An analysis of superconducting acoustic sensor with Josephson junction

This article presents a theoretical analysis of the effect of an elastic wave incident upon a deformable Josephson junction, which is a basic component of superconducting acoustic sensors. The model introduced for the analysis is based on the generalized London equations which account for the effect of inertia of superconducting electron pairs in the dynamically deformed superconductors that form the junction. The result indicates possible Josephson pair tunneling current induced by the transverse elastic wave, but not by the longitudinal elastic wave. It is shown that for a transverse elastic wave incident on the Josephson junction, the induced Josephson pair tunneling current may appear theoretically at any non-zero frequency, which is different from the well-known phonon-assisted single electron tunneling phenomenon where a minimum frequency exists. It is also shown that a DC current step structure may appear in the current-voltage characteristics of the deformable Josephson junction biased by a DC voltage and exerted by a transverse elastic wave.<>