RUI: PM: Optical Molecular Clocks for New Physics Searches

RUI：PM：用于新物理搜索的光学分子钟

• 批准号: 2207623
• 负责人: David Hanneke
• 金额: $ 56.11万
• 依托单位: Amherst College
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-07-15 至 2025-06-30
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2207623&HistoricalAwards=false
• 关键词: RUI; PM; Optical; Molecular; Clocks

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.

一些原子和分子具有量子态，其特性特别适合用于计时、量子信息或物理定律测试。该项目将重点关注分子振动——原子核拉伸和压缩化学键。展示了使用分子振动作为精确频率参考（即良好的时钟）所需的工具，并且是寻找自然基本物理参数变化（例如质子比质子重多少倍）的踏脚石。一些模型预测了这种变化。量子引力或暗物质，但尚未在实验室中观察到这项研究是在文理学院进行的，本科生参与了该项目的各个方面，将促进博士后学者的职业生涯。除了培训下一代科学家之外，这项工作还培养了实验物理学方面的技能，这些技能可转移到未来的各种工作中。该奖项能够研究分子离子中激光驱动的振动跃迁，即来自地面的特殊跃迁。振动状态到振动激发状态双原子氧分子阳离子 - 具有较窄的自然线宽，对基本常数变化具有高敏感性，并且具有作为光学分子钟的长期前景。分子的非极性性质抑制了与电场相关的系统位移，例如交流斯塔克位移和黑体。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广阔的前景。该项目建立在 PI 在捕获带电粒子方面的经验以及现有基础设施的基础上。产生量子态选择的分子离子。这些离子将被加载到陷阱中，并与共同捕获的原子离子一起冷却。捕获可以实现较长的探测时间，这将需要精确确定跃迁频率并证明-对质子与电子质量比变化的原理性研究是对额外维度、新标量场和超轻暗物质的探索。该奖项反映了 NSF 的法定使命，并被认为是值得的。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来提供支持。