Excited-state quantum phase transitions in many-body systems with infinite-range interaction : localization, dynamics, and bifurcation
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Publication Date
2016 -
Publisher
American Physical Society -
Citation
Santos, L.F., Távora, M., Pérez Bernal, F.: "Excited-state quantum phase transitions in many-body systems with infinite-range interaction : localization, dynamics, and bifurcation". Physical Review A. Vol. 94, (2016). DOI: 10.1103/PhysRevA.94.012113 -
Abstract
Excited state quantum phase transitions (ESQPTs) are generalizations of quantum phase transitions (QPTs) to excited levels. They are associated with local divergences in the density of states. Here, we investigate how the presence of an ESQPT can be detected from the analysis of the structure of the Hamiltonian matrix, the level of localization of the eigenstates, the onset of bifurcation, and the speed of the system evolution. Our findings are illustrated for a Hamiltonian with infinite-range Ising interaction in a transverse field. This is a version of the Lipkin-Meshkov-Glick (LMG) model and the limiting case of the one-dimensional spin-1/2 system with tunable interactions realized with ion traps. From our studies for the dynamics, we uncover similarities between the LMG and the noninteracting XX models. -
Project
info:eu-repo/grantAgreement/MINECO [FIS2014-53448-C2-2-P]
Fichero | Tamaño | Formato |
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Excited-state quantum phase.pdf | 609.7Kb | View/ | versión editor |
Fichero | Tamaño | Formato |
| Description |
---|---|---|---|---|
Excited-state quantum phase.pdf | 609.7Kb | View/ | versión editor |