Critical Current of a Granular d-wave superconductor

TL;DR

This paper investigates how the Josephson critical current in granular d-wave superconductors depends on twist angle and magnetic field, revealing similarities with single junction behavior and differences based on junction geometry.

Contribution

It demonstrates the twist angle dependence of critical current is consistent between single junctions and granular systems, and compares magnetic field effects in rectangular and circular junction models.

Findings

Critical current depends on twist angle similarly in single and granular systems.

Circular junction models yield larger critical currents than rectangular models.

Magnetic field influences critical current in predictable ways based on junction geometry.

Abstract

The twist angle {\gamma} dependence of the Josephson critical current of d-wave superconductors in one junction and a granular system is considered. Our results show that the twist angle {\gamma} dependence of the d-wave Josephson critical current is the same for one junction and a granular system. The magnetic field dependences of the critical-current of a granular d-wave superconductor has also been determined by considering the rectangular and circular junction model of an array of small superconducting particles which interacting by Josephson coupling through insulating barriers. We will show that in the case of circular model, the critical current of the Josephson current is larger than that of rectangular one.