Novel Josephson Effects in d-wave Superconductor Junctions with Antiferromagnetic Interlayers

TL;DR

This paper investigates the Josephson effect in d-wave superconductor junctions with antiferromagnetic interlayers, revealing complex current behaviors and the influence of magnetic correlations on critical current depending on orientation.

Contribution

It introduces a detailed analysis of Josephson currents in d/AF/d junctions and explores how magnetic correlations affect critical currents in different orientations.

Findings

d/AF/d junctions show 0-pi transitions with temperature and thickness.

Induced magnetism can suppress critical current in 110-oriented junctions.

Results may explain the critical current versus grain boundary angle in high-T_c superconductors.

Abstract

We calculate the dc supercurrent through a Josephson tunnel junction consisting of an antiferromagnetic (AF) interlayer sandwiched between two d-wave superconductors (d). Such d/AF/d junctions exhibit a rich dependence of the Josephson current on the interlayer parameters, including the possibility of 0-pi transitions with varying temperature or interlayer thickness. Furthermore, we study d/I/d junctions when the dSC leads include subdominant magnetic correlations. In this case induced magnetism near the interface can strongly diminish the critical current for 110 oriented junctions whereas no suppression is obtained for the 100 orientation. This may help resolve a long-standing puzzle of the critical current versus grain boundary angle in high-T_c superconductors.