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Nonfuel antineutrino contributions in the high flux isotope reactor

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arXiv 2020年

作者： Balantekin, A.B. Band, H.R. Bass, C.D. Bergeron, D.E. Berish, D. Bowden, N.S. Brodsky, J.P. Bryan, C.D. Classen, T. Conant, A.J. Deichert, G. Diwan, M.V. Dolinski, M.J. Erickson, A. Foust, B.T. Gaison, J.K. Galindo-Uribarri, A. Gilbert, C.E. Hackett, B.T. Hans, S. Hansell, A.B. Heeger, K.M. Heffron, B. Jaffe, D.E. Ji, X. Jones, D.C. Kyzylova, O. Lane, C.E. Langford, T.J. LaRosa, J. Littlejohn, B.R. Lu, X. Maricic, J. Mendenhall, M.P. Milincic, R. Mitchell, I. Mueller, P.E. Mumm, H.P. Napolitano, J. Neilson, R. Nikkel, J.A. Norcini, D. Nour, S. Palomino-Gallo, J.L. Pushin, D.A. Qian, X. Romero-Romero, E. Rosero, R. Surukuchi, P.T. Tyra, M.A. Varner, R.L. White, C. Wilhelmi, J. Woolverton, A. Yeh, M. Zhang, A. Zhang, C. Zhang, X. Brookhaven National Laboratory UptonNY11973 United States Department of Physics Drexel University PhiladelphiaPA19104 United States George W. Woodruff School of Mechanical Engineering Georgia Institute of Technology AtlantaGA30332 United States Department of Physics & Astronomy University of Hawaii HonoluluHA 96822 United States Department of Physics Illinois Institute of Technology ChicagoIL60616 United States Nuclear and Chemical Sciences Division Lawrence Livermore National Laboratory LivermoreCA94550 United States Department of Physics Le Moyne College SyracuseNY13214 United States National Institute of Standards and Technology GaithersburgMD20899 United States High Flux Isotope Reactor Oak Ridge National Laboratory Oak RidgeTN37830 United States Physics Division Oak Ridge National Laboratory Oak RidgeTN37830 United States Department of Physics Temple University PhiladelphiaPA19122 United States Department of Physics and Astronomy University of Tennessee KnoxvilleTN37996 United States Institute for Quantum Computing Department of Physics and Astronomy University of Waterloo WaterlooONN2L 3G1 Canada Department of Physics University of Wisconsin Madison MadisonWI53706 United States Wright Laboratory Department of Physics Yale University New HavenCT06520 United States

Reactor neutrino experiments have seen major improvements in precision in recent years. With the experimental uncertainties becoming lower than those from theory, carefully considering all sources of νe is important when making theoretical predictions. One source of νe that is often neglected arises from the irradiation of the nonfuel materials in reactors. The νe rates and energies from these sources vary widely based on the reactor type, configuration, and sampling stage during the reactor cycle and have to be carefully considered for each experiment independently. In this article, we present a formalism for selecting the possible νe sources arising from the neutron captures on reactor and target materials. We apply this formalism to the High Flux Isotope Reactor (HFIR) at Oak Ridge National Laboratory, the νe source for the the Precision Reactor Oscillation and Spectrum Measurement (PROSPECT) experiment. Overall, we observe that the nonfuel νe contributions from HFIR to PROSPECT amount to 1% above the inverse beta decay threshold with a maximum contribution of 9% in the 1.8-2.0 MeV range. Nonfuel contributions can be particularly high for research reactors like HFIR because of the choice of structural and reflector material in addition to the intentional irradiation of target material for isotope production. We show that typical commercial pressurized water reactors fueled with low-enriched uranium will have significantly smaller nonfuel νe contribution. Copyright © 2020, The Authors. All rights reserved.

关键词： Pressurized water reactors

Generation and manipulation of tripartite frequency correlation in optical superlattice

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Generation and manipulation of tripartite frequency correlat...

第十八届全国量子光学学术会议

作者：张群永 Ping Xu Guang-Tai Xue Yan-Xiao Gong Zhenda Xie Shining Zhu 南京大学 National Laboratory of Solid State Microstructures and School of Physics Nanjing University Institute for Quantum Information and State Key Laboratory of High Performance Computing College of ComputingNational University of Defense Technology National Laboratory of Solid State Microstructures and School of Electronic Science and Engineering Nanjing University

A monolithic optical superlattice which contains two segments of periodically poled area is designed to generated triplets. We investigate how to manipulate the tripartite frequency correlation of triplets under extended phase-matching conditions. By choosing proper pump bandwidth and crystal length, the tripartite frequency will show a full correlation, partial correlation or no correlation, corresponding to one none-separable triplet, separable one photon and biphoton or three separable photons, respectively. We found that the spacetime wave packets of the triplets could show a variety of fine structures when the physical parameters were adjusted. This research plays an important role in understanding the basic properties of multi-body correlation and can also supply key elements for developing new quantum technologies.

关键词： Generation and manipulation of tripartite frequency correlation in optical superlattice

Separability-entanglement classifier via machine learning

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Physical Review A 2018年第1期98卷 012315-012315页

作者： Sirui Lu Shilin Huang Keren Li Jun Li Jianxin Chen Dawei Lu Zhengfeng Ji Yi Shen Duanlu Zhou Bei Zeng Department of Physics Tsinghua University Beijing 100084 China Institute for Quantum Computing University of Waterloo Waterloo Ontario Canada N2L 3G1 Institute for Interdisciplinary Information Sciences Tsinghua University Beijing 100084 China Institute for Quantum Science and Engineering and Department of Physics Southern University of Science and Technology Shenzhen 518055 China Department of Mathematics & Statistics University of Guelph Guelph Ontario Canada N1G 2W1 Joint Center for Quantum Information and Computer Science University of Maryland College Park Maryland 20742 USA Centre for Quantum Software and Information School of Software Faculty of Engineering and Information Technology University of Technology Sydney Sydney Australia State Key Laboratory of Computer Science Institute of Software Chinese Academy of Sciences Beijing China Department of Statistics and Actuarial Science University of Waterloo Waterloo Ontario Canada N2L 3G1 Institute of Physics Chinese Academy of Sciences Beijing 100190 China

The problem of determining whether a given quantum state is entangled lies at the heart of quantum information processing. Despite the many methods—such as the positive partial transpose criterion and the k-symmetric extendibility criterion—to tackle this problem, none of them enables a general, practical solution due to the problem's NP-hard complexity. Explicitly, separable states form a high-dimensional convex set of vastly complicated structures. In this work, we build a different separability-entanglement classifier underpinned by machine learning techniques. We use standard tools from machine learning to learn the entanglement feature of arbitrary given quantum states. We perform substantial numerical tests on two-qubit and two-qutrit systems, and the results indicate that our method can outperform the existing methods in generic cases in terms of both speed and accuracy. This opens up avenues to explore quantum entanglement via the machine learning approach.

关键词： Machine learning quantum entanglement

Bidirectional spin-wave-driven domain wall motion in antiferromagnetically coupled ferrimagnets

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arXiv 2019年

作者： Oh, Se-Hyeok Kim, Se Kwon Xiao, Jiang Lee, Kyung-Jin Department of Nano-Semiconductor and Engineering Korea University Seoul02841 Korea Republic of Department of Physics and Astronomy University of Missouri ColumbiaMO65211 United States Department of Physics State Key Laboratory of Surface Physics Fudan University Shanghai200433 China Collaborative Innovation Center of Advanced Microstructures Nanjing210093 China Institute for Nanoelectronics Devices and Quantum Computing Fudan University Shanghai200433 China Department of Materials Science and Engineering Korea University Seoul02841 Korea Republic of KU-KIST Graduate School of Converging Science and Technology Korea University Seoul02841 Korea Republic of

We investigate ferrimagnetic domain wall dynamics induced by circularly polarized spin waves theoretically and numerically. We find that the direction of domain wall motion depends on both the circular polarization of spin waves and the sign of net spin density of ferrimagnet. Below the angular momentum compensation point, left- (right-) circularly polarized spin waves push a domain wall towards (away from) the spin-wave source. Above the angular momentum compensation point, on the other hand, the direction of domain wall motion is reversed. This bidirectional motion originates from the fact that the sign of spin-wave-induced magnonic torque depends on the circular polarization and the subsequent response of the domain wall to the magnonic torque is governed by the net spin density. Our finding provides a way to utilize a spin wave as a versatile driving force for bidirectional domain wall motion. Copyright © 2019, The Authors. All rights reserved.

关键词： Spin waves

Implementation vulnerabilities in general quantum cryptography

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arXiv 2018年

作者： Huang, Anqi Barz, Stefanie Andersson, Erika Makarov, Vadim Institute for Quantum Information and State Key Laboratory of High Performance Computing College of Computer National University of Defense Technology Changsha410073 China Institute for Quantum Computing University of Waterloo WaterlooONN2L 3G1 Canada Department of Electrical and Computer Engineering University of Waterloo WaterlooONN2L 3G1 Canada Institute for Functional Matter and Quantum Technologies University of Stuttgart Stuttgart70569 Germany Center for Integrated Quantum Science and Technology University of Stuttgart Iqst Stuttgart70569 Germany Institute of Photonics and Quantum Sciences Heriot-Watt University EdinburghEH14 4AS United Kingdom Russian Quantum Center and Misis University Moscow Russia Department of Physics and Astronomy University of Waterloo WaterlooONN2L 3G1 Canada

quantum cryptography is information-theoretically secure owing to its solid basis in quantum mechanics. However, generally, initial implementations with practical imperfections might open loopholes, allowing an eavesdropper to compromise the security of a quantum cryptographic system. This has been shown to happen for quantum key distribution (QKD). Here we apply experience from implementation security of QKD to several other quantum cryptographic primitives. We survey quantum digital signatures, quantum secret sharing, source-independent quantum random number generation, quantum secure direct communication, and blind quantum computing. We propose how the eavesdropper could in principle exploit the loopholes to violate assumptions in these protocols, breaking their security properties. Applicable countermeasures are also discussed. It is important to consider potential implementation security issues early in protocol design, to shorten the path to future applications. Copyright © 2018, The Authors. All rights reserved.

关键词： quantum cryptography

Device-independent verification of Einstein-Podolsky-Rosen steering

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arXiv 2019年

作者： Zhao, Yuan-Yuan Zhang, Chao Cheng, Shuming Li, Xinhui Guo, Yu Liu, Bi-Heng Ku, Huan-Yu Chen, Shin-Liang Wen, Qiaoyan Huang, Yun-Feng Xiang, Guo-Yong Li, Chuan-Feng Guo, Guang-Can College of the Science China University of Petroleum Qingdao266580 China National Laboratory of Solid State Microstructures School of Physics Collaborative Innovation Center of Advanced Microstructure Nanjing University Nanjing210093 China Peng Cheng Laboratory Shenzhen518055 China Synergetic Innovation Center of Quantum Information and Quantum Physics University of Science and Technology of China Hefei230026 China Department of Control Science and Engineering Tongji University Shanghai201804 China Institute for Advanced Study Tongji University Shanghai200092 China Institute for Quantum Computing Baidu Research Beijing100193 China State Key Laboratory of Networking and Switching Technology Beijing University of Posts and Telecommunications Beijing100876 China National Laboratory of Solid State Microstructures School of Physics Nanjing University Nanjing210093 China Faculty of Physics University of Vienna Boltzmanngasse 5 Vienna1090 Austria Austrian Academy of Sciences Boltzmanngasse 3 Vienna1090 Austria Department of Physics National Chung Hsing University Taichung40227 Taiwan

Entanglement lies at the heart of quantum mechanics, and has been identified an essential resource for diverse applications in quantum information. If entanglement could be verified without any trust in the devices of observers, i.e., in a device-independent (DI) way, then the high security can be guaranteed for various quantum information processing tasks. In this work, we propose and experimentally demonstrate a DI protocol to certify the presence of entanglement based on Einstein-Podolsky-Rosen (EPR) steering. We first establish the DI verification framework by taking the advantages of measurement-device-independent technique and self-testing, which is able to verify all bipartite EPR-steerable states. In the scenario of three-measurement settings for per party, the protocol is robust in tolerance of inefficient measurements and imperfect self-testing. Moreover, a four-photon experiment is implemented for verification beyond Bell nonlocal states. Our work presents the new insight into quantum physics and paves the way for realistic implementations of secure quantum information processing tasks. Copyright © 2019, The Authors. All rights reserved.

关键词： quantum optics

Generation and detection of coherent longitudinal acoustic waves in ultrathin 1T'-MoTe2

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arXiv 2019年

作者： Rivas, Nicolas Zhong, Shazhou Dekker, Tina Cheng, Meixin Gicala, Patrick Chen, Fangchu Luo, Xuan Sun, Yuping Petruk, Ariel A. Pichugin, Kostyantyn Tsen, Adam W. Sciaini, Germán Ultrafast Electron Imaging Lab Department of Chemistry Waterloo Institute for Nanotechnology University of Waterloo WaterlooONN2L3G1 Canada Institute for Quantum Computing Department of Physics and Astronomy Department of Electrical and Computer Engineering Department of Chemistry University of Waterloo WaterlooONN2L3G1 Canada Key Laboratory of Materials Physics Institute of Solid-State Physics Chinese Academy of Sciences Hefei230031 China University of Science and Technology of China Hefei230026 China High Magnetic Field Laboratory Chinese Academy of Sciences Hefei230031 Collaborative Innovation Center of Advanced Microstructures Nanjing University Nanjing210093 China

Layered transition metal dichalcogenides have attracted substantial attention owing to their versatile functionalities and compatibility with current nanofabrication technologies. Thus, noninvasive means to determine the mechanical properties of nanometer (nm) thick specimens are of increasing importance. Here, we report on the detection of coherent longitudinal acoustic phonon modes generated by impulsive femtosecond (fs) optical excitation. Broadband fs-transient absorption experiments in 1T-f-MoTe2 flakes as a function of thickness (7 nm . 30 nm) yield a longitudinal sound speed of vl = (2990± 90) m s-1. In addition, temperature dependent measurements unveil a linear decrease of the normalized Young-fs modulus El/El,295Kwith a slope of δ(***,%' ))/δT = (.2.0± 0.1) 10-3K-1and no noticeable change caused by the Td-1T-f structural phase transition or variations in film thickness. Copyright © 2019, The Authors. All rights reserved.

关键词： Elastic moduli

Security-proof framework for two-way Gaussian quantum-key-distribution protocols

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Physical Review A 2018年第3期98卷 032332-032332页

作者： Quntao Zhuang Zheshen Zhang Norbert Lütkenhaus Jeffrey H. Shapiro Research Laboratory of Electronics Massachusetts Institute of Technology Cambridge Massachusetts 02139 USA Department of Physics Massachusetts Institute of Technology Cambridge Massachusetts 02139 USA Department of Materials Science and Engineering University of Arizona Tucson Arizona 85721 USA Perimeter Institute for Theoretical Physics 31 Caroline Street North Waterloo Ontario N2L 2Y5 Canada Institute for Quantum Computing and Department of Physics and Astronomy University of Waterloo Waterloo Ontario N2L 3G1 Canada

Two-way Gaussian protocols have the potential to increase quantum key distribution (QKD) protocols' secret-key rates by orders of magnitudes [Phys. Rev. A 94, 012322 (2016)]. Security proofs for two-way protocols, however, are underdeveloped at present. In this paper, we establish a security proof framework for the general coherent attack on two-way Gaussian protocols in the asymptotic regime. We first prove that coherent-attack security can be reduced to collective-attack security for all two-way QKD protocols. Next, we identify two different constraints that each provide intrusion parameters which bound an eavesdropper's coherent-attack information gain for any two-way Gaussian QKD protocol. Finally, we apply our results to two such protocols.

关键词： quantum channels quantum communication quantum cryptography quantum protocols

Characterizing the Analogy Between Hyperbolic Embedding and Community Structure of Complex Networks

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Physical Review Letters 2018年第9期121卷 098301-098301页

作者： Ali Faqeeh Saeed Osat Filippo Radicchi MACSI Department of Mathematics and Statistics University of Limerick Limerick V94 T9PX Ireland Center for Complex Networks and Systems Research School of Informatics Computing and Engineering Indiana University Bloomington Indiana 47408 USA Quantum Complexity Science Initiative Skolkovo Institute of Science and Technology Skoltech Building 3 Moscow 143026 Russia

We show that the community structure of a network can be used as a coarse version of its embedding in a hidden space with hyperbolic geometry. The finding emerges from a systematic analysis of several real-world and synthetic networks. We take advantage of the analogy for reinterpreting results originally obtained through network hyperbolic embedding in terms of community structure only. First, we show that the robustness of a multiplex network can be controlled by tuning the correlation between the community structures across different layers. Second, we deploy an efficient greedy protocol for network navigability that makes use of routing tables based on community structure.

关键词： Attacks on networks Community structure Network navigation Robustness