QUANTUM CRITICALITY OF TWO GENERALIZED DICKE MODELS: WITH EITHER QUADRATIC FIELD TERMS OR WITH DIPOLE-DIPOLE INTERACTION
Yueming Wang, Minglong Zhao
Abstract
In this work we analytically derived the critical behavior of zero-temperature quantum phase transition for two generalized Dicke models: one model includes quadratic field terms (the A 2 -term) and the other one has dipole-dipole interaction. It was pointed out that both the A 2 -term and dipole-dipole interaction lead to a corrected position of the critical point, amounting to inducing a shift of radiation field frequency and atomic transition frequency.