研究了Kerr介质中两个耦合二能级原子的纠缠演化规律,通过concurrence计算了系统的纠缠度,讨论了系统初态、Kerr介质和原子之间的偶极相互作用对腔中两个原子纠缠度的影响.结果表明:通过适当选取Kerr介质的耦合系数和偶极相互作用强度,可以获得固定的两原子纠缠,并且可以提高两原子之间的纠缠,甚至彻底消除纠缠猝死现象.
We have investigated the entanglement time evolution of two coupled two-level atoms in Kerr medium. Entanglement of the system is calculated by making use of concurrence. The influences of initial state, Kerr medium, and dipole-dipole coupling intensity between two atoms on the entanglement degree of the two atoms are revealed. Results show that the appropriate choice for the nonlinear coupling constant of Kerr medium and the dipole-dipole coupling intensity can improve the degree of atom-atom entanglement and eliminate the entanglement sudden death completely. We also find that invariant and stable entanglement occurs for a particular initial state.