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Entirety of quantum Uncertainty and Its Experimental Verification

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Chinese Physics Letters 2021年第7期38卷 11-16页

作者： Jie Xie Li Zhou Aonan Zhang Huichao Xu Man-Hong Yung Ping Xu Nengkun Yu Lijian Zhang National Laboratory of Solid State Microstructures College of Engineering and Applied Sciences and School of PhysicsNanjing UniversityNanjing 210093China Collaborative Innovation Center of Advanced Microstructures Nanjing UniversityNanjing 210093China Department of Computer Science and Technology Tsinghua UniversityBeijing 100084China Shenzhen Institute for Quantum Science and Engineering and Department of Physics Southern University of Science and TechnologyShenzhen 518055China Shenzhen Key Laboratory of Quantum Science and Engineering Southern University of Science and TechnologyShenzhen 518055China Institute for Quantum Information&State Key Laboratory of High Performance Computing College of ComputerNational University of Defense TechnologyChangsha 410073China Centre for Quantum Software and Information School of SoftwareFaculty of Engineering and Information TechnologyUniversity of Technology SydneyNSWAustralia

As a foundation of quantum physics,uncertainty relations describe ultimate limit for the measurement uncertainty of incompatible ***,uncertainty relations are formulated by mathematical bounds for a specific *** we present a method for geometrically characterizing uncertainty relations as an entire area of variances of the observables,ranging over all possible input *** find that for the pair of position and momentum operators,Heisenberg's uncertainty principle points exactly to the attainable area of the variances of position and ***,for finite-dimensional systems,we prove that the corresponding area is necessarily semialgebraic;in other words,this set can be represented via finite polynomial equations and inequalities,or any finite union of such *** particular,we give the analytical characterization of the areas of variances of(a)a pair of one-qubit observables and(b)a pair of projective observables for arbitrary dimension,and give the first experimental observation of such areas in a photonic system.

关键词： observable union operators

performance and Portability Analysis of OPS Structured Grid Parallel Library 3

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Performance and Portability Analysis of OPS Structured Grid ...

3rd IEEE International Conference on Frontiers Technology of Information and Computer, ICFTIC 2021

作者： Chen, Fengting Che, Yonggang Wang, Wenke Ma, Jian National University of Defense Technology Institute for Quantum Information State Key Laboratory of High Performance Computing College of Computer Science and Technology Changsha410073 China National University of Defense Technology Changsha410073 China National University of Defense Technology School of Military Basic Education Changsha410073 China

ISBN: (纸本)9781665406055

The complexity and diversity of high-performance computer architectures have brought great challenges to parallel application development. Using DSL (Domain Specific Language) to achieve multi-platform automatic parallelization is a solution to this problem. This paper tests and analyzes the multi-platform parallel performance of OPS (Oxford Parallel Library for Structured Mesh Solvers), a typical DSL framework for scientific applications. Two representative structured mesh applications are used in our evaluation. The performance of their MPI, hybrid MPI/OpenMP and CUDA versions generated by OPS are evaluated on the Intel Xeon E5-2600 V3 CPU and the NVIDIA Tesla K80 GPU. The performance of OPS generated codes are compared against the corresponding manually parallelized and optimized codes. The results show that for the two applications, OPS based approach can generate parallel codes with comparable performance to manually parallelized and optimized codes. This paper further analyzes the differences between OPS-based multi-platform parallel code generation and manual parallelization approaches and their impact on performance. It also quantitatively evaluates the cross-platform portability of OPS, and points out some possible directions of improvement. © 2021 IEEE.

关键词： Parallel programming

The MPI + CUDA Gaia AVU–GSR Parallel Solver Toward Next-generation Exascale Infrastructures

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arXiv 2023年

作者： Cesare, Valentina Becciani, Ugo Vecchiato, Alberto Lattanzi, Mario Gilberto Pitari, Fabio Aldinucci, Marco Bucciarelli, Beatrice INAF Astrophysical Observatory of Catania via Santa Sofia 78 CT Catania95123 Italy ICSC–Centro Nazionale di Ricerca in High Performance Computing Big Data and Quantum Computing Italy INAF Astrophysical Observatory of Turin via Osservatorio 20 TO Pino Torinese10025 Italy CINECA via Magnanelli 6/3 BO Casalecchio di Reno40033 Italy University of Turin Computer Science Department corso Svizzera 185 TO Turin10149 Italy

We ported to the GPU with CUDA the Astrometric Verification Unit–Global Sphere Reconstruction (AVU–GSR) Parallel Solver developed for the ESA Gaia mission, by optimizing a previous OpenACC porting of this application. The code aims to find, with a [10, 100] µarcsec precision, the astrometric parameters of ∼108 stars, the attitude and instrumental settings of the Gaia satellite, and the global parameter γ of the parametrized Post-Newtonian formalism, by solving a system of linear equations, A × x = b, with the LSQR iterative algorithm. The coefficient matrix A of the final Gaia dataset is large, with ∼1011 × 108 elements, and sparse (Becciani et al., 2014), reaching a size of ∼10-100 TB, typical for the Big Data analysis, which requires an efficient parallelization to obtain scientific results in reasonable timescales. The speedup of the CUDA code over the original AVU–GSR solver, parallelized on the CPU with MPI + OpenMP, increases with the system size and the number of resources, reaching a maximum of ∼14x, >9x over the OpenACC application (Cesare et al., 2021, 2022c,b). This result is obtained by comparing the two codes on the CINECA cluster Marconi100, with 4 V100 GPUs per node. After verifying the agreement between the solutions of a set of systems with different sizes computed with the CUDA and the OpenMP codes and that the solutions showed the required precision, the CUDA code was put in production on Marconi100, essential for an optimal AVU–GSR pipeline and the successive Gaia Data Releases. This analysis represents a first step to understand the (pre-)Exascale behavior of a class of applications that follow the same structure of this code. In the next months, we plan to run this code on the pre-Exascale platform Leonardo of CINECA, with 4 next-generation A200 GPUs per node, toward a porting on this infrastructure, where we expect to obtain even higher performances. © 2023, CC BY.

关键词： Application programming interfaces (API)

Radio Modulation Recognition Based on Attention-based Convolutional Neural Network and Time-frequency Analysis

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Radio Modulation Recognition Based on Attention-based Convol...

Artificial Intelligence, Networking and Information Technology (AINIT), International Seminar on

作者： Xinlong Li Da Huang Wenjing Yang Xueqiong Li Institute for Quantum Information & State Key Laboratory of High Performance Computing College of Computer Science and Technology National University of Defense Technology Changsha China

ISBN: (纸本)9781665412971

Radio modulation recognition is the key link of modern electronic warfare. This paper applies the idea of deep learning to radio modulation recognition. Since the modulation type is the most important information about the subtle features of the radio signal, we use short time Fourier transform (STFT) to convert the radio signal into a time-frequency distribution map to form a joint distribution of frequency and time. The attention-based convolutional neural network is used to classify and recognize the modulation types of time-frequency distribution maps. The simulation results show that time-frequency analysis can improve the accuracy of recognition, and adding attention can effectively improve the performance of the network.

关键词： Training Seminars Time-frequency analysis Electronic warfare Fourier transforms Simulation Noise reduction

Indirect influence in social networks as an induced percolation phenomenon (vol 119, e2100151119, 2022)

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PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA 2022年第24期119卷 e2100151119-e2100151119页

作者： Xie, Jiarong Wang, Xiangrong Feng, Ling Zhao, Jin-Hua Liu, Wenyuan Moreno, Yamir Hu, Yanqing School of Computer Science and Engineering Sun Yat-sen University 510006 Guangzhou China Institute of Future Networks Southern University of Science and Technology 518055 Shenzhen China Peng Cheng Laboratory 518066 Shenzhen China Institute of High Performance Computing A*STAR 138632 Singapore Department of Physics National University of Singapore 117551 Singapore Guangdong Provincial Key Laboratory of Nuclear Science Institute of Quantum Matter South China Normal University 510006 Guangzhou China Guangdong-Hong Kong Joint Laboratory of Quantum Matter Southern Nuclear Science Computing Center South China Normal University 510006 Guangzhou China Division of Physics and Applied Physics School of Physical and Mathematical Sciences Nanyang Technological University 637371 Singapore Institute for Biocomputation and Physics of Complex Systems University of Zaragoza 50018 Zaragoza Spain Department of Theoretical Physics University of Zaragoza 50018 Zaragoza Spain ISI Foundation 10126 Torino Italy Department of Statistics and Data Science College of Science Southern University of Science and Technology 518055 Shenzhen China

Percolation theory has been widely used to study phase transitions in network systems. It has also successfully explained various macroscopic spreading phenomena across different fields. Yet, the theoretical frameworks have been focusing on direct interactions among nodes, while recent empirical observations have shown that indirect interactions are common in many network systems like social and ecological networks, among others. By investigating the detailed mechanism of both direct and indirect influence on scientific collaboration networks, here we show that indirect influence can play the dominant role in behavioral influence. To address the lack of theoretical understanding of such indirect influence on the macroscopic behavior of the system, we propose a percolation mechanism of indirect interactions called induced percolation. Surprisingly, our model exhibits a unique anisotropy property. Specifically, directed networks show first-order abrupt transitions as opposed to the second-order continuous transition in the same network structure but with undirected links. A mix of directed and undirected links leads to rich hybrid phase transitions. Furthermore, a unique feature of the nonmonotonic pattern is observed in network connectivities near the critical point. We also present an analytical framework to characterize the proposed induced percolation, paving the way to further understanding network dynamics with indirect interactions.

关键词： percolation indirect interactions social network phase transition behavioral contagion

Implicit Feature Alignment For Knowledge Distillation

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Implicit Feature Alignment For Knowledge Distillation

International Conference on Tools for Artificial Intelligence (ICTAI)

作者： Dingyao Chen Mengzhu Wang Xiang Zhang Tianyi Liang Zhigang Luo College of computer National University of Defense Technology Changshan Hunan P.R. China Institute for Quantum Information & State Key Laboratory of High Performance Computing National University of Defense Technology Changsha Hunan P.R. China

Knowledge distillation is a technique of transferring knowledge from a large teacher network to a light student one. Existing studies purely use immediate layers' features for distillation and may fail to gain insufficient semantic knowledge from the teacher. Inspired by recent advances in contrastive learning, we propose to introduce extra light embedding layers of the teacher to enforce its generalization ability and further align the mixup-type features for knowledge distillation in an implicit fashion (IFKD). IFKD allows the student to learn richer structural knowledge, thanks to the learned embedding layers of the teacher. Crucially, benefitting from a plethora of mixed samples, we can further adequately mine much semantic knowledge of the teacher. For efficiency, we propose a simple reversed mixup scheme to organize images and implicitly ensure complete positive information comparisons. Extensive experiments on image classification on two popular datasets including CIFAR-100 and ImageNet verify the effectiveness of our approach as compared to the previous methods.

关键词： Knowledge engineering Semantics Image classification

Characterization of Intensity Correlation via Single-photon Detection in quantum Key Distribution

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arXiv 2024年

作者： Xing, Tianyi Liu, Junxuan Zhang, Likang Wang, Min-Yan Li, Yu-Huai Liu, Ruiyin Peng, Qingquan Wang, Dongyang Wang, Yaxuan Liu, Hongwei Li, Wei Cao, Yuan Huang, Anqi Institute for Quantum Information State Key Laboratory of High Performance Computing College of Computer Science and Technology National University of Defense Technology Changsha410073 China Hefei National Research Center for Physical Sciences The Microscale and School of Physical Sciences University of Science and Technology of China Hefei230026 China Shanghai Research Center for Quantum Science CAS Center for Excellence in Quantum Information and Quantum Physics University of Science and Technology of China Shanghai201315 China Hefei National Laboratory University of Science and Technology of China Hefei230088 China China Information Technology Security Evaluation Center Beijing100085 China

One of the most significant vulnerabilities in the source unit of quantum key distribution (QKD) is the correlation between quantum states after modulation, which shall be characterized and evaluated for its practical security performance. In this work, we propose a methodology to characterize the intensity correlation according to the single-photon detection results in the measurement unit without modifying the configuration of the QKD system. In contrast to the previous research that employs extra classical optical detector to measure the correlation, our method can directly analyse the detection data generated during the raw key exchange, enabling to characterize the feature of correlation in real-time system operation. The basic method is applied to a BB84 QKD system and the characterized correlation significantly decreases the secure key rate shown by the security proof. Furthermore, the method is extended and applied to characterize the correlation from the result of Bell-state measurement, which demonstrates its applicability to a running full-scheme MDI QKD system. This study provides an approach for standard certification of a QKD system. Copyright © 2024, The Authors. All rights reserved.

关键词： Photons

Matter power spectrum induced by primordial magnetic fields: from the linear to the non-linear regime

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arXiv 2024年

作者： Ralegankar, Pranjal Garaldi, Enrico Viel, Matteo SISSA - International School for Advanced Studies Via Bonomea 265 Trieste34136 Italy INFN National Institute for Nuclear Physics Via Valerio 2 TriesteI-34127 Italy IFPU Institute for Fundamental Physics of the Universe via Beirut 2 Trieste34151 Italy INAF Osservatorio Astronomico di Trieste Via G. B. Tiepolo 11 TriesteI-34131 Italy ICSC - Italian Research Center on High Performance Computing Big Data and Quantum Computing via Magnanelli 2 Casalecchio di Reno40033 Italy

Linear theory predicts that primordial magnetic fields (PMFs) enhance the matter power spectrum on small scales. However, the linear approximation breaks down on sufficiently small scales where PMF-induced baryon perturbations back-react onto the magnetic fields. Previous studies assumed that the baryon power spectrum would be sharply suppressed in this non-linear regime, based on arguments related to the magnetic Jeans scale. For the first time, we perform dedicated magnetohydrodynamic (MHD) simulations to investigate the transition from the linear to the non-linear regime. Our simulations confirm the expected linear behavior on large scales. In the non-linear regime, however, we find that the dimensionless baryon power spectrum saturates to an O(1) value, which contrasts with previous analytical expectations. Additionally, our results show that several past studies overestimated the total matter power spectrum by orders of magnitude near the transition to non-linearity. Thus, the results presented in this work are useful to obtain more accurate constraints on PMFs from structure formation processes and/or different tracers of cosmic structures. © 2024, CC BY.

关键词： Magnetic fields

Particularities of polaron formation in the extended Holstein model with next nearest neighbor transfer

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arXiv 2023年

作者： Chakraborty, Monodeep Chatterjee, Jayita Fehske, Holger Centre for Quantum Science and Technology Chennai Institute of Technology Chennai600069 India Department of Physics Sarojini Naidu College for Women 30 Jessore Road Kolkata700028 India Institute of Physics University of Greifswald Felix-Hausdorff-Straße 6 Greifswald17489 Germany Erlangen National High Performance Computing Center Erlangen91058 Germany

Employing a largely unbiased variational exact diagonalization technique, we analyze the consequences of longer-ranged electron hopping and electron-phonon interaction on polaron formation in one dimension. Having at our disposal the accurate ground-state energy and wave function, we calculate and discuss various physical quantities, such as the renormalized band structure, effective mass, wave-function renormalization factor, phonon dressing, and Drude weight, characterizing the properties of the polaronic quasiparticle. We demonstrate that the electron-phonon coupling affects the relative strength of the nearest neighbor (NN) and next nearest neighbor (NNN) hopping processes in a dynamic way. Most notably we observe that the minimum of the polaron band, occurring at a finite momentum for large negative ratio between NN and NNN transfer, jumps to zero momentum as the electron-phonon coupling exceeds a critical one, thereby causing a rather sharp polaron transition in the one-dimensional extended Holstein model. The signatures of this transition are seen in the effective mass and polaron mobility, and therefore should be easily detectable by transport measurements. Copyright © 2023, The Authors. All rights reserved.

关键词： Electron-phonon interactions