论文标题
$^{113} $ cd $^+$的交感冷却，由激光冷却$^{40} $ ca $^+$在线性保罗陷阱中用于微波炉离子时钟
Sympathetic cooling of $^{113}$Cd$^+$ by laser-cooled $^{40}$Ca$^+$ in a linear Paul trap for Microwave Ion Clocks
论文作者
论文摘要
我们报告$^{113}的交感冷却$ cd $^+$由激光冷却$^{40} $ ca $^+$在线性保罗陷阱中用于微波时钟。 $^{113} $ cd $^+$ ions的长期低温限制已实现。这些离子的温度为90美元（10）$ MK，二阶多普勒偏移产生的相应不确定性估计为$ 2 \ times10^{ - 17} $的水平。最高$ 4.2 \ times10^5 $ cd $^+$离子被限制在陷阱中，并且限制时间常数为84小时。经过三个小时的限制后，仍然有$ 10^5 $ cd $^+$离子，这表明此CA $^+$ - CD $^+$双离子系统令人惊讶地稳定。 CA $^+$激光器和荧光诱导了交流的偏移，仔细估计，使用高准确性\ textit \ textIt {ab ibrio}方法，其精度为$ 5.4（0.5）\ times10^{ - 17} $。由于较短的时间，迪克效应限制的艾伦（Allan）偏差也被推导出来。这些结果表明，基于此交感神经冷却方案的微波钟有望提供超高的频率准确性和稳定性。
We report sympathetic cooling of $^{113}$Cd$^+$ by laser-cooled $^{40}$Ca$^+$ in a linear Paul trap for microwave clocks. Long-term low-temperature confinement of $^{113}$Cd$^+$ ions was achieved. The temperature of these ions was measured at $90(10)$ mK, and the corresponding uncertainty arising from the second-order Doppler shifts was estimated to a level of $2\times10^{-17}$. Up to $4.2\times10^5$ Cd$^+$ ions were confined in the trap, and the confinement time constant was measured to be 84 hours. After three hours of confinement, there were still $10^5$ Cd$^+$ ions present, indicating that this Ca$^+$--Cd$^+$ dual ion system is surprisingly stable. The ac Stark shift was induced by the Ca$^+$ lasers and fluorescence, which was carefully estimated to an accuracy of $5.4(0.5)\times10^{-17}$ using a high-accuracy \textit{ab initio} approach. The Dick-effect-limited Allan deviation was also deduced because deadtimes were shorter. These results indicate that a microwave clock based on this sympathetic cooling scheme holds promise in providing ultra-high frequency accuracy and stability.
