Light scalar dark matter (DM) with scalar couplings to matter is expected within several scenarios to induce variations in the fundamental constants of nature. Such variations can be searched for, among other ways, via atomic spectroscopy. Sensitive atomic observables arise primarily due to possible changes in the fine-structure constant or the electron mass. Most of the searches to date have focused on slow variations of the constants (i.e. modulation frequencies <1Hz). In a recent experiment (2019 Phys. Rev. Lett. 123 141102) called weekend relaxion-search laboratory (WReSL), we reported on a direct search for rapid variations in the radio-frequency band. Such a search is particularly motivated within a class of relaxion DM models. We discuss the WReSL experiment, report on progress toward improved measurements of rapid fundamental constant variations, and discuss the planned extension of the work to molecules, in which rapid variations of the nuclear mass can be sensitively searched for.

与物质标量耦合的轻标量暗物质 (DM) 预计在几种情况下会引起自然基本常数的变化。除其他方式外，可以通过原子光谱搜索此类变化。敏感原子可观测值的出现主要是由于精细结构常数或电子质量的可能变化。迄今为止，大多数搜索都集中在常数的缓慢变化上（即调制频率 <1Hz）。在最近的一项实验中 (2019 Phys. Rev. Lett. 123141102) 称为周末松弛搜索实验室 (WReSL)，我们报告了对无线电频段快速变化的直接搜索。这种搜索在一类松弛 DM 模型中特别受到启发。我们讨论了 WReSL 实验，报告了改进快速基本常数变化测量的进展，并讨论了将工作扩展到分子的计划，其中可以灵敏地搜索核质量的快速变化。