Abstract
We have investigated theoretically the asymmetrical photoionization yields into the 6s(1/2), 5d(3/2) and 5d(5/2) continuum channels of atomic barium observed by Wang, Chen and Elliott [Phys. Rev. Lett. 77, 2416 (1996)] in the study of coherent control through two-color resonant interfering paths. The atomic parameters obtained from a theoretical approach based on a combination of jj-coupled eigenchannel R-matrix and Multichannel Quantum Defect Theory are used to analyze the photoionization spectra from the 6s6p P-1(1) and 6s7p P-1(1) states with polarized light beams. The studied energy range includes the 6p7p, autoionizing resonances. The dynamics of the two-color photoionization is governed by the coherent excitation of the 6s6p, and 6s7p P-1(1) intermediate states. This excitation is described as an adiabatic process in the rotating wave approximation. The influence of the radiative decay, spatial distribution of the intensities of the laser beams and hyperfine interaction is discussed.