论文标题
四倍离子化的钡作为高准确光学时钟的候选者
Quadruply Ionized Barium as a Candidate for a High-Accuracy Optical Clock
论文作者
论文摘要
我们将BA $^{4+} $（Te Like）确定为高准确光学时钟的有前途的候选人。最低的电子状态是$^3p_j $良好结构歧管的一部分，具有异常的能量订购，在$ j $中是非单调的。我们提出了一个基于地面（$^3p_2 $）和先开启（$^3p_0 $）电子状态的338.8 THZ电动四极转变的时钟。我们执行相对论的多体计算，以确定该离子的相关特性。发现激发时钟状态的寿命为几秒钟，可容纳低统计不确定性，单个离子用于实用平均时间。发现差异静态标量极化率很小且负面，从而抑制了对黑体辐射的敏感性，同时允许取消Stark和过量的微功能移动。除Hg $^+$和Yb $^+$外，对良好结构常数变化的敏感性大于迄今为止所证明的其他光学时钟。
We identify Ba$^{4+}$ (Te-like) as a promising candidate for a high-accuracy optical clock. The lowest-lying electronic states are part of a $^3P_J$ fine structure manifold with anomalous energy ordering, being non-monotonic in $J$. We propose a clock based on the 338.8 THz electric quadrupole transition between the ground ($^3P_2$) and first-excited ($^3P_0$) electronic states. We perform relativistic many-body calculations to determine relevant properties of this ion. The lifetime of the excited clock state is found to be several seconds, accommodating low statistical uncertainty with a single ion for practical averaging times. The differential static scalar polarizability is found to be small and negative, providing suppressed sensitivity to blackbody radiation while simultaneously allowing cancellation of Stark and excess micromotion shifts. With the exception of Hg$^+$ and Yb$^+$, sensitivity to variation of the fine structure constant is greater than other optical clocks thus far demonstrated.
