Coherent Control and Precision Spectroscopy of a Polyatomic Molecular Ion

多原子分子离子的相干控制和精密光谱

• 批准号: 1806209
• 负责人: David Leibrandt
• 金额: $ 26.55万
• 依托单位: University of Colorado at Boulder
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-09-01 至 2022-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1806209&HistoricalAwards=false
• 关键词: Coherent; Control; Precision; Spectroscopy; Polyatomic

This project is motivated by the opportunity to achieve coherent control of the quantum state of a single polyatomic molecule, and to exploit this control for precision measurements. This project will focus on trapping and controlling the molecular ion N_2H+, but the approach can be generalized to many other molecular ions. The N_2H+ molecular ion will be co-trapped and sympathetically cooled with a calcium ion to near the ground state of their shared motion. Pure quantum states of the molecular ion can then be initialized by projective measurements using quantum-logic spectroscopy, as recently demonstrated on the calcium hydride ion CaH+ by the investigators. This is important because this approach can advance quantum chemistry and may impact materials science and the chemical, biological, and pharmaceutical industries. In addition, new and superior reference spectra for astronomical observations could lead to a better understanding of interstellar gas clouds and the universe, including stringent tests of physics beyond the standard model. Ultimately, controlling molecules at the quantum level may enable precisely orchestrated collisions and fully controlled quantum chemistry.While laser cooling, trapping, and precision measurements of diatomic molecules are making tremendous progress, polyatomic molecules have eluded precision studies due to their complicated level structures and vast number of populated states. This project will extend the technique of quantum-logic spectroscopy to prepare pure quantum states of polyatomic molecules, and to manipulate and detect their states with minimal perturbations such as Doppler or pressure shifts. Precision spectroscopy will ultimately only be limited by the lifetime of the states and can therefore be pushed to levels that have only been reached previously in optical atomic clocks. The molecule N_2H+ was one of the first ions observed in interstellar clouds and remains one of the most important tracers in astrophysics. Improved spectroscopic precision might enable improved constraints on possible spatial or temporal variations of fundamental constants. This work will also train a student at the University of Colorado in techniques needed for quantum logic spectroscopy.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.

该项目的动机是有机会实现对单个多原子分子的量子状态的连贯控制，并利用该控制进行精确测量的机会。该项目将着重于捕获和控制分子离子N_2H+，但是该方法可以推广到许多其他分子离子。 N_2H+分子离子将被钙离子共同捕获，并交感神经冷却其共享运动的接近基态。然后，可以通过使用量子 - 逻辑光谱法来初始测量分子离子的纯量子状态，如研究者最近在氢化钙离子CAH+上所证明的那样。 这很重要，因为这种方法可以推进量子化学，并可能影响材料科学以及化学，生物学和制药行业。此外，天文观测的新的和优质的参考光谱可能会导致对星际气体云和宇宙的更好理解，包括对标准模型以外的物理学的严格测试。最终，在量子水平上控制分子可能会实现精确精心策划的碰撞和完全控制的量子化学。而激光冷却，捕获和精确测量双原子分子正在取得巨大进展，而多原子分子由于其广泛的结构和复杂水平的结构而导致了精确的研究，人口稠密的状态数量。该项目将扩展量子逻辑光谱的技术，以制备多原子分子的纯量子状态，并以最小的扰动（例如多普勒或压力移动）来操纵和检测其状态。精度光谱法最终只会受状态的寿命限制，因此可以将其推向以前仅在光原子时钟中达到的水平。分子N_2H+是星际云中观察到的第一个离子之一，仍然是天体物理学中最重要的示踪剂之一。改进的光谱精度可以改善对基本常数可能的空间或时间变化的约束。 这项工作还将在科罗拉多大学的一名学生培训量子逻辑光谱所需的技术。该奖项反映了NSF的法定任务，并且使用基金会的知识分子优点和更广泛的影响评估标准，被认为值得通过评估来获得支持。