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

西北大学的乔治·沙茨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，以计算能量转移过程的速率。能量转移过程在电信、太阳能利用、光合作用和电子设备中起着非常重要的作用，在电子设备中，能量通过光的发射然后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新设备设计中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，该项目使人们能够理解涉及量子光的能量转移（即，具有固有量子特性的光）。 研究活动用于培训研究生、本科生和博士后。 它们还用于开发公开提供的软件工具。 此外，还有几个外展活动，使用相关的研究材料。该研究计划描述了新的理论和计算方法的发展，用于确定供体-受体能量转移的速率以及与发射体和吸收体相关的辐射过程，这些辐射过程存在复杂的色散光学结构，包括半导体，介电和金属纳米颗粒，表面，以及其它光子或等离子体结构。有越来越多的实验中，复杂的光学环境在能量转移中起着重要的作用，有时提高能量转移率的许多数量级和扩展的范围内的能量转移超过静电相互作用是足够的。 在这种情况下，传统的F？Rster理论及其标准改进是不够的。 最近，Schatz小组开发了一种新的方法来解决这些问题，这种方法本质上是完全量子电动力学的，但只涉及光学响应的经典电动力学计算，使得可以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。 此外，该方法可以在时域中进行评估，这在复杂结构的处理中是重要的，并且允许研究非稳态施主和受主态，其中相干态和纠缠态被激发。 该提案描述了建立在这一最新工作基础上的理论发展，包括（1）在能量转移中适当地结合竞争性辐射和非辐射过程，（2）包含对于点偶极近似来说太大的施主和受主，（3）超越标准Drude/Lorentz介电模型的光学介质中介电响应的处理，以及（4）与量子态（包括纠缠态）的相干叠加相关联的能量转移过程的描述。 该提案描述了合作者和其他人将该理论应用于最近和计划中的实验的一些应用，涉及粒子和界面存在下的供体/受体能量转移，该奖项反映了NSF的法定使命，并被认为值得通过使用基金会的知识价值和更广泛的影响审查进行评估来支持的搜索.

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.