Journal of Physics Conference Series
Quantum information approach to the description of quantum phase transitions
Octavio Castaños, Ramón López–Peña, Eduardo Nahmad-Achar, Jorge G. Hirsch
Abstract
The fidelity, linear entropy and entanglement entropy, concepts of information theory, are used to determine the localization of quantum phase transitions of the Lipkin–Meshkov–Glick (LMG) and the Dicke models for a finite number of particles. Another concept, the so-called fidelity susceptibility, gives us information of the scaling behavior of the quantum phase transitions of the models. In particular universal curves are presented for the specific susceptibility. It is shown that the control parameters of both models have a similar dependence in the number of particles when the systems approach to the thermodynamic limit.