The Physics Society of Iran Iranian Journal of Physics Research 1682-6957 7 2 2019 11 26 Quantum averaging and resonances: two-level atom in a one-mode classical laser field Quantum averaging and resonances: two-level atom in a one-mode classical laser field 128 128 576 FA M. Amniat-Talab H. Sedghi R. Khoda-Bakhsh Journal Article 2019 11 26   We use a nonperturbative method based on quantum averaging and an adapted from of resonant transformations to treat the resonances of the Hamiltonian of a two-level atom interacting with a one-mode classical field in Floquet formalism. We illustrate this method by extraction of effective Hamiltonians of the system in two regimes of weak and strong coupling. The results obtained in the strong-coupling regime, are valid in the whole range of the coupling constant for the one-photon zero-field resonance.   We use a nonperturbative method based on quantum averaging and an adapted from of resonant transformations to treat the resonances of the Hamiltonian of a two-level atom interacting with a one-mode classical field in Floquet formalism. We illustrate this method by extraction of effective Hamiltonians of the system in two regimes of weak and strong coupling. The results obtained in the strong-coupling regime, are valid in the whole range of the coupling constant for the one-photon zero-field resonance. https://ijpr.iut.ac.ir/article_576_02437fd2f212489efe173a272e1230fe.pdf