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Efficient thermal dissipation in wafer-scale heterogeneous integration of single-crystalline𝛽β-Ga_(2)O_(3)thin film on SiC

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Fundamental Research 2021年第6期1卷 691-696页

作者： Wenhui Xu Tiangui You Yibo Wang Zhenghao Shen Kang Liu Lianghui Zhang Huarui Sun Ruijie Qian Zhenghua An Fengwen Mu Tadatomo Suga Genquan Han Xin Ou Yue Hao Xi Wang State Key Laboratory of Functional Materials for Informatics Shanghai Institute of Microsystem and Information TechnologyChinese Academy of SciencesShanghai 200050China The State Key Discipline Laboratory of Wide Band Gap Semiconductor Technology School of MicroelectronicsXidian UniversityXi’an 710071China School of Science and Ministry of Industry and Information Technology Key Laboratory of Micro-Nano Optoelectronic Information System Harbin Institute of TechnologyShenzhen 518055China Department of Physics State Key Laboratory of Surface PhysicsInstitute of Nanoelectronic Devices and Quantum ComputingFudan UniversityShanghai 200433China High-Frequency High-Voltage Device and Integrated Circuits R&D Center Institute of MicroelectronicsChinese Academy of SciencesBeijing 100029China Collaborative Research Center Meisei UniversityHinoJapan Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China

The semiconductor,β-Ga_(2)O_(3)is attractive for applications in high power electronic devices with low conduction loss due to its ultra-wide bandgap(∼4.9 eV)and large Baliga’s figure of ***,the thermal conductivity of𝛽β-Ga_(2)O_(3)is much lower than that of other wide/ultra-wide bandgap semiconductors,such as SiC and GaN,which results in the deterioration of𝛽β-Ga_(2)O_(3)-based device performance and reliability due to *** overcome this problem,a scalable thermal management strategy was proposed by heterogeneously integrating wafer-scale single-crystalline𝛽β-Ga_(2)O_(3)thin films on a highly thermally conductive SiC *** of the transferred𝛽β-Ga_(2)O_(3)thin film indicated a uniform thickness to within±2.01%,a smooth surface with a roughness of 0.2 nm,and good crystalline quality with an X-ray rocking curves(XRC)full width at half maximum of 80 *** thermoreflectance measurements were employed to investigate the thermal *** thermal performance of the fabricated𝛽β-Ga_(2)O_(3)/SiC heterostructure was effectively improved in comparison with that of the𝛽β-Ga_(2)O_(3)bulk wafer,and the effective thermal boundary resistance could be further reduced to 7.5 m 2 K/GW by a post-annealing *** barrier diodes(SBDs)were fabricated on both a𝛽β-Ga_(2)O_(3)/SiC heterostructured material and a𝛽β-Ga_(2)O_(3)bulk *** thermal imaging revealed the temperature increase of the SBDs on𝛽β-Ga_(2)O_(3)/SiC to be one quarter that on the𝛽β-Ga_(2)O_(3)bulk wafer with the same applied power,which suggests that the combination of the𝛽-Ga_(2)O_(3)thin film and SiC substrate with high thermal conductivity promotes heat dissipation in𝛽β-Ga_(2)O_(3)-based devices.

关键词： Thermal management Heterogeneous integration Wafer scale𝛽β-Ga_(2)O_(3)on SiC Ion-cutting technique Schottky barrier diodes(SBDs) Transient thermoreflectance(TTR) measurements

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Random node reinforcement and K-core structure of complex networks

arXiv

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arXiv 2022年

作者： Ma, Rui Hu, Yanqing Zhao, Jin-Hua Guangdong Provincial Key Laboratory of Nuclear Science Institute of Quantum Matter South China Normal University Guangzhou510006 China Guangdong-Hong Kong Joint Laboratory of Quantum Matter Southern Nuclear Science Computing Center South China Normal University Guangzhou510006 China Department of Statistics and Data Science College of Science Southern University of Science and Technology Shenzhen518055 China School of Data Science and Engineering South China Normal University Shanwei516622 China

To enhance robustness of complex networked systems, a simple method is introducing reinforced nodes which always function during failure propagation. A random scheme of node reinforcement can be considered as a benchmark for finding an optimal reinforcement solution. Yet there still lacks a systematic evaluation on how node reinforcement affects network structure at a mesoscopic level upon failures. Here we study this problem through the lens of K-cores of networks. Based on an analytical percolation framework, we first show that, on uncorrelated random graphs, with a critical size of reinforced nodes, an abrupt emergence of K-cores is smoothed out to a continuous one, and a detailed phase diagram is derived. We then show that, with a cost-benefit analysis on random reinforcement, for proper weight factors in cost functions with constant and increasing marginal costs, a gain function shows a unimodality, thus we can analytically find an optimal reinforcement fraction by locating the maximal gain. In all, our framework offers a gain-oriented analytical perspective to designing robust interconnected systems. Copyright © 2022, The Authors. All rights reserved.

关键词： Reinforcement

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Study on Deep Reinforcement Learning for Multi-Task Scheduling in Cloud Manufacturing

SSRN

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SSRN 2022年

作者： Xiao, Jiuhong Cai, Yishuai Wang, Wanru Chen, Yong College of Economic and Social Development Nankai University Tianjin300072 China Institute for Quantum Information State Key Laboratory of High Performance Computing College of Computer Science and Technology National University of Defense Technology Changsha410073 China School of Information Management and Artificial Intelligence Zhejiang University of Finance and Economics Hangzhou310018 China College of Civil Engineering and Architecture Zhejiang University Hangzhou310058 China

Cloud manufacturing is an emerging manufacturing paradigm, which enables the simultaneous processing of multiple manufacturing tasks submitted by customers through centralized management and planning of manufacturing services offered by distributed enterprises. To date, various meta-heuristics algorithms such as ant colony optimization algorithm, and genetic algorithm have been widely employed to solve the cloud manufacturing multi-task scheduling (CMMS) problem to improve the efficiency of multi-task scheduling. However, these algorithms need sophisticated design procedures and laborious parameter tuning, making their adaptation to dynamic, large-scale manufacturing environments difficult. Deep reinforcement learning (DRL), because of its efficiency and flexibility, has recently attracted increasing attention from researchers and has shown promising performance in solving combinatorial optimization problems. Nevertheless, little is known about the performance of DRL technologies in solving the CMMS problem. Therefore, in this study, three state-of-the-art DRL technologies, including proximal policy optimization (PPO), deep deterministic policy gradient, and normalized advantage function, are selected to systematically investigate the potential of DRL in solving the CMMS problem. A comprehensive comparison of these DRL technologies is conducted in terms of effectiveness and efficiency, robustness and adaptability, and scalability. Experimental results indicate that PPO is superior to other technologies in solving the CMMS problem. © 2022, The Authors. All rights reserved.

关键词： Reinforcement learning

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Detection and evaluation of abnormal user behavior based on quantum generation adversarial network

arXiv

引用

arXiv 2022年

作者： Pan, Minghua Wang, Bin Tao, Xiaoling Zheng, Shenggen Situ, Haozhen Li, Lvzhou Guangxi Key Laboratory of Cryptography and Information Security Guilin University of Electronic Technology Guilin541004 China Peng Cheng Laboratory Shenzhen518055 China College of Mathematics and Informatics South China Agricultural University Guangzhou510642 China Institute of Quantum Computing and Software School of Computer Science and Engineering Sun Yat-sen University Guangzhou510006 China

quantum computing holds tremendous potential for processing high-dimensional data, capitalizing on the unique capabilities of superposition and parallelism within quantum states. As we navigate the noisy intermediate-scale quantum (NISQ) era, the exploration of quantum computing applications has emerged as a compelling frontier. One area of particular interest within the realm of cyberspace security is Behavior Detection and Evaluation (BDE). Notably, the detection and evaluation of internal abnormal behaviors pose significant challenges, given their infrequent occurrence or even their concealed nature amidst vast volumes of normal data. In this paper, we introduce a novel quantum behavior detection and evaluation algorithm (QBDE) tailored for internal user analysis. The QBDE algorithm comprises a quantum Generative Adversarial Network (QGAN) in conjunction with a classical neural network for detection and evaluation tasks. The QGAN is built upon a hybrid architecture, encompassing a quantum Generator (GQ) and a Classical Discriminator (DC). GQ, designed as a parameterized quantum circuit (PQC), collaborates with DC, a classical neural network, to collectively enhance the analysis process. To address the challenge of imbalanced positive and negative samples, GQ is employed to generate negative samples. Both GQ and DC are optimized through gradient descent techniques. Through extensive simulation tests and quantitative analyses, we substantiate the effectiveness of the QBDE algorithm in detecting and evaluating internal user abnormal behaviors. Our work not only introduces a novel approach to abnormal behavior detection and evaluation but also pioneers a new application scenario for quantum algorithms. This paradigm shift underscores the promising prospects of quantum computing in tackling complex cybersecurity challenges. Copyright © 2022, The Authors. All rights reserved.

关键词： Generative adversarial networks

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Multivariate trace estimation in constant quantum depth

arXiv

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arXiv 2022年

作者： Quek, Yihui Kaur, Eneet Wilde, Mark M. Department of Mathematics Massachusetts Institute of Technology CambridgeMA02139 United States Dahlem Center for Complex Quantum Systems Freie Universität Berlin Berlin14195 Germany Information Systems Laboratory Stanford University Palo AltoCA94305 United States Cisco Quantum Lab Los Angeles United States Institute for Quantum Computing Department of Physics and Astronomy University of Waterloo WaterlooONN2L 3G1 Canada School of Electrical and Computer Engineering Cornell University IthacaNY14850 United States Hearne Institute for Theoretical Physics Department of Physics and Astronomy Center for Computation and Technology Louisiana State University Baton RougeLA70803 United States

There is a folkloric belief that a depth-Θ(m) quantum circuit is needed to estimate the trace of the product of m density matrices (i.e., a multivariate trace), a subroutine crucial to applications in condensed matter and quantum information science. We prove that this belief is overly conservative by constructing a constant quantum-depth circuit for the task, inspired by the method of Shor error correction. Furthermore, our circuit demands only local gates in a two dimensional circuit – we show how to implement it in a highly parallelized way on an architecture similar to that of Google’s Sycamore processor. With these features, our algorithm brings the central task of multivariate trace estimation closer to the capabilities of near-term quantum processors. We instantiate the latter application with a theorem on estimating nonlinear functions of quantum states with "well-behaved" polynomial approximations. © 2022, CC BY-NC-SA.

关键词： Polynomial approximation

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Study of Asymptotic Free Scalar Field Theories from Adaptive Perturbation Method

arXiv

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arXiv 2023年

作者： Ma, Chen-Te Zhang, Hui Department of Physics and Astronomy Iowa State University AmesIA50010 United States Asia Pacific Center for Theoretical Physics Pohang University of Science and Technology Gyeongsangbuk-do Pohang37673 Korea Republic of Guangdong Provincial Key Laboratory of Nuclear Science Institute of Quantum Matter South China Normal University Guangdong Guangzhou510006 China School of Physics and Telecommunication Engineering South China Normal University Guangdong Guangzhou510006 China Guangdong-Hong Kong Joint Laboratory of Quantum Matter Southern Nuclear Science Computing Center South China Normal University Guangdong Guangzhou510006 China The Laboratory for Quantum Gravity and Strings Department of Mathematics and Applied Mathematics University of Cape Town Private Bag Rondebosch7700 South Africa Key Laboratory of Atomic and Subatomic Structure and Quantum Control Institute of Quantum Matter South China Normal University Guangdong Guangzhou510006 China Physics Department Center for Exploration of Energy and Matter Indiana University BloomingtonIN47408 United States

We focus on the behavior of (2+1)d λ4 and (5+1)d λ3 or λ||3 theories in different regimes and compare the results obtained from the adaptive perturbation method with those obtained from lattice simulation. These theories are simple models that exhibit asymptotic freedom, which is a property that is also observed in more complex theories such as QCD, which describes the strong interaction between quarks and gluons. Asymptotic freedom is an important feature of these theories because it allows for a perturbative treatment of interactions at high energies. However, the standard perturbation scheme breaks down in the presence of strong interactions, and the adaptive perturbation method, which involves resuming the Feynman diagrams, is more suitable for studying these interactions. Our research involves comparing the perturbation result to lattice simulation. In the case of the 3 theory, there is no stable vacuum, so we explore evidence from the ||3 theory instead. Our results appear to show that resummation improves the strong coupling result for both the λ4 and λ||3 theories. Additionally, we improve the resummation method for the three-point coupling vertex and study the RG flow to analyze the resummation contribution and theoretical properties. Copyright © 2023, The Authors. All rights reserved.

关键词： Lattice theory

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Universal Dynamical Scaling of Quasi-Two-Dimensional Vortices in a Strongly Interacting Fermionic Superfluid

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Physical Review Letters 2021年第18期126卷 185302-185302页

作者： Xiang-Pei Liu Xing-Can Yao Youjin Deng Xiao-Qiong Wang Yu-Xuan Wang Chun-Jiong Huang Xiaopeng Li Yu-Ao Chen Jian-Wei Pan Hefei National Laboratory for Physical Sciences at the Microscale and Department of Modern Physics University of Science and Technology of China Hefei 230026 China Shanghai Branch CAS Center for Excellence in Quantum Information and Quantum Physics University of Science and Technology of China Shanghai 201315 China Shanghai Research Center for Quantum Sciences Shanghai 201315 China MinJiang Collaborative Center for Theoretical Physics College of Physics and Electronic Information Engineering Minjiang University Fuzhou 350108 China State Key Laboratory of Surface Physics Institute of Nanoelectronics and Quantum Computingand Department of Physics Fudan University Shanghai 200433 China Collaborative Innovation Center of Advanced Microstructures Nanjing 210093 China

Vortices play a leading role in many fascinating quantum phenomena. Here we generate a large number of vortices by thermally quenching a fermionic superfluid of Li6 atoms in an oblate optical trap and study their annihilation dynamics and spatial distribution. Over a wide interaction range from the attractive to the repulsive side across the Feshbach resonance, these quasi-two-dimensional vortices are observed to follow algebraic scaling laws both in time and space, having exponents consistent with the two-dimensional universality. We further simulate the classical XY model on the square lattice by a Glauber dynamics and find good agreement between the numerical and experimental behaviors. Our work provides a direct demonstration of the universal 2D vortex dynamics.

关键词： Fermi gases Vortices in superfluids Fermionic condensates Ultracold gases

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Size-consistency and orbital-invariance issues revealed by VQE-UCCSD calculations with the FMO scheme

arXiv

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arXiv 2024年

作者： Sugisaki, Kenji Nakano, Tatsuya Mochizuki, Yuji Graduate School of Science and Technology Keio University 7-1 Shinkawasaki Saiwai-ku Kanagawa Kawasaki212-0032 Japan Quantum Computing Center Keio University 3-14-1 Hiyoshi Kohoku-ku Kanagawa Yokohama223-8522 Japan Centre for Quantum Engineering Research and Education TCG Centres for Research and Education in Science and Technology Sector V Salt Lake Kolkata700091 India Division of Medicinal Safety Science National Institute of Health Sciences 1-18-1 Kamiyoga Setagaya-ku Tokyo158-8501 Japan Department of Chemistry Research Center for Smart Molecules Faculty of Science Rikkyo University 3-34-1 Nishi-ikebukuro Toshima-ku Tokyo171-8501 Japan Institute of Industrial Science The University of Tokyo 4-6-1 KomabaMeguro-ku Tokyo153-8505 Japan

The fragment molecular orbital (FMO) scheme is one of the popular fragmentation-based methods and has the potential advantage of making the circuit flat in quantum chemical calculations on quantum computers. In this study, we used a GPU-accelerated quantum simulator (cuquantum) to perform the electron correlation part of the FMO calculation as unitary coupled-cluster singles and doubles (UCCSD) with the variational quantum eigensolver (VQE) for hydrogen-bonded (FH)3 and (FH)2-H2O systems with the STO-3G basis set. VQE-UCCD calculations were performed using both canonical and localized MO sets, and the results were examined from the point of view of size-consistency and orbital-invariance affected by the Trotter error. It was found that the use of localized MO leads to better results, especially for (FH)2-H2O. The GPU acceleration was substantial for the simulations with larger numbers of qubits, and was about a factor of 6.7–7.7 for 18 qubit systems. Copyright © 2024, The Authors. All rights reserved.

关键词： Graphics processing unit

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Minimum Trotterization Formulas for a Time-Dependent Hamiltonian

arXiv

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arXiv 2022年

作者： Ikeda, Tatsuhiko N. Abrar, Asir Chuang, Isaac L. Sugiura, Sho RIKEN Center for Quantum Computing Saitama Wako351-0198 Japan Department of Physics Boston University BostonMA02215 United States Institute for Solid State Physics University of Tokyo Chiba Kashiwa277-8581 Japan Physics and Informatics Laboratory NTT Research Inc. 940 Stewart Dr. SunnyvaleCA94085 United States Department of Physics Department of Electrical Engineering and Computer Science Co-Design Center for Quantum Advantage Massachusetts Institute of Technology CambridgeMA02139 United States Laboratory for Nuclear Science Massachusetts Institute of Technology CambridgeMA02139 United States

When a time propagator eδtA for duration δt consists of two noncommuting parts A = X + Y, Trotterization approximately decomposes the propagator into a product of exponentials of X and Y. Various Trotterization formulas have been utilized in quantum and classical computers, but much less is known for the Trotterization with the time-dependent generator A(t). Here, for A(t) given by the sum of two operators X and Y with time-dependent coefficients A(t) = x(t)X + y(t)Y, we develop a systematic approach to derive high-order Trotterization formulas with minimum possible exponentials. In particular, we obtain fourth-order and sixth-order Trotterization formulas involving seven and fifteen exponentials, respectively, which are no more than those for time-independent generators. We also construct another fourth-order formula consisting of nine exponentials having a smaller error coefficient. Finally, we numerically benchmark the fourth-order formulas in a Hamiltonian simulation for a quantum Ising chain, showing that the 9-exponential formula accompanies smaller errors per local quantum gate than the well-known Suzuki formula. © 2022, CC BY.

关键词： Hamiltonians

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AdS3 Einstein Gravity and Boundary Description: Pedagogical Review

arXiv

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arXiv 2023年

作者： Ma, Chen-Te Department of Physics and Astronomy Iowa State University AmesIA50011 United States Asia Pacific Center for Theoretical Physics Pohang University of Science and Technology Gyeongsangbuk-do Pohang37673 Korea Republic of Guangdong Provincial Key Laboratory of Nuclear Science Institute of Quantum Matter South China Normal University Guangdong Guangzhou510006 China School of Physics and Telecommunication Engineering South China Normal University Guangdong Guangzhou510006 China Guangdong-Hong Kong Joint Laboratory of Quantum Matter Southern Nuclear Science Computing Center South China Normal University Guangzhou510006 China The Laboratory for Quantum Gravity and Strings Department of Mathematics and Applied Mathematics University of Cape Town Private Bag Rondebosch7700 South Africa

We review the various aspects of the 3D Einstein gravity theory with a negative cosmological constant and its boundary description. We also explore its connections to CFTs, modular symmetry, and holography. It is worth noting that this particular theory is topological in nature, which means that all the physical degrees of freedom are located on the boundary. Additionally, we can derive the boundary description on a torus, which takes the form of a 2D Schwarzian theory. This observation suggests that the relevant degrees of freedom for the theory can be described using this 2D theory. Because of the renormalizability of the 3D gravity theory, one can probe the quantum regime. This suggests that it is possible to investigate quantum phenomena. Unlike the conventional CFTs, when considering the AdS3 background, the boundary theory loses modular symmetry. This represents a departure from the usual behavior of CFT and is quite intriguing. The Weyl transformation induces anomaly in CFTs, and we indicate that applying this transformation to the 2D Schwarzian theory leads to similar results. Summing over all geometries with the asymptotic AdS3 boundary condition is equivalent to summing over a modular group. The partition function is one-loop exact and therefore an analytical expression from the summation. This theory holds potential applications in quantum Information and is a recurring theme in the study of holography, where gravitational theories are connected with CFTs. Copyright © 2023, The Authors. All rights reserved.

关键词： Holography

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