  Surface plasmon resonances of metallic nanostructures offer great
opportunities to guide and manipulate light on the nanoscale. In the design of
novel plasmonic devices, a central topic is to clarify the intricate
relationship between the resonance spectrum and the geometry of the
nanostructure. Despite the many advances, the design becomes quite challenging
when the desired spectrum is highly complex. Here we develop a new theoretical
model for surface plasmons of interacting nanoparticles to reduce the
complexity of the design process significantly. Our model is developed by
combining plasmon hybridization theory with transformation optics, which yields
an efficient way of simultaneously controlling both global and local features
of the resonance spectrum. As an application, we propose a design of
metasurface whose absorption spectrum can be controlled over a large class of
complex patterns through only a few geometric parameters in an intuitive way.
Our approach provides fundamental tools for the effective design of plasmonic
metamaterials with on-demand functionality.
