Pérez Fernández, P.Cejnar, P.Arias, J. M.Dukelsky, J.García Ramos, J. E.Relaño Pérez, Armando2023-06-202023-06-202011-03-031050-294710.1103/PhysRevA.83.033802https://hdl.handle.net/20.500.14352/44413©2011 American Physical Society. P.C. acknowledges useful discussions with M. Kastner and J. Hirsch. This work has been partially supported by the Czech Science Foundation (Grant No. 202/09/0084), by the Czech Ministry of Education (Grant No. MSM 0021620859), by the Spanish Ministerio de Educación y Ciencia and the European regional development fund FEDER (Grants No. FIS2009-07277, No. FIS2008-04189, No. FIS2006-12783-C03-01, No. FPA2006 13807-C02-02, No. FPA2007-63074, and No. FIS2009-11621-C02-01), by CPAN Ingenio (Grant No. CSPD-2007-00042 Ingenio), by Junta de Andalucía (Grants No. FQM160, No. FQM318, No. P05-FQM437, and No. P07-FQM-02962), and by the Universidad Complutense de Madrid (Grant No. UCM-910059). P.P-F. is supported by a FPU grant of the Spanish Ministerio de Educación y Ciencia. A.R. is supported by the Spanish program CPAN Consolider-ingenio.We analyze excited-state quantum phase transitions (ESQPTs) in three schematic (integrable and nonintegrable) models describing a single-mode bosonic field coupled to a collection of atoms. It is shown that the presence of the ESQPT in these models affects the quantum relaxation processes following an abrupt quench in the control parameter. Clear-cut evidence of the ESQPT effects is presented in integrable models, while in a nonintegrable model the evidence is blurred due to chaotic behavior of the system in the region around the critical energy.engjournal articlehttp://dx.doi.org/10.1103/PhysRevA.83.033802http://journals.aps.org/open access536Radiation-fieldSystemsNucleiModelDynamicsOrbitsMaserTermodinámica2213 Termodinámica