Optical and spin coherence of Er\(^{3+}\) in epitaxial CeO\(_2\) on silicon

• Published in: arXiv.org 2023-09
• Main Authors: Zhang, Jiefei, Grant, Gregory D, Masiulionis, Ignas, Solomon, Michael T, Bindra, Jasleen K, Niklas, Jens, Dibos, Alan M, Poluektov, Oleg G, Heremans, F Joseph, Guha, Supratik, Awschalom, David D
• Format: Article
• Language: English
• Subjects: Coherence; Electron spin; Epitaxial growth; Erbium; Nuclear spin; Optical transition; Polarization (spin alignment); Silicon substrates
• ISSN: 2331-8422
• DOI: 10.48550/arxiv.2309.16785

Solid-state atomic defects with optical transitions in the telecommunication bands, potentially in a nuclear spin free environment, are important for applications in fiber-based quantum networks. Erbium ions doped in CeO\(_2\) offer such a desired combination. Here we report on the optical homogeneous linewidth and electron spin coherence of Er\(^{3+}\) ions doped in CeO\(_2\) epitaxial film grown on a Si(111) substrate. The long-lived optical transition near 1530 nm in the environmentally-protected 4f shell of Er\(^{3+}\) shows a narrow homogeneous linewidth of 440 kHz with an optical coherence time of 0.72 \(\mu\)s at 3.6 K. The reduced nuclear spin noise in the host allows for Er\(^{3+}\) electron spin polarization at 3.6 K, yielding an electron spin coherence of 0.66 \(\mu\)s (in the isolated ion limit) and a spin relaxation of 2.5 ms. These findings indicate the potential of Er\(^{3+}\):CeO\(_2\) film as a valuable platform for quantum networks and communication applications.