In this paper we consider a system of identical three two-level atoms
interacting at resonance with a single-mode of the quantized field in a
lossless cavity. The initial cavity field is prepared in the coherent state
while the atoms are taken initially to be either in the uppermost excited state
"∣eee>" or The GHZ-state or the W-state. For this
system we investigate different kinds of atomic inversion and entanglement,
which arise between the different parts of the system due to the interaction.
Also the relationship, between entanglement and some other nonclassical effects
in the statistical properties, such as collapses and revivals in the atomic
inversion where superharmonic effects appear, is discussed. The Q-functions
for different cases are discussed. Most remarkably it is found that the
GHZ-state is more robust against energy losses, showing almost
coherent trapping and Schr\"odinger-cat states can not be produced from such
state. Also the entanglement of GHZ-state is more robust than the
W-state. Another interesting feature found is that the state which
has no pairwise entanglement initially will have a much improvement of such
pairwise entanglement through the evolution. Sudden death and sudden revival of
atoms-pairwise entanglement are produced with the W-state.Comment: 14 pages, 7 figure