High-accuracy determination of Paul-trap stability parameters for electric-quadrupole-shift prediction
High-accuracy determination of Paul-trap stability parameters for electric-quadrupole-shift prediction
复制标题
用于电四极杆位移预测的保罗陷阱稳定性参数的高精度测定
DOI：
10.1063/5.0106633
复制
发表时间：
2022
影响因子：
3.2
通讯作者：
A. Wallin
中科院分区：
文献类型：
--
作者：
T. Lindvall;K. Hanhijärvi;T. Fordell;A. Wallin
在射频（rf）保罗陷阱的离子的运动描述的马蒂厄方程和相关的稳定性参数，是成比例的射频和直流电场梯度。在这里，提出了一种高阶迭代方法来精确地解决从测量的长期频率的稳定性参数。然后，它是用来表征端盖陷阱的陷阱的径向不对称性占主导地位的直流场梯度和测量所施加的电压和梯度之间的关系。结果表明是在良好的协议与静电有限元法模拟的陷阱。此外，一种方法来确定的方向的径向陷阱轴使用“挠痒痒”电压，并讨论了射频电压的温度依赖性。作为光学离子钟的应用，该方法被用来预测和最小化的电四极移（EQS）使用所施加的直流电压。最后，在交错的低/高EQS时钟测量中确定塞曼平均EQS消除方法的消除因子的下限1070。这将我们的[公式：见正文]Sr[公式：见正文]光学时钟的EQS不确定性降低到小数频率单位的[公式：见正文]。
The motion of an ion in a radiofrequency (rf) Paul trap is described by the Mathieu equation and the associated stability parameters that are proportional to the rf and dc electric field gradients. Here, a higher-order, iterative method to accurately solve the stability parameters from measured secular frequencies is presented. It is then used to characterize an endcap trap by showing that the trap’s radial asymmetry is dominated by the dc field gradients and by measuring the relation between the applied voltages and the gradients. The results are shown to be in good agreement with an electrostatic finite-element-method simulation of the trap. Furthermore, a method to determine the direction of the radial trap axes using a “tickler” voltage is presented, and the temperature dependence of the rf voltage is discussed. As an application for optical ion clocks, the method is used to predict and minimize the electric quadrupole shift (EQS) using the applied dc voltages. Finally, a lower limit of 1070 for the cancellation factor of the Zeeman-averaging EQS cancellation method is determined in an interleaved low-/high-EQS clock measurement. This reduces the EQS uncertainty of our [Formula: see text]Sr[Formula: see text] optical clock to [Formula: see text] in fractional frequency units.