Lee Jong-Chan, Park Kwang-Kyoon, Zhao Tian-Ming, Kim Yoon-Ho
Department of Physics, Pohang University of Science and Technology (POSTECH), Pohang 37673, Korea.
Phys Rev Lett. 2016 Dec 16;117(25):250501. doi: 10.1103/PhysRevLett.117.250501. Epub 2016 Dec 13.
Einstein-Podolsky-Rosen (EPR) entanglement introduced in 1935 deals with two particles that are entangled in their positions and momenta. Here we report the first experimental demonstration of EPR position-momentum entanglement of narrow-band photon pairs generated from cold atoms. By using two-photon quantum ghost imaging and ghost interference, we demonstrate explicitly that the narrow-band photon pairs violate the separability criterion, confirming EPR entanglement. We further demonstrate continuous variable EPR steering for positions and momenta of the two photons. Our new source of EPR-entangled narrow-band photons is expected to play an essential role in spatially multiplexed quantum information processing, such as, storage of quantum correlated images, quantum interface involving hyperentangled photons, etc.
1935年提出的爱因斯坦-波多尔斯基-罗森（EPR）纠缠涉及两个在位置和动量上纠缠的粒子。在此，我们报告了首次对由冷原子产生的窄带光子对的EPR位置-动量纠缠进行的实验演示。通过使用双光子量子鬼成像和鬼干涉，我们明确证明了窄带光子对违反了可分离性标准，证实了EPR纠缠。我们还进一步演示了对两个光子的位置和动量的连续变量EPR操控。我们新的EPR纠缠窄带光子源有望在空间复用量子信息处理中发挥重要作用，例如量子关联图像的存储、涉及超纠缠光子的量子接口等。
