  Coherent control of the atomic two-photon absorption with shaped single-cycle
pulses is examined theoretically in the weak-field regime. The control over the
stabilized carrier-envelope phase (CEP) of the pulses is determined as a key
parameter allowing the full utilization of the ultrabroad pulse spectrum. This
bandwidth is sufficient to provide besides the sequential two-photon pathways,
additional Raman-type pathways coupling between the ground and the excited
states. The interference between the different pathways is efficiently
controlled via the control over the CEP. Simplified two-level model is analyzed
in the frequency domain where the rational pulse shaping is applied. The
developed intuition is applied to atomic Cs and verified by the exact numerical
solution of time-dependent Schrodinger equation.
