CAREER: From Quantum to Classical and Back: Bringing 2D Spectroscopy Insights into Focus

职业生涯：从量子到经典再回归：聚焦二维光谱学见解

• 批准号: 2236625
• 负责人: Michael Reppert
• 金额: $ 65万
• 依托单位: Purdue University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-02-01 至 2028-01-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2236625&HistoricalAwards=false
• 关键词: CAREER; Quantum; Classical; Back; Bringing

Mike Reppert of Purdue University is supported by an award from the Chemical Theory, Models and Computational Methods program in the Division of Chemistry to explore the interplay between quantum and classical coherence in two-dimensional (2D) spectroscopy. Two-dimensional infrared (2DIR) spectroscopy and two-dimensional electronic spectroscopy (2DES) use ultrafast laser pulses to monitor the motion of atoms and electrons on timescales faster than one trillionth of a second. Such experiments have the potential to provide unprecedented insight into fundamental biological processes such as protein folding and photosynthesis. However, the data they produce is often difficult to interpret, limiting their usefulness in real-world applications. Dr. Reppert and his research group are developing new theoretical tools to better understand the physical origins of 2DIR and 2DES signals (especially the distinct roles played by quantum and classical effects), paving the way for more transparent and efficient interpretation of 2D data. Newly developed 2DIR simulation methods will be made available to other researchers by incorporating them into an online application for protein 2DIR simulations. In addition, the Reppert group will work with K-12 educators to develop 2D acoustic experiments that demonstrate the working principles of 2DES and 2DIR measurements using audible signals. Together, these efforts are expand expand both accessibility to these spectroscopic tools and the application of these 2D methods to a broad class of problems in the chemical sciences. Despite the impressive array of quantum and semiclassical dynamics methods available for simulating two-dimensional (2D) optical spectra, a surprising gap remains in the 2D theory arsenal: no classical theory for 2D spectroscopy or systematic framework for classifying quantum effects has been thoroughly developed. On the one hand, this limitation leaves largely unexplored the potential numerical advantages of fully classical simulations; on the other hand, the inability to systematically classify quantum and classical effects obscures the physical origins of coherence in coupled molecular systems. To explore these issues, the Reppert group is working to develop a systematic, diagrammatic framework for disentangling quantum and classical contributions to coherent vibrational dynamics, beginning with the relatively simple case of 2D infrared (2DIR) spectroscopy and working toward more complex vibronic dynamics and the quantitative interpretation of Amide I (protein C=O stretch) 2DIR experiments. To test the limits of classical models for coherent nonlinear processes, a new class of 2D measurements investigating acoustic nonlinear response will be designed and implemented experimentally. The broader impact of this work will be maximized by developing educational materials (K-12 through graduate level) that illustrate nonlinear processes through conceptually approachable “ball and spring” models. In addition, the Reppert group will incorporate newly developed Amide I simulation methods into the AmideSpec app, offering a research-grade online tool for interpreting protein 2DIR data to researchers around the globe.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.

普渡大学的迈克·雷珀特（Mike Reppert）得到了化学理论，模型和计算方法计划的奖励，以探索二维（2D）光谱中量子和经典相干性之间的相互作用。二维红外（2DIR）光谱和二维电子光谱（2DES）使用超快激光脉冲来监测与时间尺度上的原子和电子在时间尺度上的运动，而不是一秒钟的时间快。这样的实验有可能对基本生物学过程（例如蛋白质折叠和光合作用）提供前所未有的见解。但是，它们产生的数据通常很难解释，从而限制了它们在现实应用程序中的有用性。 Reppert博士和他的研究小组正在开发新的理论工具，以更好地了解2DIR和2DES信号的物理起源（尤其是量子和经典效应所扮演的独特角色），为对2D数据的更透明和有效的解释铺平了道路。新开发的2DIR仿真方法将通过将其纳入在线蛋白2DIR模拟的在线应用程序中，从而提供给其他研究人员。此外，Reppert组将与K-12教育者合作开发2D声学实验，这些实验证明了使用可听见信号的2DES和2DIR测量的工作原理。这些努力共同扩大了对这些光谱工具的可访问性，以及将这些2D方法应用于化学科学中的各种问题。尽管可用于模拟二维（2D）光谱的量子和半经典动力学方法令人印象深刻，但在2D理论中仍然存在一个令人惊讶的差距：未针对量子效应进行分类的2D光谱或系统框架。一方面，这种限制在很大程度上留下了完全经典模拟的潜在数值优势。另一方面，无法系统地对量子和经典效应进行分类，掩盖了耦合分子系统相干性的物理起源。为了探索这些问题，Reppert小组正在努力开发一个系统的，图形的框架，以解开量子和对相干振动动力学的经典贡献，从相对简单的情况开始，即2D红外（2DIR）光谱镜检查，并致力于更复杂的振动动力学和更复杂的振动振动和更复杂的振动和定量解释I（Protein i（Protein c = o Stretchents）2DDIR。为了测试相干非线性过程的经典模型的限制，将通过实验设计和实施研究和实施的新的2D测量结果。通过开发教育材料（K-12至研究生层），通过概念上可接近的“球和春季”模型来说明非线性过程，从而最大程度地提高了这项工作的更广泛影响。此外，Reppert小组将将新开发的酰胺I模拟方法纳入AmidesPec应用程序，为全球研究人员提供一种研究级的在线工具，以将蛋白质2DIR数据解释为全球研究人员。该奖项反映了NSF的法定任务，并通过使用该基金会的智力功能和广泛的影响来评估NSF的法定任务。