Cross-correlations of coherent multiple Andreev reflections

TL;DR

This paper investigates current cross-correlations in a three-terminal superconducting junction, revealing large positive correlations at low bias due to coherent multiple Andreev reflections and potential sign reversals influenced by scattering parameters.

Contribution

It applies the Landauer-Büttiker scattering theory to analyze cross-correlations in a superconducting junction, highlighting the impact of coherent Andreev reflections and scattering properties on correlation behavior.

Findings

Large cross-correlations at low bias voltage

Sign reversal of cross-correlations depending on scattering parameters

Enhanced correlations compared to normal-state systems

Abstract

We use the Landauer-B\"uttiker scattering theory for electronic transport to calculate the current cross-correlations in a voltage-biased three-terminal junction with all superconducting leads. At low bias voltage, when charge transport is due to coherent multiple Andreev reflections, we find large cross-correlations compared with their normal-state value. Furthermore, depending on the parameters that characterize the properties of the scattering region between the leads, the cross-correlations can reverse their sign with respect to the case of non-interacting fermionic systems.