Incoherent multiple Andreev reflection in an array of SNS junctions

TL;DR

This paper investigates incoherent multiple Andreev reflection in SNS junction arrays, showing that subharmonic structures can appear at unexpected voltages, advancing understanding of electron transport in disordered systems.

Contribution

It provides a theoretical explanation for the appearance of subharmonic structures at unusual voltages in SNS arrays, extending previous experimental findings.

Findings

Subharmonic structures occur at non-standard voltages.

Theoretical model explains incoherent MAR in disordered SNS arrays.

Advances understanding of electron transport in dirty SNS systems.

Abstract

Last years many interesting effects related to incoherent MAR have been experimentally found, but only few of them were theoretically explained. It was shown, for example, that if the voltage at the edges of a linear array is $V$ then subgarmonic structures in the current -voltage characteristics appear not only at usual for nonstationary Josephson effect positions, $V_n=2\Delta/n$, where $n$ is integer, but also at voltages other than $V_n$. A step towards description of electron transport in a dirty array of SNS junctions is done in this letter. It is shown that subgarmonic structures may indeed appear at ``unusual'' voltages.