Information entropies of multi-qubit Rabi model beyond the rotating wave approximation

In this paper, we present an analytical solution for the multi-qubit Rabi model for the general case without the rotating wave approximation. We discuss three different cases, one-qubit, two-qubit and three-qubit Rabi model, as applications to the presented solution. In addition, we study the effect of the qubit-photon coupling constants and the detuning parameters on the information entropies \(H(\sigma _{X})\), \(H(\sigma _{Y})\) and \(H(\sigma _{Z}),\) by which we note that, in the case of two-qubit Rabi model, there are collapse and revivals in the curves of the information entropies \(H(\sigma _{Z})\) and \(H(\sigma _{X})\) that vary in their numbers and amplitudes depending on the detuning parameter. The effects of the coupling constants and the detuning parameters on other cases are discussed. Besides, we explain that the dynamic nonlinear properties of the system have strong proportional relationship with the number of atoms.