Nano-Focused Vibrational Spectroscopy Reaching the Single Quantum Level: Imaging Structure, Function, and Dynamics on the Nanoscale

1 Department of Physics, Department of Chemistry, and JILA, University of Colorado, Boulder, CO 80309, USA Structure, function, and dynamics of many interfacial soft-matter systems, including polymer heterostructures, organic photovoltaics, or biomembranes are typically defined on the mesoscopic few nm to sub-micron scale. Tip-enhanced and scattering scanning near-field optical microscopy (s-SNOM) has already demonstrated its ability to spectroscopically access that relevant spatial regime. In combination with IR-vibrational spectroscopy s-SNOM provides molecular structural information. We demonstrated how the combination of s-SNOM with plasmonic and optical antenna concepts and ultrafast and shaped laser pulses allows for the precise control of an optical excitation on femtosecond time and nanometer length scales extending s-SNOM into the nonlinear and ultrafast regime. I will then discuss how, from the multi-spectral combination of different coherent and incoherent light sources we gain insight into the microscopic intraand intermolecular interaction. I will discuss several specific implementations from our recent work on block-copolymers, proteins, and self-assembled monolayers.