Abstract
We present an ab initio study of the hybridization of localized surface plasmons in a metal nanoparticle dimer. The atomic structure, which is often neglected in theoretical studies of quantum nanoplasmonics, has a strong impact on the optical absorption properties when subnanometric gaps between the nanoparticles are considered. We demonstrate that this influences the hybridization of optical resonances of the dimer, and leads to significantly smaller electric field enhancements as compared to the standard jellium model. In addition, we show that the corrugation of the metal surface at a microscopic scale becomes as important as other well-known quantum corrections to the plasmonic response, implying that the atomic structure has to be taken into account to obtain quantitative predictions for realistic nanoplasmonic devices.
Highlights
We present an ab initio study of the hybridization of localized surface plasmons in a metal nanoparticle dimer
The ionic structure is typically neglected and replaced by a homogeneous jellium background or by an unstructured effective potential. This approximation is sometimes justified by the collective nature of plasmon excitations [30,31], the charge oscillations associated with a localized surface plasmon (LSP) are mainly concentrated on the metal-vacuum interface
Since the aim of the present Rapid Communication is to analyze the impact of the atomic structure per se, in what follows we will work with nanodimers in which the underlying ionic structure of the two clusters is maintained when the distance between them is varied [40]
Summary
We present an ab initio study of the hybridization of localized surface plasmons in a metal nanoparticle dimer. The hybridization will depend very sensitively on the spacing between the effective surfaces of the clusters, which is determined by the amount of electron-density spillout at the metal-vacuum interfaces [25,39].
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have