Donor-acceptor energy transfer in the presence of photonic and plasmonic structures

西北大学的George Schatz得到了化学系化学理论、模型和计算方法项目的支持。他们正在开发一种理论和计算方法来计算能量传递过程的速率。能量传递过程在通信、太阳能利用、光合作用和电子设备中发挥着非常重要的作用，在电子设备中，能量通过光的发射和吸收从一个分子传递到另一个分子。Schatz和同事们正在开发的理论对于设计新设备的工程应用非常重要。它提供了一个组织组件的框架，以便有选择地优化发射器和吸收器之间的能量传递。此外，该项目能够理解涉及量子光（即具有内在量子特性的光）的能量转移。研究活动用于培养研究生、本科生和博士后。它们也用于开发公开可用的软件工具。此外，还有一些使用与研究相关材料的外展活动。该研究项目描述了用于确定供体-受体能量转移速率的新理论和计算方法的发展，以及与复杂色散光学结构（包括半导体、电介质和金属纳米粒子、表面和其他光子或等离子体结构）存在的发射器和吸收器相关的辐射过程。越来越多的实验表明，复杂的光学环境在能量传递中起着重要的作用，有时可以提高许多数量级的能量传递速率，并将能量传递的范围扩展到超过静电相互作用足够的点。在这种情况下，传统的F？Rster理论和标准的改进是不够的。最近，Schatz小组开发了一种解决这些问题的新方法，一种本质上完全是量子电动力学的方法，但只涉及光学响应的经典电动力学计算，这使得使用现有的计算电动力学方法进行相对简单的修改来计算能量转移率成为可能。此外，该方法可以在时域进行评估，这对于处理复杂结构非常重要，并且允许研究激发相干态和纠缠态的非平稳供体态和受体态。该提案描述了建立在这项最新工作基础上的理论发展，包括(1)在能量传递中适当地结合相互竞争的辐射和非辐射过程，(2)包含对于点偶极子近似来说太大的供体和受体，(3)光学介质中介电响应的处理，超出了标准的德鲁德/洛伦兹介电模型，(4)描述与量子态相干叠加相关的能量传递过程，包括纠缠态。该提案描述了该理论在最近和计划中的实验中的许多应用，这些实验由合作者和其他人进行，涉及粒子和界面存在下的供体/受体能量转移，包括测试该理论所有提出的新元素的应用。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。

George Schatz, of Northwestern University, is supported by the Chemical Theory, Models and Computational Methods program in the Division of Chemistry. They are developing a theory and computational methods to enable calculating the rate of energy transfer processes. Energy transfer processes play a very significant role in telecommunications, in solar energy utilization, in photosynthesis, and in electronic devices where energy is transmitted from one molecule to another through the emission and then absorption of light. The theory that Schatz and coworkers are developing is important for engineering applications in the design of new devices. It provides a framework for organizing components so that energy transfer between emitters and absorbers is selectively optimized. In addition, the project enables an understanding of energy transfer involving quantum light (i.e., light with intrinsically quantum properties). The research activities are used in the training of graduates, undergraduates and postdocs. They are also used in the development of software tools that are made publicly available. In addition, there are several outreach activities that use material related to the research.This program of research describes the development of new theories and computational methods for determining the rates of donor-acceptor energy transfer and related radiative processes associated with emitters and absorbers that are in the presence of complex dispersive optical structures, including semiconductor, dielectric and metallic nanoparticles, surfaces, and other photonic or plasmonic structures. There are a growing number of experiments where the complex optical environment plays an important role in energy transfer, sometimes enhancing energy transfer rates by many orders of magnitude and extending the range of energy transfer beyond the point where electrostatic interactions are adequate. In this situation, traditional F?rster theory and standard improvements thereto are inadequate. Recently the Schatz group has developed a new approach to these problems, one that is fully quantum electrodynamic in nature but which only involves classical electrodynamics calculations for the optical response, making it possible to use existing computational electrodynamics methods with relatively simple modifications to calculate energy transfer rates. In addition, the method can be evaluated in the time domain, which is important in the treatment of complex structures, and allowing for the study of nonstationary donor and acceptor states where coherences and entangled states are excited. The proposal describes the development of theory that builds on this recent work, including (1) the proper incorporation of competing radiative and nonradiative processes in energy transfer, (2) the inclusion of donors and acceptors that are too large for point dipole approximations, (3) the treatment of dielectric response in the optical medium that goes beyond the standard Drude/Lorentz dielectric models, and (4) the description of energy transfer processes associated with coherent superpositions of quantum states, including entangled states. The proposal describes a number of applications of the theory to recent and planned experiments, by collaborators and others, involving donor/acceptor energy transfer in the presence of particles and interfaces, including applications that test all the proposed new elements of the theory.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.