Four-wave mixing in three-level systems: Interference and entanglement
Four-wave mixing in three-level systems: Interference and entanglement
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DOI：
10.1103/physreva.76.013803
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发表时间：
2007-07
影响因子：
2.9
通讯作者：
Shengwang Du;E. Oh;J. Wen;M. Rubin
中科院分区：
文献类型：
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作者：
Shengwang Du;E. Oh;J. Wen;M. Rubin
三能级系统中简并四波混频 (FWM) 的干涉在经典体系和具有向后配置的量子体系中进行了研究。在经典的 FWM 中，我们发现两个不可区分的 FWM 过渡路径之间的相位差可以通过不同的驱动激光参数来改变，并导致所生成的共轭场的幅度和偏振的干扰。在成对光子生成情况下，由于双光子生成中的时间顺序，非线性干扰消失了。然而，由于简并频率和偏振下的群速度较慢，两个费曼路径之间的双光子振幅干涉可以消除探测器上的时间排序信息。对于小群延迟，由三阶非线性决定的双光子相关性显示出反聚束和阻尼拉比振荡。对于大群延迟，双光子带宽由相位匹配决定，我们表明双光子干扰会导致聚束效应。还讨论了产生偏振纠缠的可行性。
The interference of degenerate four-wave mixing (FWM) in three-level systems is examined in both the classical and quantum regimes with a backward configuration. In classical FWM, we find that the phase difference between two indistinguishable FWM transition paths can be varied by different driving laser parameters, and leads to interference in the amplitude and polarization of the generated conjugate field. In the paired-photon generation case, the interference in the nonlinearity disappears because of the time ordering in biphoton generation. However, because of the slow group velocity at the degenerate frequency and polarization, the biphoton-amplitude interference between two Feynman paths can erase the time-ordering information at the detectors. For small group delay, the biphoton correlation, determined by the third-order nonlinearity, shows antibunching and damped Rabi oscillations. For large group delay, where the biphoton bandwidth is determined by phase matching, we show that the biphoton interference leads to a bunching effect. The feasibility of generating polarization entanglement is also discussed.