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Mostrando ítems 11-20 de 38
Artículo
Relation between E(5) models and the interacting boson model
(The American Physical Society, 2008)
The connections between the E(5) models [the original E(5) using an infinite square well, E(5)-β4, E(5)-β6, and E(5)-β8], based on particular solutions of the geometrical Bohr Hamiltonian with γ-unstable potentials, and ...
Artículo
An extended Agassi model: Algebraic structure, phase diagram, and large size limit
(Institute of Physics Publishing, 2019)
The Agassi model (Agassi 1968 Nucl. Phys. A 116 49) is a schematic two-level model that involves pairing and monopole-monopole interactions. It is, therefore, an extension of the well known Lipkin-Meshkov-Glick model (Lipkin ...
Artículo
Excited-state phase transition and onset of chaos in quantum optical models
(American Physical Society, 2011)
We study the critical behavior of excited states and its relation to order and chaos in the Jaynes-Cummings and Dicke models of quantum optics. We show that both models exhibit a chain of excited-state quantum phase ...
Artículo
Number conserving particle-hole RPA for superfluid nuclei
(Elsevier, 2019-08)
We present a number conserving particle-hole RPA theory for collective excitations in the transition from normal to superfluid nuclei. The method derives from an RPA theory developed long ago in quantum chemistry using ...
Artículo
Quantum phase transitions in the interacting boson model: Integrability, level repulsion, and level crossing
(American Physical Review, 2003-10-17)
We study the quantum phase transition mechanisms that arise in the interacting boson model. We show that the second-order nature of the phase transition from U(5) to O(6) may be attributed to quantum integrability, whereas ...
Artículo
Decoherence due to an excited-state quantum phase transition in a two-level boson model
(American Physical Society, 2009)
The decoherence induced on a single qubit by its interaction with the environment is studied. The environment is modeled as a scalar two-level boson system that can go through either first-order or continuous-excited-state ...
Artículo
β4 potential at the U(5)–O(6) critical point of the interacting boson model
(American Physical Society, 2005)
Exact numerical results of the interacting boson model Hamiltonian along the integrable line from U(5) to O(6) are obtained by diagonalization within boson seniority subspaces. The matrix Hamiltonian reduces to a block ...
Artículo
Anharmonic double-phonon excitations in the interacting boson model
(American Physical Society, 2002-12-01)
Double−γ vibrations in deformed nuclei are analyzed in the context of the interacting boson model. A simple extension of the original version of the model towards higher-order interactions is required to explain the observed ...
Artículo
Phase transitions and critical points in the rare-earth region
(American Physical Society, 2003-08-01)
A systematic study of isotope chains in the rare-earth region is presented. For chains 60 144 2 154Nd, 62 146 2 160Sm, 64 148 2 162Gd, and 66 150 2 166 Dy, energy levels, E2 transition rates, and two-neutron separation ...
Artículo
Anharmonic double-γ vibrations in nuclei and their description in the interacting boson model
(American Physical Society, 2000-04-01)
Double-γ vibrations in deformed nuclei are studied in the context of the interacting boson model with special reference to their anharmonic character. It is shown that large anharmonicities can be obtained with interactions ...