Plasmon Coupling in Silver Nanosphere Pairs

EZEQUIEL R. ENCINA; EDUARDO A. CORONADO

AMER CHEMICAL SOC

Lugar: Washington; Año: 2010 vol. 114 p. 3918 - 3918

In this work we study the optical properties of silver metal nanosphere pairs by means of rigorouselectrodynamics calculations based on the generalized multiparticle Mie theory. By correlating the dipolelongitudinal plasmon wavelength with its corresponding value of the real part of the dielectric constant, andbased on the dipole quasi-electrostatic approximation, we were able to derive a new plasmon ruler equationfor the longitudinal dipole plasmon resonance of Ag dimers, suitable for a wide range of interparticle distancesand radii. The new resonance condition equation, at variance with previous work on noble metal nanoparticlepairs, takes into account empirically retardation effects and multipole interactions, being a novel, accurate,and potentially useful tool for future applications in plasmonic nanometrology or sensor devices.