Full counting statistics of Andreev scattering in an asymmetric chaotic cavity

TL;DR

This paper analyzes charge transport in a chaotic cavity with asymmetric contacts, deriving full counting statistics and cumulants, revealing a sign change in the third cumulant linked to Andreev reflection properties.

Contribution

It provides a general solution for Green's functions in chaotic cavities and explores the full counting statistics for asymmetric superconductor-normal metal junctions.

Findings

Third cumulant changes sign with contact asymmetry

Derived Green's function solutions for chaotic cavities

Linked Andreev reflection eigenvalues to transport statistics

Abstract

We study the charge transport statistics in coherent two-terminal double junctions within the framework of the circuit theory of mesoscopic transport. We obtain the general solution of the circuit-theory matrix equations for the Green's function of a chaotic cavity between arbitrary contacts. As an example we discuss the full counting statistics and the first three cumulants for an open asymmetric cavity between a superconductor and a normal-metal lead at temperatures and voltages below the superconducting gap. The third cumulant shows a characteristic sign change as a function of the asymmetry of the two quantum point contacts, which is related to the properties of the Andreev reflection eigenvalue distribution.