Noise correlations in three-terminal diffusive superconductor-normal-metal-superconductor nanostructures.

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. In the latter regime, negative cross correlations are observed in samples with closely spaced junctions.