论文标题
辐射离子光钟
Radium Ion Optical Clock
论文作者
论文摘要
我们报告了RA $^{+} $光学时钟的第一个操作，这是一个有希望的高性能时钟候选人。时钟使用单个被困的$ ^{226} $ ra $ ^{+} $ ion，并在$ 7S \ ^2S_ {1/2} \ rightArrow $ 6D \ ^2d_ {5/2} $ electric quadrupole transition上运行。通过自我引用三对对称Zeeman的过渡，我们演示了频率不稳定为1.1 $ \ times10^{ - 13} $/$/$/$/$ \sqrtτ$，其中$τ$是几秒钟内的平均时间。总体系统不确定性评估为$ {Δν/ν= 9 \ times 10^{ - 16}} $。使用时钟，我们意识到$ d_ {5/2} $状态与$ s_ {1/2} $ statelandé$ g $ -factors：$ g_ {d}/g_ {s} $ = 0.5988053（11）的第一个测量。在光学频率比较中，ra $^{+} $光学时钟可以提高罚款结构常数（$ \dotα/α$）的时间变化的限制。离子还具有多个功能，使其成为适合可运输光学时钟的合适系统。
We report the first operation of a Ra$^{+}$ optical clock, a promising high-performance clock candidate. The clock uses a single trapped $^{226}$Ra$^{+}$ ion and operates on the $7s\ ^2S_{1/2}\rightarrow$ $6d\ ^2D_{5/2}$ electric quadrupole transition. By self-referencing three pairs of symmetric Zeeman transitions, we demonstrate a frequency instability of 1.1$\times10^{-13}$/$\sqrtτ$, where $τ$ is the averaging time in seconds. The total systematic uncertainty is evaluated to be ${Δν/ ν= 9 \times 10^{-16}}$. Using the clock, we realize the first measurement of the ratio of the $D_{5/2}$ state to the $S_{1/2}$ state Landé $g$-factors: $g_{D}/g_{S}$ = 0.5988053(11). A Ra$^{+}$ optical clock could improve limits on the time variation of the fine structure constant, $\dot α/ α$, in an optical frequency comparison. The ion also has several features that make it a suitable system for a transportable optical clock.
