Quantum Control of Single Polyatomic Molecules

单个多原子分子的量子控制

• 批准号: 1912105
• 负责人: David Patterson
• 金额: $ 47.85万
• 依托单位: University of California-Santa Barbara
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-07-15 至 2024-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1912105&HistoricalAwards=false
• 关键词: Quantum; Control; Single; Polyatomic; Molecules

The molecules which surround us typically occupy millions of distinct quantum states - for example, individual molecules in the air are moving and spinning in many different directions. In order to take advantage of the quantum properties of these molecules, one needs to learn how to prepare individual molecules in a single quantum state, and to measure which state they are in. This will require absolute control over the movement and rotation of the molecule. Today, physicists can prepare atoms in single quantum states, and measure which state they are in with high fidelity. This ability underpins many of the recent advances in atomic physics. The ability to prepare and measure the state of molecules lags far behind, and no molecule containing more than two atoms has ever been prepared in a single quantum state. This project, funded by the Atomic, Molecular and Optical Physics Program of the Division of Physics, and the Chemical Structure, Dynamics and Mechanisms-A Program of the Division of Chemistry, develops the tools for this goal. An important application of this work is that it will enable the identification of individual molecules without destroying them, including identifying the chirality of these molecules. Chirality is the subtle difference between left-handed or right-handed molecules that can play a big role in how the molecule functions, for example in pharmaceuticals. This work will be done by graduate and undergraduate students at the University of California Santa Barbara (UCSB), including financially disadvantaged students enrolled in UCSB's EUREKA program. The program will allow these students to gain valuable, hands-on scientific skills while earning stipends that allow them to stay in school.The scientists leading this research have proposed a set of methods that will allow them to control a broad range of molecular ions at the single quantum state level. The centerpiece of this proposal is a new state readout method, quantum bolometry, which leverages the rich internal level structure of these molecules to provide high-fidelity quantum state readout of individual molecules. A single molecular ion will be trapped in a hybrid Paul trap/optical lattice, along with a single laser-cooled strontium ion. The molecular ion's motion will be driven via a combination of a state-dependent optical lattice and rotational transitions within the molecule which are driven directly via microwave-frequency electric fields. The method does not require sideband resolution or ground state cooling, in contrast to related quantum logic spectroscopy methods. Quantum bolometry can be applied to most reasonably small (4 - 15 atoms), nonspherical polyatomic ions. These methods will allow for non-destructive measurement of the isomer and enantiomer of individual molecules for the first time, and allow for spectroscopy with a resolution significantly greater than existing ensemble molecular spectroscopy techniques. Spectroscopy at this level would represent our most accurate determination of molecular structure.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.

我们周围的分子通常占据数百万个不同的量子态-例如，空气中的单个分子在许多不同的方向上移动和旋转。为了利用这些分子的量子特性，人们需要学习如何在单个量子状态下制备单个分子，并测量它们处于哪个状态。 这将需要对分子的运动和旋转进行绝对控制。今天，物理学家可以在单量子状态下制备原子，并以高保真度测量它们处于哪个状态。这种能力支撑了原子物理学的许多最新进展。制备和测量分子状态的能力远远落后，并且没有包含两个以上原子的分子在单个量子态中制备过。该项目由物理学系的原子、分子和光学物理方案以及化学系的化学结构、动力学和机制方案资助，为这一目标开发工具。 这项工作的一个重要应用是，它将能够在不破坏分子的情况下识别单个分子，包括识别这些分子的手性。手性是左手或右手分子之间的微妙差异，可以在分子的功能中发挥重要作用，例如在药物中。这项工作将由加州大学圣巴巴拉分校（UCSB）的研究生和本科生完成，包括参加UCSB尤里卡项目的经济困难学生。该计划将使这些学生获得宝贵的，实践的科学技能，同时赚取助学金，让他们留在学校。领导这项研究的科学家提出了一套方法，使他们能够控制在单量子态水平的分子离子的范围广泛。该提案的核心是一种新的状态读出方法，量子测辐射热法，它利用这些分子丰富的内部能级结构来提供单个分子的高保真度量子状态读出。一个单一的分子离子将被困在一个混合保罗陷阱/光学晶格，沿着一个单一的激光冷却锶离子。 分子离子的运动将通过依赖于状态的光学晶格和分子内的旋转跃迁的组合来驱动，所述旋转跃迁直接通过微波频率电场来驱动。与相关的量子逻辑光谱方法相比，该方法不需要边带分辨率或基态冷却。量子测辐射热法可以应用于最合理的小（4 - 15个原子），非球形多原子离子。这些方法将首次允许对单个分子的异构体和对映体进行非破坏性测量，并允许光谱的分辨率显著大于现有的系综分子光谱技术。 该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。