Polarization Controlled Supercurrent in Ferroelectric Josephson Junction

TL;DR

This paper predicts how ferroelectric polarization can electrically control supercurrent in Josephson junctions, enabling non-volatile, programmable superconducting switches for cryogenic memory and logic.

Contribution

It introduces a model for electrically controlling supercurrent via ferroelectric polarization in Josephson junctions, with practical design guidelines.

Findings

Achieves non-volatile switching of critical current with high efficiency.

Provides a compact linear expression for critical current at small polarizations.

Identifies ferroelectric Josephson junctions as potential cryogenic memory switches.

Abstract

Josephson junctions are essential devices in superconducting electronics and quantum computing hardware. Here we predict electrical control of the supercurrent in composite superconductor-insulator-ferroelectric-insulator-superconductor (S-I-FE-I-S) Josephson junctions. Inversion symmetry broken by unequal dielectric barrier thicknesses and/or potentials converts ferroelectric polarization reversal into a substantial change of the critical current. With a WKB tunneling model we obtain non-volatile switching of the critical current with on-off efficiency up to 0.9 for physically realistic parameters. This can be achieved by optimizing the thicknesses and potential barriers of the insulating layers, as well as the thickness and dielectric constant of the ferroelectric layer. We also derive a compact linear expression for the critical current valid for small polarizations. Our results identify ferroelectric Josephson junctions as electrically programmable superconducting current switches for cryogenic memory and logic applications.