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Tesis Doctoral
Estudio de transiciones de fase cuánticas en sistemas de dos niveles
(2011)
El trabajo se estructura en 6 capítulos. El capítulo 1 posee fundamentalmente un carácter de introducción teórica a las herramientas de campo medio que se usan en los diferentes modelos que se presentan, además de introducirse ...
Ponencia
Decoherence and quantum quench: Their relationship with excited state quantum phase transitions
(American Institute of Physics, 2012)
We study the similarities and differences between the phenomena of Quantum Decoherence and Quantum Quench in presence of an Excited State Quantum Phase Transition (ESQPT). We analyze, on one hand, the decoherence induced ...
Artículo
Continuous unitary transformations in two-level boson systems
(American Physical Society, 2005-12-01)
Two-level boson systems displaying a quantum phase transition from a spherical (symmetric) to a deformed (broken) phase are studied. A formalism to diagonalize Hamiltonians with O(2L+1) symmetry for large number ...
Artículo
Scalar two-level boson model to study the interacting boson model phase diagram in the Casten triangle
(American Physical Society, 2006)
We introduce a simple two-level boson model with the same energy surface as the Q-consistent interacting boson model Hamiltonian. The model can be diagonalized for large number of bosons and the results used to check ...
Artículo
Disentangling phase transitions and critical points in the proton-neutron interacting boson model by catastrophe theory
(Elsevier, 2014)
We introduce the basic concepts of catastrophe theory needed to derive analytically the phase diagram of the proton–neutron interacting boson model (IBM-2). Previous studies [1–3] were based on numerical solutions. We here ...
Artículo
Intrinsic state for an extended version of the interacting boson model
(American Physical Society, 2000-03-01)
An intrinsic-state formalism for the interacting boson model IBM-4 is presented. A basis of deformed bosons is introduced which allows the construction of a general trial wave function that has Wigner’s spin-isospin SU(4) ...
Ponencia
Decoherence as a Signature of an Excited State Quantum Phase Transition in Two Level Boson Systems
(American Institute of Physics, 2009)
We analyze the decoherence induced on a single qubit by the interaction with a two-level boson system with critical internal dynamics. We explore how the decoherence process is affected by the presence of quantum phase ...
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 ...