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arXiv · 2508.12429

Spin decoherence dynamics of Er$^{3+}$ in CeO$_2$ film

Sagar Kumar Seth·Jonah Nagura·Vrindaa Somjit·Aneesh Bapat·Xinhao Li·Gregory D. Grant·Ignas Masiulionis·Xu Han·F. Joseph Heremans·Giulia Galli·David D. Awschalom·Supratik Guha·Jiefei Zhang
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Abstract

Developing telecom-compatible spin-photon interfaces is essential towards scalable quantum networks. Erbium ions (Er$^{3+}$) exhibit a unique combination of a telecom (1.5 $\mu$m) optical transition and an effective spin-$1/2$ ground state, but identifying a host that enables heterogeneous device integration while preserving long optical and spin coherence remains an open challenge. We explore a new platform of Er$^{3+}$:CeO$_2$ films on silicon, offering low nuclear spin density and the potential for on-chip integration. We demonstrate a 38.8 $\mu$s spin coherence, which can be extended to 176.4\nobreakspace $\mu$s with dynamical decoupling. Pairing experiments with cluster correlation expansion calculations, we identify spectral diffusion-induced Er$^{3+}$ spin flips as the dominant decoherence mechanism and provide pathways to millisecond-scale coherence.

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Sagar Kumar Seth, Jonah Nagura, Vrindaa Somjit, Aneesh Bapat, Xinhao Li, Gregory D. Grant, Ignas Masiulionis, Xu Han, F. Joseph Heremans, Giulia Galli, David D. Awschalom, Supratik Guha, Jiefei Zhang. 2025-08-17. Spin decoherence dynamics of Er$^{3+}$ in CeO$_2$ film. https://arxiv.org/abs/2508.12429

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