2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/27077The low-frequency shot-noise power of a normal-metal-superconductor junction is studied for arbitrary normal region. Through a scattering approach, a formula is derived which expresses the shot-noise power in terms of the transmission eigenvalues of the normal region. The noise power divided by the current is enhanced by a factor two with respect to its normal-state value, due to Cooper-pair transport in the superconductor. For a disordered normal region, it is still smaller than the Poisson noise, as a consequence of noiseless open scattering channels.4 pages, RevTeX v3.0, including 1 figure, Submitted to Physical Review BCondensed Mattertext