrinoless double-beta (0νββ) decay of 136Xe using the full KamLAND-Zen 800 dataset with 745 kg of enriched xenon, corresponding to an exposure of 2.097 ton yr of 136Xe. This updated search benefits from a more than twofold increase in exposure, recovery of photo-sensor gain, and reduced background from muon-induced spallation of xenon. Combining with the search in the previous KamLAND-Zen phase, we obtain a lower limit for the 0νββ decay half-life of T1/20ν > 3.8 × 1026 yr at 90% C.L., a factor of 1.7 improvement over the previous limit. The corresponding upper limits on the effective Majorana neutrino mass are in the range 28–122 meV using phenomenological nuclear matrix element calculations. © 2024, CC BY.

关键词： Xenon

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Mimicking the motion of metallic interfaces with spacetime switching

Mimicking the motion of metallic interfaces with spacetime s...

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International Congress on Advanced Electromagnetic Materials in Microwaves and Optics (METAMATERIALS)

作者： D. M. Solís S. Yin E. Galiffi A. Alù N. Engheta Departamento de Tecnología de los Computadores y de las Comunicaciones University of Extremadura Cáceres Spain Photonics Initiative Advanced Science Research Center City University of New York New York USA Physics Program Graduate Center City University of New York New York USA Department of Electrical and Systems Engineering University of Pennsylvania Philadelphia PA USA

ISBN: (数字)9798350373493

ISBN: (纸本)9798350373509

Inspired by the need of recognizing novel mechanisms to engineer time and spacetime inhomogeneities, we theoretically explore the possibilities of inducing fast temporal changes in the structural dispersion of a one-dimensional parallel-plate cavity. In this work, we delve into the variation of interplate distance not by actual motion of the cavity’s metallic boundaries, but through the effective subluminal synthetic motion that emerges from a judicious switching operation in the metallic region, parameterized as a lossless spacetime-varying plasma. We theoretically show how, depending on the nature of this time-dispersive switching process, different boundary conditions apply, providing richer physics than true motion.

关键词： Frequency synthesizers Resonant frequency Switches Boundary conditions Nonhomogeneous media Frequency conversion Metamaterials Plasmas Fabry-Perot physics

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Intersubband polaritonic metasurfaces for high-contrast ultra-fast power limiting and optical switching

arXiv

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arXiv 2024年

作者： Cotrufo, Michele Krakofsky, Jonas Mann, Sander Böhm, Gerhard Belkin, Mikhail A. Alù, Andrea Photonics Initiative Advanced Science Research Center City University of New York New YorkNY10031 United States The Institute of Optics University of Rochester RochesterNY14627 United States Walter Schottky Institute Technical University of Munich Garching85748 Germany Physics Program Graduate Center of the City University of New York New YorkNY10016 United States

Nonlinear intersubband polaritonic metasurfaces support one of the strongest known ultrafast nonlinear responses in the mid-infrared frequency range across all condensed matter systems. Beyond harmonic generation and frequency mixing, these nonlinearities can be leveraged for ultrafast optical switching and power limiting, based on tailored transitions from strong to weak polaritonic coupling. Here, we demonstrate synergistic optimization of materials and photonic nanostructures to achieve large reflection contrast in ultrafast polaritonic metasurface limiters. The devices are based on optimized semiconductor heterostructure materials that minimize the intersubband transition linewidth and reduce absorption in optically saturated nanoresonators, achieving a record-high reflection contrast of 54% experimentally. We also discuss opportunities to further boost the metrics of performance of this class of ultrafast limiters, showing that reflection contrast as high as 94% may be realistically achieved using all-dielectric intersubband polaritonic metasurfaces. © 2024, CC BY.

关键词： Optical switches

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Revisiting the Assessment of Magnetic Texture of Magnets: The Role of Coercivity

SSRN

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SSRN 2024年

作者： Quispe, Luis T. Antunes, Leonardo F. Baldárrago-Alcántara, Apuniano A. Macedo, Wagner C. Rosa, Marcelo Augusto Rebelo, Querem H.F. Lopes, Leonardo U. Souza, Sérgio Michielon Wendhausen, Paulo Antônio Pereira Magnetic Materials Laboratory MAGMA Federal University of Santa Catarina Florianopolis88040-900 Brazil Graduate Program in Materials Science and Engineering PGMAT Federal University of Santa Catarina Florianopolis88040-900 Brazil Institute of Engineering and Geosciences Federal University of Western Pará Pará Santarém68035-110 Brazil Department of Materials Physics Federal University of Manaus Manaus69077-000 Brazil

A crucial figure of merit of magnets is their magnetic texture, because it is closely related to the maximum remanence a magnet can achieve, hence assessing the magnetic texture is pivotal in terms of magnet’s performance. Fernengel et al. (1996) developed a methodology based on magnetometry, which allows for a quick determination of the texture by calculating the degree of alignment 〈cosθ〉 from the remanent magnetization in directions parallel and perpendicular to the texture axis of the magnet. Although this method provided reliable values, its application was limited to magnets with high degrees of alignment (〈cosθ〉 > 95%), a restriction that was corrected by Quispe et al. (2020). Nevertheless, recent experiments have indicated that the magnetometry technique can introduce errors in texture assessment when the magnet presents high levels of coercivity. This work presents an approach that incorporates a correction factor into the magnetometry technique, accounting for the effect of the coercivity and circumventing this error source in texture assessment. The proposed methodology has been successfully applied to magnets with varying levels of coercivity. © 2024, The Authors. All rights reserved.

关键词： Coercive force

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Spikes and spines in 4D Lorentzian simplicial quantum gravity

arXiv

引用

arXiv 2024年

作者： Borissova, Johanna Dittrich, Bianca Qu, Dongxue Schiffer, Marc Perimeter Institute 31 Caroline Street North WaterlooONN2L 2Y5 Canada Department of Physics and Astronomy University of Waterloo 200 University Avenue West WaterlooONN2L 3G1 Canada Theoretical Sciences Visiting Program Okinawa Institute of Science and Technology Graduate University Onna904-0495 Japan

Simplicial approaches to quantum gravity such as quantum Regge calculus and spin foams include configurations where bulk edges can become arbitrarily large while the boundary edges are kept small. Spikes and spines are prime examples for such configurations. They pose a significant challenge for a desired continuum limit, for which the average lengths of edges ought to become very small. Here we investigate spike and spine configurations in four-dimensional Lorentzian quantum Regge calculus. We find that the expectation values of arbitrary powers of the bulk length are finite. To that end, we explore new types of asymptotic regimes for the Regge amplitudes, in which some of the edges are much larger than the remaining ones. The amplitudes simplify considerably in such asymptotic regimes and the geometric interpretation of the resulting expressions involves a dimensional reduction, which might have applications to holography. Copyright © 2024, The Authors. All rights reserved.

关键词： Differentiation (calculus)

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Spikes and spines in 3D Lorentzian simplicial quantum gravity

arXiv

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arXiv 2024年

Simplicial approaches to quantum gravity such as Quantum Regge Calculus and Spin Foams include configurations where bulk edges can become arbitrarily large while keeping the lengths of the boundary edges small. Such configurations pose significant challenges in Euclidean Quantum Regge Calculus, as they lead to infinities for the partition function and length expectation values. Here we investigate such configurations in three-dimensional Lorentzian Quantum Regge Calculus, and find that the partition function and length expectation values remain finite. This shows that the Lorentzian approach can avoid a key issue of the Euclidean approach. We also find that the space of configurations, for which bulk edges can become very large, is much richer than in the Euclidean case. In particular, it includes configurations with irregular light-cone structures, which lead to imaginary terms in the Regge action and branch cuts along the Lorentzian path integral contour. Hence, to meaningfully define the Lorentzian Regge path integral, one needs to clarify how such configurations should be handled. Copyright © 2024, The Authors. All rights reserved.

关键词： Differentiation (calculus)

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Anomalous Shiba states in topological iron-based superconductors

arXiv

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arXiv 2022年

作者： Ghazaryan, Areg Kirmani, Ammar Fernandes, Rafael M. Ghaemi, Pouyan Institute of Science and Technology Austria Am Campus 1 Klosterneuberg3400 Austria Physics Department City College of the City University of New York NY10031 United States School of Physics and Astronomy University of Minnesota MinneapolisMN55455 United States Physics Program Graduate Center of City University of New York NY10031 United States

We demonstrate the formation of robust zero energy modes close to magnetic impurities in the iron-based superconductor FeSe1−xTex. We find that the Zeeman field generated by the impurity favors a spin-triplet inter-orbital pairing as opposed to the spin-singlet intra-orbital pairing prevalent in the bulk. The preferred spin-triplet pairing preserves time-reversal symmetry and is topological, as robust, topologically-protected zero modes emerge at the boundary between regions with different pairing states. Moreover, the zero modes form Kramers doublets that are insensitive to the direction of the spin polarization or to the separation between impurities. We argue that our theoretical results are consistent with recent experimental measurements on FeSe1−xTex. © 2022, CC BY.

关键词： Spin polarization

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Radiative hadronization: Photon emission at hadronization from quark-gluon plasma

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Physical Review C 2022年第3期106卷 034906-034906页

作者： Hirotsugu Fujii Kazunori Itakura Katsunori Miyachi Chiho Nonaka Institute of Physics University of Tokyo Komaba Tokyo 153-8902 Japan Nagasaki Institute of Applied Science Nagasaki 851-0193 Japan KEK Theory Center IPNS KEK Tsukuba 305-0801 Japan Department of Physics Nagoya University Nagoya 464-8602 Japan Physics Program Graduate School of Advanced Science and Engineering Hiroshima University Higashi-Hiroshima 739-8526 Japan Kobayashi-Maskawa Institute for the Origin of Particles and the Universe (KMI) Nagoya University Nagoya 464-8602 Japan

We investigate photon emission at the hadronization stage from a quark-gluon plasma created in relativistic heavy-ion collisions. A recombination-model picture suggests that a quark and an antiquark bind into a meson state in hadronization, which would apparently violate the energy conservation if there is nothing else involved. We consider here a hadronization process where the recombination accompanies a photon emission. This is an analog of the “radiative recombination” known in plasma physics, such as e−+p+→H0+γ, which occurs when an electromagnetic plasma goes back to a neutral atomic gas. The “radiative hadronization” picture will bring about (i) an enhancement of the photon yield, (ii) significant flow of photons similar to that of hadrons, and (iii) the photon transverse momentum (pT) distribution with a thermal profile whose effective temperature is given by the blue-shifted temperature of quarks. Here as a simplest and phenomenological realization of the radiative hadronization, we modify the recombination model to involve a photon emission and evaluate the photon yield with this modified model. Adding this contribution to the direct photon yield along with the thermal photon contribution calculated with a hydrodynamic model and a parametrized contribution of prompt photons, we study the pT spectrum and elliptic flow of the photons produced in heavy-ion collisions at energies available at the BNL Relativistic Heavy Ion Collider and CERN Large Hadron Collider.

关键词： Collective flow Hydrodynamic models Photon, lepton & quark production QCD phase transitions Quark-gluon plasma Relativistic heavy-ion collisions

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