Entangling Two-Atom Through Cooperative Interaction Under Stimulated   Emission
  We discuss the generation of two-atom entanglement inside a resonant microcavity under stimulated emission (STE) interaction. The amount of entanglement is shown based on different atomic initial state. For each kind of intial state, we obtain the entanglement period and the entanglement critical point, which are found to deeply depend on driving field density. In case of atomic state $| ee >$, the entanglement can be induced due to STE. In case of atomic state $| eg >$, there is a competition between driving field indued entanglement and STE induced entanglement. When two atoms are initially in $| gg >$, we can find a lumbar region where STE increases the amount and period of entanglement. 
Y. Q. Guo, H. S. Song, L. Zhou and X. X. Yi