Capturing Plasmon/Polariton Dynamics Of Molecular Dye Monolayers On Metallic Core-Shell Nanoparticles Using Classical Electrodynamics With Quantum Embedding

A multiscale hybrid quantum/classical approach using n-level quantum systems embedded in a classical electrodynamics background is used to simulate thousands of triphenylmethane dyes on the surface of gold, silver-gold core-shell, and gold-silver-gold core-shell-shell nanoparticles. This method employs a finite-difference time-domain (FDTD) approach to describe the plasmonic response of the NP within the main FDTD framework and a n-level quantum description for the mols. coupled via a Maxwell/Liouville approach. Addnl., second harmonic generation measurements are used to det. the adsorbate population on the surface of these NPs, and these results are used to parameterize the quantum mols. Extinction spectroscopic measurements reveal strong coupling, leading to new polaritonic states sepd. by a splitting energy DEp and overlapped in a Fano-type resonance profile, as well as, plasmon and mol. depletions. The theor. model allows us to predict the relative coupling strengths between the adsorbed mols. and NP, allowing for the design of new and efficient devices for chem. sensing, bioimaging, photovoltaics and drug delivery.