标题： 基于黑体辐射斯塔克效应的低温光学晶格钟$1.7\times 10^{-20}$ 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Stark扰动（来自环境热辐射）是提升许多原子频率标准性能的关键，包括最先进的光晶格钟（OLC）。 我们展示了一种低温光晶格钟，它利用动态致动的辐射屏蔽来控制在$1.7\times10^{-20}$频率下的扰动，这一水平比迄今为止最好的光晶格钟高出$\sim$因子40倍。 我们的屏蔽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，为原子提供了接近理想的低温黑体辐射（BBR）环境，克服了之前低温BBR控制方案在光晶格钟中的关键限制。 尽管最低的BBR偏移不确定性是在低温操作下实现的，但我们进一步利用屏蔽在广泛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 Stark动态校正系数。 这项独立测量使该系数的文献综合不确定性降低了30%，从而有益于在室温下运行的最先进的镱光晶格钟。 我们在低$10^{-18}$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.