Ultracold Triatomic Molecules

超冷三原子分子

• 批准号: 2109995
• 负责人: John Doyle
• 金额: $ 75.8万
• 依托单位: Harvard University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-09-01 至 2024-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2109995&HistoricalAwards=false
• 关键词: Ultracold; Triatomic; Molecules

Atoms and molecules are the microscopic building blocks of the world. Their behavior and interactions are governed by the theory of quantum mechanics, which describes at a fundamental level much of modern science and technology. However, advancing quantum science and technology in the second quantum revolution requires cooling to temperatures around one millionth of a degree above absolute zero. Over the past several decades, powerful laser cooling techniques have been developed to reach these “ultracold” temperatures with atoms; in turn, a number of discoveries were made that shed light on the intricacies of quantum physics in complicated systems and led to the creation of a useful quantum computer. These techniques have more recently been extended to diatomic molecules (containing two atoms), but larger molecules (“polyatomic”) have so far eluded full quantum control. Cooling polyatomic molecules will shed light on the quantum nature of chemical reactions and be a resource for yet even more powerful quantum simulation, which can lead to the development of new technological materials. In this project, Professor John Doyle and his research team of graduate and undergraduate students and postdoctoral researchers will use laser cooling to trap CaOH (calcium monohydroxide) molecules at ultracold temperatures and then study their collisions, which will shed light on the quantum physics underlying molecular interactions. The aim is to eventually build a quantum computer using single molecule arrays of CaOH molecules.The experimental starting point of this work will be to cool and trap CaOH molecules in a magneto-optical trap (MOT). This will require scattering tens of thousands of optical photons from the molecules to remove energy and momentum, which is enabled by a careful understanding of the vibrational structure of CaOH developed recently by Professor Doyle and his research group. Because polyatomic molecules like CaOH cannot scatter photons indefinitely, they will then be transferred into a conservative optical dipole trap (ODT) -- where they can be held for several seconds without being lost. There, they can also be sub-Doppler cooled to temperatures near 1μK. By loading approximately 104 molecules into the ODT, sufficient density should be obtained to study collisions between CaOH molecules. After populating the molecules in an excited vibrational state and applying modest DC electric fields of ~1 kV/cm, it is expected that inelastic collisions will be effectively shielded, enabling evaporative cooling of triatomic molecules to even lower temperatures. The researchers additionally propose to load CaOH molecules into optical tweezers, which present an alternative route to collisional studies and could also be used to implement novel quantum simulation and computation schemes.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.

原子和分子是世界上的微观构建块。他们的行为和互动受量子力学理论的控制，量子力学理论在基本层面上描述了现代科学和技术的基本水平。但是，在第二个量子革命中促进量子科学和技术需要冷却到超过绝对零的一百万度的温度。在过去的几十年中，已经开发出强大的激光冷却技术，以达到原子的“超低”温度。反过来，已经发现了许多发现，这些发现揭示了复杂系统中量子物理的复杂性，并导致了有用的量子计算机的创建。这些技术最近已扩展到双原子分子（包含两个原子），但是较大的分子（“多原子”）迄今已完全完全量子控制。冷却多原子分子将阐明化学反应的量子性质，并成为更强大的量子模拟的资源，这可能导致新技术材料的发展。在这个项目中，约翰·道尔（John Doyle）教授和他的研究生和本科生和博士后研究人员的研究团队将在超低温度下使用激光冷却来捕获CAOH（钙一羟化钙）分子，然后研究其碰撞，然后研究他们的碰撞，这将散发出量子的基础物理学相互作用。目的是最终使用CAOH分子的单分子阵列构建量子计算机。这项工作的实验起点将是在磁光陷阱（MOT）中冷却和TRAP CAOH分子。这将需要从分子中散射成千上万的光学照片，以消除能量和动量，这可以通过对Doyle教授和他的研究小组最近开发的CAOH的振动结构进行仔细的理解。由于像CAOH这样的多原子分子不能无限期地分散照片，因此它们将被转移到一个保守的光学偶极子陷阱（ODT）中 - 可以将它们保存几秒钟而不会丢失。在那里，它们也可以将其冷却至1μk附近的温度。通过将大约104个分子加载到ODT中，应获得足够的密度来研究CAOH分子之间的碰撞。在激发振动状态下填充分子并施加〜1 kV/cm的适度DC电场后，预计无弹性碰撞将有效地屏蔽，从而使triatomic分子的蒸发冷却至较低的温度。研究人员还建议将CAOH分子加载到光学镊子中，这是进行碰撞研究的另一种途径，还可以用于实施新型的量子模拟和计算方案。该奖项反映了NSF的法定任务，并通过使用该基金会的知识分子和更广泛的影响来评估NSF的法定任务。

项目成果

Blackbody thermalization and vibrational lifetimes of trapped polyatomic molecules

• DOI: 10.1103/physreva.107.062802
• 发表时间: 2023-03
• 期刊: Physical Review A
• 影响因子: 2.9
• 作者: N. Vilas;Christian Hallas;L. Anderegg;Paige Robichaud;Chaoqun Zhang;Sam Dawley;Lan Cheng;J. Doyle

Magneto-optical trapping and sub-Doppler cooling of a polyatomic molecule

• DOI: 10.1038/s41586-022-04620-5
• 发表时间: 2022-06-02
• 期刊: NATURE
• 影响因子: 64.8
• 作者: Vilas, Nathaniel B.;Hallas, Christian;Doyle, John M.
• 通讯作者: Doyle, John M.