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

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.