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Glassy Behavior and Anomalous Transport in Chimney Ladder Crystals Induced by Soft Optical Phonons

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arXiv 2025年

作者： Mandyam, Srinivas V. Dong, Weicen Yan, Xiaoxian Zhao, Binru Lin, Junfa Xia, Tianlong Zhao, Zhiying Chen, Xi Ma, Jie Xing, Hui Grosche, F. Malte Baggioli, Matteo Department of Physics Harvard University CambridgeMA02135 United States Wilczek Quantum Center School of Physics and Astronomy Shanghai Jiao Tong University Shanghai200240 China Shanghai Research Center for Quantum Sciences Shanghai201315 China Key Laboratory of Artificial Structures and Quantum Control School of Physics and Astronomy Shanghai Jiao Tong University Shanghai200240 China Shanghai Center for Complex Physics School of Physics and Astronomy Shanghai Jiao Tong University Shanghai China School of Physics Beijing Key Laboratory of Opto-electronic Functional Materials & Micro-nano Devices Renmin University of China Beijing100872 China Renmin University of China Beijing100872 China Laboratory for Neutron Scattering Renmin University of China Beijing100872 China State Key Laboratory of Structural Chemistry Fujian Institute of Research The Structure of Matter Chinese Academy of Sciences Fujian Fuzhou350002 China Department of Electrical and Computer Engineering University of California RiversideCA92521 United States Collaborative Innovation Center of Advanced Microstructures Jiangsu Nanjing210093 China Cavendish Laboratory University of Cambridge JJ Thomson Avenue CambridgeCB30HE United Kingdom

Nowotny chimney ladder (NCL) crystals present physical properties in between the contrasting paradigms of ideal crystal and amorphous solid, making them promising candidates for thermoelectric applications due to their inherently low thermal conductivity. Here, we report an extensive experimental characterization of the thermodynamic and thermoelectric transport properties of a large class of NCL materials, focusing on the intermetallic compound Ru2Sn3−δ. We show that the heat capacity of these NCL compounds exhibits a boson-peak-like glassy anomaly between 8 K and 14 K. By combining experimental measurements with density functional theory (DFT), we attribute its microscopic origin to extremely soft optical phonons that universally appear as a consequence of the chimney ladder sublattice structure. Additionally, the measured thermal conductivity and the thermoelectric response present distinct anomalous glass-like features that strongly correlate with the dynamics of the abundant soft optical phonons revealed by DFT. Our work demonstrates that soft modes in ordered crystals can induce glassy behavior, outlining a pathway to design metallic materials with low thermal conductivity and unique thermoelectric properties without the need for disorder or strong electronic correlations. © 2025, CC BY.

关键词： Glass

Guided Crowd Evacuation:Approaches and Challenges

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IEEE/CAA Journal of Automatica Sinica 2019年第5期6卷 1081-1094页

作者： Min Zhou Hairong Dong Petros A.Ioannou Yanbo Zhao Fei-Yue Wang the State Key Laboratory of Rail Traffic Control and Safety Beijing Jiaotong UniversityBeijing 100044China the Department of Electrical Engineering University of Southern CaliforniaLos AngelesCA 90089-2560 USA the Center for Advanced Transportation Technologies University of Southern CaliforniaLos AngelesCA 90089 USA the State Key Laboratory of Management and Control for Complex Systems Institute of AutomationChinese Academy of SciencesBeijing 100190 the Research Center of Computational Experiments and Parallel Systems the National University of Defense TechnologyChangsha 410073China

Evacuation leaders and/or equipment provide route and exit information for people and guide them to the expected destinations, which could make crowd evacuation more efficient in case of emergency. The purpose of this paper is to provide an overview of recent advances in guided crowd evacuation. Different guided crowd evacuation approaches are classified according to guidance approaches and technologies. A comprehensive analysis and comparison of crowd evacuation with static signage, dynamic signage, trained leader, mobile devices, mobile robot and wireless sensor networks are presented based on a single guidance mode perspective. In addition, the different evacuation guidance systems that use high-tech means such as advanced intelligent monitoring techniques, AI techniques, computer technology and intelligent inducing algorithms are reviewed from a system’s perspective. Future researches in the area of crowd evacuation are also discussed.

关键词： Auxiliary equipment evacuation guidance system (EGS) guided crowd evacuation leader signage

Wide-angle giant photonic spin Hall effect

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Physical Review B 2022年第7期106卷 075409-075409页

作者： Zhihao Chen Yu Chen Yaodong Wu Xinxing Zhou Handong Sun Tony Low Hongsheng Chen Xiao Lin Key Laboratory of Low-Dimensional Quantum Structures and Quantum Control of Ministry of Education Synergetic Innovation Center for Quantum Effects and Applications School of Physics and Electronics Hunan Normal University Changsha 410081 China International Collaborative Laboratory of 2D Materials for Optoelectronics Science and Technology Engineering Technology Research Center for 2D Material Information Function Devices and Systems of Guangdong Province Institute of Microscale Optoelectronics Shenzhen University Shenzhen 518060 China Division of Physics and Applied Physics School of Physical and Mathematical Sciences Nanyang Technological University Singapore 637371 Singapore Centre for Disruptive Photonic Technologies (CDPT) School of Physical and Mathematical Sciences Nanyang Technological University Singapore 637371 Singapore Department of Electrical and Computer Engineering University of Minnesota Minneapolis Minnesota 55455 USA Interdisciplinary Center for Quantum Information State Key Laboratory of Modern Optical Instrumentation ZJU-Hangzhou Global Scientific and Technological Innovation Center College of Information Science and Electronic Engineering Zhejiang University Hangzhou 310027 China International Joint Innovation Center ZJU-UIUC Institute The Electromagnetics Academy at Zhejiang University Zhejiang University Haining 314400 China

The photonic spin Hall effect is a manifestation of the spin-orbit interaction of light and can be measured by a transverse shift δ of photons with opposite spins. The precise measurement of transverse shifts can enable many spin-related applications, such as precise metrology and optical sensing. However, this transverse shift is generally small (i.e., δ/λ<10−1, where λ is the wavelength), which impedes its precise measurement. To date, proposals to generate a giant spin Hall effect (namely, with δ/λ>102) have severe limitations, particularly its occurrence only over a narrow angular cone (with a width of Δθ<1∘). Here we propose a universal scheme to realize the wide-angle giant photonic spin Hall effect with Δθ>70∘ by exploiting the interface between free space and uniaxial epsilon-near-zero media. The underlying mechanism is ascribed to the almost-perfect polarization splitting between s and p polarized waves at the designed interface. Remarkably, this almost-perfect polarization splitting does not resort to the interference effect and is insensitive to the incident angle, which then gives rise to the wide-angle giant photonic spin Hall effect.

关键词： Light-matter interaction Photonics Spin Hall effect Spin-orbit coupling

On PID control for synchronization of complex dynamical network with delayed nodes

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Science China(Technological Sciences) 2019年第8期62卷 1412-1422页

作者： GU HaiBo Lv JinHu LIN ZongLi Key Laboratory of Systems and Control Academy of Mathematics and Systems Science Chinese Academy of Sciences Beijing 100190 China School of Mathematical Sciences University of Chinese Academy of Sciences Beijing 100049 China School of Automation Science and Electrical Engineering State Key Laboratory of Software Development Environment and Beijing Advanced Innovation Center for Big Data and Brain Machine Intelligence Beihang University Beijing 100083 China Charles L. Brown Department of Electrical and Computer Engineering University of Virginia Charlottesville VA 22904-4743 USA

Over the past two decades, synchronization, as an interesting collective behavior of complex dynamical networks, has been attracting much attention. To reveal and analyze the inherent mechanism of synchronization in complex dynamical networks with time delays in nodes, this paper attempts to use PD and PI control protocols to achieve synchronization. Based on a classical network model, we investigate the PD and PI control for synchronization of complex dynamical networks with delayed nodes and obtain some sufficient conditions. By using Lyapunov functions and appropriate state transformations, we prove that global synchronization can be achieved via the above control protocols. Finally, some simulation examples are illustrated to validate the effectiveness of the proposed theoretical results.

关键词： synchronization PID control complex dynamical network networked control system delayed node

controlling a Networked SIS Model via a Single Input over Undirected Graphs ⁎

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IFAC-PapersOnLine 2020年第2期53卷 10981-10986页

作者： Dan Wang Ji Liu Philip E. Paré Wei Chen Li Qiu Carolyn L. Beck Tamer Başar Department of Electronic & Computer Engineering The Hong Kong University of Science and Technology Clear Water Bay Kowloon Hong Kong China Department of Electrical and Computer Engineering Stony Brook University NY 11794 USA Division of Decision and Control Systems KTH Royal Institute of Technology Stockholm Sweden Department of Mechanics and Engineering Science & Beijing Innovation Center for Engineering Science and Advanced Technology Peking University Beijing China Coordinated Science Laboratory University of Illinois at Urbana-Champaign IL 61801 USA

This paper formulates and studies the problem of controlling a networked SIS model using a single input in which the network structure is described by a connected undirected graph. A necessary and sufficient condition on the values of curing and infection rates for the healthy state to be exponentially stable is obtained via the analysis of signed Laplacians when the control input is the curing budget of a single agent. In the case when the healthy state is stabilizable, an explicit expression for the minimum curing budget is provided. The utility of the algorithm is demonstrated using a simulation over a network of cities in the northeastern United States.

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Low-velocity-favored transition radiation

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arXiv 2022年

作者： Chen, Jialin Chen, Ruoxi Gong, Zheng Hu, Hao Yang, Yi Zhang, Xinyan Wang, Chan Kaminer, Ido Chen, Hongsheng Zhang, Baile Lin, Xiao Interdisciplinary Center for Quantum Information State Key Laboratory of Extreme Photonics and Instrumentation ZJUHangzhou Global Scientific and Technological Innovation Center College of Information Science & Electronic Engineering Zhejiang University Hangzhou310027 China International Joint Innovation Center The Electromagnetics Academy Zhejiang University Zhejiang University Haining314400 China Department of Electrical and Computer Engineering Technion-Israel Institute of Technology Haifa32000 Israel School of Electrical and Electronic Engineering Nanyang Technological University Singapore639798 Singapore Department of Physics University of Hong Kong 999077 Hong Kong Key Lab of Advanced Micro/Nano Electronic Devices & Smart Systems of Zhejiang Jinhua Institute of Zhejiang University Zhejiang University Jinhua321099 China Shaoxing Institute of Zhejiang University Zhejiang University Shaoxing312000 China Division of Physics and Applied Physics School of Physical and Mathematical Sciences Nanyang Technological University Singapore637371 Singapore Centre for Disruptive Photonic Technologies Nanyang Technological University Singapore637371 Singapore

When a charged particle penetrates through an optical interface, photon emissions emerge — a phenomenon known as transition radiation. Being paramount to fundamental physics, transition radiation has enabled many applications from high-energy particle identification to novel light sources. A rule of thumb in transition radiation is that the radiation intensity generally decreases with the particle velocity v;as a result, low-energy particles are not favored in practice. Here we find that there exist situations where transition radiation from particles with extremely low velocities (e.g. v/c −3) exhibits comparable intensity as that from high-energy particles (e.g. v/c = 0. 999), where c is light speed in free space. The comparable radiation intensity implies an extremely high photon extraction efficiency from low-energy particles, up to eight orders of magnitude larger than that from high-energy particles. This exotic phenomenon of low-velocity-favored transition radiation originates from the excitation of Ferrell-Berreman modes in epsilon-near-zero materials. Our findings may provide a promising route towards the design of integrated light sources based on low-energy electrons and specialized detectors for beyond-standard-model particles. © 2022, CC BY.

关键词： Light sources

High-quality Thermal Gibbs Sampling with Quantum Annealing Hardware

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arXiv 2021年

作者： Nelson, Jon Vuffray, Marc Lokhov, Andrey Y. Albash, Tameem Coffrin, Carleton Center for Non Linear Studies Los Alamos National Laboratory Los AlamosNM United States Advanced Network Science Initiative Los Alamos National Laboratory Los AlamosNM United States Theoretical Division Los Alamos National Laboratory Los AlamosNM United States Department of Electrical and Computer Engineering University of New Mexico AlbuquerqueNM United States Department of Physics and Astronomy Center for Quantum Information and Control University of New Mexico AlbuquerqueNM United States

Quantum Annealing (QA) was originally intended for accelerating the solution of combinatorial optimization tasks that have natural encodings as Ising models. However, recent experiments on QA hardware platforms have demonstrated that, in the operating regime corresponding to weak interactions, the QA hardware behaves like a noisy Gibbs sampler at a hardware-specific effective temperature. This work builds on those insights and identifies a class of small hardware-native Ising models that are robust to noise effects and proposes a procedure for executing these models on QA hardware to maximize Gibbs sampling performance. Experimental results indicate that the proposed protocol results in high-quality Gibbs samples from a hardware-specific effective temperature. Furthermore, we show that this effective temperature can be adjusted by modulating the annealing time and energy scale. The procedure proposed in this work provides an approach to using QA hardware for Ising model sampling presenting potential new opportunities for applications in machine learning and physics simulation. Copyright © 2021, The Authors. All rights reserved.

关键词： Ising model

High Performance GaN HEMT and Ge Fin FET Device Realizing by Atomic-layer Defect-free Etching with Chlorine Neutral Beam

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High Performance GaN HEMT and Ge Fin FET Device Realizing by...

2020 International Symposium on VLSI Technology, Systems and Applications, VLSI-TSA 2020

作者： Ohori, Daisuke Shrestha, Niraj Man Li, Yiming Tarng, Jenn-Hwan Samukawa, Seiji National Chiao Tung University Department of Electrical and Computer Engineering Hsinchu30010 Taiwan Institute of Fluid Science Tohoku University 2-1-1 Katahira Aoba-ku Sendai980-8577 Japan Center for MmWave Smart Radar System and Technologies National Chiao Tung University Hsinchu30010 Taiwan Ibaraki305-8568 Japan Advanced Institute for Materials Research Tohoku University 2-1-1 Katahira Aoba-ku Sendai980-8577 Japan

ISBN: (纸本)9781728142326

In the fabrication of semiconductor devices, reactive plasmas are widely used in key processes such as microfabrication, surface modification and film deposition, and there are now demands for processing precision at the atomic layer level, and for deposition accuracy that allows the control of structures at the molecular level. However, in ultra-miniature nanoscale devices that will become the mainstream in the future, the use of plasma processes can cause serious problems such as abnormal etching and breakdown of insulation films by the accumulation of ions or electrons emitted from the plasma as shown in Fig. 1, also the formation of surface defects (dangling bond) of over a few tens nm in depth by exposure to ultraviolet (UV) emissions from the plasma. [1] -[4] In particular, since nano-scale devices have a larger surface area compared with the bulk material, plasma processes can have a large influence on the electrical and optical properties of devices due to process-induced defects caused by ultraviolet exposure, which has not caused a problem in the presented devices of 32 nm. Furthermore, since future nanodevices will require size control of three-dimensional structures at the atomic layer level, it will be absolutely essential to control surface chemical reactions with high precision and selectivity at the atomic layer level. Neutral beam process technology has attracted attention as a way of solving these issues [5], [6], as shown in Fig. 2. The neutral beam suppresses the incidence of charged particles and UV photon radiation onto the substrate, and is able to expose the substrate only to energy controlled neutral beam (neutral beam motion energy can be precisely controlled by ion acceleration energy with the applied electric field before neutralization), resulting in ultra-precise nano-processing that can suppress the formation of defects at the atomic layer level and control surface chemical reactions with high precision. © 2020 IEEE.

关键词： Substrates

EXPLAINABLE ARTIFICIAL INTELLIGENCE (XAI) 2.0: A MANIFESTO OF OPEN CHALLENGES AND INTERDISCIPLINARY RESEARCH DIRECTIONS

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arXiv 2023年

作者： Longo, Luca Brcic, Mario Cabitza, Federico Choi, Jaesik Confalonieri, Roberto Ser, Javier Del Guidotti, Riccardo Hayashi, Yoichi Herrera, Francisco Holzinger, Andreas Jiang, Richard Khosravi, Hassan Lecue, Freddy Malgieri, Gianclaudio Páez, Andrés Samek, Wojciech Schneider, Johannes Speith, Timo Stumpf, Simone The Artificial Intelligence and Cognitive Load Research Lab Technological University Dublin Ireland University of Zagreb Faculty of Electrical Engineering and Computing Croatia University of Milano-Bicocca Milan Italy IRCCS Ospedale Galeazzi Sant’Ambrogio Milan Italy Kim Jaechul Graduate School of AI Korea Advanced Institute of Science & Technology Korea Republic of INEEJI Corporation Korea Republic of Department of Mathematics University of Padua Italy Derio Spain Bilbao Spain University of Pisa Pisa Italy Department of Computer Science Meiji University Tokyo Japan Department of Computer Science and Artificial Intelligence DaSCI Andalusian Institute in Data Science & Computational Intelligence University of Granada Granada Spain Human-Centered AI Lab University of Natural Resources and Life Sciences Vienna Austria School of Computing and Communications Lancaster University United Kingdom The University of Queensland Brisbane Australia Sophia Antipolis France eLaw Center for Law and Digital Technologies Leiden University Netherlands Department of Philosophy Universidad de los Andes Bogotá Colombia Center for Research & Formation in Artificial Intelligence Universidad de los Andes Bogotá Colombia Technical University of Berlin Berlin Germany Fraunhofer Heinrich Hertz Institute Berlin Germany Berlin Germany Department of Information Systems and Computer Science University of Liechtenstein Liechtenstein Liechtenstein Department of Philosophy University of Bayreuth Bayreuth Germany Center for Perspicuous Computing Saarland University Saarbrücken Germany School of Computing Science University of Glasgow United Kingdom

As systems based on opaque Artificial Intelligence (AI) continue to flourish in diverse real-world applications, understanding these black box models has become paramount. In response, Explainable AI (XAI) has emerged as a field of research with practical and ethical benefits across various domains. This paper not only highlights the advancements in XAI and its application in real-world scenarios but also addresses the ongoing challenges within XAI, emphasizing the need for broader perspectives and collaborative efforts. We bring together experts from diverse fields to identify open problems, striving to synchronize research agendas and accelerate XAI in practical applications. By fostering collaborative discussion and interdisciplinary cooperation, we aim to propel XAI forward, contributing to its continued success. Our goal is to put forward a comprehensive proposal for advancing XAI. To achieve this goal, we present a manifesto of 27 open problems categorized into nine categories. These challenges encapsulate the complexities and nuances of XAI and offer a road map for future research. For each problem, we provide promising research directions in the hope of harnessing the collective intelligence of interested stakeholders. © 2023, CC BY-SA.

关键词： Ethical technology