Experimental Generation of Spin-Photon Entanglement in Silicon Carbide

• Published in: Physical review letters 2024-04, Vol.132 (16), p.160801-160801, Article 160801
• Main Authors: Fang, Ren-Zhou, Lai, Xiao-Yi, Li, Tao, Su, Ren-Zhu, Lu, Bo-Wei, Yang, Chao-Wei, Liu, Run-Ze, Qiao, Yu-Kun, Li, Cheng, He, Zhi-Gang, Huang, Jia, Li, Hao, You, Li-Xing, Huo, Yong-Heng, Bao, Xiao-Hui, Pan, Jian-Wei
• Format: Article
• Language: English
• ISSN: 0031-9007; 1079-7114
• DOI: 10.1103/PhysRevLett.132.160801

A solid-state approach for quantum networks is advantageous, as it allows the integration of nanophotonics to enhance the photon emission and the utilization of weakly coupled nuclear spins for long-lived storage. Silicon carbide, specifically point defects within it, shows great promise in this regard due to the easy of availability and well-established nanofabrication techniques. Despite of remarkable progresses made, achieving spin-photon entanglement remains a crucial aspect to be realized. In this Letter, we experimentally generate entanglement between a silicon vacancy defect in silicon carbide and a scattered single photon in the zero-phonon line. The spin state is measured by detecting photons scattered in the phonon sideband. The photonic qubit is encoded in the time-bin degree of freedom and measured using an unbalanced Mach-Zehnder interferometer. Photonic correlations not only reveal the quality of the entanglement but also verify the deterministic nature of the entanglement creation process. By harnessing two pairs of such spin-photon entanglement, it becomes straightforward to entangle remote quantum nodes at long distance.