AN ANALYSIS OF SUPERCONDUCTING ACOUSTIC SENSOR WITH JOSEPHSON-JUNCTION

This article presents a theoretical analysis of the effect of elastic wave incident upon a deformable Josephson junction, which is a basic c omponent of superconducting acoustic sensors. The model introduced for the analysis is based on the generalized London equations which accou nt for the effect of inertia of superconducting electron pairs in the dynamically deformed superconductors that form the junction. The resul t indicates possible Josephson pair tunneling current induced by the t ransverse elastic wave, but not by the longitudinal elastic wave. It i s shown that for transverse elastic wave incident on the Josephson jun ction, the induced Josephson pair tunneling current may appear theoret ically at any non-zero frequency, which is different from the well-kno wn phonon-assisted single electron tunneling phenomenon where a minimu m frequency exists. It is also shown that the DC current step structur e may appear in the current-voltage characteristics of the deformable Josephson junction biased by a DC voltage and exerted by a transverse elastic wave.