Control of entanglement sudden death by Kerr medium

The entanglement dynamics of system, where atoms A and B interactwith single mode cavity fields a and b respectively, isstudied. The interaction between atom A and cavity a may bedescribed by using the typical Jaynes--Cummings model, while thatbetween the atom B and cavity b filled with a Kerr medium is of atwo-photon process. For a certain initial atom entanglement state,there is an entanglement sudden death effect between the two atoms.The Kerr medium in the cavity b can effectively prevent theundesirable entanglement sudden death from occurring. Also, from theviewpoint of the population dynamics, we discuss why the Kerrmedium can do so.