  We describe an entanglement purification protocol (EPP) for multipartite
three-level atomic entangled pair using photonic Faraday rotation. In this EPP,
the multipartite atomic entangled state can be purified with the help of some
single photons. This protocol resorts to the photonic Faraday rotation to
realize the function of the controlled-Not (CNOT) gate. The purified
multipartite atomic entangled state can be retained and to be repeated to reach
a higher fidelity.
