Publications (41)
Antisymmetrization of composite fermionic states for quantum simulations of nuclear reactions in first-quantization mapping
Ionel Stetcu
I present a first-quantization deterministic algorithm for antisymmetrizing a spatially separated target-projectile system containing and identical fermions, respective…
Scalar ground-state observables in the random phase approximation
Calvin W. Johnson, Ionel Stetcu
We calculate the ground-state expectation value of scalar observables in the matrix formulation of the random phase approximation (RPA). Our expression, derived using the quasiboso…
From non-Hermitian effective operators to large-scale no-core shell model calculations for light nuclei
Bruce R. Barrett, Ionel Stetcu, Petr Navratil +1
No-core shell model (NCSM) calculations using ab initio effective interactions are very successful in reproducing experimental nuclear spectra. The main theoretical approach is the…
Spatial orientation of the fission fragment intrinsic spins and their correlations
Guillaume Scamps, Ibrahim Abdurrahman, Matthew Kafker +2
New experimental and theoretical results obtained in 2021 made it acutely clear that more than 80 years after the discovery of nuclear fission we do not understand the generation a…
QRPA calculations for M1 transitions with the noniterative finite amplitude method and the application to neutron radiative capture cross sections
Hirokazu Sasaki, Toshihiko Kawano, Ionel Stetcu
We derive the equations of quasiparticle random-phase approximation (QRPA) based on the finite amplitude method (FAM) with the Hartree-Fock+BCS (HF+BCS) single-particle states, and…
Electromagnetic transitions with effective operators
Ionel Stetcu, Bruce R. Barrett, Petr Navratil +1
In the no-core shell model formalism we compute effective one- and two-body operators, using the Lee-Suzuki procedure within the two-body cluster approximation. We evaluate the val…
A time-dependent wave-packet approach to reactions for quantum computation
Evan Rule, Ionel Stetcu
We describe a method for obtaining the scattering matrix for nuclear or chemical reactions on a finite lattice. Aside from the preparation of the initial and final states as wave p…
SU(3) versus deformed Hartree-Fock
Calvin W. Johnson, Ionel Stetcu, J. P. Draayer
Deformation is fundamental to understanding nuclear structure. We compare two ways to efficiently realize deformation for many-fermion wavefunctions, the leading SU(3) irrep and th…
Solving reaction dynamics with quantum computing algorithms
Ronen Weiss, Alessandro Baroni, Joseph Carlson +1
The description of quantum many-body dynamics is extremely challenging on classical computers, as it can involve many degrees of freedom. On the other hand, the time evolution of q…
Deep Quantum Circuit Simulations of Low-Energy Nuclear States
Ang Li, Alessandro Baroni, Ionel Stetcu +1
Numerical simulation is an important method for verifying the quantum circuits used to simulate low-energy nuclear states. However, real-world applications of quantum computing for…
Correlations between energy and -ray emission in
Nathan P. Giha, Stefano Marin, James A. Baker +15
We study -ray emission following over an incident neutron energy range of MeV. We present the first experimental evidence for p…
Time Evolution of Prompt Gamma-Ray Emission in Cf(sf) and U(,f) Reactions
Patrick Talou, Amy E. Lovell, Ionel Stetcu +3
We investigate the time evolution of prompt fission emission due to the presence of ns to ms isomers in the fragments produced in the neutron-induced fission of U…
Microscopic Theory of Nuclear Fission
Aurel Bulgac, Shi Jin, Piotr Magierski +2
We describe the fission dynamics of Pu within an implementation of the Density Functional Theory (DFT) extended to superfluid systems and real-time dynamics. We demonstrate…
RPA vs. exact shell-model correlation energies
Ionel Stetcu, Calvin W. Johnson
The random phase approximation (RPA) builds in correlations left out by mean-field theory. In full 0-hbar-omega shell-model spaces we calculate the Hartree-Fock + RPA binding energ…
Induced Fission of Pu within a Real-Time Microscopic Framework
Aurel Bulgac, Piotr Magierski, Kenneth J. Roche +1
We describe the fissioning dynamics of Pu240 from a configuration in the proximity of the outer fission barrier to full scission and the formation of the fragments within an implem…
Neck Rupture and Scission Neutrons in Nuclear Fission
Ibrahim Abdurrahman, Matthew Kafker, Aurel Bulgac +1
Just before a nucleus fissions a neck is formed between the emerging fission fragments. It is widely accepted that this neck undergoes a rather violent rupture, despite no direct e…
Consideration of memory of spin and parity in the fissioning compound nucleus by applying the Hauser-Feshbach fission fragment decay model to photonuclear reactions
Toshihiko Kawano, Amy E. Lovell, Shin Okumura +3
Prompt and -delayed fission observables, such as the average number of prompt and delayed neutrons, the independent and cumulative fission product yields, and the prompt -r…
Fragment Intrinsic Spins and Fragments' Relative Orbital Angular Momentum in Nuclear Fission
Aurel Bulgac, Ibrahim Abdurrahman, Kyle Godbey +1
We present the first fully unrestricted microscopic calculations of the primary fission fragment intrinsic spins and of the fission fragments' relative orbital angular momentum for…
Future of Nuclear Fission Theory
Michael Bender, Remi Bernard, George Bertsch +30
There has been much recent interest in nuclear fission, due in part to a new appreciation of its relevance to astrophysics, stability of superheavy elements, and fundamental theory…
Recent developments in no-core shell-model calculations
Petr Navratil, Sofia Quaglioni, Ionel Stetcu +1
We present an overview of recent results and developments of the no-core shell model (NCSM), an ab initio approach to the nuclear many-body problem for light nuclei. In this approa…
Influence of the Exit Channel in U(n,f) and Pu(n,f) Reactions in Time-Dependent Density Functional Theory
Ibrahim Abdurrahman, Matthew Kafker, Aurel Bulgac +1
This study investigates the consequences of the intrinsic deformation of the fissioning nuclear system near the outer saddle point on the shape evolution of the nucleus from saddle…
Simplified projection on total spin zero for state preparation on quantum computers
Evan Rule, Ionel Stetcu, Joseph Carlson
We introduce a simple algorithm for projecting on states of a many-body system by performing a series of rotations to remove states with angular momentum projections greater…
Gamow-Teller transitions and deformation in the proton-neutron random phase approximation
Ionel Stetcu, Calvin W. Johnson
We investigate reliability of Gamow-Teller transition strengths computed in the proton-neutron random phase approximation, comparing with exact results from diagonalization in full…
Non-Markovian character and irreversibility of real-time quantum many-body dynamics
Aurel Bulgac, Matthew Kafker, Ibrahim Abdurrahman +1
The presence of pairing correlations within the time-dependent density functional theory (TDDFT) extension to superfluid systems, is tantamount to the presence of a quantum collisi…
Structure in the Event-by-Event Energy-Dependent Neutron-Gamma Multiplicity Correlations in (sf)
Stefano Marin, Mustapha Stephan Okar, Eoin P. Sansevero +13
The emission of neutrons and gamma rays by fission fragments reveal important information about the properties of fragments immediately following scission. The initial fragment pro…
Benchmark calculation of inclusive electromagnetic responses in the four-body nuclear system
Ionel Stetcu, Sofia Quaglioni, Sonia Bacca +6
Both the no-core shell model and the effective interaction hyperspherical harmonic approaches are applied to the calculation of different response functions to external electromagn…
Tests of the random phase approximation for transition strengths
Ionel Stetcu, Calvin W. Johnson
We investigate the reliability of transition strengths computed in the random-phase approximation (RPA), comparing with exact results from diagonalization in full shell-…
An Alternative Approach to Quantum Imaginary Time Evolution
Pejman Jouzdani, Calvin W. Johnson, Eduardo R. Mucciolo +1
There is increasing interest in quantum algorithms that are based on the imaginary-time evolution (ITE), a successful classical numerical approach to obtain ground states. However,…
Time-Dependent Density Functional Theory Description of U(n,f), Pu(n,f) and Np(n,f) Reactions
Aurel Bulgac, Ibrahim Abdurrahman, Matthew Kafker +1
In nuclei with an odd nucleon number the non-vanishing spin number density is the source of a pseudo-magnetic field, which favors the splitting of the nucleon Cooper pairs. Such an…
State preparation and symmetries
Ivana Miháliková, Joseph Carlson, Duff Neill +1
We demonstrate the importance of symmetries in Variational Quantum Eigensolver (VQE) algorithms to prepare the ground or specific low-lying states of quantum Hamiltonians. We exami…
Shortcuts to nuclear structure: lessons in Hartree-Fock, RPA, and the no-core shell model
Calvin W. Johnson, Ionel Stetcu
While the no-core shell model is a state-of-the-art microscopic approach to low-energy nuclear structure, its intense computational requirements lead us to consider time-honored ap…
Effective operators within the ab initio no-core shell model
Ionel Stetcu, Bruce R. Barrett, Petr Navratil +1
We implement an effective operator formalism for general one- and two-body operators, obtaining results consistent with the no-core shell model (NCSM) wave functions. The Argonne V…
Non-iterative finite amplitude methods for E1 and M1 giant resonances
Hirokazu Sasaki, Toshihiko Kawano, Ionel Stetcu
The finite amplitude method (FAM) is a very efficient approach for solving the fully self-consistent random-phase approximation (RPA) equations. We use FAM to rederive the RPA matr…
Unitary evolution with fluctuations and dissipation
Aurel Bulgac, Shi Jin, Ionel Stetcu
We outline an extension of the classical Langevin equation to a quantum formulation of the treatment of dissipation and fluctuations of all collective degrees of freedom with unita…
Collapse of the random phase approximation: examples and counter-examples from the shell model
Calvin W. Johnson, Ionel Stetcu
The Hartree-Fock approximation to the many-fermion problem can break exact symmetries, and in some cases by changing a parameter in the interaction one can drive the Hartree-Fock m…
Quantum Information Science and Technology for Nuclear Physics. Input into U.S. Long-Range Planning, 2023
Douglas Beck, Joseph Carlson, Zohreh Davoudi +98
In preparation for the 2023 NSAC Long Range Plan (LRP), members of the Nuclear Science community gathered to discuss the current state of, and plans for further leveraging opportun…
The LISE package: solvers for static and time-dependent superfluid local density approximation equations in three dimensions
Shi Jin, Kenneth J. Roche, Ionel Stetcu +2
Nuclear implementation of the density functional theory (DFT) is at present the only microscopic framework applicable to the whole nuclear landscape. The extension of DFT to superf…
Long- and short-range correlations in the ab-initio no-core shell model
Ionel Stetcu, Bruce R. Barrett, Petr Navratil +1
In the framework of the ab-initio no-core shell model (NCSM), we describe the longitudinal-longitudinal distribution function, part of the inclusive (e,e') longitudinal response. I…
Influence of non-statistical properties in nuclear structure on emission of prompt fission neutrons
Toshihiko Kawano, Shin Okumura, Amy E. Lovell +2
The Hauser-Feshbach Fission Fragment Decay (HFD) model is extended to calculate the prompt fission neutron spectrum (PFNS) for the thermal neutron induced fission on U,…
Nuclear Fission Dynamics: Past, Present, Needs, and Future
Aurel Bulgac, Shi Jin, Ionel Stetcu
Recent developments in theoretical modeling and in computational power have allowed us to make significant progress on a goal not achieved yet in nuclear theory: a fully microscopi…
Fission Dynamics of 240Pu from Saddle-to-Scission and Beyond
Aurel Bulgac, Shi Jin, Kenneth Roche +2
Calculations are presented for the time evolution of Pu from the proximity of the outer saddle point until the fission fragments are well separated, using the time-dependen…