The n-Qubit W State of Ground-State Atoms Using Cavity QED and Single Photon Detection

We present a simple scheme for the probabilistic generation of the n-qubit W state of three-level systems in cavity quantum electrodynamics. Once the W state is prepared, it will be insensitive to the spontaneous emission of atoms due to the fact that only the two degenerate ground states of the three-level atoms are involved. With time evolution of the system, the success probability and the experimental feasibility are also discussed.