Full counting statistics of a superconducting beam splitter

The complete information about a charge transfer process is contained in the so-called full counting statistics. We study the statistics of charge transport in a mesoscopic three-terminal device with one superconducting terminal and two normal-metal terminals. We calculate the full distribution of transmitted charges into the two symmetrically biased normal terminals. On one hand, in the limit of weak proximity we find positive crosscorrelations and show that this is due to splitting of uncorrelated Cooper pairs. On the other hand, correlated Cooper pairs lead to negative crosscorrelation, as usually expected for a fermionic system.