  The dynamics of a coupled system comprised of a two-level atom and cavity
field assisted by continuous external classical field (driving Jaynes-Cummings
model) is studied. When the initial field is prepared in a coherent state, the
dynamics strongly depends on the algebraic sum of both fields. If this sum is
zero (the compensative case) in the system only the vacuum Rabi oscillations
occur. The results with the dissipation and external field detuning from the
cavity field are also discussed.
