Mixed Quantum-Classical Semiclassical Theory: Finding Reaction Paths in Open Quantum Systems

在化学系化学理论、模型和计算方法（CTMC）项目的支持下，康奈尔大学的Nandini Ananth正在开发一个严格的半经典框架，用于模拟开放量子系统。在原子和电子的层面上，理解酶的工作方式，或者能量和电荷通过太阳能收集装置的方式，仍然是重要的科学挑战。Ananth和她的研究小组将致力于开发新的理论和计算方法，以准确和预测地描述这些固有的量子力学过程。这项研究的成功完成有可能在从药物设计到节能材料的开发到设计量子计算机等领域产生广泛的重大影响。Ananth小组还将继续开展外展工作，以确保初高中学生以及化学专业的本科生和研究生具备在科学、技术、工程和数学（STEM）领域的现代职业生涯所必需的计算技能。在这个奖项下，Nandini Ananth和她的研究团队将建立在半经典理论作为一个严谨和预测理论的优势上，同时系统地解决理论的各个方面，使其在计算上难以处理。这将通过在半经典框架中使用一种创新的混合量化方法来实现，该方法不依赖于空间碎片化方案，而是依赖于对每个自由度对整体相位的敏感控制。Ananth和她的研究小组将对这一理论进行控制近似，以实现在半经典框架内对绝热和非绝热过程的大规模原子模拟和实时模拟。然后，这些方法将用于进行酶催化的详细研究，这是生物开放量子系统的模型。在这项酶研究的背景下开发的原子模拟工具有望在自旋电子学和量子信息科学到多相催化等领域找到广泛的适用性。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。

With support from the Chemical Theory, Models and Computational Methods (CTMC) program in the Division of Chemistry, Nandini Ananth of Cornell University is developing a rigorous semiclassical framework for the simulation of open quantum systems. Understanding, at the levels of atoms and electrons, the way enzymes work, or the way energy and charge move through a solar energy harvesting device remain important scientific challenges. Ananth and her research group will work to develop new theories and computational methods that can describe these inherently quantum mechanical processes accurately and predictively. Successfully completion of this research has the potential for broad significant impact in areas ranging from drug design, to the development of energy-efficient materials, to designing quantum computers. The Ananth group will also continue their outreach efforts to ensure that middle-high school students as well as undergraduate and graduate students in chemistry are equipped with the computational skills that are necessary for a modern career in science, technology, engineering and mathematics (STEM) fields.Under this award, Nandini Ananth and her research team will build on the strengths of semiclassical theory as a rigorous and predictive theory, while systematically addressing the facets of the theory that make it computationally intractable. This will be achieved using an innovative approach to mixed quantization in the semiclassical framework that does not rely on spatial fragmentation schemes, but rather on sensitive control of that each degree of freedom contributes to the overall phase. Ananth and her research group will develop controlled approximations to this theory to enable large scale atomistic simulations and on-the-fly simulations of both adiabatic and nonadiabatic processes within a semiclassical framework. These methods will then be used to perform a detailed study of enzyme catalysis, a model for biological open quantum systems. The tools for atomistic simulations developed in the context of this enzyme study are expected to find broad applicability in areas ranging from spintronics and quantum information science to heterogeneous catalysis.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.