@conference{10272/6375, year = {2012}, url = {http://hdl.handle.net/10272/6375}, abstract = {In this contribution, the critical behavior of excited state quantum phase transitions (ESQPT’s) and its relation to order and chaos in the Dicke model are studied. This model is nonintegrable. For comparison, the same problem is studied for the Jaynes-Cummings model which is, somehow, the integrable version of the Dicke model. The existence of an ESQPT is confirmed in both cases. However, in the Dicke model the signatures of criticality in excited states are blurred by the onset of quantum chaos. It is concluded that the emergence of quantum chaos is caused by the precursors of the excited state quantum phase transition.}, publisher = {American Institute of Physics}, title = {Excited state quantum phase transitions and chaos in the Dicke model}, doi = {10.1063/1.4759413}, author = {Pérez Fernández, Pedro and Relaño Pérez, Armando and Cejnar, P. and Arias Carrasco, José Miguel and Dukelsky, J. and García Ramos, José Enrique}, }