A1 Journal article (refereed)
Ultrastrong Coupling of a Single Molecule to a Plasmonic Nanocavity : A First-Principles Study (2022)

Kuisma, M., Rousseaux, B., Czajkowski, K. M., Rossi, T. P., Shegai, T., Erhart, P., & Antosiewicz, T. J. (2022). Ultrastrong Coupling of a Single Molecule to a Plasmonic Nanocavity : A First-Principles Study. ACS Photonics, 9(3), 1065-1077. https://doi.org/10.1021/acsphotonics.2c00066

JYU authors or editors

Publication details

All authors or editors: Kuisma, Mikael; Rousseaux, Benjamin; Czajkowski, Krzysztof M.; Rossi, Tuomas P.; Shegai, Timur; Erhart, Paul; Antosiewicz, Tomasz J.

Journal or series: ACS Photonics

ISSN: 2330-4022

eISSN: 2330-4022

Publication year: 2022

Publication date: 02/03/2022

Volume: 9

Issue number: 3

Pages range: 1065-1077

Publisher: American Chemical Society (ACS)

Publication country: United States

Publication language: English

DOI: https://doi.org/10.1021/acsphotonics.2c00066

Publication open access: Openly available

Publication channel open access: Partially open access channel

Publication is parallel published (JYX): https://jyx.jyu.fi/handle/123456789/80178


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

Keywords: nanostructures; plasmonics; photonics; density functional theory

Free keywords: strong coupling; time-dependent density functional theory; plasmonics; nanophotonics; excitons

Contributing organizations

Ministry reporting: Yes

Reporting Year: 2022

Preliminary JUFO rating: 2

Last updated on 2022-20-09 at 15:55