On Electrostriction of a Granular Superconductor

TL;DR

This paper models the electrostriction effects in granular superconductors using a 3D Josephson junction array framework, highlighting the dominance of bulk-modulus-driven electrostriction over phase change effects.

Contribution

It introduces a theoretical model for electrostriction in granular superconductors, analyzing both volume change and phase-dependent polarization contributions.

Findings

Bulk-modulus-driven electrostriction dominates over phase change effects.

Electrostriction behavior is predicted to be similar across all applied fields.

The model provides insights into the electroelastic properties of granular superconductors.

Abstract

Zero-temperature field-induced polarization, supercurrent density, and the related electrostriction (ES) of a granular superconductor are calculated within a model of 3D Josephson junction arrays. Both the "bulk-modulus-driven ES" (the change of the sample's volume in the free energy upon the applied stress) and the "change-of-phase ES" (due to the stress dependence of the weak-links-induced polarization) are considered. In contrast to magnetostriction of a granular superconductor, its electroelastic behavior is predicted to be dominated by the former contribution for all applied fields.