  In this paper, we investigate the coherent control over a complex multi-level
atomic system using the stimulated Raman adiabatic passage (STIRAP). Based on
the example of rubidium-87 atoms, excited with circularly-polarized light at
the D1 line, we demonstrate the ability to decompose the system into three- and
four-level subsystems independently interacting with light beams. Focusing on
the four-level system, we demonstrate that the presence of an additional
excited state significantly affects the dynamics of the system evolution.
Specifically, it is shown that, through the appropriate tuning of the light
beams, some of the transfer channels can be blocked, which leads to better
control over the system. We also demonstrate that this effect is most
significant in media free from inhomogeneous broadening (e.g., Doppler effect)
and deteriorates if such broadening is present. For instance, motion of atoms
affects both the efficiency and selectivity of the transfer.
