论文标题
Erbium电子旋转的稳健毫秒相干时间
Robust millisecond coherence times of erbium electron spins
论文作者
论文摘要
由于Erbium的电信C波段发射，掺杂的固体是光学量子通信网络的主要候选者。具有毫秒相干时间的ERBIUM的长寿命电子自旋对于在相邻量子中继器节点之间建立纠缠非常需要，而纠缠的长期存储可能依赖于转移到Erbium的第二长相干核旋转。在这里，我们报告了$^{167} \ mathrm {er}^{3+} $的GHz范围电子自旋转换（氧化物yttrium {$ \ mathrm {y_2o_3} $）矩阵与相干时间持续长于一个millisecond。我们没有解决特定于场的零一阶zeeman跃迁，而是沿较低的g因子探测弱混合的电子旋转。使用脉冲电子自旋谐振光谱，我们发现顺磁杂质是反应的主要来源，通过极化，我们实现了Hahn Echo spin $ \ mathrm {t_2} $最高1.46 ms，并且在动态解耦合后达到7.1毫秒。这些相干的寿命是晶体宿主中最长的寿命之一，尤其是那些核自旋的宿主。我们使用定制的序列同时减轻光谱扩散和ER-ER偶极相互作用，进一步增强了传统动力解耦之外的相干时间。尽管宿主中有核和杂质旋转，但这项工作表明，可以实现与非核自旋宿主相当的长寿命旋转。我们的研究不仅建立了$^{167} \ mathrm {er}^{3+} $：$ \ mathrm {y_2 o_3} $作为一个显着有希望的量子存储平台，但也为工程型载有各种量子技术材料的工程型ERBIUM旋转提供了一般指南。
Erbium-doped solids are prime candidates for optical quantum communication networks due to erbium's telecom C-band emission. A long-lived electron spin of erbium with millisecond coherence time is highly desirable for establishing entanglement between adjacent quantum repeater nodes while long-term storage of the entanglement could rely on transferring to erbium's second-long coherence nuclear spins. Here we report GHz-range electron spin transitions of $^{167}\mathrm{Er}^{3+}$ in yttrium oxide ($\mathrm{Y_2O_3}$) matrix with coherence times that are consistently longer than a millisecond. Instead of addressing field-specific Zero First-Order Zeeman transitions, we probe weakly mixed electron spins with the field orientation along the lower g-factors. Using pulsed electron spin resonance spectroscopy, we find paramagnetic impurities are the dominant source of decoherence, and by polarizing them we achieve a Hahn echo spin $\mathrm{T_2}$ up to 1.46 ms, and a coherence time up to 7.1 ms after dynamical decoupling. These coherence lifetimes are among the longest found in crystalline hosts especially those with nuclear spins. We further enhance the coherence time beyond conventional dynamical decoupling, using customized sequences to simultaneously mitigate spectral diffusion and Er-Er dipolar interactions. Despite nuclear and impurity spins in the host, this work shows that long-lived erbium spins comparable to non-nuclear spin hosts can be achieved. Our study not only establishes $^{167}\mathrm{Er}^{3+}$: $\mathrm{Y_2 O_3}$ as a significantly promising quantum memory platform but also provides a general guideline for engineering long-lived erbium spins in a variety of host materials for quantum technologies.
