Diagrammatic method of integration over the unitary group, with applications to quantum transport in mesoscopic systems

TL;DR

This paper introduces a diagrammatic technique for averaging over the circular ensemble in random-matrix theory, applied to quantum transport phenomena in mesoscopic systems like quantum dots and normal metal-superconductor interfaces.

Contribution

It presents a novel diagrammatic method for ensemble averaging in random-matrix theory with applications to quantum transport in mesoscopic systems.

Findings

Effective diagrammatic approach for quantum transport calculations

Application to phase-coherent conduction in chaotic cavities

Analysis of normal metal-superconductor interface transport

Abstract

A diagrammatic method is presented for averaging over the circular ensemble of random-matrix theory. The method is applied to phase-coherent conduction through a chaotic cavity (a ``quantum dot'') and through the interface between a normal metal and a superconductor.