近日，韩国浦项工业大学的Heedeuk Shin及其研究团队取得一项新进展。经过不懈努力，他们对频域中的NOON态干涉进行研究。相关研究成果已于2024年4月15日在国际知名学术期刊《光：科学与应用》上发表。

在本文中，该研究团队运用频率分束器在频域中演示了光子数路径纠缠，这一分束器通过布拉格散射四波混频技术，能够以50%的概率将单光子频率转换为另一个频率。研究人员在频域内生成了单模光纤的双光子NOON态，该态展现出了双光子干涉相较于单光子干涉分辨率提升两倍的特性，从而凸显了干涉仪的卓越稳定性。频域量子态的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。

据悉，研究不同自由度的纠缠，对于深化人们对基础物理学的理解、推动高维量子态的研究以及提升量子技术的可扩展性至关重要。

附：英文原文

Title: NOON-state interference in the frequency domain

Author: Lee, Dongjin, Shin, Woncheol, Park, Sebae, Kim, Junyeop, Shin, Heedeuk

Issue&Volume: 2024-04-15

Abstract: 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.

DOI: 10.1038/s41377-024-01439-9

Source: https://www.nature.com/articles/s41377-024-01439-9