Bell态原子与双模纠缠相干光场相互作用系统的原子布居数演化  

The Time-evolution of the Atomic Population in the System of Atoms in Bell States Interacting with Two-mode Entangled Coherent Field

作　　者：林继成[1] 郑小虎[2] 曹卓良[2] 

机构地区：[1]南京晓庄学院物理系,江苏南京210017 [2]安徽大学物理与材料科学学院,安徽合肥230039

出　　处：《量子光学学报》2007年第3期170-176,共7页Journal of Quantum Optics

基　　金：安徽省自然科学基金(03042401);安徽省教育厅重点项目基金(2004kj005zd)

摘　　要：运用全量子理论并结合数值计算方法,研究了处于Bell态的两个全同二能级纠缠原子与双模纠缠相干光场相互作用系统的原子布居数演化特性。讨论了双原子体系的初态、光场的平均光子数、双模纠缠相干光场的纠缠程度以及双原子体系的原子间耦合强度对原子布居时间演化的影响。结果表明:双原子体系的初态为|β11〉时,原子布居数不随时间变化;初态为|β00〉、|β01〉和|β10〉时,当初始平均光子数增大到一定数值时演化特性呈现出周期性的崩塌和回复效应,随初始光子数的增加时间演化曲线的振荡频率增大振幅减小,且初态为|β00〉或|β10〉时原子布居的回复周期是初态为时|β01〉的两倍;双模纠缠相干光场的纠缠程度以及原子间偶极相互作用的强弱对Rabi振荡频率没有影响但对振幅有着显著的影响。The time-evolution of atomic population of a light-atoms interaction system, two atoms in Bell states Interacting with two-mode entangled coherent field, are investigated by means of quantum thoery and numerical method. The effect of the atomic initial state, mean photon numbers of field, the degree of the entanglment for the entangled coherent fields, and the coupling strength of dipole-dipole interaction between atoms on the atom＇ s population are discussed by numerical calculation. The results show that the atomic population is time- independent provided that the atom is in ｜β11〉 state. For the other three Bell states, there will appear the periodical collapse-revival of the atomic population if the initial mean photon number reaches some special value. With the increase of the initial mean photon number, the oscillation frequency of the time-evolution of atomic population increases correspondingly, and the amplitude decreases. The revival period of the atomic population for the initial states I ｜β00〉 and ｜β10〉 is twice of that for the initial state ｜β01 〉. The degree of entanglement of the two-mode entangled coherent field and the intensity of two dipole-dipole interaction between atoms have no effects on the frequency of the Rabi oscillation, but have obvious effects on the amplitude of the oscillation.

关 键 词：量子光学 BELL态 双模纠缠相干光场 原子布居 

分 类 号：O431[机械工程—光学工程]