RUI: Driving Forbidden Vibrational Overtones in Trapped Molecular Ions

一些原子和分子的量子态具有特别适合计时、量子信息处理或物理定律测试的性质。这个项目的重点是分子振动，它对基本常数很敏感，如电子质量和质子质量。当原子核拉伸和压缩化学键时，这些振动就会发生，它们的振动频率取决于质子与电子的质量比。该团队将利用振动状态进行原理验证实验，以寻找基本常量随时间的变化。量子引力或暗物质的一些模型预测到了这种变化，但尚未在实验中检测到。这个项目通过开发研究分子振动的新方法来促进科学进步，作为基础物理的精确测试。这项研究发生在一所文科大学，本科生参与了这项工作的方方面面。除了培训下一代科学家外，这项工作还开发了实验物理方面的技能，这些技能可用于未来的广泛努力。这个项目将研究被捕获的分子离子中的电偶极禁止振动泛音。该团队将在双原子氧分子离子中驱动泛音作为双光子跃迁，这既是一个光学分子钟，也是质子与电子质量比随时间变化的探测器，这是长期感兴趣的。分子的非极性抑制了与电场相关的系统漂移，如交流斯塔克漂移和黑体辐射。这项工作的一个关键工具是一个稳定的光学本机振荡器，它参考一个单独的光时钟。为了展示这个系统的前景，这个团队将把泛音转换频率的不确定性降低几个数量级，并在一年的时间里对其进行监控。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Some atoms and molecules have quantum states with properties that are particularly well-suited for timekeeping, for quantum information processing, or for tests of physical laws. This project focuses on molecular vibrations that are sensitive to fundamental constants such as the electron mass and the proton mass. These vibrations occur when atomic nuclei stretch and compress a chemical bond, and their vibration frequencies depend on the proton-to-electron mass ratio. This team will conduct a proof-of-principle experiment using vibrational states to search for time dependent changes in fundamental constants. Such changes are predicted by some models of quantum gravity or dark matter, but have not yet been detected experimentally. This project promotes the progress of science by developing new ways to study molecular vibrations as precision tests of fundamental physics. This research takes place at a liberal arts college where undergraduate students are involved in all aspects of the work. In addition to training the next generation of scientists, this work develops skills in experimental physics that are transferable to a wide array of future endeavors.This project will investigate electric-dipole-forbidden vibrational overtones in trapped molecular ions. The team will drive an overtone as a two-photon transition in the diatomic oxygen molecular ion, which is of long-term interest as both an optical molecular clock and as a probe for time-variation of the proton-to-electron mass ratio. The nonpolar nature of the molecule suppresses systematic shifts related to electric fields, such as AC Stark shifts and blackbody radiation. A key tool for this work is a stable optical local oscillator that is referenced to a separate optical clock. To demonstrate the promise of this system, this team will reduce the uncertainty on an overtone transition frequency by several orders of magnitude and monitor it over the course of a year.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.