${\mathrm{Er}}^{3+}\text{:}{\mathrm{Y}}_2{\mathrm{SiO}}_5$ is a material of particular interest due to its suitability for telecom-band quantum memories and quantum transducers interfacing optical communication with quantum computers working in the microwave regime. Extending the coherence lifetimes of the electron spins and the nuclear spins is essential for implementing efficient quantum information processing based on such hybrid electron-nuclear spin systems. The electron spin coherence time of ${\mathrm{Er}}^{3+}\text{:}{\mathrm{Y}}_2{\mathrm{SiO}}_5$ is so far limited to several microseconds, and there are significant challenges in optimizing coherence lifetimes simultaneously for both the electron and nuclear spins. Here we perform a pulsed-electron-nuclear-double-resonance investigation for an ${\mathrm{Er}}^{3+}$-doped material at subkelvin temperatures. At the lowest working temperature, the electron spin coherence time reaches 290 $\pm$ 17 $\mathrm{\mu }\mathrm{s}$, which has been enhanced by 40 times compared with the previous results. In the subkelvin regime, a rapid increase in the nuclear spin coherence time is observed, and the longest coherence time of 738 $\pm$ 6 $\mathrm{\mu }\mathrm{s}$ is obtained. These extended coherence lifetimes could be valuable resources for further applications of ${\mathrm{Er}}^{3+}\text{:}{\mathrm{Y}}_2{\mathrm{SiO}}_5$ in fiber-based quantum networks.

中文翻译：

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延长 Er3+167:Y2SiO5 在亚开尔文温度下的自旋相干寿命

${呃}^{3+}\text{：}{\mathrm{是}}_2{\mathrm{二氧化硅}}_5$是一种特别令人感兴趣的材料，因为它适用于电信波段的量子存储器和与在微波范围内工作的量子计算机进行光通信接口的量子换能器。延长电子自旋和核自旋的相干寿命对于实现基于这种混合电子-核自旋系统的有效量子信息处理至关重要。电子自旋相干时间${呃}^{3+}\text{：}{\mathrm{是}}_2{\mathrm{二氧化硅}}_5$到目前为止，它仅限于几微秒，并且在同时优化电子和核自旋的相干寿命方面存在重大挑战。在这里，我们对一个脉冲电子核双共振研究${呃}^{3+}$亚开尔文温度下的掺杂材料。在最低工作温度下，电子自旋相干时间达到290$\pm$17$\mathrm{\mu }\mathrm{s}$，与之前的结果相比，提高了 40 倍。在亚开尔文状态下，观察到核自旋相干时间迅速增加，最长相干时间为 738$\pm$6$\mathrm{\mu }\mathrm{s}$获得。这些延长的相干寿命可能是进一步应用的宝贵资源${呃}^{3+}\text{：}{\mathrm{是}}_2{\mathrm{二氧化硅}}_5$在基于光纤的量子网络中。