  The influence of photon-momentum recoil on adiabatic population transfer in
an atomic three-level lambda system is studied. It is shown that the Doppler
frequency shifts, due to atomic motion can play an important role in adiabatic
population transfer processes of atomic internal states by a pair of laser
fields. For the limiting case of slow atoms ( Doppler shift much smaller than
the photon recoil energy) the atoms occupy the same target state regardless of
the order of switching of laser fields, while for the case of fast atoms
interacting with the intuitive sequence of pulses, the target state is the
intermediate atomic state. It is shown that these processes are robust with
respect to parameter fluctuations, such as the laser pulse area and the
relative spatial offset (delay) of the laser beams. The obtained results can be
used for the control of temporal evolution of atomic populations in atomic
beams by externally adjustable Doppler shifts.
