On the surface plasmon wave propagation along single metal wire

Recently, the single metal wire (SW) becomes attractive for its potential applications in terahertz and higher frequency range. However, as the most simple and typical surface plasmon polariton (SPP) transmission line, its study seems far from enough. Many important transmission behaviours have not been explained satisfactorily from the viewpoint of physics. In this paper, making use of the modified Drude model (MDM) based on the Sommerfeld theory, the transmission behaviours of SPPs along SW are systemically investigated theoretically. Some important physical phenomena such as the mode transformation, the lifetime of radiative mode and the resonance frequency are revealed, and their mechanisms are explored. The results obtained in the paper will facilitate the general understanding of the features and the physical essence of the SPP transmission, not only for SW itself but also for other SPP transmission lines.