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。该提案探讨了最近在主办机构（JILA物理前沿中心）通过开创性实验提供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，我们建议研究极性分子在光学晶格中的人工晶体的性质，这是一个最近在主办机构实验实现的精致量子多体系统。这项拟议中的研究将增强我们对电子在真实的材料中行为的理解（现代凝聚态物理学和材料科学的一个关键目标）和用电磁场控制化学反应的新方法（现代化学物理学的一个重要目标）。该提案旨在解决冷分子气体物理学和化学中两个悬而未决的公开问题：（i）缺乏对存在外部电磁场的低温分子碰撞的量子立体动力学的理解和控制，以及（ii）最近在主办机构首次创建的光学晶格中化学反应性极性分子的超冷气体的相图的性质（JILA Physics Frontier Center）利用分子碰撞的数值精确量子理论，我们建议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，利用最近的发展，在计算凝聚态物理学，探索的超冷KRb分子在二维光学晶格的扩展耗散费米-哈伯德模型的相图。这项研究可能会带来新的方法来控制分子碰撞的量子动力学，并在光学晶格中用超冷分子设计新颖的量子多体状态。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。

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.