近日，美国国家标准与技术研究院的Anouar Rahmouni&Lijun Ma及其研究小组与美国卡耐基梅隆大学的Qing Li等人合作并取得一项新进展。经过不懈努力，他们实现集成碳化硅平台中纠缠光子对的产生。相关研究成果已于2024年5月9日在国际知名学术期刊《光：科学与应用》上发表。

本文首次在集成碳化硅平台上展示了一种纠缠光子源。具体而言，通过在4H -绝缘体上碳化硅平台的紧凑微环谐振腔中实现自发四波混频，在电信C波段有效地产生了强关联光子对。当泵浦功率为0.17mW时，最大符合-偶然比超过600，对应的对产生速率为(9±1)×10³对/s。针对这样的信号闲置光子对，研究人员成功产生并验证了其能量-时间纠缠，双光子干涉条纹的可见性高达99%以上。

进一步地，研究人员测量了预示的单光子特性，预示的g⁽²⁾(0)值达到10^-3量级，这一成果充分展示了碳化硅平台作为量子应用的完全集成、与互补金属氧化物半导体兼容的单光子源的前景。

据悉，量子纠缠在量子信息处理中起着至关重要的作用。由于其独特的材料特性，碳化硅最近成为可扩展实现先进量子信息处理能力的有希望的候选者。然而，到目前为止，在碳化硅中只报道了核自旋的纠缠，而纠缠光子源，无论是基于体技术还是芯片级技术，仍然存在挑战。

附：英文原文

Title: Entangled photon pair generation in an integrated SiC platform

Author: Rahmouni, Anouar, Wang, Ruixuan, Li, Jingwei, Tang, Xiao, Gerrits, Thomas, Slattery, Oliver, Li, Qing, Ma, Lijun

Issue&Volume: 2024-05-09

Abstract: Entanglement plays a vital role in quantum information processing. Owing to its unique material properties, silicon carbide recently emerged as a promising candidate for the scalable implementation of advanced quantum information processing capabilities. To date, however, only entanglement of nuclear spins has been reported in silicon carbide, while an entangled photon source, whether it is based on bulk or chip-scale technologies, has remained elusive. Here, we report the demonstration of an entangled photon source in an integrated silicon carbide platform for the first time. Specifically, strongly correlated photon pairs are efficiently generated at the telecom C-band wavelength through implementing spontaneous four-wave mixing in a compact microring resonator in the 4H-silicon-carbide-on-insulator platform. The maximum coincidence-to-accidental ratio exceeds 600 at a pump power of 0.17mW, corresponding to a pair generation rate of (9±1)×10³ pairs/s. Energy-time entanglement is created and verified for such signal-idler photon pairs, with the two-photon interference fringes exhibiting a visibility larger than 99%. The heralded single-photon properties are also measured, with the heralded g⁽²⁾(0) on the order of 10^-3, demonstrating the SiC platform as a prospective fully integrated, complementary metal-oxide-semiconductor compatible single-photon source for quantum applications.

DOI: 10.1038/s41377-024-01443-z

Source: https://www.nature.com/articles/s41377-024-01443-z