A mathematical analysis of dressed photon in ground state of generalized quantum Rabi model using pair theory *
Masao Hirokawa, Jacob Schach Møller, Itaru Sasaki · Journal of Physics A Mathematical and Theoretical · 2017
Abstract We consider the generalized quantum Rabi model with the so-called A 2 -term in the light of the Hepp–Lieb–Preparata quantum phase transition. We investigate the dressed photon in its ground state when the atom-light coupling strength is in the deep-strong coupling regime. This regime is introduced by Casanova et al (2010 Phys. Rev. Lett . 105 263603 ) as the coupling regime exceeding the ultra-strong one. We show how the dressed photon appears in the ground state.