论文标题
在Millikelvin温度下，电子自旋光谱扩散在Erbium掺杂晶体中
Electron-spin spectral diffusion in an erbium doped crystal at millikelvin temperatures
论文作者
论文摘要
掺杂的晶体为混合量子设备提供了多功能平台，因为它们将磁敏感的电子旋转过渡与电信波长光学转变相结合。但是，在许多量子应用所需的高掺杂浓度下，电子旋转浴的强磁相互作用会导致过量的光谱扩散和快速的分解。在这里，我们在$ \ text {cawo} _ {4} $ crystal掺杂er离子的$ \ text {cawo} _ {cawo} _ {cawo} _ {cawo} _ {cawo} $二十一部分，相对于CA的浓度为二十个。使用微波谐振器，我们表征了光谱扩散过程，该过程通过应用2和3脉冲回声序列来限制Millikelvin温度下ER离子的电子旋转相干性。相干时间显示出强烈的温度依赖性，在23 mk处达到1.3 ms，用于$^{167} \ text {er} $的电子旋转过渡。
Erbium-doped crystals offer a versatile platform for hybrid quantum devices because they combine magnetically-sensitive electron-spin transitions with telecom-wavelength optical transitions. At the high doping concentrations necessary for many quantum applications, however, strong magnetic interactions of the electron-spin bath lead to excess spectral diffusion and rapid decoherence. Here we lithographically fabricate a 4.4 GHz superconducting planar micro-resonator on a $\text{CaWO}_{4}$ crystal doped with Er ions at a concentration of twenty parts per million relative to Ca. Using the microwave resonator, we characterize the spectral diffusion processes that limit the electron-spin coherence of Er ions at millikelvin temperatures by applying 2- and 3-pulse echo sequences. The coherence time shows a strong temperature dependence, reaching 1.3 ms at 23 mK for an electron-spin transition of $^{167}\text{Er}$.
