Symmetric and Asymmetric Quantum Rabi Model

We introduce a modified Jaynes-Cummings model with single-photon cavity radiation field but with the atomic system instead of exchanging a single photon as in the Jaynes-Cummings model, it exchanges instead a squeezed photon. After a unitary transformation and requiring the decoupling of the spin up from the spin down, we diagonalize the resulting Hamiltonian via a Bogoliubov transformation. This allows to determine the energy eigenvalues for the quantum Rabi model. We obtain the energy eigenvalues albeit for the asymmetric Rabi model in the limit of large coupling strength, where it approaches the symmetric Rabi model energy eigenvalues.