RT Journal Article
T1 Excited-state quantum phase transitions in many-body systems with infinite-range interaction : localization, dynamics, and bifurcation
A1 Santos, Lea F.
A1 Távora, Marco
A1 Pérez Bernal, Francisco
AB Excited state quantum phase transitions (ESQPTs) are generalizations of quantum phase transitions (QPTs) to excitedlevels. They are associated with local divergences in the density of states. Here, we investigate how the presence of anESQPT can be detected from the analysis of the structure of the Hamiltonian matrix, the level of localization of theeigenstates, the onset of bifurcation, and the speed of the system evolution. Our findings are illustrated for a Hamiltonianwith infinite-range Ising interaction in a transverse field. This is a version of the Lipkin-Meshkov-Glick (LMG) model andthe limiting case of the one-dimensional spin-1/2 system with tunable interactions realized with ion traps. From our studiesfor the dynamics, we uncover similarities between the LMG and the noninteracting XX models.
PB American Physical Society
SN 2469-9926
SN 2469-9934 (electrónico)
YR 2016
FD 2016
LK http://hdl.handle.net/10272/13056
UL http://hdl.handle.net/10272/13056
LA eng
NO 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
NO LFS and MT were supported by the NSF grant No. DMR-1147430. FPB was funded by MINECO grant FIS2014- 53448-C2-2-P and by Spanish Consolider-Ingenio 2010 (CPANCSD2007-00042). LFS and FPB thank Pedro Perez- Fernandez and JorgeDukelsky for discussions, as well as the hospitality of AlejandroFrank and the Centro de Ciencias de la Complejidad (C3) at theUNAM in Mexico, where part of this work was carried out.
DS Repositorio Institucional de la Universidad de Huelva
RD 31 may 2026