Eigenstates of two-level systems in a single-mode quantum field: from quantum Rabi model to $N$-atom Dicke model

A. U. Leonau, N. Q. San, A. P. Ulyanenkov +2

In the present paper we show that the Hamiltonian describing the resonant interaction of $N$ two-level systems with a single-mode electromagnetic quantum field in the Coulomb gauge…