Optical resonators can enhance light\textendashmatter interaction, modify intrinsic molecular properties such as radiative emission rates, and create new molecule\textendashphoton hybrid quantum states. To date, corresponding implementations are based on electronic transitions in the visible spectral region with large transition dipoles yet hampered by fast femtosecond electronic dephasing. In contrast, coupling molecular vibrations with their weaker dipoles to infrared optical resonators has been less explored, despite long-lived coherences with 2 orders of magnitude longer dephasing times. Here, we achieve excitation of molecular vibrations through configurable optical interactions of a nanotip with an infrared resonant nanowire that supports tunable bright and nonradiative dark modes. The resulting antenna\textendashvibrational coupling up to 47 \textpm 5 cm\textendash1\ exceeds the intrinsic dephasing rate of the molecular vibration, leading to hybridization and mode splitting. We observe nanotip-induced quantum interference of vibrational excitation pathways in spectroscopic nanoimaging, which we model classically as plasmonic electromagnetically induced scattering as the phase-controlled extension of the classical analogue of electromagnetically induced transparency and absorption. Our results present a new regime of IR spectroscopy for applications of vibrational coherence from quantum computing to optical control of chemical reactions.
BT - ACS Photonics DA - 2018-08 DO - 10.1021/acsphotonics.8b00425 N2 -Optical resonators can enhance light\textendashmatter interaction, modify intrinsic molecular properties such as radiative emission rates, and create new molecule\textendashphoton hybrid quantum states. To date, corresponding implementations are based on electronic transitions in the visible spectral region with large transition dipoles yet hampered by fast femtosecond electronic dephasing. In contrast, coupling molecular vibrations with their weaker dipoles to infrared optical resonators has been less explored, despite long-lived coherences with 2 orders of magnitude longer dephasing times. Here, we achieve excitation of molecular vibrations through configurable optical interactions of a nanotip with an infrared resonant nanowire that supports tunable bright and nonradiative dark modes. The resulting antenna\textendashvibrational coupling up to 47 \textpm 5 cm\textendash1\ exceeds the intrinsic dephasing rate of the molecular vibration, leading to hybridization and mode splitting. We observe nanotip-induced quantum interference of vibrational excitation pathways in spectroscopic nanoimaging, which we model classically as plasmonic electromagnetically induced scattering as the phase-controlled extension of the classical analogue of electromagnetically induced transparency and absorption. Our results present a new regime of IR spectroscopy for applications of vibrational coherence from quantum computing to optical control of chemical reactions.
PY - 2018 SP - 3594 EP - 3600 T2 - ACS Photonics TI - Nanoimaging and Control of Molecular Vibrations through Electromagnetically Induced Scattering Reaching the Strong Coupling Regime UR - https://pubs.acs.org/doi/pdf/10.1021/acsphotonics.8b00425 VL - 5 SN - 2330-4022 ER -