CAREER: Theoretical studies of optical properties of molecules near metal nanostructures

宾夕法尼亚州立大学的Lesse Jensen，University Park得到了化学部理论、模型和计算方法计划颁发的职业奖的支持，该计划旨在开发理论方法和分子模拟策略，以了解金属纳米结构附近分子的光学性质。PI将量子力学和电动力学描述结合起来，模拟分子-金属体系的光学性质，并阐明表面增强拉曼散射(SERS)的机理。这项技术是目前唯一能够同时检测和识别单个分子的方法。DNA检测和化学和生物战的早期检测就是这种实验技术广泛影响的例子。这种新颖的理论方法弥合了电子局域分子的量子力学描述和多纳米范围内电子非局域金属纳米结构的电动力学描述之间的差距。该方案中的方法能够准确地描述分子，显式地处理分子-金属耦合，以及真实地描述具有复杂形状的金属纳米结构。提出了一个系统的计划来了解不同的增强机制以及它们之间的协同作用，以期建立对SERS的统一描述。Broader Impact努力结合了最先进的方法，将从根本上促进对SERS的理解，这些方法将被广泛分布并整合到NWChem和ADF等软件包中。纳米光学模拟器的开发将促进纳米科学的基本概念，培养对科学计算和可视化的兴趣，并鼓励青年科学家从事纳米技术职业。

Lesse Jensen of the Pennsylvania State University, University Park is supported by a CAREER award from the Theory, Models and Computational Methods Program in the Chemistry Division to develop theoretical approaches and molecular simulation strategies for understanding optical properties of molecules near metal nanostructures. The PI bridges quantum mechanics with electrodynamics descriptions to simulate optical properties of molecule-metal systems and elucidate the mechanisms for surface-enhanced Raman scattering (SERS). This technique is currently the only method capable of detecting and identifying simultaneously a single molecule. DNA detection and early detection of chemical and biological warfare are examples of the broad implications of this experimental technique. The novel theoretical methodology bridges the gap between quantum mechanics descriptions of electronically localized molecules with the electrodynamics descriptions of electronically delocalized metal nanostructures over many nanometers. The approaches in this proposal enable accurate descriptions of molecules, explicit treatment of molecule-metal coupling, and realistic descriptions of metal nanostructures with complex shapes. A systematic plan to understand the different enhancement mechanisms and the synergy between them is put forward with the expectation of establishing a unified description of SERS.Broader impact efforts combine state-of-the-art methods that will fundamentally advance the understanding of SERS, which will be distributed broadly and incorporated in packages such as NWChem and ADF. The development of the nano-optics simulator, a visualization module to be integrated in a variety of educational platforms, will promote essential concepts in nanoscience, foster interests in scientific computing and visualization, and encourage young scientists to pursue careers in nanotechnology.