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arXiv · 2502.16222

Ultralong-lived Coherent States in Eu$^{3+}$:Y$_2$O$_3$ Optical Ceramics for Quantum Memories

Shuping Liu·Miaomiao Ren·Wanting Xiao·Jun Wang·Yuting Liu·Diana Serrano·Philippe Goldner·Dingyuan Tang·Xiantong An·Fudong Wang·Manjin Zhong
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Abstract

Rare earth ions (REI) in solid materials are among the leading systems for quantum technology applications. However, developing practical REI quantum devices with long-lived coherent states remains challenging due to great growth difficulties of high-quality REI materials and a lack of comprehensive understanding of REI's decoherence mechanisms. Here we realize a record optical coherence time of 421.5 $\pm$ 10.5 $\mu$s for the $^7$F$_0\rightarrow^5$D$_0$ transition and more than 30 hours lifetime for the $^7$F$_0$ hyperfine spin states in Eu$^{3+}$:Y$_2$O$_3$ optical ceramics. We report the elimination of two-level-system induced optical decoherence in short-range ordered crystals. Meanwhile, a new decoherence mechanism caused by new kinds of perturbing magnetic centers is identified below 1.5 K. We further demonstrate the coherent light storage over 5 $\mu$s by using the atomic frequency comb protocol. These results open up prospects for the realization of practical quantum memories and large scale quantum communications with REI optical ceramics.

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Shuping Liu, Miaomiao Ren, Wanting Xiao, Jun Wang, Yuting Liu, Diana Serrano, Philippe Goldner, Dingyuan Tang, Xiantong An, Fudong Wang, Manjin Zhong. 2025-02-22. Ultralong-lived Coherent States in Eu$^{3+}$:Y$_2$O$_3$ Optical Ceramics for Quantum Memories. https://arxiv.org/abs/2502.16222

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