Controlled cavity quantum electrodynamics with molecular ensembles in infrared nanocavities

Molecular ensembles in confined infrared (IR) fields have emerged as a promising platform for condensed-phase cavity QED at room temperature [1]. The demonstration of strong and ultrastrong coupling regimes with molecular vibrations in Fabry-Perot cavities have stimulated the development of scalable architectures for IR quantum optics also at the nanoscale. We develop a Markovian open quantum system approach to study the dynamics of molecular vibrations in infrared nanocavities under femtosecond pulse driving. By comparing with recent nanoprobe spectroscopy data on polymer-coated IR gold antennas as test cases [2,3], we successfully describe the time-domain signatures of the crossover from weak to strong coupling regimes. Our model also provides mechanistic insights on the conditions needed for implementing coherent π/2 phase-space rotations of the nanocavity field using a tip nanoprobe. Our work thus offers microscopic design strategies for quantum state preparation and control with emitter-nanocavity hybrids using infrared quantum optics.

[1] T. W. Ebbesen. Acc. Chem. Res. 49, 2403, 2016; F. Herrera and J. Owrutsky. J. Chem. Phys. 152, 100902, 2020.
[2] B. Metzger et al. Phys. Rev. Lett. 123, 153001, 2019.
[3] E. A. Muller et al. ACS Photonics, 5, 3594, 2018.