纠缠Ξ-型三能级原子与纠缠腔场相互作用熵的纠缠演化

The entropy evolution of entangled Ξ-type three-level atoms interacting with entangled cavity fields

文章利用一对处于纠缠态的Ξ-型三能级原子与一对处于纠缠态的单模腔场,初始时刻原子与腔场之间互不纠缠,使其中一个原子与一个腔场发生相互作用,即纠缠交换,合适选择相互作用时间就可实现原子与腔场之间产生纠缠,并研究了系统原子熵的演化特性,运用量子熵理论,讨论了原子-腔场的耦合常数对原子熵的影响,结果表明:原子与光场跃迁耦合常数对系统熵的最大纠缠度有影响.当原子与光场两种跃迁耦合常数之比k值增大时,最大纠缠度在减小;当k增大到某一程度时,系统熵随时间周期性变化,并出现双峰现象.

An entangled pair of v-type three-level atoms and an entangled pair of one-mode cavity fields are not entangled with each other originally. Entanglement swapping can be realized by means of resonant interaction between one atom and a cavity field by choosing proper interaction time, and the entanglement between atom and cavity field can be realized in entanglement swapping protocol. The evolution properties of the atomic entropy of the system are also studied. The influences of atom-field coupling constants k on the atom entropy are discussed by using the quantum entropy theory. The results indicate that atom-field coupling constants affect the maximum value of the entropy. The maximum value of the system decreases when the atom-field coupling constant k increases;The entropy of the system changes periodically with time and there are bimodal phenomena when k increases to a certain degree.