  In this paper, we are interested in studying entropy and dynamics
entanglement between a single time dependent three-level atom interacting with
one-mode cavity field when the atomic motion is taken into account. An exact
analytical solution for the wave function is given by using Schr\"odinger
equation for a specific initial condition. The field entropy of this system is
investigated in the non-resonant case. The influences of the detuning
parameters and atomic motion on the entanglement degree are examined. We show
that both of the detuning parameters and atomic motion play important roles in
the evolution of von Neumann entropy and atomic populations. Finally,
conclusion and some features are given.
