Plasmon Dispersion at a Superconductor-Dielectric Interface

Abstract

Dispersion of the plasmon behaviour at an interface between a dielectric and a superconducting material is studied and numerically analyzed considering the electron gas is moving along the interface at a temperature of 44 K greater than Tc, which is the critical temperature. The high-temperature superconductor, YBCO (Yttrium Barium Copper Oxide), is used as the superconducting material and air as the dielectric material. A normalized dispersion equation is used to study the plasmonic behaviour at the interface. Considering the electron stream to behave as a compressible gas, new surface plasmon wave solutions of the dispersion equation have been obtained. The normalized form of the derived dispersion equation is employed to study the behaviour of the plasmon dispersion numerically using typical superconductor material parameters found recently in a study. The results indicate the SPPs travelling along the electron stream and the SPPs travelling against the electron stream interact and engage in an exchange of energy. The exchange of energy leads to amplification of the surface plasmon polaritons and increase in its propagation length. These results have the possibility of leading to novel applications of plasmonic effects.