Quantum shot noise in a normal-metal–superconductor point contact

Abstract

The distribution function for the current noise in a normal-metal--superconductor quantum point contact is calculated. It is shown that this distribution describes independent processes when a charge \ifmmode\pm\else\textpm\fi{}${\mathit{e}}_{0}$ or \ifmmode\pm\else\textpm\fi{}2${\mathit{e}}_{0}$ passes through the contact. At low temperature and voltage only processes with double-charge transfer are relevant. At zero temperature and low voltage the distribution has a binomial form.