Controllable shape-matched propagation of two signal beams in a double-Λ atomic ensemble
Controllable shape-matched propagation of two signal beams in a double-Λ atomic ensemble
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DOI：
10.1140/epjd/e2006-00141-0
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发表时间：
2006-06
期刊：
影响因子：
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通讯作者：
Zhuan Li;L. Deng;Li-sen Xu;Kaige Wang
中科院分区：
文献类型：
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作者：
Zhuan Li;L. Deng;Li-sen Xu;Kaige Wang
研究了四能级双Λ原子系综与两个含时信号场和两个稳态控制场的相互作用。虽然在每个Λ通道中，一对信号场和控制场与两个较低能级的原子共振耦合，但电磁感应透明（EIT）的发生受到四个场的相干性的影响。在对原子相干性的讨论中，我们证明了四个光场的相位匹配可以决定两个低能级之间的量子相干性的形成或释放。我们分析了这两个信号场的传播方程，并找到了两个特征解：稳态透射波和瞬态衰减波。前者对应于两个信号脉冲形状匹配的相关EIT效应。后者是一个相反的效果的相关EIT中，两个脉冲同时淬灭，因此被称为相关双信号吸收（CTSA）。我们提出了CTSA条件对应于EIT条件。数值模拟结果表明，双Λ组态能够操纵同步光信号，从而为量子信息处理提供了多样性和通用性。
We study a four-level double-Λ atomic ensemble interacting with two time-dependent signal fields and two stationary control fields. Though, in each Λ channel, a pair of signal and control fields couple resonantly with the two lower levels of atoms, the occurrences of electromagnetically induced transparency (EIT) is affected by the coherence of the four fields. In the discussion of atomic susceptibilities, we show that the quantum coherence between the two lower levels can be either formed or released according to the phase matching of the four fields. We analyze the propagation equation of the two signal fields, and find two characteristic solutions: the stationary transmission wave and the transient decay wave. The former corresponds to a correlated EIT effect in which two signal pulses are shape-matched. The latter is an opposite effect to the correlated EIT in which two pulses quench simultaneously, thus named as the correlated two-signal absorption (CTSA). We propose the CTSA condition in correspondence with the EIT condition. The numerical simulation shows that the double-Λ configuration is capable of manipulating synchronous optical signals and thus provides multiplicity and versatility in quantum information process.