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, for 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, as implemented in recent nanoprobe spectroscopy experiments with polymer-coated IR gold antennas. We describe the time-domain signatures of the crossover from weak to strong coupling regimes in these nanocavities, provide mechanistic insights on the conditions for implementing coherent phase-space rotations of the nanocavity field using a tip nanoprobe, and discuss the tunable role of molecular anharmonicity as a function of pump power. Our work offers microscopic design strategies for quantum state preparation and control with emitter-nanocavity hybrids using infrared quantum optics.