原子在弱相干场光纤耦合腔系统中的纠缠特性

Entanglement properties of two atoms interacting with weak coherent states trapped in two distant cavities connected by an optical fiber

研究由两个相同的二能级原子分别处于用单模光纤耦合的两弱相干光场系统的共生纠缠特性,通过数值计算研究了光纤模-腔模与原子-腔模的耦合强度比、弱相干光场的强度和两光场相对相位差等因素对系统纠缠演化的影响.结果表明:两腔中的两原子之间、两光场之间和每个腔中的原子与光场之间的纠缠随时间呈现周期或准周期性演化,两腔场之间的纠缠与腔中的两原子的纠缠可以相互转换,与两原子之间和两光场之间的纠缠相比,每个腔中光场与原子之间的纠缠随时间变化的周期缩短.光纤模-腔模与原子-腔模的耦合强度比与两腔中光场相位差对系统纠缠的影响很大,较小的光纤模-腔模与原子-腔模的耦合强度之比可以获得较大的系统纠缠度.

Considering a system comprised of two-level atoms resonantly interacting with weak coherent states trapped in two distant cavities connected by an optical fiber initially, we study the entanglement properties of the atom-atom, the cavity-cavity and the atom-cavity. Then the influences of the ratio between fiber-cavity and atom-cavity coupling intensity, the intensity and the phase of the cavity field on the entanglement properties are investigated numerically. It is shown that the entanglements of the atom-atom, the cavity-cavity and the atom-cavity vary with time in the periodical or approximately periodical manner;the entanglement can be transferred from cavity-cavity to atom-atom reciprocally. Compared with the entanglements of atom-atom and cavity-cavity, the varying period of atom-cavity entanglement is short. The ratio of fiber-cavity coupling intensity to atom-cavity coupling intensity and the phase of cavity field affect the entanglement properties greatly. The great entanglement can be achieved by using a smaller ratio of coupling intensity between fiber-cavity and atom-cavity.