Park Jiho, Kim Danbi, Kim Heonoh, Moon Han Seb
Opt Lett. 2019 Aug 1;44(15):3681-3684. doi: 10.1364/OL.44.003681.
We experimentally demonstrate Franson interference of a time-energy entangled photon pair generated via collective two-photon coherence in the 5S-5P-5D transition of warm Rb87 atoms. The two unbalanced Michelson interferometers used in our setup are spatially separated in order to understand entanglement as a nonlocal property of the photon pairs from the warm atomic ensemble. We observe a Franson interference fringe with a high visibility of 99.1±1.3% with continuous-wave-mode photon pairs from the cascade-type atomic ensemble. To the best of our knowledge, this work is the first demonstration of the nonlocal two-photon interference experiment in separated photon channels by use of two-photon pairs emitted from a cascade-type atomic system as originally proposed by Franson [Phys. Rev. Lett.62, 2205 (1989)PRLTAO0031-900710.1103/PhysRevLett.62.2205].
我们通过实验证明了在热铷87原子的5S - 5P - 5D跃迁中，通过集体双光子相干产生的时间 - 能量纠缠光子对的弗兰森干涉。我们实验装置中使用的两个不平衡迈克尔逊干涉仪在空间上是分开的，以便将纠缠理解为来自热原子系综的光子对的一种非局域性质。我们用来自级联型原子系综的连续波模式光子对观察到了可见度高达99.1±1.3%的弗兰森干涉条纹。据我们所知，这项工作首次通过使用级联型原子系统发射的双光子对，在分离的光子通道中演示了非局域双光子干涉实验，这正是弗兰森最初提出的[《物理评论快报》62, 2205 (1989)PRLTAO0031 - 900710.1103/PhysRevLett.62.2205]。
