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Ultra-high sensitive 2D photonic crystal for gas and chemical sensing applications

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Ultra-high sensitive 2D photonic crystal for gas and chemica...

Optical Sensors 2023

作者： Salama, Norhan A. Swillam, Mohamed A. Hameed, Mohamed Farhat O. Alexeree, Shaimaa M. Obayya, Salah S.A. Laser Applications in Metrology Photochemistry and Agriculture National Institute of Laser Enhanced Sciences Cairo University Giza Egypt Department of Physics The American University in Cairo Cairo11835 Egypt Centre for Photonics and Smart Materials Zewail City of Science Technology and Innovation October Gardens 6th of October City Giza12578 Egypt Nanotechnology and Nanoelectronics Engineering Program Zewail City of Science Technology and Innovation October Gardens 6th of October City Giza12578 Egypt Faculty of Engineering University of Mansoura Mansoura Egypt

ISBN: (数字)9781510662650

ISBN: (纸本)9781510662643

Mid infrared (MID-IR) band of electromagnetic radiation plays the key role for gas and chemical sensing application because it provides molecular fingerprints for most trace gases and molecules. Photonic crystal cavity coupled waveguide (PC-CWG) based sensors is a remarkable platform for sensing applications due to its capability to confine light modes on small volume displaying high sensitivity and high quality factors. In this work, we report a novel design of (PC-CWG) based on square lattice of silicon pillars in air with radius of 0.2μm and lattice constant of 1 μm. A waveguide is introduced by removing three columns of silicon pillars, and a microcavity is created by removing a number of silicon pillars forming curved shapes on both sides of the waveguide. The proposed design demonstrates multiple resonances covering a broad spectral range in MID-IR ranging from 2.4 μm to 4.2 μm that represents the bandgap region. Remarkable resonances are observed at operating wavelengths 2.67 μm, 2.88 μm, 3.03 μm, 3.2 μm and 3.5 μm. Moreover, the reported design shows ultra-high sensitivity reaching 2680 nm/RIU with a significant quality factor of Q=6475 giving rise to a figure-of-merit of 5.7 × 106 at the operating wavelength of (λ=3.03μm). The suggested photonic crystal design offers simple fabrication and broad applicability for refractive index sensing applications. © 2023 SPIE.

关键词： Photonic crystals

engineering the directionality of hot carrier tunneling in plasmonic tunneling structures

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arXiv 2023年

作者： Abbasi, Mahdiyeh Liao, Shusen Zhu, Yunxuan Natelson, Douglas Department of Electrical and Computer Engineering Rice University HoustonTX77005 United States Applied Physics Graduate Program Smalley-Curl Institute Rice University HoustonTX77005 United States Department of Physics and Astronomy Engineering Rice University HoustonTX77005 United States Department of Materials Science and Nanoengineering Rice University HoustonTX77005 United States

Tunneling metal-insulator-metal (MIM) junctions can exhibit an open-circuit photovoltage (OCPV) response under illumination that may be useful for photodetection. One mechanism for photovoltage generation is hot carrier tunneling, in which photoexcited carriers generate a net photocurrent that must be balanced by a drift current in the open-circuit configuration. We present experiments in electromigrated planar MIM structures, designed with asymmetric plasmonic properties using Au and Pt electrodes. Decay of optically excited local plasmonic modes preferentially creates hot carriers on the Au side of the junction, leading to a clear preferred directionality of the hot electron photocurrent and hence a preferred polarity of the resulting OCPV. In contrast, in an ensemble of symmetric devices constructed from only one Au, polarity of the OCPV has no preferred direction. Copyright © 2023, The Authors. All rights reserved.

关键词： Plasmonics

Isolation and identification of natural green and yellow pigments from pineapple pulp and peel

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Materials Today: Proceedings 2022年 63卷 S406-S410页

作者： Hamidin, Nurul Ain Shahanaz Abdullah, Shakila Nor, Farhah Husna Mohd Hadibarata, Tony Department of Technology and Natural Resources Faculty of Applied Sciences and Technology Universiti Tun Hussein Onn Malaysia Pagoh Education Hub 84600 Pagoh Muar Johor Malaysia Department of Physics and Chemistry Faculty of Applied Sciences & Technology Universiti Tun Hussein Onn Malaysia Pagoh Education Hub 84600 Pagoh Muar Johor Malaysia Environmental Engineering Program Curtin University Malaysia CDT250 Miri 98009 Malaysia

The isolation of pineapple pulp and peels can produce natural pigments which contain bioactive compounds that have an antimicrobial effect and benefit human health. Therefore, the aim of this study is to isolate the green and yellow pigments from the pineapple pulp and peels. The isolated pigments were used for phytochemical analysis and antimicrobial activity. These pigments were identified by Fourier transform infrared (FTIR) spectroscopy and Ultraviolet–Visible (UV–Vis). These pigments present phytochemicals have the potential to act as antimicrobial agents. This study would be one of the alternatives in developing food colouring that is beneficial in preserving the quality of food against foodborne pathogens using both isolated pigments. © 2022

关键词： Fourier transform infrared spectroscopy

Atomic excitation delocalization at the clean to disordered interface in a chirally-coupled atomic array

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arXiv 2023年

作者： Wu, C.-C. Lin, K.-T. Handayana, I.G.N.Y. Chien, C.-H. Goswami, S. Lin, G.-D. Chen, Y.-C. Jen, H.-H. Institute of Atomic and Molecular Sciences Academia Sinica Taipei10617 Taiwan Department of Physics Center for Quantum Science and Engineering National Taiwan University Taipei10617 Taiwan Molecular Science and Technology Program Taiwan International Graduate Program Academia Sinica Taiwan Department of Physics National Central University Taoyuan City320317 Taiwan Physics Division National Center for Theoretical Sciences Taipei10617 Taiwan Trapped-Ion Quantum Computing Laboratory Hon Hai Research Institute Taipei11492 Taiwan

In one-dimensional quantum emitter systems, the dynamics of atomic excitations are influenced by the collective coupling between emitters through photon-mediated dipole-dipole interactions. By introducing positional disorders in a portion of the atomic array, we investigate the delocalization phenomena at the interface between disordered zone and clean zone. The excitation is initialized as symmetric Dicke states in the disordered zone, and several measures are used to quantify the excitation localization. We first use population imbalance and half-chain entropy to investigate the excitation dynamics under time evolutions, and further investigate the crossover of excitation localization to delocalization via the gap ratio from the eigenspectrum in the reciprocal coupling case. In particular, we study the participation ratio of the whole chain and the photon loss ratio between both ends of the atomic chain, which can be used to quantify the delocalization crossover in the non-reciprocal coupling cases. Furthermore, by increasing the overall size or the ratio of the disordered zone under a fixed number of the whole chain, we observe that excitation localization occurs at a smaller disorder strength in the former case, while in the latter, a facilitation of the delocalization appears when a significant ratio of clean zone to disordered zone is applied. Our results can reveal the competition between the clean zone and the disordered zone sizes on localization phenomenon, give insights to non-equilibrium dynamics in the emitter-waveguide interface, and provide potential applications in quantum information processing. Copyright © 2023, The Authors. All rights reserved.

关键词： Photons

Embedding quantum optimization problems using AC driven quantum ferromagnets

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arXiv 2023年

作者： Mossi, Gianni Oganesyan, Vadim Kapit, Eliot KBR Inc. 601 Jefferson St. HoustonTX77002 United States NASA Ames Research Center Moffett Field CA94035 United States Department of Physics and Astronomy College of Staten Island CUNY Staten Island NY10314 United States Physics program and Initiative for the Theoretical Sciences The Graduate Center CUNY New YorkNY10016 United States Department of Physics and Quantum Engineering Program Colorado School of Mines GoldenCO80401 United States

Analog quantum optimization methods, such as quantum annealing, are promising and at least partially noise tolerant ways to solve hard optimization and sampling problems with quantum hardware. However, they have thus far failed to demonstrate broadly applicable quantum speedups, and an important contributing factor to this is slowdowns from embedding, the process of mapping logical variables to long chains of physical qubits, enabling arbitrary connectivity on the short-ranged 2d hardware grid. Beyond the spatial overhead in qubit count, embedding can lead to severe time overhead, arising from processes where individual chains "freeze" into ferromagnetic states at different times during evolution, and once frozen the tunneling rate of this single logical variable decays exponentially in chain length. We show that this effect can be substantially mitigated by local AC variation of the qubit parameters as in the RFQA protocol (Kapit and Oganesyan, Quant. Sci. Tech. 6, 025013 (2021)), through a mechanism we call Symphonic Tunneling. We provide general arguments and substantial numerical evidence to show that AC-driven multi-qubit tunneling is dramatically faster than its DC counterpart, and since ST is not a 1d-specific mechanism, this enhancement should extend to clusters of coupled chains as well. And unlike a uniform transverse field, in higher dimensions this method cannot be efficiently simulated classically. We explore schemes to synchronize the AC tones within chains to further improve performance. Implemented at scale, these methods could significantly improve the prospects for achieving quantum scaling advantages in near-term hardware. © 2023, CC BY.

关键词： Embeddings

Quantifying Environmental Radiation: Comparative Analysis of Monitoring Tools in Indonesia's Highest Radiation Area

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SSRN

SSRN 2024年

作者： Abdullah, Adi Rahmansyah Amir Permana, Sidik Srigutomo, Wahyu Maulana, Alan Seno, Haryo Purnama, Dikdik Sidik Rasito Humolungo, Ismail Zulfahmi Doctoral Program in Nuclear Engineering Department Bandung Institute of Technology Jl. Ganesha No. 10 Bandung Indonesia Master Program in Nuclear Science and Engineering Department Bandung Institute of Technology Jl. Ganesha No. 10 Bandung Indonesia Physics Department Bandung Institute of Technology Jl. Ganesha No. 10 Bandung Indonesia Indonesia’s National Research and Inovation Agency Jl. Tamansari No. 71 Bandung Indonesia

We employed three radiation detection devices: NaI(Tl) Scintillator, Geiger Muller Counter (GMC), and Electronic Personal Dosimeter (EPD) in highest natural background radiastion area in Inonesia. Direct measurements conducted with these three devices were validated by measuring radionuclide activities in the soil using HPGe Gamma Spectrometry. Among these three devices, two of them measure ambient dose equivalent (H*(10)), while one measures personal dose equivalent (Hp(10)). The measurement results indicating average H*(10) values of 0.457 µSv/h from NaI(Tl) Scintillator data and 0.769 µSv/h from GMC data, while the average Hp(10) value measured by EPD shows 0.986 µSv/h. The measurement of H*(10) by GMC is 45% higher than that of the NaI(Tl) Scintillator. This difference is also evident from the degenerate 2D map, where GMC data highlights locations of high flux gamma ray anomalies more clearly. This suggests that both devices exhibit different efficiencies under high gamma radiation exposure, with GMC showing better efficiency. However, under conditions of high radiation exposure, phenomena such as saturation may affect the performance of the device. The difference in measurement results does not indicate that one device is superior to the other;the naturally high radiation exposure conditions in the research environment affect the performance of both devices. Meanwhile, in the measurement of Hp(10) by EPD, it was found that the Hp(10) readings are higher than H*(10), which should not happen considering Hp(10) depends on the incident angle of radiation. The EPD detector type allows for the detection of radiation at low energies, but if it is not calibrated at this energy level, it might cause overreading when lower energy radiation, such as X-rays, is detected. Dead time and saturation may occur in environments with high background radiation, causing the detector readings to be less than ideal. © 2024, The Authors. All rights reserved.

关键词： Gamma rays

BPS2025 - Cell-cell communication patterns in growing tissues

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Biophysical Journal 2025年第3期124卷 302a-302a页

作者： Abdul Malmi Kakkada Jonathan Dawson Physics and Biophysics Program Augusta University Augusta GA USA Department of Engineering and Physics Whitworth University Spoken WA USA

Metallization of colloidal crystals

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arXiv 2021年

作者： Ehlen, Ali Lopez-Rios, Hector de la Cruz, Monica Olvera Applied Physics Program Northwestern University Department of Materials Science and Engineering Northwestern University

Colloidal crystals formed by size-asymmetric binary particles co-assemble into a wide variety of colloidal compounds with lattices akin to ionic crystals. Recently, a transition from a compound phase with a sublattice of small particles to a metal-like phase in which the small particles are delocalized has been predicted computationally and observed experimentally. In this colloidal metallic phase, the small particles roam the crystal maintaining the integrity of the lattice of large particles, as electrons do in metals. A similar transition also occurs in superionic crystals, termed sublattice melting. Here, we use energetic principles and a generalized molecular dynamics (MD) model of a binary system of functionalized nanoparticles (NPs) to analyze the transition to sublattice delocalization in different co-assembled crystal phases as a function of temperature (T), number of grafted chains on the small particles, and number ratio between the small and large particles ns:nl. We find that ns:nl is the primary determinant of crystal type due to energetic interactions and interstitial site filling, while the number of grafted chains per small particle determines the stability of these crystals. We observe first-order sublattice delocalization transitions as T increases, in which the host lattice transforms from low- to high-symmetry crystal structures, including A20 → BCT → BCC, Ad → BCT → BCC, and BCC → BCC/FCC → FCC transitions and lattices. Analogous sublattice transitions driven primarily by lattice vibrations have been seen in some atomic materials exhibiting an insulator-metal transition also referred to as metallization. We also find minima in the lattice vibrations and diffusion coefficient of small particles as a function of ns:nl, indicating enhanced stability of certain crystal structures for ns:nl values that form compounds. © 2021, CC BY.

关键词： Molecular dynamics

Cascaded Multiparameter Quantum Metrology

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arXiv 2023年

作者： Krueper, Gregory Cohen, Lior Gopinath, Juliet T. Department of Physics University of Colorado Boulder BoulderCO80309 United States Department of Electrical Computer and Energy Engineering University of Colorado Boulder BoulderCO80309 United States Materials Science and Engineering Program University of Colorado Boulder BoulderCO80309 United States

We present an innovative, platform-independent concept for multiparameter sensing where the measurable parameters are in series, or cascaded, enabling measurements as a function of position. With temporally resolved detection, we show that squeezing can give a quantum enhancement in sensitivity over that of classical states by a factor of e2r, where r ≈ 1 is the squeezing parameter. As an example, we have modeled an interferometer that senses multiple phase shifts along the same path, demonstrating a maximal quantum advantage by combining a coherent state with squeezed vacuum. Further classical modeling with up to 100 phases shows linear scaling potential for adding nodes to the sensor. The approach can be applied to remote sensing, geophysical surveying, and infrastructure monitoring. © 2023, CC BY.

关键词： Interferometers