Shot noise and Coulomb blockade of Andreev reflection

TL;DR

This paper derives an effective action for NS conductors, linking Coulomb effects and shot noise, and predicts a fourfold increase in interaction correction due to doubled shot noise and charge in diffusive systems.

Contribution

It introduces a low energy effective action for NS conductors and reveals a quantitative relation between Coulomb effects and shot noise, with specific predictions for diffusive limits.

Findings

Interaction correction to Andreev conductance is related to shot noise.

Doubling shot noise and charge increases correction magnitude four times.

Predictions are testable in future experiments.

Abstract

We derive low energy effective action for a short coherent conductor between normal (N) and superconducting (S) reservoirs. We evaluate interaction correction $\delta G$ to Andreev conductance and demonstrate a close relation between Coulomb effects and shot noise in NS systems. In the diffusive limit doubling of both shot noise power and charge of the carriers yields $|\delta G|$ four times bigger than in the normal case. Our predictions can be directly tested in future experiments.