We propose a scheme for entangling two field modes in two high-Q optical cavities. Making use of a virtual two-photon process, our scheme achieves maximally entangled states without any real transitions of atomic internal states, hence it is immune to the atomic decay.
@article{arxiv.quant-ph/0306035,
title = {Entangled two cavity modes preparation via a two-photon process},
author = {X. X. Yi and L. Zhou and H. S. Song},
journal= {arXiv preprint arXiv:quant-ph/0306035},
year = {2009}
}