RII Track-4: Quantum Control of Molecular Interactions with External Electromagnetic Fields: From Few to Many-Body Physics

超冷分子气体在物理和化学领域具有变革性应用的潜力，从量子信息处理和新材料的量子模拟到探测和控制外部电磁场的化学反应。这一提议探索了最近在主办机构（JILA物理前沿中心）的开创性实验中获得的两个令人兴奋的前沿。首先，我们打算探索接近分子的相对取向如何影响分子碰撞或化学反应的结果。其次，我们建议研究光学晶格中极性分子的人工晶体的性质，这是最近在主办机构实验中实现的一种精致的量子多体系统。提出的研究将增强我们对电子在真实材料中的行为的理解（现代凝聚态物理和材料科学的关键目标），并为控制电磁场化学反应提供新方法（现代化学物理的重要目标）。本提案旨在解决冷分子气体物理和化学中两个突出的开放问题：(i)缺乏对外部电磁场存在下低温分子碰撞的量子立体动力学的理解和控制，以及（ii）最近在主持机构（JILA物理前沿中心）首次创建的光学晶格中化学反应极性分子的超冷气体的相图的性质。利用分子碰撞的数值精确量子理论，我们提出阐明外场对冷分子碰撞立体动力学的影响，重点是目前在JILA实验研究的Ne-OH碰撞。我们还计划利用计算凝聚态物理的最新发展，探索二维光学晶格中超冷KRb分子的扩展耗散费米-哈伯德模型的相图。该研究可能为控制分子碰撞的量子动力学以及在光学晶格中设计具有超冷分子的新型量子多体态提供新的方法。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。

Ultracold molecular gases hold potential for transformative applications across physics and chemistry, ranging from quantum information processing and quantum simulation of novel materials to probing and controlling chemical reactions with external electromagnetic fields. This proposal explores two exciting frontiers recently made available by pioneering experiments at the host institution (JILA Physics Frontier Center). First, we intend to explore how the relative orientation of approaching molecules affects the outcome of a molecular collision or chemical reaction. Second, we propose to study the properties of an artificial crystal of polar molecules in an optical lattice, an exquisite quantum-many body system recently realized experimentally at the host institution. The proposed research will enhance our understanding of how electrons behave in real materials (a key goal of modern condensed-matter physics and material science) and to novel ways to control chemical reactions with electromagnetic fields (an important goal of modern chemical physics).This proposal aims to address two outstanding open problems in the physics and chemistry of cold molecular gases: (i) the lack of understanding and control of quantum stereodynamics of low-temperature molecular collisions in the presence of external electromagnetic fields, and (ii) the nature of the phase diagram of an ultracold gas of chemically reactive polar molecules in an optical lattice recently created for the first time at the host institution (JILA Physics Frontier Center). Using numerically exact quantum theory of molecular collisions, we propose to elucidate the effects of external fields on the stereodynamics of cold molecular collisions, with a focus on Ne-OH collisions currently studied experimentally at JILA. We also plan, by taking advantage of recent developments in computational condensed-matter physics, to explore the phase diagram of the extended dissipative Fermi-Hubbard model of ultracold KRb molecules in a two-dimensional optical lattice. The proposed research may lead to new ways to control the quantum dynamics of molecular collisions and to engineer novel quantum many-body states with ultracold molecules in optical lattices.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.