Landau-damping-induced limits to light–matter interactions in sub-10-nm planar plasmonic nanocavities
Landau damping has previously been shown to be the dominant nonlocal effect in sub-10nm plasmonic nanostructures, although its effects on the performance of plasmonic nanocavities are still poorly understood. In this work, the effects of Landau damping in sub-10-nm planar plasmonic nanocavities are analyzed theoretically, and it is shown that while Landau damping does not affect the confinement of the cavity modes, it decreases the quality factor 10-fold due to the introduction of extra loss for sub-10nm gap sizes. As compared to purely classical models, this results in a suppression in the Purcell factor by 10 fold, the spontaneous emission rate by almost two orders of magnitude, and the required oscillator strength to achieve strong light-matter coupling by two orders of magnitude as the gap is reduced to ∼0.5nm. Therefore, it is crucial to consider Landau damping in plasmonic-nanocavity design because it breaks the classical norm of achieving higher light–matter interaction strength in sub-10-nm gap-plasmon nanocavities.
© 2021 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement. Received 23 Sep 2021; accepted 11 Oct 2021; published 15 Nov 2021. This work was supported by Samsung Electronics and the Samsung Global Research Outreach program. The authors declare no conflicts of interest. Data availability. Data underlying the results presented in this paper are not publicly available at this time but may be obtained from the authors upon reasonable request.
Supplemental Material - 5505929.pdf
Published - oe-29-24-39801.pdf