Generation of a \chi-type four-atom entangled state

This paper proposes a scheme to generate a new \chi-type four-atom entangled state for the first time by using linear optics elements, four one-sided cavities (one three-level atom) and a conventional photon detector. The linear optical elements and conventional photon detector are simple and accessible in experiments, which makes the scheme more feasible with current technology. In addition, the state |\chi^00\rangle_3214 with probability 1 can be generated as long as there is no photon loss.