Maximally entangled coherent states and strong violations of Bell-type inequalities

Recently, Wildfeuer et al. [Phys. Rev. A 76, 052101 (2007)] studied possible experiments demonstrating nonlocal correlation effects through the violation of various Bell-type inequalities by maximally path-entangled number states of the form (|N⟩|0⟩+e^iφ|0⟩|N⟩)/√2, the so-called $N00N$ states, and some strong violations were found. In this paper, we re-examine the same Bell-type inequalities with respect to maximally path-entangled coherent states of the form N(|α⟩ₐ|0⟩b+e^iΦ|0⟩ₐ|α e^iθ⟩b). We find in many cases even stronger violations of the Bell-type inequalities than appear to be possible with the $N00N$ states.