Lee Dongjin, Shin Woncheol, Park Sebae, Kim Junyeop, Shin Heedeuk
Department of Physics, Pohang University of Science and Technology (POSTECH), Pohang, 37673, South Korea.
Light Sci Appl. 2024 Apr 15;13(1):90. doi: 10.1038/s41377-024-01439-9.
The examination of entanglement across various degrees of freedom has been pivotal in augmenting our understanding of fundamental physics, extending to high dimensional quantum states, and promising the scalability of quantum technologies. In this paper, we demonstrate the photon number path entanglement in the frequency domain by implementing a frequency beam splitter that converts the single-photon frequency to another with 50% probability using Bragg scattering four-wave mixing. The two-photon NOON state in a single-mode fiber is generated in the frequency domain, manifesting the two-photon interference with two-fold enhanced resolution compared to that of single-photon interference, showing the outstanding stability of the interferometer. This successful translation of quantum states in the frequency domain will pave the way toward the discovery of fascinating quantum phenomena and scalable quantum information processing.
对跨越各种自由度的纠缠进行研究，对于深化我们对基础物理学的理解、拓展到高维量子态以及推动量子技术的可扩展性而言至关重要。在本文中，我们通过实现一个频率分束器来展示频域中的光子数路径纠缠，该频率分束器利用布拉格散射四波混频以50%的概率将单光子频率转换为另一个频率。单模光纤中的双光子NOON态在频域中产生，与单光子干涉相比，表现出具有两倍增强分辨率的双光子干涉，展示了干涉仪出色的稳定性。量子态在频域中的这一成功转换将为发现迷人的量子现象和可扩展的量子信息处理铺平道路。
