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Strong nonreciprocal acoustic extinction and asymmetric audibility from spinning fluid scatterers

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Physical Review B 2023年第16期108卷 165129-165129页

作者： Yao-Ting Wang Heedong Goh Sander A. Mann Andrea Alù Photonics Initiative Advanced Science Research Center City University of New York New York New York 10031 USA Department of Photonics National Sun Yat-Sen University Kaohsiung 804201 Taiwan Department of Electrical and Computer Engineering The University of Texas at Austin Austin Texas 78712 USA Physics Program Graduate Center City University of New York New York New York 10026 USA

Lorentz reciprocity places important constraints on the response of systems to wave excitations, and surpassing these constraints is of both fundamental and applied interest. In the context of scattering, reciprocity requires that the total extinction of an object is identical when excited from opposite directions, regardless of the asymmetry of the scatterer. Here, we demonstrate that, by combining multiple scatterers that break time-reversal symmetry, this extinction symmetry can be largely violated. We consider spinning cylinders, demonstrating that nonreciprocity must be paired with broken parity symmetry to enable large extinction contrast. As a dramatic example, we show a system that strongly scatters when excited from one side, but it is cloaked for the opposite excitation. Our results pave the way for approaches to asymmetric audibility and scattering manipulation, and they may readily translate to other wave domains.

关键词： Acoustic metamaterials Acoustics Non-reciprocal propagation

Manipulating Fano coupling in an opto-thermoelectric field

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arXiv 2024年

作者： Lin, Linhan Lepeshov, Sergey Krasnok, Alex Huang, Yu Jiang, Taizhi Peng, Xiaolei Korgel, Brian A. Alu, Andrea Zheng, Yuebing State Key Laboratory of Precision Measurement Technology and Instruments Department of Precision Instrument Tsinghua University Beijing100084 China Department of Electrical and Photonics Engineering DTU Electro Technical University of Denmark Building 343 Kgs. LyngbyDK-2800 Denmark Department of Electrical and Computer Engineering Florida International University MiamiFL33174 United States School of Physics and Electronics Hunan University Changsha410082 China Mc Ketta Department of Chemical Engineering The University of Texas at Austin AustinTX78712 United States Materials Science & Engineering Program Texas Materials Institute The University of Texas at Austin AustinTX78712 United States Department of Electrical and Computer Engineering The University of Texas at Austin AustinTX78712 United States Advanced Science Research Center City University of New York New YorkNY10031 United States Physics Program Graduate Center City University of New York NY10016 United States Walker Department of Mechanical Engineering The University of Texas at Austin AustinTX78712 United States

Fano resonances in photonics arise from the coupling and interference between two resonant modes in structures with broken symmetry. They feature an uneven and narrow and tunable lineshape, and are ideally suited for optical spectroscopy. Many Fano resonance structures have been suggested in nanophotonics over the last ten years, but reconfigurability and tailored design remain challenging. Herein, we propose an all-optical "pick-and-place" approach aimed at assemble Fano metamolecules of various geometries and compositions in a reconfigurable manner. We study their coupling behavior by in-situ dark-field scattering spectroscopy. Driven by a light-directed opto-thermoelectric field, silicon nanoparticles with high quality-factor Mie resonances (discrete states) and low-loss BaTiO3 nanoparticles (continuum states) are assembled into all-dielectric heterodimers, where distinct Fano resonances are observed. The Fano parameter can be adjusted by changing the resonant frequency of the discrete states or the light polarization. We also show tunable coupling strength and multiple Fano resonances by altering the number of continuum states and discrete states in dielectric heterooligomers. Our work offers a general design rule for Fano resonance and an all-optical platform for controlling Fano coupling on demand. Copyright © 2024, The Authors. All rights reserved.

关键词： Light polarization

Free Space Few-Photon Nonlinearity in Critically Coupled Polaritonic Metasurfaces

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arXiv 2025年

作者： Fang, Jie Kala, Abhinav Johnson, Rose Sharp, David Chen, Rui Chang, Cheng Munley, Christopher Frӧech, Johannes E. Varnakavi, Naresh Tang, Andrew Manna, Arnab Tara, Virat Datta, Biswajit Zhou, Zhihao Ginger, David S. Menon, Vinod M. Lin, Lih Y. Majumdar, Arka Department of Electrical and Computer Engineering University of Washington SeattleWA98195 United States Department of Physics University of Washington SeattleWA98195 United States Department of Physics City College of New York New YorkNY10031 United States Department of Chemistry University of Washington SeattleWA98195 United States Physics Program Graduate Center City University of New York New YorkNY10016 United States

Few-photon optical nonlinearity in planar solid-state systems is challenging yet crucial for quantum and classical optical information processing. Polaritonic nonlinear metasurfaces have emerged as a promising candidate to push the photon number down – but have often been hindered by challenges like the poor photon-trapping efficiency and lack of modal overlap. Here, we address these issues in a self-hybridized perovskite metasurface through critical coupling engineering, and report strong polaritonic nonlinear absorption at an ultra-low incident power density of only 519 W/cm2 (2 orders of magnitude lower than the state of art in free-space planar devices), with an estimated photon number of 6.12 per cavity lifetime. Taking advantage of a quasi-bound-state-in-the-continuum design with asymmetry-controlled quality-(Q)-factor, we systematically examine the Q-dependent device nonlinearity and determine the optimal cavity critical coupling condition. With the optimized device, we demonstrate at 6 Kelvin a tunable nonlinear response from reverse saturable absorption to saturable absorption at varying pump powers, with a maximal effective nonlinear absorption coefficient up to 29.4±5.8 cm/W (6 orders of magnitude larger than unpatterned perovskites) at 560 nm wavelength. In addition, the cavity-exciton detuning dependent device response is analyzed and well explained by a phase-space-filling model, elucidating the underlying physics and the origin of giant nonlinearity. Our study paves the way towards practical flat nonlinear optical devices with large functional areas and massive parallel operation capabilities. Copyright © 2025, The Authors. All rights reserved.

关键词： Hybrid systems

Semiconductor quantum well magnetic memory using confinement from proximity exchange fields for high magnetoresistances in a field-effect transistor

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arXiv 2025年

作者： Rogers, William S. Incorvia, Jean Anne C. Graduate Program in Applied Physics Northwestern University EvanstonIL United States Chandra Department of Electrical and Computer Engineering The University of Texas at Austin AustinTX United States

There is a growing demand for highly-performant memories and memristive technologies for use in in-memory computing. Magnetic tunnel junctions (MTJs) have thus far addressed this need in the field of spintronics. Despite their low write power and high speeds, MTJs are limited by their modest on/off ratio at room temperature, which motivates a search for beyond-MTJ spintronic devices. In this work, we propose a device that uses two layers of ferromagnetic insulator (FMI) cladding a semiconductor QW, which is able to modulate the QW bandgap via electronic confinement resulting from proximity magnetization at the interfaces of the quantum well depending on the relative magnetization of the FMI layers. We predict that this device has the potential for very high magnetoresistances (MRs) possibly exceeding 10,000% at room temperature. We also predict that this device will operate with maximal MR in charge neutrality, and that electrostatic gating may promote the device to act as a magnetic memtransistor. This motivates the search for candidate materials and ultimately experimental demonstration of magnetic QW memories or memtransistors, which may have the potential to advance the state of the art in logic, memory, or neuromorphic circuits. © 2025, CC BY.

关键词： Magnetic core storage

Hot Carrier Injection (HCI) Reliability of Fabricated Y-gate HEMT with Various Top Length

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ECS Journal of Solid State Science and Technology 2023年第3期12卷 035001-035001页

作者： Chen, Yu-Lin Yeh, Wen-Kuan Chen, Ke-Horng Hsu, Heng-Tung Hsu, Chin-Tsai Godwin Raj, D. Chou, Hung-Ting Wu, Jui-Sheng Yu, Tien-Han Godfrey, D. Graduate Degree Program of College of Electrical and Computer Engineering National Yang Ming Chiao Tung University Hsinchu Taiwan International College of Semiconductor Technology National Yang Ming Chiao Tung University Hsinchu Taiwan National Applied Research Laboratories Hsinchu Taiwan Dept of ECE Amal Jyothi College of Engineering Kerala India National Chung Shan Institute of Science and Technology Taoyuan Taiwan Deparment of Materials Science and Engineering National Yang Ming Chiao Tung University Hsinchu Taiwan Dept of Electronics and Communication Engineering Dayananda Sagar University Bengaluru India

Device degradation due to hot carrier injection (HCI) in different Y-gate HEMT devices is thoroughly analyzed. To further understand the HCI reliability of the Y-gate HEMT devices, the device is fabricated with AlGaN/GaN structure with different top lengths (Ltop). An HCI stress time of 6000 s was conducted on these devices, while V t stability in other stress time domains, leakage current, and transconductance degradation are also discussed. In this work, we have demonstrated that increasing the LTop length could avoid the virtual gate effect and disperse the influence of the electric field under HCI stress. Furthermore, the effects of trapping in various locations, such as in the bulk SiN or AlGaN/GaN interface has been discussed. These trapping effects caused by the HCI stress might be the source of the Vth shift. Overall, The large Y-gate HEMT showed the lowest degradation of DC characteristics after the long HCI stress test. © 2023 The Electrochemical Society ("ECS"). Published on behalf of ECS by IOP Publishing Limited.

关键词： High electron mobility transistors

Nonsaturated large magnetoresistance and transport dynamics in a n-doped cryogenic WSe2 field-effect device

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Physical Review B 2025年第12期111卷 125307-125307页

作者： Wei-Chen Lin Ching-Chen Yeh Jia-Zhu Zou Nhat Anh Nguyen Phan Inayat Uddin Hai Yen Le Thi Kenji Watanabe Takashi Taniguchi Gil-Ho Kim Department of Engineering and System Science National Tsing Hua University Hsinchu 300 Taiwan Taiwan International Graduate Program Academia Sinica Taipei 115 Taiwan Department of Physics National Taiwan University Taipei 106 Taiwan Department of Electrical and Computer Engineering Sungkyunkwan University (SKKU) Suwon 164 Republic of Korea Sungkyunkwan Advanced Institute of Nano Technology (SAINT) Sungkyunkwan University (SKKU) Suwon 16419 Republic of Korea Research Center for Electronic and Optical Materials National Institute for Materials Science 1-1 Namiki Tsukuba 305-0044 Japan Research Center for Materials Nanoarchitectonics National Institute for Materials Science 1-1 Namiki Tsukuba 305-0044 Japan

Interest in the two-dimensional (2D) semiconducting transition metal dichalcogenides (TMDs) continues to intensify, driven by their suitable band gaps to supplant silicon as next-generation semiconductor materials. Among various TMDs, tungsten diselenide (WSe2) is renowned for its superior electrical properties in carrier density and mobility under ambient conditions. Despite its notable attributes, the behavior of monolayer WSe2 in the electron-doped regime under cryogenic conditions remains largely uncharted, particularly concerning its magnetotransport properties. In this study, we reveal the transport mechanisms of monolayer WSe2 from high temperatures down to the cryogenic regime. As evident by Efros–Shklovskii variable-range hopping (E-S VRH) in the cryogenic regime, strong Coulomb interactions arise between electrons. Above 8 K, an uncommon nonsaturated quadratic large magnetoresistance (MR) can be explained by the wave-function shrinkage model, which is consistent with the E-S VRH transport mechanism. Notably, the nonsaturated quadratic large MR shows a magnitude up to 1740% at 13 T. These findings underscore the potential applications for monolayer WSe2 in cryogenic field-effect devices, magnetic sensors, and memory devices and mark a significant advance in magnetotransport research.

关键词： Monolayers

Towards Robust and Scalable Dispatch Modeling of Long-Duration Energy Storage

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arXiv 2024年

作者： Guerra, Omar J. Dalvi, Sourabh Thatte, Amogh A. Cowiestoll, Brady Jorgenson, Jennie Hodge, Bri-Mathias National Renewable Energy Laboratory 15013 Denver West Parkway GoldenCO80401 United States Colorado School of Mines Advanced Energy Systems Graduate Program 1500 Illinois Street GoldenCO80401 United States Renewable and Sustainable Energy Institute University of Colorado BoulderCO80309 United States Department of Electrical Computer & Energy Engineering University of Colorado BoulderCO80309 United States

Energy storage technologies, including short-duration, long-duration, and seasonal storage, are seen as technologies that can facilitate the integration of larger shares of variable renewable energy, such as wind and solar photovoltaics, in power systems. However, despite recent advances in the techno-economic modeling of energy storage (particularly for short-duration applications), the operation and economics of long-duration energy storage are still incomplete in power systems modeling platforms. For instance, existing modeling approaches for long-duration storage are often based either on an oversimplified representation of power system operations or limited representation of storage technologies, e.g., evaluation of only a single application. This manuscript presents an overview of the challenges of modeling long-duration energy storage technologies, as well as a discussion regarding the capabilities and limitations of existing approaches. We used two test power systems with high shares of both solar photovoltaics- and wind (70% - 90% annual variable renewable energy shares) to assess long-duration energy storage dispatch approaches. Our results estimate that better dispatch modeling of long-duration energy storage could increase the associated operational value by 4% - 14% and increase the standard capacity credit by 14% - 34%. Thus, a better long-duration energy storage dispatch could represent significant cost saving opportunities for electric utilities and system operators. In addition, existing long-duration dispatch modeling approaches were tested in terms of both improved system value (e.g., based on production cost and standard capacity credit) and scalability (e.g., based on central processing unit time and peak memory usage). Both copper plate and nodal representations of the power system were considered. Although the end volume target dispatch approach, i.e., based on mid-term scheduling, showed promising performance in terms of both improved system

关键词： Scalability

Nanoslot-Induced Ultrastrong Phonon-Photon and Phonon-Phonon Coupling in Hybrid Organic-Inorganic Perovskites 16

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Nanoslot-Induced Ultrastrong Phonon-Photon and Phonon-Phonon...

16th Pacific Rim Conference on Lasers and Electro-Optics, CLEO-PR 2024

作者： Kim, Dasom Hou, Jin Lee, Geon Agrawal, Ayush Kim, Sunghwan Zhang, Hao Bao, Di Baydin, Andrey Wu, Wenjing Tay, Fuyang Huang, Shengxi Hagenmüller, Daivd Chia, Elbert E. M. Kim, Dai-Sik Seo, Minah Mohite, Aditya D. Kono, Junichiro Applied Physics Graduate Program Smalley-Curl Institute Rice University HoustonTX77005 United States Department of Electrical and Computer Engineering Rice University HoustonTX77005 United States Department of Materials Science and NanoEngineering Rice University HoustonTX77005 United States Sensor System Research Center Korea Institute of Science and Technology Seoul02792 Korea Republic of Department of Physics and Astronomy Seoul National University Seoul08826 Korea Republic of Department of Chemical and Biomolecular Engineering Rice University HoustonTX77005 United States Ulsan44919 Korea Republic of Division of Physics and Applied Physics School of Physical and Mathematical Sciences Nanyang Technological University 637371 Singapore Smalley-Curl Institute Rice University HoustonTX77005 United States Université de Strasbourg Cnrs Strasbourg67000 France KU-KIST Graduate School of Converging Science and Technology Korea University Seoul02841 Korea Republic of Department of Physics and Astronomy Rice University HoustonTX77005 United States

Methods for harnessing vibrational states are desired for phonon-based technologies. We realized ultrastrong coupling of two phonon modes in perovskite materials induced by ultrastrong coupling with a common photonic ... 详细信息

ISBN: (纸本)9798350372076

关键词： Organic-inorganic materials

Recurrence plots and convolutional neural networks applied to nonintrusive load monitoring

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Recurrence plots and convolutional neural networks applied t...

2020 IEEE Power and Energy Society General Meeting, PESGM 2020

作者： Cavalca, Diego L. Fernandes, Ricardo A. S. Federal University of São Carlos Graduate Program in Computer Science São Carlos Brazil Federal University of São Carlos Electrical Engineering Department São Carlos Brazil

ISBN: (纸本)9781728155081

The need to increasingly promote the efficient use of electricity for residential consumers motivated some researches to obtain solutions that allow the identification of loads for use in demand response programs and in the energy consumption disaggregation. Recently, the use of Convolutional Neural Networks for load identification has been common. However, it is necessary to transform the temporal signal into an image. In this sense, the present paper proposes a novel feature engineering stage, based on Recurrence Plots, to obtain the images for Nonintrusive Load Monitoring. In order to prove its effectiveness, the Recurrence Plots were compared to the Gramian Angular Difference Fields, which had already been applied in this context. For this purpose, it was used the REDD dataset, in which only the low frequency data measured in the main distribution panel were considered. Individual load measurements were only used for the labelling of the 90-seconds windows. The Convolutional Neural Network was trained and validated, considering two different strategies (multi-label and binary models), obtaining an F1-score of 66.05% and 72.65%, respectively. © 2020 IEEE.

关键词： Machine learning