Robust spin-photon interfaces with optical transitions in the telecommunication band are essential for quantum networking technologies. Erbium (Er) ions are the ideal candidate with environmentally protected transitions in telecom-C band. Finding the right technologically compatible host material to enable long-lived spins remains a major hurdle. We introduce a new platform based on Er ions in cerium dioxide (CeO₂) as a nearly-zero nuclear spin environment (0.04%) epitaxially grown on silicon, offering silicon compatibility for opto-electrical devices. Our studies focus on Er³⁺ ions and show a narrow homogeneous linewidth of 440 kHz with an optical coherence time of 0.72 μs at 3.6 K. The reduced nuclear spin noise enables a slow spin-lattice relaxation with a spin relaxation time up to 2.5 ms and an electron spin coherence time of 0.66 μs (in the isolated ion limit) at 3.6 K. These findings highlight the potential of Er³⁺:CeO₂ platform for quantum networks applications.

在电信频段中具有光跃迁的稳健自旋光子接口对于量子网络技术至关重要。铒 （Er） 离子是在电信 C 波段具有环保跃迁的理想候选者。找到合适的技术兼容的宿主材料来实现长寿命旋转仍然是一个主要障碍。我们引入了一种基于二氧化铈 （CeO₂） 中铈离子的新平台，作为在硅上外延生长的近乎零的核自旋环境 （0.04%），为光电器件提供硅兼容性。我们的研究集中在 Er³⁺ 离子上，并显示出 440 kHz 的窄均匀线宽，在 3.6 K 下的光学相干时间为 0.72 μs。降低的核自旋噪声可实现缓慢的自旋晶格弛豫，在 3.6 K 时自旋弛豫时间高达 2.5 ms，电子自旋相干时间为 0.66 μs（在孤立离子极限内）。这些发现突出了 Er³⁺：CeO₂ 平台在量子网络应用方面的潜力。