Strong Coupling with Organic Materials and Natural Hyperbolic Materials

Courtney Ragle
Vanderbilt University, Nashville, Tennessee, USA _______________________________________

Within the realm of vibropolaritonic chemistry, much work has been done to observe polariton formation using cavities and metalloorganic materials with strong dipole moments such as metal carbonyls. To truly advance the field of polariton chemistry, organic materials lacking strong dipole moments need to be studied. Harnessing the evanescent waves at the material interface produced by vibrational polaritons inside of the hyperbolic material, hexagonal boron nitride (h-BN), we couple with vibrational modes in the organic material polymethylmethacrylate (PMMA). With a focus on the upper Reststrahlen band of both of the isotopically pure crystals, h-10BN and h-11BN, we quantify coupling strengths between the h-BN layer and the PMMA layer using scanning near-field optical microscopy (SNOM) to directly measure polariton propagation wavelengths over a variety of free-space wavelengths near the Reststrahlen bands of the respective material. Both isotopes of h-BN displayed shifts in the polariton dispersion upon coupling with the organic layer underneath, as well as significant absorption at the PMMA modes involved in the coupling producing observable rabi splittings in the dispersion. Observation of strong coupling between a hyperbolic material and an organic layer is a promising step in ePorts to use strong coupling for manipulation of chemical reactions.

Email: courtney.ragle@vanderbilt.edu