Noise Correlations in Three-Terminal Diffusive Superconductor-Normal Metal-Superconductor Nanostructures

TL;DR

This paper reports measurements of current noise and cross-correlations in three-terminal S-N-S nanostructures, revealing negative correlations in the incoherent multiple Andreev reflection regime, relevant for solid-state entanglement.

Contribution

It provides experimental insights into noise correlations across different regimes in S-N-S nanostructures, highlighting the transition to negative correlations in IMAR.

Findings

Negative cross-correlations observed in IMAR regime

Noise measurements span from interaction to incoherent regimes

Potential implications for solid-state entanglement

Abstract

We present measurements of current noise and cross-correlations in three-terminal Superconductor-Normal metal-Superconductor (S-N-S) nanostructures that are potential solid-state entanglers thanks to Andreev reflections at the N-S interfaces. The noise correlation measurements spanned from the regime where electron-electron interactions are relevant to the regime of Incoherent Multiple Andreev Reflection (IMAR). In the latter regime, negative cross-correlations are observed in samples with closely-spaced junctions.