Discussion on Maximally Entangled States of Two Coupled Two-Level Particles by Coherent State Approximation

We analyse the best condition for generating the maximally entangled states of the system containing two coupled two-level particles by the coherent approximation method beyond rotating wave approximation. It is found that the maximally entangled states are obtained when the detuning ν and the strength Ω of driving laser satisfy the condition ν/Ω =2.5. The maximum average probability of entangled state p_{a max}(ν, Ω) has the best stability relying on ν and Ω when ν approx 2Ω.