Paper detail

Complex band structure and plasmon lattice Green's function of a periodic metal-nanoparticle chain

When the surface plasmon resonance in a metal-nanoparticle chain is excited at one point, the response signal will generally decay down the chain due to absorption and radiation losses. The decay length is a key parameter in such plasmonic systems. By studying the plasmon lattice Green's function, we found that the decay length is generally governed by two exponential decay constants with phase factors corresponding to guided Bloch modes and one power-law decay with a phase factor corresponding to that of free space photons. The results show a high level of similarity between the absorptive and radiative decay channels. By analyzing the poles (and the corresponding residues) of the Green's function in a transformed complex reciprocal space, the dominant decay channel of the real-space Green's function is understood.