The electric dipole moment of the electron (eEDM) can be measured with high precision using heavy polar molecules. In this paper, we report on a series of new techniques that have improved the statistical sensitivity of the YbF eEDM experiment. We increase the number of molecules participating in the experiment by an order of magnitude using a carefully designed optical pumping scheme. We also increase the detection efficiency of these molecules by another order of magnitude using an optical cycling scheme. In addition, we show how to destabilise dark states and reduce backgrounds that otherwise limit the efficiency of these techniques. Together, these improvements allow us to demonstrate a statistical sensitivity of $1.8 \times 10^{-28}$ e cm after one day of measurement, which is 1.2 times the shot-noise limit. The techniques presented here are applicable to other high-precision measurements using molecules.

中文翻译：

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测量电子电偶极矩的新技术

可以使用重极性分子高精度测量电子的电偶极矩 (eEDM)。在本文中，我们报告了一系列提高 YbF eEDM 实验统计灵敏度的新技术。我们使用精心设计的光泵浦方案将参与实验的分子数量增加了一个数量级。我们还使用光学循环方案将这些分子的检测效率提高了另一个数量级。此外，我们展示了如何破坏暗状态并减少背景，否则会限制这些技术的效率。总之，这些改进使我们能够在一天的测量后展示 $1.8 \times 10^{-28}$ e cm 的统计灵敏度，这是散粒噪声限制的 1.2 倍。