检索结果-内蒙古大学图书馆

A qubit-ADAPT Implementation for H2 Molecules using an Explicitly Correlated Basis

学校读者我要写书评

暂无评论

arXiv 2023年

作者： Volkmann, Hakon Sathyanarayanan, Raamamurthy Saenz, Alejandro Jansen, Karl Kühn, Stefan AG Moderne Optik Institut für Physik Humboldt-Universität zu Berlin Newtonstraße 15 Berlin12489 Germany CQTA DESY Zeuthen Platanenallee 6 Zeuthen15738 Germany Computation-Based Science and Technology Research Center The Cyprus Institute 20 Kavafi Street Nicosia2121 Cyprus

With the recent advances in the development of devices capable of performing quantum computations, a growing interest in finding near-term applications has emerged in many areas of science. In the era of non-fault tolerant quantum devices, algorithms that only require comparably short circuits accompanied by high repetition rates are considered to be a promising approach for assisting classical machines with finding solution on computationally hard problems. The ADAPT approach previously introduced in Nat. Commun. 10, 3007 (2019) extends the class of variational quantum eigensolver (VQE) algorithms with dynamically growing ansätze in order to find approximations to ground and excited state energies of molecules. In this work, the ADAPT algorithm has been combined with a first-quantized formulation for the hydrogen molecule in the Born-Oppenheimer approximation, employing the explicitly correlated basis functions introduced in J. Chem. Phys. 43, 2429 (1965). By the virtue of their explicit electronic correlation properties, it is shown in classically performed simulations that relatively short circuits yield chemical accuracy ( Copyright © 2023, The Authors. All rights reserved.

关键词： Molecules

Investigation of two-particle contributions to nucleon matrix elements

学校读者我要写书评

暂无评论

arXiv 2023年

作者： Alexandrou, Constantia Koutsou, Giannis Li, Yan Petschlies, Marcus Pittler, Ferenc Department of Physics University of Cyprus P.O. Box 20537 Nicosia1678 Cyprus Computation-based Science and Technology Research Center The Cyprus Institute 20 Kavafi Str. Nicosia2121 Cyprus Rheinische Friedrich-Wilhelms-Universität Bonn Nußallee 14-16 Bonn53115 Germany

We investigate contributions of excited states to nucleon matrix elements by studying the two- and three-point functions using nucleon and pion-nucleon interpolating fields. This study is carried out using twisted mass fermion ensembles with pion masses 346 MeV and 131 MeV. We compare the results obtained using these two ensembles and show preliminary results for nucleon charges. © 2023, CC BY.

关键词： Hadrons

The torelon spectrum and the world-sheet axion 38

学校读者我要写书评

暂无评论

The torelon spectrum and the world-sheet axion

38th International Symposium on Lattice Field Theory, LATTICE 2021

作者： Athenodorou, Andreas Teper, Michael Computation-Based Science and Technology Research Center The Cyprus Institute Cyprus Dipartimento di Fisica Universitá di Pisa INFN Sezione di Pisa Largo Pontecorvo 3 Pisa56127 Italy Rudolf Peierls Centre for Theoretical Physics University of Oxford Parks Road OxfordOX1 3PU United Kingdom All Souls College University of Oxford High Street OxfordOX1 4AL United Kingdom

We present a major update on the spectrum of the closed flux-tube (torelon) in D = 3+1 SU(N) gauge theories. Namely, we calculate the excitation spectrum of a confining flux-tube which winds around a spatial torus as a function of its length l, for short as well as long tubes. We do so for N = 3,5,6 and two different values of the lattice spacing. Our states are characterised by the quantum numbers of spin J, transverse parity P⌋⌊, longitudinal parity P as well as by the longitudinal momentum p. Our extended basis of operators used in combination with the generalized eigenvalue method enables us to extract masses for all irreducible representations characterised by {|J|,P⌋⌊,P}. We confirm that most of the low-lying states are well described by the spectrum of the Goddard-Goldstone-Rebbi-Thorn string. In addition we provide strong evidence, that in addition to string like states, massive modes exist on the world-sheet. More precisely the ground state with quantum numbers |J|P⌋⌊,P = 0−− exhibits a behaviour which is in agreement with the interpretation of being an axion on the world-sheet of the flux-tube. This state arises from a topological interaction term included in the effective world-sheet action. In addition we observe that the second excited state with |J|P⌋⌊,P = 0++ behaves as a massive mode with mass twice that of the axion. © Copyright owned by the author(s) under the terms of the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License (CC BY-NC-ND 4.0)

关键词： Excited states

Open science in Lattice Gauge Theory community

学校读者我要写书评

暂无评论

arXiv 2022年

作者： Athenodorou, Andreas Bennett, Ed Lenz, Julian Papadopoullou, Elli Computation-based Science and Technology Research Center The Cyprus Institute Cyprus Swansea Academy of Advanced Computing Swansea University Fabian Way SwanseaSA1 8EN United Kingdom ATHENA research center Artemidos 6 & Epidavrou 15125 Marousi Greece

Open science aims to make scientific research processes, tools and results accessible to all scientific communities, creating trust in science and enabling digital competences to be realized in research, leading to increased innovation. It provides standard and transparent pathways to conducting research and fosters best practices for collecting, analysing, preserving, sharing and reusing data, software, workflows and other outputs through collaborative networks. Open science appears to be becoming the norm with its applications spanning throughout the whole research cycle of a project. The importance of making Open science a reality is nowadays reflected in funding policies, research infrastructure and politics. In these proceedings we present the basic Open science principles explaining briefly best practices for materialising Open science. Subsequently, we present the results of the landscaping survey of Open science in the Lattice Gauge Theories community. Finally, we provide directions in which the Lattice Gauge Theory community could move in order to enhance Openness and FAIRness (Findability, Accessibility, Interoperability, Reusability) in science. © 2022, CC BY-NC-ND.

关键词： Reusability

Antiheavy-Antiheavy-Light-Light Four-Quark Bound States 39

学校读者我要写书评

暂无评论

Antiheavy-Antiheavy-Light-Light Four-Quark Bound States

39th International Symposium on Lattice Field Theory, LATTICE 2022

作者： Pflaumer, Martin Alexandrou, Constantia Finkenrath, Jacob Leontiou, Theodoros Meinel, Stefan Wagner, Marc Institut für Theoretische Physik Goethe-Universität Frankfurt am Main Max-von-Laue-Straße 1 Frankfurt am MainD-60438 Germany Department of Physics University of Cyprus Nicosia20537 Cyprus Computation-based Science and Technology Research Center The Cyprus Institute 20 Konstantinou Kavafi Street Nicosia2121 Cyprus Department of Mechanical Engineering Frederick University Nicosia1036 Cyprus Department of Physics University of Arizona TucsonAZ85721 United States Helmholtz Research Academy Hesse for FAIR Campus Riedberg Max-von-Laue-Straße 12 Frankfurt am MainD-60438 Germany

We present our recent results on antiheavy-antiheavy-light-light tetraquark systems using lattice QCD. Our study of the b¯b¯us four-quark system with quantum numbers JP = 1+ and the b¯c¯ud four-quark systems with I(JP) = 0(0+) and I(JP) = 0(1+) utilizes scattering operators at the sink to improve the extraction of the low-lying energy levels. We found a bound state for b¯b¯us with Ebind, b¯b¯us = (-86 ± 22 ± 10) MeV, but no indication for a bound state in both b¯c¯ud channels. Moreover, we show preliminary results for b¯b¯ud with I(JP) = 0(1+), where we used scattering operators both at the sink and the source. We found a bound state and determined its infinite-volume binding energy with a scattering analysis, resulting in Ebind, b¯b¯ud = (-103 ± 8) MeV. © Copyright owned by the author(s) under the terms of the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License (CC BY-NC-ND 4.0).

关键词： Binding energy

CP-violating Dashen phase transition in the two-flavor Schwinger model: A study with matrix product states 38

学校读者我要写书评

暂无评论

CP-violating Dashen phase transition in the two-flavor Schwi...

38th International Symposium on Lattice Field Theory, LATTICE 2021

作者： Funcke, Lena Jansen, Karl Kühn, Stefan Center for Theoretical Physics Co-Design Center for Quantum Advantage NSF AI Institute for Artificial Intelligence and Fundamental Interactions Massachusetts Institute of Technology 77 Massachusetts Avenue CambridgeMA02139 United States Perimeter Institute for Theoretical Physics 31 Caroline Street North WaterlooONN2L 2Y5 Canada Deutsches Elektronen-Synchrotron DESY Platanenallee 6 Zeuthen15738 Germany Computation-Based Science and Technology Research Center The Cyprus Institute 20 Kavafi Street Nicosia2121 Cyprus

We numerically study the Hamiltonian lattice formulation of the two-flavor Schwinger model using matrix product states. Keeping the mass of the first flavor at a fixed positive value, we tune the mass of the second flavor through a range of negative values, thus exploring a regime where conventional Monte Carlo methods suffer from the sign problem and may run into instabilities due to zero modes. Our results indicate a phase transition at the point where the absolute value of the second flavor mass approaches the first flavor mass. The phase transition is accompanied by the formation of a fermion condensate, a steep drop of the average electric field, and a peak in the bipartite entanglement entropy. Our data hints at a second order transition, which is the 1+1D analog of the CP-violating Dashen phase transition in QCD. © Copyright owned by the author(s) under the terms of the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License (CC BY-NC-ND 4.0)

关键词： Monte Carlo methods

Small-scale Hamiltonian optimization of interpolating operators for Lagrangian lattice quantum field theory

学校读者我要写书评

暂无评论

arXiv 2024年

作者： Avkhadiev, Artur Funcke, Lena Jansen, Karl Kühn, Stefan Shanahan, Phiala E. Center for Theoretical Physics Massachusetts Institute of Technology CambridgeMA02139 United States DOE Co-Design Center for Quantum Advantage United States University of Bonn Nussallee 14-16 Bonn53115 Germany Center for Quantum Technology and Applications Deutsches Elektronen-Synchrotron DESY Platanenallee 6 Zeuthen15738 Germany Computation-Based Science and Technology Research Center The Cyprus Institute 20 Kavafi Street Nicosia2121 Cyprus NSF AI Institute for Artificial Intelligence and Fundamental Interactions United States

Lattice quantum field theory calculations may potentially combine the advantages of Hamiltonian formulations with the scalability and control of conventional Lagrangian frameworks. However, such hybrid approaches need to consider (1) the differences in renormalized coupling values between the two formulations, and (2) finite-volume and discretization effects when the Hamiltonian component of the calculation is characterized by a smaller volume or coarser lattice spacing than the Lagrangian component. This work investigates the role of both factors in the application of Hamiltonian-optimized interpolating operator constructions for the conventional Lagrangian framework. The numerical investigation is realized for the pseudoscalar meson in the Schwinger model, using tensor-network and Monte-Carlo calculations. It is demonstrated that tensor-network-optimized constructions are robust to both (1) and (2). In particular, accurate optimized constructions for the pseudoscalar meson can be obtained from calculations with a smaller number of Hamiltonian lattice sites, even when the meson mass itself receives significant finite-volume corrections. To the extent that these results generalize to theories with more complicated spectra, the method holds promise for near-term applications in large-scale calculations of lattice quantum field theory. © 2024, CC BY.

关键词： Hamiltonians

Slender phoretic loops and knots

学校读者我要写书评

暂无评论

Physical Review Fluids 2024年第5期9卷 054201-054201页

作者： Panayiota Katsamba Matthew D. Butler Lyndon Koens Thomas D. Montenegro-Johnson Computation-based Science and Technology Research Center (CaSToRC) The Cyprus Institute Nicosia 2121 Cyprus School of Mathematics University of Birmingham Birmingham B15 2TT United Kingdom Department of Mathematics University College London London WC1H 0AY United Kingdom Mathematics Institute University of Warwick Coventry CV4 7EZ United Kingdom Department of Mathematics University of Hull Hull HU6 7RX United Kingdom

We present an asymptotic theory for solving the dynamics of slender autophoretic loops and knots. Our formulation is valid for nonintersecting three-dimensional center lines, with arbitrary chemical patterning and varying (circular) cross-sectional radius, allowing a broad class of slender active loops and knots to be studied. The theory is amenable to closed-form solutions in simpler cases, allowing us to analytically derive the swimming speed of chemically patterned tori, and the pumping strength (stresslet) of a uniformly active slender torus. Using simple numerical solutions of our asymptotic equations, we then elucidate the behavior of many exotic active particle geometries, such as a bumpy uniformly active torus that spins and a Janus trefoil knot, which rotates as it swims forwards.

关键词： Diffusiophoresis Fluid-particle interactions Microswimmers Slender body theory

Testing the SU(2) lattice Hamiltonian built from S3 partitionings 40

学校读者我要写书评

暂无评论

Testing the SU(2) lattice Hamiltonian built from S3 partitio...

40th International Symposium on Lattice Field Theory, LATTICE 2023

作者： Garofalo, Marco Hartung, Tobias Jakobs, Timo Jansen, Karl Ostmeyer, Johann Rolfes, Dominik Romiti, Simone Urbach, Carsten Rheinische Friedrich-Wilhelms-Universität Bonn Nußallee 14-16 BonnD-53115 Germany Northeastern University - London Devon House St Katharine Docks LondonE1W 1LP United Kingdom Khoury College of Computer Sciences Northeastern University 440 Huntington Avenue 202 West Village H BostonMA02115 United States CQTA DESY Zeuthen Platanenallee 6 Zeuthen15738 Germany Computation-Based Science and Technology Research Center The Cyprus Institute 20 Kavafi Street Nicosia2121 Cyprus Department of Mathematical Sciences University of Liverpool LiverpoolL69 7ZL United Kingdom

We test a possible digitization of SU(2) lattice gauge theories based on partitionings of the sphere S3. In our construction the link operators are unitary and diagonal, with eigenvalues determined by the vertices of the partitioning. The canonical momenta are finite difference operators approximating the Lie derivatives on the manifold. In this formalism we implement the standard Wilson Hamiltonian. We show results for a 2-site Schwinger-type model in 1D and a single-plaquette system in 2D. Our calculations are performed on a classical computer, though in principle they can be implemented also on a quantum device. © Copyright owned by the author(s) under the terms of the Creative Commons.

关键词： Hamiltonians