CAREER: Laser-Cooled Molecules in an AC-Storage Ring

该奖项全部或部分由《2021年美国救援计划法案》（公法117-2）资助。摘要：粒子物理学的标准模型代表了我们目前对宇宙基本组成部分的理解，但我们知道肯定还有其他未被发现的物理现象。例如，宇宙中物质和反物质之间存在着一种不平衡，这是标准模型无法完全解释的。对原子和分子的精确测量可以帮助寻找超越标准模型的物理学。该项目旨在生产一种对一类新物理学特别敏感的冷分子样本。冷分子还有许多其他潜在的应用，包括控制化学反应的结果和实现新的量子计算和模拟平台。所有这些应用都需要将分子物种冷却到非常低的温度，从而可以完全控制分子。然而，分子复杂的内部结构使得激光冷却技术对许多原子物种具有挑战性，并且仅对有限种类的分子实用。将激光冷却扩展到更多样化的物种是可取的，因为它为许多新颖的应用打开了可能性。PI和他的学生将开发一种电储存环，作为冷却和捕获不适合传统激光冷却方案的物种的先驱。这是通过结合环中的无限传播距离和任何长寿命状态的固有自发衰变来实现的。在该计划的教育部分，PI将开发一个便携式铷原子磁光阱，作为可移动装置库的一部分，用于当地高中和当地科学展览。该计划的一个主要重点是为河滨县当地社区的人们提供原子和分子微观量子世界的体验，并培养他们对未来STEM职业的兴趣，河滨县的大部分人口来自目前在STEM中代表性不足的群体。技术观众摘要：该职业奖支持原子和分子交流电流存储环的开发，它作为一个减速阶段，使各种分子低于磁光阱的捕获速度。冷却原理在环内的每一次旋转中应用减速激光脉冲，并依靠长寿命中间态的自发衰变作为泵浦机制，使粒子保持在光子散射周期中。这种激光冷却和存储环中自发衰变的结合为需要冷却和捕获具有亚稳态的原子或具有非对角弗兰克-康顿因子的分子的新应用开辟了可能性。例如，该环将允许冷却和捕获氟化汞，这有可能提高目前搜索电子电偶极矩的统计灵敏度。在这里，通过自发衰变的重新泵送方案可以显着减少有效重新泵送冷却过程中填充的氟化汞的激发振动状态所需的光学开销。此外，这个存储环将允许研究冷量子化学和原子和分子的碰撞，而激光冷却目前是不切实际的。该奖项反映了美国国家科学基金会的法定使命，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。

This award is funded in whole or in part under the American Rescue Plan Act of 2021 (Public Law 117-2).General audience abstract: The Standard Model of Particle Physics represents our current understanding of the basic building blocks of the universe, but we know there must be additional undiscovered physics. There is, for example, an imbalance between matter and antimatter in the universe which cannot be fully accounted for by the Standard Model. Precise measurements on atoms and molecules can help search for beyond the Standard Model physics. This project seeks to produce a sample of cold molecules chosen to be particularly sensitive to one class of new physics. There are many other potential applications for cold molecules including the control of the outcome of chemical reactions and the realization of novel quantum computing and simulation platforms. All these applications require the cooling of the molecular species to very low temperatures where full control over the molecule is possible. The complex internal structure of molecules, however, renders laser cooling techniques that have been applied to many atomic species challenging and is only practical for a limited class of molecules. Extending laser cooling to a more diverse set of species is desirable as it opens the possibility for many novel applications. The PI and his students will develop an electric storage ring as a precursor for cooling and trapping species which are not suitable for traditional laser cooling schemes. This is achieved by combining the infinite travel distance in a ring with the intrinsic spontaneous decay of any long-lived state. Within the educational part of this program, the PI will develop a portable magneto-optical trap for rubidium atoms as part of a library of transportable setups to be used in local high schools and at local science fairs. A major focus of this program is to provide people in the local community of Riverside county, where a large proportion of the population is from groups currently underrepresented in STEM, with an experience of the microscopic quantum world of atoms and molecules, and to foster their interest in a future STEM career.Technical audience abstract:This CAREER award supports the development of an alternating-current storage ring for atoms and molecules, which acts as a slowing stage to bring a diverse set of molecules below the capture velocity of a magneto-optical trap. The cooling principle applies slowing laser pulses at each revolution inside the ring and relies on the spontaneous decay of long-lived intermediate states as a repumping mechanism to keep the particles in the photon scattering cycle. This combination of laser cooling and spontaneous decay in the storage ring opens up possibilities for new applications that require cooling and trapping atoms with metastable states or molecules with non-diagonal Franck-Condon factors. The ring will, for instance, allow for cooling and trapping mercury fluoride, which offers the potential to improve the current statistical sensitivity of searches for an electric dipole moment of the electron. Here, the repumping scheme through spontaneous decay can significantly reduce the optical overhead required to effectively repump excited vibrational states of mercury fluoride that get populated during the cooling process. Furthermore, this storage ring will allow for studies of cold quantum chemistry and collisions of atoms and molecules for which laser cooling is currently impractical.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.