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A common approach to minimizing the cost of quantum computations is by transforming a quantum system into a basis that can be optimally truncated. Here, we derive classical equations of motion subjected to similar unitary transformations,…

Quantum Physics · Physics 2024-04-25 Ken Miyazaki , Alex Krotz , Roel Tempelaar

Drip-line nuclei have very different properties from those of the valley of stability, as they are weakly bound and resonant. Therefore, the models devised for stable nuclei can no longer be applied therein. Hence, a new theoretical tool,…

Computational Physics · Physics 2020-02-19 Nicolas Michel , Hasan Metin Aktulga , Yannen Jaganathen

The no-core shell model (NCSM) is an \textit{ab initio} method that solves the nuclear many-body problem by expanding the many-particle wave function into a (typically) harmonic oscillator basis and minimizing the energy to obtain the…

Nuclear Theory · Physics 2024-02-06 Konstantinos Kravvaris , Sofia Quaglioni , Petr Navratil

We present a nucleus-dependent valence-space approach for calculating ground and excited states of nuclei, which generalizes the shell-model in-medium similarity renormalization group to an ensemble reference with fractionally filled…

Nuclear Theory · Physics 2017-01-24 S. R. Stroberg , A. Calci , H. Hergert , J. D. Holt , S. K. Bogner , R. Roth , A. Schwenk

Quantum phase estimation (QPE) is a promising quantum algorithm for obtaining molecular ground-state energies with chemical accuracy. However, its computational cost, dominated by the Hamiltonian 1-norm $\lambda$ and the cost of the block…

We investigate the suitability of natural orbitals as a basis for describing many-body excitations. We analyze to which extend the natural orbitals describe both bound as well as ionized excited states and show that depending on the…

Other Condensed Matter · Physics 2011-01-14 N. Helbig , I. V. Tokatly , A. Rubio

For light nuclei, ab initio many-body methods such as the no-core shell model are the tools of choice for predictive, high-precision nuclear structure calculations. The applicability and the level of precision of these methods, however, is…

Nuclear Theory · Physics 2024-07-29 Tobias Wolfgruber , Marco Knöll , Robert Roth

Background: Ab initio many-body methods have been developed over the past ten years to address mid-mass nuclei... As progress in the design of inter-nucleon interactions is made, further efforts must be made to tailor many-body methods.…

Nuclear Theory · Physics 2017-02-01 J. Ripoche , D. Lacroix , D. Gambacurta , J. -P. Ebran , T. Duguet

Precise theoretical calculations of open-shell atomic systems are critical for extracting fundamental physics parameters from precision experiments. Here we present proof-of-principle calculations illustrating the effectiveness of the…

Atomic Physics · Physics 2022-12-19 G. Tenkila , V. Chand , T. Miyagi , H. Patel , S. R. Stroberg , R. F. Garcia Ruiz , J. D. Holt

Structures of $p$- and $sd$-shell nuclei are studied with the deformed-basis antisymmetrized molecular dynamics method using the Gogny D1S and Skyrme SLy7 forces as effective interactions. By the energy variation with a constraint, energy…

Nuclear Theory · Physics 2009-06-25 Yasutaka Taniguchi , Yoshiko Kanada-En'yo , Masaaki Kimura

Nuclear pairing gaps of normally deformed and superdeformed nuclei are investigated using the particle-number conserving (PNC) formalism for the cranked shell model, in which the blocking effects are treated exactly. Both rotational…

Nuclear Theory · Physics 2015-05-27 X. Wu , Z. H. Zhang , J. Y. Zeng , Y. A. Lei

We present an approach to accelerate real-space electronic structure methods several fold, without loss of accuracy, by reducing the dimension of the discrete eigenproblem that must be solved. To accomplish this, we construct an efficient,…

Computational Physics · Physics 2018-05-01 Qimen Xu , Phanish Suryanarayana , John E. Pask

The goal of this presentation is to highlight various computational techniques used to study dynamics of quantum many-body systems. We examine the projection and variable phase methods being applied to multi-channel problems of scattering…

Nuclear Theory · Physics 2014-12-22 Alexander Volya

The periodic-orbit theory based on the improved stationary-phase method within the phase-space path integral approach is presented for the semiclassical description of the nuclear shell structure, concerning the main topics of the fruitful…

Nuclear Theory · Physics 2017-03-08 A. G. Magner , M. V. Koliesnik , K. Arita

Structure-preserving algorithms and algorithms with uniform error bound have constituted two interesting classes of numerical methods. In this paper, we blend these two kinds of methods for solving nonlinear Hamiltonian systems with highly…

Numerical Analysis · Mathematics 2021-02-08 Bin Wang , Yaolin Jiang

In the last years, chiral effective field theory has been successfully developed for and applied to systems with few nucleons. Here, I present a new approach for ab initio calculations of nuclei that combines these precise and systematic…

Nuclear Theory · Physics 2015-05-27 Ulf-G. Meißner

Nuclear quantum phenomena beyond the Born-Oppenheimer approximation are known to play an important role in a growing number of chemical and biological processes. While there exists no unique consensus on a rigorous and efficient…

When moving away from stability or in loosely-bound systems, few-body clusterized structures like two-neutron halo nuclei appear. These emerge from the interplay between the many- and few-body degrees of freedom, and/or strong coupling…

Nuclear Theory · Physics 2026-02-24 Patrick McGlynn , Chloë Hebborn

Model calculations of nuclear properties are peformed using quantum computing algorithms on simulated and real quantum computers. The models are a realistic calculation of deuteron binding based on effective field theory, and a simplified…

Nuclear Theory · Physics 2022-05-12 Isaac Hobday , Paul D Stevenson , James Benstead

The perovskite oxides are known to be susceptible to structural distortions over a long wavelength when compared to their parent cubic structures. From an ab initio simulation perspective, this requires accurate calculations including many…

Computational Physics · Physics 2022-02-16 Jack S. Baker , Tsuyoshi Miyazki , David R. Bowler