THEORY OF THE ADIABATIC PASSAGE IN 2-LEVEL QUANTUM-SYSTEMS WITH SUPERPOSITIONAL INITIAL STATES

An analytic theory of the adiabatic passage (AP) regime of interaction of short frequency chirped laser pulses with a two-lever quantum syst em (QS) being initially in the superpositional quantum state is presen ted. We show that the initial value of the non-diagonal elements of th e density matrix can influence the dynamics of the population transfer during the action of the laser pulse, but do not influence essentiall y the final populations of the states of the QS obtained at the end of the interaction near the AP regime. A novel solution to the Bloch equ ations is obtained in the form of a converging power series generalizi ng the ordinary AP solution.