Plasmonics in composite nanostructures

Plasmonics is a rapidly developing research field with many potential applications in fields ranging from bioscience, information processing and communication to quantum optics. It is based on the generation, manipulation and transfer of surface plasmons (SPs) that have the ability to manipulate light at the nanoscale. Realizing plasmonic applications requires understanding how the SP-based properties depend on the nanostructures and how these properties can be controlled. For that purpose composite nanostructures are particularly interesting because many novel and extraordinary properties unattainable in single nanostructures can be obtained by designing composite nanostructures with various materials. Here, we review recent advances in the studies of three classes of composite nanostructure that are important for plasmonics: metal–metal, metal–dielectric, and metal–semiconductor composite nanostructures.