RUI: PM: Optical Molecular Clocks for New Physics Searches

一些原子和分子具有特别适合用于计时、量子信息或物理定律测试的量子态。该奖项的重点是分子振动--原子核拉伸和压缩化学键。该项目将展示使用分子振动作为精确频率基准所需的工具(也就是良好的时钟)，并成为探索自然界基本物理参数(如质子比电子重多少倍)变化的垫脚石。量子引力或暗物质的一些模型预测到了这样的变化，但实验室还没有观察到任何变化。这项研究在一所文科学院进行，本科生参与了这项工作的方方面面。该项目将促进博士后学者的职业生涯。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。该奖项使分子离子中激光驱动的振动跃迁的研究成为可能。这里的特殊跃迁--从双原子氧分子阳离子中的基态振动态到振动激发态--具有窄的自然线宽，对基本常数的变化高度敏感，作为光学分子时钟具有长期的前景。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。分子振动为下一代寻找质子与电子质量比的漂移或振荡提供了巨大的希望。该项目建立在PI在捕获带电粒子方面的经验以及生产量子态选择分子离子的现有基础设施的基础上。这些离子将被装载到一个陷阱中，并与共捕获的原子离子一起进行同步冷却。捕获可以实现较长的探测时间，这将是精确确定跃迁频率和演示对质子与电子质量比变化的证明原则搜索所必需的。这样的搜索是对额外维度、新标量场和超轻暗物质的探索。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 possess quantum states with properties that are particularly well-suited to use in timekeeping, quantum information, or tests of physical laws. This award focuses on molecular vibrations – where the atomic nuclei stretch and compress the chemical bond. The project will demonstrate the tools needed to use molecular vibrations as precise frequency references (that is as good clocks) and is a stepping stone on the way towards searching for changes in the basic physical parameters of nature (such as how many times heavier the proton is than the electron). Such changes are predicted by some models of quantum gravity or dark matter, but none have yet been observed in the lab. This research takes place at a liberal arts college, and undergraduate students are involved in all aspects of the work. The project will advance the career of a postdoctoral scholar. 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 award enables investigation of laser-driven vibrational transitions in molecular ions. The particular transition here – from the ground vibrational state to a vibrationally excited state in the diatomic oxygen molecular cation – has a narrow natural linewidth, high sensitivity to changing fundamental constants, and long-term prospects as an optical molecular clock. The nonpolar nature of the molecule suppresses systematic shifts related to electric fields, such as AC Stark shifts and blackbody radiation. Molecular vibrations hold great promise for next-generation searches for drifts or oscillations in the proton-to-electron mass ratio. This project builds on the PI’s experience with trapped charged particles as well as existing infrastructure for producing quantum-state-selected molecular ions. These ions will be loaded into a trap and sympathetically cooled with co-trapped atomic ions. The trapping enables long probe times, which will be needed to precisely determine the transition frequency and to demonstrate a proof-of-principle search for variation in the proton-to-electron mass ratio. Such a search is a probe of additional dimensions, new scalar fields, and ultralight dark matter.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.