Combining symmetry breaking and restoration with configuration interaction: a highly accurate many-body scheme applied to the pairing Hamiltonian
| Autor: | D. Gambacurta, Thomas Duguet, Jean-Paul Ebran, Denis Lacroix, J. Ripoche |
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| Přispěvatelé: | Institut de Physique Nucléaire d'Orsay (IPNO), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), DAM Île-de-France (DAM/DIF), Direction des Applications Militaires (DAM), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Département de Physique Nucléaire (ex SPhN) (DPHN), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11) |
| Rok vydání: | 2016 |
| Předmět: |
Physics
Quantum phase transition Nuclear Theory [PHYS.NUCL]Physics [physics]/Nuclear Theory [nucl-th] Strongly Correlated Electrons (cond-mat.str-el) 010308 nuclear & particles physics Hilbert space FOS: Physical sciences Observable Configuration interaction 01 natural sciences 7. Clean energy Nuclear Theory (nucl-th) Condensed Matter - Strongly Correlated Electrons symbols.namesake Variational method Quantum state Quantum mechanics Pairing 0103 physical sciences symbols Symmetry breaking 010306 general physics |
| Zdroj: | Physical Review C Physical Review C, 2017, 95, pp.014326. ⟨10.1103/PhysRevC.95.014326⟩ Physical Review C, American Physical Society, 2017, 95, pp.014326. ⟨10.1103/PhysRevC.95.014326⟩ |
| ISSN: | 2469-9985 2469-9993 |
| DOI: | 10.48550/arxiv.1610.04063 |
| Popis: | 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. Methods: We formulate a truncated configuration interaction method that consists of diagonalizing the Hamiltonian in a highly truncated subspace of the total N-body Hilbert space. The reduced Hilbert space is generated via the particle-number projected BCS state along with projected seniority-zero two and four quasi-particle excitations. Furthermore, the extent by which the underlying BCS state breaks U(1) symmetry is optimized in presence of the projected two and four quasi-particle excitations... The quality of the newly designed method is tested against exact solutions of the so-called attractive pairing Hamiltonian problem. Results: By construction, the method reproduce exact results for N=2 and N=4. For N=(8,16,20) the error on the ground-state correlation energy is less than (0.006, 0.1, 0.15) % across the entire range of inter-nucleon coupling defining the pairing Hamiltonian and driving the normal-to-superfluid quantum phase transition. The presently proposed method offers the advantage to automatically access the low-lying spectroscopy, which it does with high accuracy. Conclusions: The numerical cost of the newly designed variational method is polynomial (N$^6$) in system size. It achieves an unprecedented accuracy on the ground-state correlation energy, effective pairing gap and one-body entropy as well as on the excitation energy of low-lying states of the attractive pairing Hamiltonian. This constitutes a strong enough motivation to envision its application to realistic nuclear Hamiltonians in view of providing a complementary, accurate and versatile ab initio description of mid-mass open-shell nuclei in the future. Comment: 15 pages, 11 figures, full abstract available in text |
| Databáze: | OpenAIRE |
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