论文标题
基于交感冷却离子的高性能微波频率标准
High-Performance Microwave Frequency Standard Based on Sympathetically Cooled Ions
论文作者
论文摘要
离子微波频率标准是下一代微波频率标准的候选者，具有非常广泛的应用。 Dick效应和二阶多普勒频移（SODF）限制了离子微波频率标准的性能。同情冷却技术的引入可以抑制鸡巴效应和SODF，并提高频率标准的稳定性和准确性。但是，以前很少研究交感冷却的离子微波频率标准。本文报告了保罗陷阱中第一个交感冷却的离子微波频率标准。使用激光冷却$ {}^{40} \ mathrm {ca}^{+} $作为冷却剂离子，$ {}^{113} \ Mathrm {CD}^{+} $ ion Crystal冷却至100 mk以下，并具有超过40 s的相干寿命。短期频率稳定性达到$ 3.48 \ times 10^{ - 13}/τ^{1/2} $，与汞离子频率标准的相当。它的不确定性为$ 1.5 \ times 10^{ - 14} $，比直接激光冷却的镉离子频率标准要好。
The ion microwave frequency standard is a candidate for the next generation of microwave frequency standard with the potential for very wide applications. The Dick effect and second-order Doppler frequency shift (SODFS) limit the performance of ion microwave frequency standards. The introduction of sympathetic cooling technology can suppress the Dick effect and SODFS and improve the stability and accuracy of the frequency standard. However, the sympathetically-cooled ion microwave frequency standard has seldom been studied before. This paper reports the first sympathetically-cooled ion microwave frequency standard in a Paul trap. Using laser-cooled ${}^{40}\mathrm{Ca}^{+}$ as coolant ions, ${}^{113}\mathrm{Cd}^{+}$ ion crystal is cooled to below 100 mK and has a coherence lifetime of over 40 s. The short-term frequency stability reached $3.48 \times 10^{-13}/τ^{1/2}$, which is comparable to that of the mercury ion frequency standard. Its uncertainty is $1.5\times 10^{-14}$, which is better than that of directly laser-cooled cadmium ion frequency standard.
