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Role of bulk viscosity in deuteron production in ultrarelativistic nuclear collisions

Physical Review C 2022年第6期106卷 064901-064901页

作者： D. Everett D. Oliinychenko M. Luzum J.-F. Paquet G. Vujanovic S. A. Bass L. Du C. Gale M. Heffernan U. Heinz L. Kasper W. Ke D. Liyanage A. Majumder A. Mankolli C. Shen D. Soeder J. Velkovska A. Angerami R. Arora S. Cao Y. Chen T. Dai R. Ehlers H. Elfner W. Fan R. J. Fries F. Garza Y. He B. V. Jacak P. M. Jacobs S. Jeon M. Kelsey M. Kordell, II A. Kumar J. Latessa Y.-J. Lee A. Lopez S. Mak C. Martin H. Mehryar T. Mengel J. Mulligan C. Nattrass J. H. Putschke G. Roland B. Schenke L. Schwiebert A. Silva C. Sirimanna R. A. Soltz J. Staudenmaier M. Strickland Y. Tachibana X.-N. Wang R. L. Wolpert Department of Physics The Ohio State University Columbus Ohio 43210 USA Institute for Nuclear Theory Department of Physics University of Washington Seattle Washington 98195 USA Nuclear Science Division Lawrence Berkeley National Laboratory Berkeley California 94270 USA Instituto de Fìsica Universidade de São Paulo C.P. 66318 05315-970 São Paulo São Paulo Brazil Department of Physics and Astronomy Vanderbilt University Nashville Tennessee 37235 USA Department of Mathematics Vanderbilt University Nashville Tennessee 37235 USA Department of Physics Duke University Durham North Carolina 27708 USA Department of Physics and Astronomy Wayne State University Detroit Michigan 48201 USA Department of Physics University of Regina Regina Saskatchewan S4S 0A2 Canada Department of Physics McGill University Montréal Québec H3A 2T8 Canada Los Alamos National Laboratory Theoretical Division Los Alamos New Mexico 87545 USA Department of Physics University of California Berkeley California 94270 USA RIKEN BNL Research Center Brookhaven National Laboratory Upton New York 11973 USA Lawrence Livermore National Laboratory Livermore California 94550 USA Research Computing Group University Technology Solutions The University of Texas at San Antonio San Antonio Texas 78249 USA Institute of Frontier and Interdisciplinary Science Shandong University Qingdao Shandong 266237 China Laboratory for Nuclear Science Massachusetts Institute of Technology Cambridge Massachusetts 02139 USA Department of Physics Massachusetts Institute of Technology Cambridge Massachusetts 02139 USA Department of Physics and Astronomy University of Tennessee Knoxville Tennessee 37996 USA Physics Division Oak Ridge National Laboratory Oak Ridge Tennessee 37830 USA GSI Helmholtzzentrum für Schwerionenforschung 64291 Darmstadt Germany Institute for Theoretical Physics Goethe University 60438 Frankfurt am Main Germany Frankfurt Institute for Advanced Studies 60438 Frankfurt am Main Ge

We use a Bayesian-calibrated multistage viscous hydrodynamic model to explore deuteron yield, mean transverse momentum and flow observables in Pb-Pb collisions at the Large Hadron Collider. We explore theoretical uncertainty in the production of deuterons, including (i) the contribution of thermal deuterons, (ii) models for the subsequent formation of deuterons (hadronic transport vs coalescence), and (iii) the overall sensitivity of the results to the hydrodynamic model, in particular to bulk viscosity, which is often neglected in studies of deuteron production. Using physical parameters set by a comparison to only light hadron observables, we find good agreement with measurements of the mean transverse momentum 〈pT〉 and elliptic flow v2 of deuterons; however, tension is observed with experimental data for the deuteron multiplicity in central collisions. The results are found to be sensitive to each of the mentioned theoretical uncertainties, with a particular sensitivity to bulk viscosity, indicating that the latter is an important ingredient for an accurate treatment of deuteron production.

关键词： Collective flow Particle & resonance production Particle correlations & fluctuations Quark-gluon plasma Relativistic heavy-ion collisions Thermal & statistical models Bayesian methods

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Tuning dzyaloshinskii-moriya interaction in ferrimagnetic GdCo: A first principles approach

arXiv

引用

arXiv 2021年

作者： Morshed, Md Golam Khoo, Khoong Hong Quessab, Yassine Xu, Jun-Wen Laskowski, Robert Balachandran, Prasanna V. Kent, Andrew D. Ghosh, Avik W. Department of Electrical and Computer Engineering University of Virginia CharlottesvilleVA22904 United States Institute of High Performance Computing Agency for Science Technology and Research 1 Fusionopolis Way Connexis Singapore138632 Singapore Center for Quantum Phenomena Department of Physics New York University New YorkNY10003 United States Department of Materials Science and Engineering University of Virginia CharlottesvilleVA22904 United States Department of Mechanical and Aerospace Engineering University of Virginia CharlottesvilleVA22904 United States Department of Physics University of Virginia CharlottesvilleVA22904 United States

We present a systematic analysis of our ability to tune chiral Dzyaloshinskii-Moriya Interactions (DMI) in compensated ferrimagnetic Pt/GdCo/Pt1−xWx trilayers by cap layer composition. Using first principles calculations, we show that the DMI increases rapidly for only ∼ 10% W and saturates thereafter, in agreement with experiments. The calculated DMI shows a spread in values around the experimental mean, depending on the atomic configuration of the cap layer interface. The saturation is attributed to the vanishing of spin orbit coupling energy at the cap layer and the simultaneous constancy at the bottom interface. Additionally, we predict the DMI in Pt/GdCo/X (X = Ta, W, Ir) and find that W in the cap layer favors a higher DMI than Ta and Ir that can be attributed to the difference in d-band alignment around the Fermi level. Our results open up exciting combinatorial possibilities for controlling the DMI in ferrimagnets towards nucleating and manipulating ultrasmall high-speed skyrmions. Copyright © 2021, The Authors. All rights reserved.

关键词： Ferrimagnetism

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General quantum Bernoulli factory: Framework analysis and experiments

arXiv

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arXiv 2020年

作者： Liu, Yong Jiang, Jiaqing Zhu, Pingyu Wang, Dongyang Ding, Jiangfang Qiang, Xiaogang Huang, Anqi Xu, Ping Zhang, Jialin Tian, Guojing Fu, Xiang Deng, Mingtang Wu, Chunqing Sun, Xiaoming Yang, Xuejun Wu, Junjie Institute for Quantum Information State Key Laboratory of High Performance Computing College of Computer Science and Technology National University of Defense Technology Changsha410073 China College of Information and Communication National University of Defense Technology Xi'an710006 China Institute of Computing Technology Chinese Academy of Sciences Beijing100190 China University of Chinese Academy of Sciences Beijing100049 China National Innovation Institute of Defense Technology AMS Beijing100071 China CAS Center of Excellence in Topological Quantum Computation University of Chinese Academy of Sciences Beijing100190 China

The unremitting pursuit for quantum advantages gives rise to the discovery of a quantum-enhanced randomness processing named quantum Bernoulli factory (QBF). This quantum enhanced process can show its priority over the corresponding classical process through readily available experimental resources, thus in the near term it may be capable of accelerating the applications of classical Bernoulli factories, such as the widely used sampling algorithms. In this work, we provide the framework analysis of the QBF. We thoroughly analyze the quantum state evolution in this process, discovering the field structure of the constructible quantum states. Our framework analysis shows that naturally, the previous works can be described as specific instances of this framework. Then, as a proof of principle, we experimentally demonstrate this framework via an entangled two-photon source along with a reconfigurable photonic logic, and show the advantages of the QBF over the classical model through a classically infeasible instance. These results may stimulate the discovery of advantages of the quantum randomness processing in a wider range of tasks, as well as its potential applications. Copyright © 2020, The Authors. All rights reserved.

关键词： Random processes

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An initialization strategy for addressing barren plateaus in parametrized quantum circuits

arXiv

引用

arXiv 2019年

作者： Grant, Edward Ostaszewski, Mateusz Wossnig, Leonard Benedetti, Marcello Rahko Limited Department of Computer Science University College London Institute of Theoretical and Applied Informatics Polish Academy of Sciences Cambridge Quantum Computing Limited Department of Computer Science University College London

Parametrized quantum circuits initialized with random initial parameter values are characterized by barren plateaus where the gradient becomes exponentially small in the number of qubits. In this technical note we theoretically motivate and empirically validate an initialization strategy which can resolve the barren plateau problem for practical applications. The technique involves randomly selecting some of the initial parameter values, then choosing the remaining values so that the circuit is a sequence of shallow blocks that each evaluates to the identity. This initialization limits the effective depth of the circuits used to calculate the first parameter update so that they cannot be stuck in a barren plateau at the start of training. In turn, this makes some of the most compact ansätze usable in practice, which was not possible before even for rather basic problems. We show empirically that variational quantum eigensolvers and quantum neural networks initialized using this strategy can be trained using a gradient based method. Copyright © 2019, The Authors. All rights reserved.

关键词： Timing circuits

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The Complexity of Bipartite Gaussian Boson Sampling

arXiv

引用

arXiv 2021年

作者： Grier, Daniel Brod, Daniel J. Arrazola, Juan Miguel de Andrade Alonso, Marcos Benicio Quesada, Nicolás Institute for Quantum Computing University of Waterloo Canada Department of Computer Science and Engineering Department of Mathematics University of California San Diego United States Instituto de Física Universidade Federal Fluminense RJ Niterói24210-340 Brazil Xanadu TorontoONM5G 2C8 Canada Department of Engineering Physics École Polytechnique de Montréal MontréalQCH3T 1JK Canada

Gaussian boson sampling is a model of photonic quantum computing that has attracted attention as a platform for building quantum devices capable of performing tasks that are out of reach for classical devices. There is therefore significant interest, from the perspective of computational complexity theory, in solidifying the mathematical foundation for the hardness of simulating these devices. We show that, under the standard Anti-Concentration and Permanent-of-Gaussians conjectures, there is no efficient classical algorithm to sample from ideal Gaussian boson sampling distributions (even approximately) unless the polynomial hierarchy collapses. The hardness proof holds in the regime where the number of modes scales quadratically with the number of photons, a setting in which hardness was widely believed to hold but that nevertheless had no definitive proof. Crucial to the proof is a new method for programming a Gaussian boson sampling device so that the output probabilities are proportional to the permanents of submatrices of an arbitrary matrix. This technique is a generalization of Scattershot BosonSampling that we call BipartiteGBS. We also make progress towards the goal of proving hardness in the regime where there are fewer than quadratically more modes than photons (i.e., the high-collision regime) by showing that the ability to approximate permanents of matrices with repeated rows/columns confers the ability to approximate permanents of matrices with no repetitions. The reduction suffices to prove that GBS is hard in the constant-collision regime. © 2021, CC BY.

关键词： Bosons

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Khuri-Treiman analysis of J/ψ → π+π−π0

arXiv

引用

arXiv 2023年

作者： Albaladejo, M. Gonzàlez-Solís, S. Bibrzycki, L. Fernández-Ramírez, C. Hammoud, N. Mathieu, V. Mikhasenko, M. Montaña, G. Perry, R.J. Pilloni, A. Rodas, A. Smith, W.A. Szczepaniak, A. Winney, D. Centro Mixto CSIC-Universidad de Valencia ValenciaE-46071 Spain Theoretical Division Los Alamos National Laboratory Los AlamosNM87545 United States AGH University of Krakow Faculty of Physics and Applied Computer Science al. Adama Mickiewicza 30 Kraków30-059 Poland MadridE-28040 Spain Instituto de Ciencias Nucleares Universidad Nacional Autónoma de México Ciudad de México04510 Mexico Institute of Nuclear Physics Polish Academy of Sciences Kraków31-342 Poland Departament de Física Quàntica i Astrofísica Institut de Ciències del Cosmos Universitat de Barcelona E08028 Spain Departamento de Física Teórica Universidad Complutense de Madrid IPARCOS Madrid28040 Spain ORIGINS Excellence Cluster Garching85748 Germany Ludwig-Maximilians-Universität Munich80539 Germany Theory Center Thomas Jefferson National Accelerator Facility Newport NewsVA23606 United States Dipartimento di Scienze Matematiche e Informatiche Scienze Fisiche e Scienze della Terra Uni-versità degli Studi di Messina MessinaI-98122 Italy INFN Sezione di Catania CataniaI-95123 Italy Department of Physics Indiana University BloomingtonIN47405 United States Center for Exploration of Energy and Matter Indiana University BloomingtonIN47403 United States 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

We study the decay J/ψ → π+π−π0 within the framework of the Khuri-Treiman equations. We find that the BESIII experimental di-pion mass distribution in the ρ(770)-region is well reproduced with a once-subtracted P-wave amplitude. Furthermore, we show that F-wave contributions to the amplitude improve the description of the data in the ππ mass region around 1.5 GeV. We also present predictions for the J/ψ → π0γ∗ transition form factor. © 2023, CC BY.

关键词： Seismic waves

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quantum computing for High-Energy Physics State of the Art and Challenges Summary of the QC4HEP Working Group

arXiv

引用

arXiv 2023年

作者： Di Meglio, Alberto Jansen, Karl Tavernelli, Ivano Alexandrou, Constantia Arunachalam, Srinivasan Bauer, Christian W. Borras, Kerstin Carrazza, Stefano Crippa, Arianna Croft, Vincent de Putter, Roland Delgado, Andrea Dunjko, Vedran Egger, Daniel J. Fernández-Combarro, Elias Fuchs, Elina Funcke, Lena González-Cuadra, Daniel Grossi, Michele Halimeh, Jad C. Holmes, Zoë Kühn, Stefan Lacroix, Denis Lewis, Randy Lucchesi, Donatella Martinez, Miriam Lucio Meloni, Federico Mezzacapo, Antonio Montangero, Simone Nagano, Lento Radescu, Voica Ortega, Enrique Rico Roggero, Alessandro Schuhmacher, Julian Seixas, Joao Silvi, Pietro Spentzouris, Panagiotis Tacchino, Francesco Temme, Kristan Terashi, Koji Tura, Jordi Tüysüz, Cenk Vallecorsa, Sofia Wiese, Uwe-Jens Yoo, Shinjae Zhang, Jinglei GenevaCH-1211 Switzerland CQTA Deutsches Elektronen-Synchrotron DESY Platanenallee 6 Zeuthen15738 Germany Computation-based Science and Technology Research Center The Cyprus Institute 20 Constantinou Kavafi str. Nicosia2121 Cyprus IBM Quantum IBM Research – Zurich Rüschlikon8803 Switzerland Department of Physics University of Cyprus PO Box 20537 Nicosia1678 Cyprus IBM Quantum IBM Research 1101 Kitchawan Rd Yorktown HeightsNY United States Physics Division LBNL - M/S 50A5104 1 Cyclotron Rd BerkeleyCA United States Deutsches Elektronen-Synchrotron DESY Notkestrasse 85 Hamburg22607 Germany RWTH Aachen University Templergraben 55 Aachen52062 Germany TIF Lab Dipartimento di Fisica Università degli Studi di Milano INFN Sezione di Milano Milan Italy Institut für Physik Humboldt-Universität zu Berlin Newtonstr. 15 Berlin12489 Germany haQaLi Applied Quantum Algorithms Leiden Netherlands Physics Division Oak Ridge National Laboratory Oak RidgeTN37831 United States Department of Computer Science Facultad de Ciencias University of Oviedo Asturias33007 Spain Institute of Theoretical Phyiscs Leibniz University Hannover Hannover30167 Germany Physikalisch-Technische Bundesanstalt Braunschweig38116 Germany University of Bonn Nußallee 14-16 Bonn53115 Germany Institute for Theoretical Physics University of Innsbruck Innsbruck6020 Austria Institute for Quantum Optics and Quantum Information the Austrian Academy of Sciences Innsbruck6020 Austria Department of Physics Arnold Sommerfeld Center for Theoretical Physics Ludwig-Maximilians-Universität München Germany Munich Center for Quantum Science and Technology Germany LausanneCH-1015 Switzerland Paris-Saclay University CNRS IN2P3 IJCLab Orsay91405 France Department of Physics and Astronomy York University TorontoONM3J 1P3 Canada Department of Physics and Astronomy Università di Padova V. Marzolo 8 PadovaI-35131 Italy INFN - Sezione di Padova Via Marzolo 8 Padova35131 Italy Ni

quantum computers offer an intriguing path for a paradigmatic change of computing in the natural sciences and beyond, with the potential for achieving a so-called quantum advantage, namely a significant (in some cases exponential) speed-up of numerical simulations. The rapid development of hardware devices with various realizations of qubits enables the execution of small scale but representative applications on quantum computers. In particular, the high-energy physics community plays a pivotal role in accessing the power of quantum computing, since the field is a driving source for challenging computational problems. This concerns, on the theoretical side, the exploration of models which are very hard or even impossible to address with classical techniques and, on the experimental side, the enormous data challenge of newly emerging experiments, such as the upgrade of the Large Hadron Collider. In this roadmap paper, led by CERN, DESY and IBM, we provide the status of high-energy physics quantum computations and give examples for theoretical and experimental target benchmark applications, which can be addressed in the near future. Having the IBM 100 100 challenge in mind, where possible, we also provide resource estimates for the examples given using error mitigated quantum computing. © 2023, CC BY-SA.

关键词： High energy physics

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Simulating Effective QED on quantum computers

arXiv

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arXiv 2020年

作者： Stetina, Torin F. Ciavarella, Anthony Li, Xiaosong Wiebe, Nathan Department of Chemistry University of Washington SeattleWA United States Simons Institute for the Theory of Computation University of California BerkeleyCA United States Institute for Nuclear Theory University of Washington SeattleWA United States Department of Physics University of Washington SeattleWA United States Pacific Northwest National Laboratory RichlandWA United States Department of Computer Science University of Toronto TorontoON Canada Challenge Institute for Quantum Computation University of Washington SeattleWA United States

In recent years simulations of chemistry and condensed materials has emerged as one of the preeminent applications of quantum computing, offering an exponential speedup for the solution of the electronic structure for certain strongly correlated electronic systems. To date, most treatments have ignored the question of whether relativistic effects, which are described most generally by quantum electrodynamics (QED), can also be simulated on a quantum computer in polynomial time. Here we show that effective QED, which is equivalent to QED to second order in perturbation theory, can be simulated in polynomial time under reasonable assumptions while properly treating all four components of the wavefunction of the fermionic field. In particular, we provide a detailed analysis of such simulations in position and momentum basis using Trotter-Suzuki formulas. We find that the number of T-gates needed to perform such simulations on a 3D lattice of ns sites scales at worst as O(n3s/∊)1+o(1) in the thermodynamic limit for position basis simulations and O(ns4+2/3/∊)1+o(1) in momentum basis. We also find that qubitization scales slightly better with a worst case scaling of Oe(ns2+2/3/∊) for lattice eQED and complications in the prepare circuit leads to a slightly worse scaling in momentum basis of Oe(ns5+2/3/∊). We further provide concrete gate counts for simulating a relativistic version of the uniform electron gas that show challenging problems can be simulated using fewer than 1013 non-Clifford operations and also provide a detailed discussion of how to prepare multi-reference configuration interaction states in effective QED which can provide a reasonable initial guess for the ground state. Finally, we estimate the planewave cutoffs needed to accurately simulate heavy elements such as gold. © 2020, CC BY.

关键词： Perturbation techniques

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Voltage Manipulation of Desired Magnetization Orientation in Multiferroic Nanomagnets

SSRN

引用

SSRN 2020年

作者： Liu, Jiahao Yang, Xiaokuo Hong, Dunhua Li, Cheng Xu, Nuo Yang, Binbin Fang, Liang Institute for Quantum Information & State Key Laboratory of High Performance Computing College of Computer National University of Defense Technology Changsha410073 China Department of Basic Sciences Air Force Engineering University Xi’an710051 China School of Physics and Electronic Science Zhunyi Normal University Zhunyi563006 China

We report the pure voltage manipulation of the desired magnetization orientation of the multiferroic nanomagnet: through integrating spintronics and multiferroics, we investigate magnetostrictive elliptical two-step-shaped nanomagnets. A pair of electrodes is fabricated on the piezoelectric substrate to generate localized stress by applying voltage. Through the inverse magnetoelectric coupling, slightly inclined stress induces the magnetization of the nanomagnet to desired orientation at room temperature. Our method liberates the electrical manipulation of multiferroic nanomagnets from the strict requirements of the voltage waveform. The results can be effectively applied to electrical induced information storage and logic writing of low- energy-consumption spintronic devices. © 2020, The Authors. All rights reserved.

关键词： Nanomagnetics

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Topological phase transition in Sb-doped Mg3Bi2 monocrystalline thin films

引用

Physical Review B 2021年第12期103卷 125405-125405页

作者： Tong Zhou Mingyu Tong Yun Zhang Xiangnan Xie Zhen-Yu Wang Tian Jiang Xie-Gang Zhu Xin-Chun Lai Science and Technology on Surface Physics and Chemistry Laboratory Jiangyou 621908 Sichuan People's Republic of China State Key Laboratory of High Performance Computing College of Computer National University of Defense Technology Changsha 410073 People's Republic of China Beijing Institute for Advanced Study National University of Defense Technology Beijing 100020 People's Republic of China Institute of Materials China Academy of Engineering Physics Mianyang 621700 Sichuan People's Republic of China College of Advanced Interdisciplinary Studies National University of Defense Technology Changsha 410073 People's Republic of China National Innovation Institute of Defense Technology Academy of Military Sciences PLA China Beijing 100010 People's Republic of China Beijing Academy of Quantum Information Sciences Beijing 100193 People's Republic of China

Mg3Bi2 has been proved to be a semimetal with topological surface states (referred to as a topological semimetal, TSM) in the presence of spin-orbit coupling (SOC), and predicted to be a type-II nodal line semimetal (NSM) in the absence of SOC. It is possible to tune the effective SOC in Mg3Bi2 by substituting the heavy Bi atom with lighter atoms, such as Sb or As, which results in topological phase transitions. Here in our work we investigate the evolution of the transport properties and band structures of Mg3Bi2 by doping different concentrations of Sb through molecular beam epitaxy. Our results demonstrate the existence of phase transitions of TSM to trivial semimetal (SM) and SM to trivial insulator, with Sb concentration x at x1≈0.44–0.64 and x2≈1.39, respectively. Further theoretical calculations give values of x1≈0.523 and x2≈1.10, which agrees well with our experimental results. And all these results are concluded into a Mg3Bi2−xSbx phase diagram. Our work will stimulate more explorations to the possibilities of the realization of type-II NSM in Mg3Bi2 by various elements substitution.

关键词： Surface states Topological materials Topological phase transition Weak antilocalization Angle-resolved photoemission spectroscopy

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