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Reversible Actuation of α-Borophene Nanoscrolls

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arXiv 2023年

作者： Fabris, Guilherme S.L. Galvão, D.S. Paupitz, Ricardo Postgraduate Program in Materials Science and Engineering Federal University of Pelotas RS Pelotas96010-610 Brazil Applied Physics Department State University of Campinas SP Campinas13083-970 Brazil Sao Paulo State University - Unesp Physics Department SP Rio ClaroCEP-13506-900 Brazil

In this work, we proposed and investigated the structural and electronic properties of boron-based nanoscrolls (armchair and zigzag) using the DFTB+ method. We also investigated the electroactuation process (injecting and removing charges). A giant electroactuation was observed, but the results show relevant differences between the borophene and carbon nanoscrolls. The molecular dynamics simulations showed that the scrolls are thermally and structurally stable for a large range of temperatures (up to 600K) and the electroactuation process can be easily tuned and can be entirely reversible for some configurations. © 2023, CC BY.

关键词： Molecular dynamics

Spin scattering and Hall effects in monolayer Fe3GeTe2

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arXiv 2023年

作者： Yu, Luyan Yu, Jie-Xiang Zang, Jiadong Lake, Roger K. Zhuang, Houlong Yin, Gen Department of Physics University of Texas at Austin AustinTX78712 United States Department of Physics University of Florida GainesvilleFL32611 United States Department of Physics and Materials Science Program University of New Hampshire DurhamNH03824 United States Department of Electrical and Computer Engineering University of California-Riverside RiversideCA92521 United States Mechanical and Aerospace Engineering Arizona State University TempeAZ85287 United States Department of Physics Georgetown University WashingtonDC20057 United States

We theoretically show that the carrier transport in monolayer Fe3GeTe2 experiences a transition between anomalous Hall effect and spin Hall effect when the spin polarization of disorders switches between out-of-plane and in-plane. These Hall effects are allowed when the magnetization is polarized in-plane, breaking the C3 rotation symmetry. The transition originates from the selection rule of spin scattering, the strong spin-orbit coupling, and the van Hove singularities near the Fermi surface. The scattering selection rule tolerates the sign change of the disorder spin, which provides a convenient method to detect the switching of antiferromagnetic insulators regardless of the interfacial roughness in a heterostructure. This provides a convenient platform for the study of 2D spintronics through various van-der-Waals heterostructures. Copyright © 2023, The Authors. All rights reserved.

关键词： Monolayers

Controlling and measuring a superposition of position and momentum

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Physical Review A 2023年第1期108卷 012215-012215页

作者： Takafumi Ono Nigam Samantarray John G. Rarity Quantum Engineering Technology Laboratories H. H. Wills Physics Laboratory and Department of Electrical & Electronic Engineering University of Bristol Bristol BS8 1FD United Kingdom Program in Advanced Materials Science Faculty of Engineering and Design Kagawa University 2217-20 Hayashi-cho Takamatsu Kagawa 761-0396 Japan JST PRESTO 4-1-8 Honcho Kawaguchi Saitama 332-0012 Japan Department of Physics University of Strathclyde John Anderson Building 107 Rottenrow Glasgow G4 0NG United Kingdom

We present an observation of quantum interference between position and momentum with photons. We prepared a superposition of position and momentum states by using slits, lenses, and an interferometer. The precise control and measuring of propagation time of the photon results in a clear quantum interference of 85% visibility. The generated quantum state is then used to verify the violation of particle propagation inequality proposed by Hofmann [Phys. Rev. A 96, 020101(R) (2017)], resulting in 5.9% below the statistically predicted lower bound. We believe that this result is a major step towards further developments in quantum theory, such as fundamental modifications to the interpretation of quantum mechanics.

关键词： Quantum control Quantum information theory Quantum measurements Quantum metrology

Growth of Wafer-Scale Single-Crystal 2D Semiconducting Transition Metal Dichalcogenide Monolayers

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Advanced Science 2024年第11期11卷 e2307839页

作者： Singh, Jitendra Astarini, Nadiya Ayu Tsai, Meng-Lin Venkatesan, Manikandan Kuo, Chi-Ching Yang, Chan-Shan Yen, Hung-Wei Department of Materials Science and Engineering National Taiwan University of Science and Technology Taipei City106335 Taiwan Department of Physics Udit Narayan Post Graduate College Padrauna Uttar Pradesh Kushinagar274304 India Department of Molecular Science and Engineering Institute of Organic and Polymeric Materials National Taipei University of Technology Taipei City106344 Taiwan Institute and Undergraduate Program of Electro-Optical Engineering National Taiwan Normal University Taipei City11677 Taiwan Department of Materials Science and Engineering National Taiwan University Taipei City106319 Taiwan

Due to extraordinary electronic and optoelectronic properties, large-scale single-crystal two-dimensional (2D) semiconducting transition metal dichalcogenide (TMD) monolayers have gained significant interest in the development of profit-making cutting-edge nano and atomic-scale devices. To explore the remarkable properties of single-crystal 2D monolayers, many strategies are proposed to achieve ultra-thin functional devices. Despite substantial attempts, the controllable growth of high-quality single-crystal 2D monolayer still needs to be improved. The quality of the 2D monolayer strongly depends on the underlying substrates primarily responsible for the formation of grain boundaries during the growth process. To restrain the grain boundaries, the epitaxial growth process plays a crucial role and becomes ideal if an appropriate single crystal substrate is selected. Therefore, this perspective focuses on the latest advances in the growth of large-scale single-crystal 2D TMD monolayers in the light of enhancing their industrial applicability. In the end, recent progress and challenges of 2D TMD materials for various potential applications are highlighted. © 2023 The Authors. Advanced Science published by Wiley-VCH GmbH.

关键词： Single crystals

Chiral metal-organic framework based spin-polarized flexible photodetector with ultrahigh sensitivity

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Materials Today Nano 2023年 21卷

作者： Mustaqeem, M. Kamal, S. Ahmad, N. Chou, P.-T. Lin, K.-H. Huang, Y.-C. Guo, G.-Y. Paul Inbaraj, C.R. Li, W.-K. Yao, H.-C. Lu, K.-L. Chen, Y.-F. Department of Chemistry National Taiwan University No. 1 Section 4 Roosevelt Rd Taipei10617 Department of Physics National Taiwan University No. 1 Section 4 Roosevelt Rd Taipei10617 Nano-Science and Technology Program Taiwan International Graduate Program Institute of Physics Academia Sinica Taipei106 Taiwan Institute of Chemistry Academia Sinica Taipei115 Taiwan Department of Materials Science and Engineering National Taiwan University of Science and Technology Taipei10607 Taiwan Institute of Physics Academia Sinica Taipei11529 Taiwan Department of Materials Engineering Ming Chi University of Technology

Spin-optoelectronics plays a key role in developing next-generation technologies with potential applications covering from pharmaceutical synthesis and quantum computing to optical communication. One of the most feasible ways to achieve high-performance spin optoelectronic devices is based on chiral materials. Chiral metal-organic frameworks (CMOFs), an emerging class of chiral hybrid materials, have sparked interest due to their structural variety and flexibility, order nanopores, cost-effectiveness, and unique chirality features. Herein, we have developed CMOF [Sr (9,10-adc) (DMAc)2]n based on achiral building blocks [(9,10-adc)] to detect circularly polarized light (CPL) with ultrahigh sensitivity. Their application in spin-polarized flexible detectors gives a detectivity (D∗) as high as 1.83 × 1012 jones, superior to all reported heterochiral MOF-based detectors. Meanwhile, the anisotropy factor (gIph) is up to 0.38 for CPL detection. The maximum photoresponsivity (Rph) and photogain (η) values of CMOFs reach up to 6.0 × 105 (A/W) and 1.8 × 106, respectively, which are also the record values among reported chiral MOFs. Additionally, the photodetector is mechanically flexible and durable, manifesting an important feature for wearable devices. Therefore, our study shown here is significant and timely to open a route for advancing spin-optoelectronics based on CMOF. © 2023 Elsevier Ltd

关键词： Photodetectors

AI Aided GPR Data Multipath Summation Using x-t Stacking Weights

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AI Aided GPR Data Multipath Summation Using x-t Stacking Wei...

International Conference on Telecommunications and Signal Processing (TSP)

作者： Economou Nikos Nasir Sobhi Al Abri Said Bader Al Shaqsi Hamdan Hamdan Applied Geophysics Lab School of Mineral Resources Engineering Technical University of Crete Chania Greece Department of Earth Sciences Sultan Qaboos University College of Science Muscat Oman Department of Applied Physics and Astronomy Petroleum Geosciences and Remote Sensing Program Sharjah University UAE

ISBN: (数字)9798350365597

ISBN: (纸本)9798350365603

Migration velocity of Ground Penetrating Radar (GPR) data is a low wavenumber attribute crucial for migration. Obtaining a migration velocity model, which is considered closer to a Root Mean Square (RMS) model, from zero-offset (ZO) data requires analysis of the available diffractions whose density and (x, t) coverage is random. Thus, accuracy and efficiency of such a velocity model either for migration or its usage for interval velocity model estimation is not guaranteed. Here, with the aid of an Artificiaal Intelligence (AI) algorithm, which detects diffractions and usage of their kinematic information, we generate a diffraction velocity model used for the assignment of 2D weights for weighted multipath summation. The scope is to efficiently focus the scattered energy within a GPR section. We describe this methodology and demonstrate its application in enhancing the lateral continuity of reflections. We compare it with the multipath summation using lD weights with simulated data and present its application on marble assessment GPR data for imaging cracks in the subsurface structure.

关键词： Analytical models Diffraction Stacking Estimation Kinematics Data models Reflection

A ghost mechanism: An analytical model of abrupt learning

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arXiv 2025年

作者： Dinc, Fatih Cirakman, Ege Jiang, Yiqi Yuksekgonul, Mert Schnitzer, Mark Tanaka, Hidenori CNC Program Stanford University StanfordCA94305 United States Physics & Informatics Laboratories NTT Research Inc. SunnyvaleCA94085 United States Stanford University StanfordCA94305 United States James H. Clark Center for Biomedical Engineering & Sciences Stanford University Stanford United States Howard Hughes Medical Institute Stanford University StanfordCA94305 United States CBS-NTT Program in Physics of Intelligence Harvard University CambridgeMA94305 United States

Abrupt learning is commonly observed in neural networks, where long plateaus in network performance are followed by rapid convergence to a desirable solution. Yet, despite its common occurrence, the complex interplay of task, network architecture, and learning rule has made it difficult to understand the underlying mechanisms. Here, we introduce a minimal dynamical system trained on a delayed-activation task and demonstrate analytically how even a one-dimensional system can exhibit abrupt learning through ghost points rather than bifurcations. Through our toy model, we show that the emergence of a ghost point destabilizes learning dynamics. We identify a critical learning rate that prevents learning through two distinct loss landscape features: a no-learning zone and an oscillatory minimum. Testing these predictions in recurrent neural networks (RNNs), we confirm that ghost points precede abrupt learning and accompany the destabilization of learning. We demonstrate two complementary remedies: lowering the model output confidence prevents the network from getting stuck in no-learning zones, while increasing trainable ranks beyond task requirements (i.e., adding sloppy parameters) provides more stable learning trajectories. Our model reveals a bifurcation-free mechanism for abrupt learning and illustrates the importance of both deliberate uncertainty and redundancy in stabilizing learning dynamics. © 2025, CC BY.

关键词： Recurrent neural networks

Generating Synthetic Values on Automatic Weather Station Dataset using GAIN 8

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Generating Synthetic Values on Automatic Weather Station Dat...

8th International Conference on Instrumentation, Control, and Automation, ICA 2023

作者： Santoso, Bayu Ryan, Muhammad Mukhlish, Faqihza Kurniadi, Deddy Institut Teknologi Bandung Master Program in Instrumentation and Control Bandung Indonesia Badan Meteorologi Klimatologi Department of Instrumentation and Calibration Dan Geofisika Medan Indonesia Badan Meteorologi Klimatologi Dan Geofisika Center of Aviation Meteorology Jakarta Indonesia Faculty of Industrial Technology Institut Teknologi Bandung Engineering Physics Research Group Bandung Indonesia Faculty of Industrial Technology Institut Teknologi Bandung Instrumentation and Control Research Group Bandung Indonesia

ISBN: (纸本)9798350301274

The Automatic Weather Station (AWS) is an automated instrument designed to gather meteorological parameters within a given environment. The dataset obtained from AWS often contains missing values due to various factors such as sensor malfunction or transmission issues. Nonetheless, the data produced by AWS plays a vital role in weather analysis and prediction. In this study, the authors employ the Generative Adversarial Imputation Network algorithm to generate synthetic values for the missing data in the AWS dataset. The dataset is divided into four schemes, each exhibiting different distributions of missing values at 5, 25, 50, and 80 gaps, respectively. The synthetic values generated by the algorithm are subsequently compared to the ground truth values using the Root Mean Square Error (RMSE) and Mean Absolute Error (MAE) metrics. The findings demonstrate that for the air pressure parameter, both the 5 gaps and 25 gaps models exhibit RMSE and MAE values below 2 hPa. Similarly, the models for the air temperature parameter demonstrate RMSE and MAE values below 2°C. As for the relative humidity parameter, the models achieve RMSE and MAE values below 15%. Therefore, both the 5 gaps and 25 gaps models satisfy the error threshold established by the Badan Meteorologi Klimatologi, dan Geofisika for AWS data quality control. © 2023 IEEE.

关键词： Quality control

Medium-entropy engineering of magnetism in layered antiferromagnet CuxNi2(1-x)CrxP2S6

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arXiv 2024年

作者： Upreti, Dinesh Basnet, Rabindra Sharma, M.M. Chhetri, Santosh Karki Acharya, Gokul Nabi, Md Rafique Un Sakon, Josh Mortazavi, Mansour Hu, Jin Department of Physics University of Arkansas FayettevilleAR72701 United States Department of Chemistry & Physics University of Arkansas at Pine Bluff Pine BluffAR71603 United States MonArk NSF Quantum Foundry University of Arkansas FayettevilleAR72701 United States Department of Chemistry & Biochemistry University of Arkansas FayettevilleAR72701 United States Materials Science and Engineering Program Institute for Nanoscience and Engineering University of Arkansas FayettevilleAR72701 United States

engineering magnetism in layered magnets could result in novel phenomena related to two-dimensional (2D) magnetism, which can be useful for fundamental research and practical applications. Extensive doping efforts such as substitution and intercalation have been adopted to tune antiferromagnetic (AFM) properties in M2P2X6 compounds. The substitutional doping in this material family has mainly focused on bimetallic substitution. Recently, the metal substitution can also be extended to more than two metal elements, leading to medium and high-entropy alloys (MEAs and HEAs), which are fairly underexplored in layered magnetic systems including M2P2X6. In this work, we explored the magnetic properties of the previously unreported Cu- and Cr-substituted Ni2P2S6 i.e., CuxNi2(1-x)CrxP2S6. Our study reveals a relatively systematic evolution of AFM phases with substitution than that observed in traditional bimetallic substitution in M2P2X6. Furthermore, the Cu and Cr substitutions in Ni2P2S6 are found to enhance the ferromagnetic (FM) correlation, which is also accompanied by a possible weak FM phase at low temperatures for the intermediate compositions 0.32≤x≤0.80. Our work provides a strategy to establish ferromagnetism in AFM M2P2X6 that can also be used for property tuning in other layered magnets. © 2024, CC BY-NC-SA.

关键词： Ferromagnetism