Surface plasmon resonances of clustered nanoparticles

Linear clusters made by tightly connecting two or more metallic nanoparticles have new types of surface plasmon resonances as compared to isolated nanoparticles. These new resonances are related to the size of the junction and to the number of interconnected particles and have direct interpretation as eigenmodes of a Boundary Integral Equation (BIE). This formulation allows effective separation of geometric and shape contribution from electric properties of the constituents. Results for particles covered by a thin shell are also provided. In addition, the present analysis sheds a new light on the interpretation of recent experiments from literature.