2021/01/23 by Jorge A. Campos-Gonzalez-Angulo, J A Campos-Gonzalez-Angulo, Raphael F. Ribeiro +3
Engineering · Physics and Astronomy · #Anharmonicity #Delocalized electron #Dipole #Excitation #Harmonic oscillator #Invariant (physics) #Photon #Plasmonic and Surface Plasmon Research #Quantum #Quantum Electrodynamics and Casimir Effect #Strong Light-Matter Interactions #physics.chem-ph #physics.optics #quant-ph
paper · pdf · doi:10.1088/1367-2630/ac00d7
37 pages, 4 figures
arxiv created 2021/01/23 · openalex created_date 2021/02/01 · openalex publication_date 2021/05/13 · arxiv updated 2021/08/11 · openalex updated_date 2026/08/05
Abstract The interaction between anharmonic quantum emitters (e.g. molecular vibrations) and confined electromagnetic fields gives rise to quantum states with optical and chemical properties that are different from those of their precursors. The exploration of these properties has been typically constrained to the first excitation manifold, the harmonic approximation, ensembles of two-level systems [Tavis–Cummings (TC) model], or the anharmonic single-molecule case. The present work studies, for the first time, a collective ensemble of identical multi-level anharmonic emitters and their dipolar interaction with a photonic cavity mode, which is an exactly solvable many-body problem. The permutational properties of the system allow identifying symmetry classified submanifolds in the energy spectrum. Notably, in this approach, the number of particles, typically in the order of several millions, becomes only a parameter from the operational standpoint, and the size of the dimension of the matrices to diagonalize is independent of it. The formalism capabilities are illustrated by showing the energy spectrum structure, up to the third excitation manifold, and the calculation of the photon contents as a permutationally invariant quantity. Emphasis is placed on (a) the collective (superradiant) scalings of light–matter couplings and the various submanifolds of dark (subradiant) states with no counterpart in the single-molecule case, as well as (b) the delocalized modes containing more than one excitation per molecule with no equivalent in the TC model. We expect these findings to be applicable in the study of non-linear spectroscopy and chemistry of polaritons.