Photonic band gap in a superconductor-dielectric superlattice

We foresee applications and interesting possibilities of incorporating the photonic crystals concept into superconducting electronics. In this paper, we present interesting features of the computed lower band structure of a n ondissipative superconductor-dielectric superlattice using the two-fluid mo del and the transcendental equation [Pochi Yeh, Optical Waves in Layered Me dia, Wiley Series in Purl and Applied Optics (Wiley, New York, 1988)]. The necessary conditions for approximating the complex conductivity by an imagi nary conductivity is derived and the feasibility of achieving the condition s are discussed. The superlattice dispersion obtained is similar to that of the phonon-polariton dispersion in ionic crystal. We found a nonlinear tem perature-dependent "polariton gap" and a low-frequency (plasma) gap, and su ggested the existence of a photon-superelectron hybrid around the polariton gap. The polariton gap may be observed in an infrared-microwave regime usi ng a high-T-c, superconductor with sufficiently low normal-fluid relaxation time (approximate to 10(-15) s), and in an optical regime using lower pene tration depth (approximate to 50 nm) and extremely low relaxation time (app roximate to 10(-17) s).