Simple schemes for generating the three-atom W state and the Greenberger–Horne–Zeilinger state among nonidentical atoms

Abstract

We present two schemes for generating the three-atom W state and the GHZ state with one Λ-type atom and two 2-level atoms interacting resonantly with two modes or one mode of a two-mode field in turns. The schemes neither require the three atoms to go through the cavity simultaneously (which is difficult to realize in experiment), nor require the detection of photons. The schemes work beyond the strong-coupling regime, so that we can obtain high-fidelity entanglement.