Enhanced shot noise in long quasi-diffusive S-N-S junctions

International audienceWe present shot noise measurements on superconducting–normal–superconducting junction (S–N–S) where the superconductor is Niobium and the normal conductor is a two-dimensional electron gas in a InAlAs/InGaAs heterojunction. The aim of the measurements was to check the recent predictions [Phys. Rev. Lett. 83 (1999) 2050] that in the limit of incoherent multiple Andreev reflection (I-MAR), i.e. in the elastic regime for Thouless energy much lower than the superconducting gap, the current–voltage characteristics should be quasi-linear but I-MAR could be detected in the shot noise