Microwave response of a nearly ferroelectric superconductor

Microwave response of a nearly ferroelectric superconductor is theoretically investigated based on the electrodynamics of nearly ferroelectric superconductors. Microwave response is studied via the calculations of the microwave surface impedances for three model structures in which dielectriclike superconductors are considered. Firstly, the calculated intrinsic surface impedance for a bulk material occupying the half space decreases with increasing frequency. Secondly, the calculated intrinsic surface resistance for a superconductor film of a finite thickness shows some anomalous resonance peaks. The distribution of these sharp peaks is strongly dependent on the film thickness. Discussion of these comblike peaks is also given. Finally, we calculate the effective microwave surface impedance of a superconductor/ dielectric layered system. The substrate resonance behavior in the surface resistance will be illustrated and discussed.