A computer simulation of the switching effect in superconducting SAW delay lines

Abstract

A novel concept for the interaction between a surface acoustic wave (SAW) and a superconducting thin film deposited on the surface of a piezoelectric substrate is presented. The thin film superconductor complex conductivity is described with the aid of the two-fluid model. The effects of the superconductor complex conductivity on the propagation characteristics of the SAW are given. The obtained results show that the attenuation of the SAW is proportional to the resistivity of the thin film even through the superconductor transitions. It is found that there is an abrupt jump in the SAW attenuation and velocity at the critical conductivity which can be used as an on/off switching mechanism in SAW delay lines. Our simulation results give good agreement with published experimental data. The SAW attenuation and velocity measurements can be used as a useful technique in superconductor characterization.