标题： 基于黑体辐射 Stark 不确定度的 Cryogenic 光晶格钟$1.7\times 10^{-20}$ 显示英文标题

标题： Cryogenic Optical Lattice Clock with $1.7\times 10^{-20}$ Blackbody Radiation Stark Uncertainty

摘要： 控制来自环境热辐射的斯塔克扰动是提升许多原子频率标准性能的关键，其中包括最先进的光学晶格钟（OLCs）。 我们展示了一种低温光学晶格钟，它利用动态致动的辐射屏蔽来控制 $1.7\times10^{-20}$ 频率分数处的扰动，这一性能比迄今为止最好的光学晶格钟高出 $\sim$ 倍。 我们的屏蔽装置通过在时钟光谱期间以百万分之一级别的精度拒绝外部热辐射，为原子提供了一个接近理想的低温黑体辐射（BBR）环境，克服了之前光学晶格钟中低温BBR控制解决方案的一个关键限制。 尽管最低的BBR位移不确定性是在低温操作下实现的，但我们进一步利用该屏蔽装置在较宽温度范围内的辐射控制能力，直接测量并验证了镱的主要BBR斯塔克动态校正系数。 这一独立测量使该系数的文献综合不确定性减少了30%，从而有助于室温下运行的最先进的镱光学晶格钟。 我们在较低的 $10^{-18}$ 水平上验证了镱的静态BBR系数。 显示英文摘要

摘要： Controlling the Stark perturbation from ambient thermal radiation is key to advancing the performance of many atomic frequency standards, including state-of-the-art optical lattice clocks (OLCs). We demonstrate a cryogenic OLC that utilizes a dynamically actuated radiation shield to control the perturbation at $1.7\times10^{-20}$ fractional frequency, a factor of $\sim$40 beyond the best OLC to date. Our shield furnishes the atoms with a near-ideal cryogenic blackbody radiation (BBR) environment by rejecting external thermal radiation at the part-per-million level during clock spectroscopy, overcoming a key limitation with previous cryogenic BBR control solutions in OLCs. While the lowest BBR shift uncertainty is realized with cryogenic operation, we further exploit the radiation control that the shield offers over a wide range of temperatures to directly measure and verify the leading BBR Stark dynamic correction coefficient for ytterbium. This independent measurement reduces the literature-combined uncertainty of this coefficient by 30%, thus benefiting state-of-the-art Yb OLCs operated at room temperature. We verify the static BBR coefficient for Yb at the low $10^{-18}$ level.