The Generation and Exchange of Entanglement via Zeeman Effect
  In this paper we show a new way to generate entanglement via two identical three-level atoms splitting in the magnetic field interacting with the cavity field. By the system we investigate, We can acquire the EPR state, multi-dimensional entangled states etc. which are more stable than usual realization by high-energy-level Rydberg atoms and we can realize the local exchange operator too. We also achieve the goal of maintaining long- time entanglement between atoms. At last, by using the procedure of local exchange, we put forward an experimental scheme for quantum feedback. 
Jian-da Wu, Jian-lan Chen, Yong-de Zhang