|dc.contributor.author||García Ramos, José Enrique||
|dc.contributor.author||Pérez Fernández, Pedro||
|dc.contributor.author||Arias Carrasco, José Miguel||
|dc.identifier.citation||García Ramos,J.E., Pérez Fernández, P., Arias Carrasco, J.M.: "Excited-state quantum phase transitions in a two-fluid Lipkin model". Physical Review C - Nuclear Physics, 95 (5), 054326-1-054326-15. DOI: 10.1103/PhysRevC.95.054326||
|dc.description.abstract||[Background:] Composed systems have became of great interest in
the framework of the ground state quantum phase transitions (QPTs) and
many of their properties have been studied in detail. However, in
these systems the study of the so called excited-state quantum phase
transitions (ESQPTs) have not received so much attention.
[Purpose:] A quantum analysis of the ESQPTs
in the two-fluid Lipkin model is presented in this
work. The study is performed through the Hamiltonian diagonalization
for selected values of the control parameters in order to cover the
most interesting regions of the system phase diagram.
[Method:] A Hamiltonian that resembles the consistent-Q
Hamiltonian of the interacting boson model (IBM) is diagonalized for
selected values of the parameters and properties such as the density
of states, the Peres lattices, the nearest-neighbor spacing
distribution, and the participation ratio are analyzed.
[Results:] An overview of the spectrum of the two-fluid Lipkin
model for selected positions in the phase diagram has been obtained.
The location of the excited-state quantum phase transition can be
easily singled out with the Peres lattice, with the
nearest-neighbor spacing distribution, with Poincar\'e
sections or with the participation ratio.
[Conclusions:] This study completes the analysis of QPTs for the
two-fluid Lipkin model, extending the previous study to excited
states. The ESQPT signatures in composed systems behave in the same
way as in single ones, although the evidences of their presence can
be sometimes blurred. The Peres lattice turns out to be a convenient
tool to look into the position of the ESQPT and to define the concept
of phase in the excited states realm.||en_US
|dc.description.sponsorship||This work has been supported by the Spanish Ministerio de Econom ́ıa y Competitividad
and the European regional development fund (FEDER) under Project No. FIS2014-53448-C2-1-P and FIS2014-53448-C2-2-P||
|dc.publisher||American Physical Society||
|dc.rights||Atribución-NoComercial-SinDerivadas 3.0 España||*
|dc.title||Excited-state quantum phase transitions in a two-fluid Lipkin model||en_US
|dc.relation.projectID||info:eu-repo/grantAgreement/European regional development fund (FEDER) [
|dc.relation.projectID||info:eu-repo/grantAgreement/Junta de Andalucia [P11-FQM-7632]||