Average shot-noise power via a diagrammatic method

Abstract

In this work we use a diagrammatic method for integration over the unitary group to obtain a quantum correction to the average shot-noise power of a chaotic cavity with non-ideal contacts. We present maximally crossed diagrams representing the physical modes of the system responsible for the dominant quantum correction. We demonstrate with explicit calculations that the suppression–amplification effect reported in Ramos et al (2008 Phys. Rev. B 78 235305) occurs both for systems in the presence of time-reversal (TR) and spin-rotation (SR) symmetries and for systems with broken SR symmetry but in the presence of TR symmetry.