Measuring Electronic Coherence at the Single-Molecule Level with Nonlinear Coherent Spectroscopy

使用非线性相干光谱测量单分子水平的电子相干性

• 批准号: 2106799
• 负责人: Elad Harel
• 金额: $ 47.62万
• 依托单位: Michigan State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-07-01 至 2025-06-30
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2106799&HistoricalAwards=false
• 关键词: Measuring; Electronic; Coherence; Single; Molecule

With support from the Chemical Measurement and Imaging (CMI) Program in the Division of Chemistry, Dr. Elad Harel and his research group at Michigan State University are developing new methods to measure the quantum mechanical behavior of single molecules. In quantum mechanics, the behavior of a molecule often depends on a delicate relationship between the different states of the system. This relationship, called coherence, is easily disrupted through interactions with the surrounding environment, and often requires experimentalists to make difficult measurements at low temperatures or in highly isolated environments in order to probe the quantum mechanical properties of a complex system. However, it is becoming increasingly clear that even under ambient conditions quantum mechanics plays an important role in the behavior of molecular systems, including photosynthetic proteins that convert sunlight into chemical energy. While coherence has been measured for collections of molecules, knowing the behavior of single molecules is important for understanding how molecular structure affects the function of complex systems. Therefore, Professor Harel’s team is developing tools to measure coherence at the single-molecule level by employing extremely sensitive detection methods. The research project also provides advanced technical training for students, as well as outreach activities targeting a wide audience of young people from a range of economic and social backgrounds.The development of nonlinear spectroscopy methods at the single-molecule level holds the promise of revealing important information that is not currently available from ensemble methods. In this project, Dr. Harel and his group are developing new methods to enable single-molecule nonlinear spectroscopy measurements at room temperature. The approach uses two-dimensional electronic spectroscopy to probe electronic coherences and electronic-vibrational coupling at the single-molecule level. These measurements reveal important structure-function-dynamics relationships in complex systems, including pigment-protein complexes and quantum-confined nanocrystals under ambient conditions. Understanding the true electronic coherence time and its physical origin free of inhomogeneous broadening are critically important for comparing experimental measurements with theoretical predictions, and for developing a deeper fundamental understanding of molecular interactions. The new approach being developed by the research team has the potential to impact understanding of molecular mechanisms that govern a wide range of complex chemical systems. In addition to enabling important new measurements of molecular systems, the research goals of the project are closely integrated with student training at the graduate and undergraduate levels, including a program in which graduate students develop five-week summer tutorial courses based on their research.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.

在化学划分的化学测量和成像（CMI）计划的支持下，密歇根州立大学的Elad Harel博士及其研究小组正在开发新方法来衡量单分子的量子机械行为。在量子力学中，分子的行为通常取决于系统不同状态之间的微妙关系。这种称为连贯性的关系很容易通过与周围环境的相互作用而破坏，并且经常要求实验者在低温或高度孤立的环境下进行艰难的测量，以探测复杂系统的量子机械性能。但是，越来越清楚的是，即使在环境条件下，量子机械在分子系统的行为中也起着重要作用，包括将阳光转化为化学能的光合蛋白。尽管已经测量了分子集合的相干性，但了解单分子的行为对于理解分子结构如何影响复杂系统的功能很重要。因此，Harel教授的团队正在开发工具，通过采用极敏感的检测方法来衡量单分子水平的连贯性。该研究项目还为学生提供了高级技术培训，以及针对来自各种经济和社会背景的众多年轻人的外展活动。单分子水平的非线性光谱方法的开发具有揭示当前从集合方法获得的重要信息的希望。在这个项目中，Harel博士和他的小组正在开发新方法，以在室温下实现单分子非分子光谱测量。该方法使用二维电子光谱探测单分子水平的电子相干和电子振动耦合。这些测量结果揭示了复杂系统中重要的结构功能 - 动力学关系，包括色素 - 蛋白质复合物和量子限制的纳米晶体。了解真实的电子相干时间及其物理起源，而没有不均匀扩展对于将实验测量与理论预测进行比较至关重要，对于理论预测，以及对分子相互作用的更深层理解。研究团队开发的新方法有可能影响对控制各种复杂化学系统的分子机制的理解。 In addition to enabling important new measurements of molecular systems, the research goals of the project are closely integrated with student training at the graduate and undergraduate levels, including a program in which graduate students develop five-week summer tutorial courses based on their research.This award reflects NSF's Statutory mission and has been deemed precious of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.