title: Strong-coupling theory of two-level atoms in periodic fields
abstract: We present a new convergent strong-coupling expansion for two-level atoms in external periodic fields, free of secular terms. As a first application, we show that the coherent destruction of tunneling is a third-order effect. We also present an exact treatment of the high-frequency region, and compare it with the theory of averaging. The qualitative frequency spectrum of the transition probability amplitude contains an effective Rabi frequency.
authors.affiliation: Instituto de Fisica, Universidade de Sao Paulo, Caixa Postal 66 318, 05315 970 Sao Paulo SP, Brasil.
authors.initials: JC
authors.lastname: Barata
authors.initials: WF
authors.lastname: Wreszinski