Seminar:

Spectroscopy in Inhomogeneous Electric Fields

November 9, 2018

Dr. Lasse Jensen, Professor in the Department of Chemistry at Penn State University

Photo: Seminar:

Profile:  Dr. Jensen received a B.S. and a M.S. in Chemistry in 1998 and 2000, respectively, the University of Copenhagen in Denmark.  He received his Ph.D. in Chemistry from Rijksuniversiteit Groningen in The Netherlands in 2004.  Dr. Jensen’s research lies in the field of theoretical chemistry and involves developing new methods for simulations of metal-molecule interactions. We seek to use computer simulations to gain a fundamental understanding of the underlying physics and chemistry. We are particularly interested in understanding the optical properties of molecules at the interface of plasmonic nanomaterials.

 

Abstract: Over the last few years we have developed new theories and computational methods for understanding vibrational spectroscopy of molecules near metal surfaces. Specifically we have developed a new computational toolbox for simulating surface-enhanced vibrational spectroscopy in inhomogeneous electric field. This kind of spectroscopy relies on the strong localized electric near-field at the surface of plasmonic metal nanoparticles. Our work has shown that it is possible to resolve intricate molecule vibrations with atomic resolution, which requires that the near-field is confined to a few A° ngstroms. Under these conditions the traditional selection rules breaks down and simulations are required for understanding the spectroscopy. Here we will discuss our latest developments in understanding surface-enhanced vibrational spectroscopy in inhomogeneous electric fields.

Check out some articles: Single-Molecule Imaging Using AtomisticNear-Field Tip-Enhanced Raman Spectroscopy (ACS Nano, 2017) and Microscopy with a single-molecule scanning electrometer (Science Advances, 2018)

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