title: Robust subnanometric plasmon ruler by rescaling of the nonlocal optical response.
abstract: We present the optical response of two interacting metallic nanowires calculated for separation distances down to angstrom range. State-of-the-art local and nonlocal approaches are compared with full quantum time-dependent density functional theory calculations that give an exact account of nonlocal and tunneling effects. We find that the quantum results are equivalent to those from classical approaches when the nanoparticle separation is defined as the separation between centroids of the screening charges. This establishes a universal plasmon ruler for subnanometric distances. Such a ruler not only impacts the basis of many applications of plasmonics, but also provides a robust rule for subnanometric metrology.
authors.affiliation: Institut d'Electronique Fondamentale, UMR 8622 CNRS-Université Paris-Sud, Bâtiment 220, 91405 Orsay Cedex, France.
authors.forename: T V
authors.initials: TV
authors.lastname: Teperik
authors.forename: P
authors.initials: P
authors.lastname: Nordlander
authors.forename: J
authors.initials: J
authors.lastname: Aizpurua
authors.forename: A G
authors.initials: AG
authors.lastname: Borisov