Nuclear Spin Coherence and All‐Optical Dynamical Decoupling in Eu 3+ :Y 2 O 3 Ceramics
Miaomiao Ren, Zhenqi Xu, Jun Wang, Nuoran Xu, Diana Serrano, Philippe Goldner, Dingyuan Tang, Fudong Wang, Shuping Liu, Manjin ZhongABSTRACT
Rare‐earth‐ion‐doped solid materials have attracted considerable interest for quantum technologies. However, achieving robust spin coherence in polycrystalline systems remains challenging due to structural disorder and limited understanding spin environments. Here, we report high‐quality : optical ceramics with optical inhomogeneous of GHz and sub‐kHz homogeneous linewidths, indicating a spectrally quiet optical environment. At cryogenic temperatures, spin‐dynamics measurements show that decoherence is strongly influenced by the surrounding nuclear spin bath. Magnetic‐field‐dependent studies, combined with radio‐frequency spectroscopy, reveal the sensitivity of spin coherence to weak magnetic perturbations and enable selective addressing of the bath spins. By applying an all‐optical Raman dynamical decoupling protocol, we substantially prolong the observed nuclear‐spin coherence decay, yielding a slow decay component of 224 ms. These results establish : ceramics as a promising platform for solid‐state quantum memories and highlight the potential of spin‐bath engineering in polycrystalline rare‐earth‐ion systems.