Ultrastrong Coupling of a Single Molecule to a Plasmonic Nanocavity: A First-Principles Study

• DOI: 10.1021/acsphotonics.2c00066
• Publication Date: 2022-03-02T22:12:58Z
• Authors: Mikael Kuisma; Benjamin Rousseaux; Krzysztof M. Czaj...; Tuomas P. Rossi; Timur Shegai; Paul Erhart; Tomasz J. Antosie...
• Keywords: Hamiltonian (control theory)

Ultrastrong coupling (USC) is a distinct regime of light-matter interaction in which the strength comparable to resonance energy cavity or emitter. In USC regime, common approximations quantum optical Hamiltonians, such as rotating wave approximation, break down ground state coupled system gains photonic character due admixing vacuum states with higher excited states, leading ground-state changes. usually achieved by collective coherent many emitters single mode cavity, whereas molecule remains challenging. Here, we show time-dependent density functional theory (TDDFT) calculations that organic can reach plasmonic dimer, consisting few hundred atoms. this context, discuss capacity TDDFT represent strong and its connection Hamiltonian. We find leads appreciable modifications accounting for non-negligible part total energy, kBT at room temperature.