Anomalous Josephson effect in p-wave dirty junctions

TL;DR

This paper theoretically investigates the Josephson effect in p-wave superconductor junctions with diffusive normal metals, revealing significantly larger currents and anomalous current-phase relations due to midgap states and proximity effects.

Contribution

It demonstrates the large Josephson currents and unusual phase relations in p-wave junctions, highlighting the role of midgap states and proximity effects in these systems.

Findings

Josephson currents are several orders larger than in s-wave junctions.

Current-phase relations are close to ballistic junctions even with impurities.

Midgap Andreev states and proximity effects cause anomalous properties.

Abstract

The Josephson effect in p-wave superconductor / diffusive normal metal / p-wave superconductor junctions is studied theoretically. Amplitudes of Josephson currents are several orders of magnitude larger than those in s-wave junctions. Current-phase (J-\phi) relations in low temperatures are close to those in ballistic junctions such as J\propto\sin(\phi/2) and J\propto\phi even in the presence of random impurity potentials. A cooperative effect between the midgap Andreev resonant states and the proximity effect causes such anomalous properties and is a character of the spin-triplet superconductor junctions.