Shot noise in normal metal-d-wave superconducting junctions

TL;DR

This paper provides theoretical predictions for shot noise behavior in normal metal-d-wave superconductor junctions, highlighting the effects of surface states, impurities, magnetic fields, and additional pairing channels.

Contribution

It introduces a detailed theoretical analysis of shot noise in d-wave superconductor junctions, including impurity effects and magnetic field dependencies, which was not previously explored.

Findings

Shot noise vanishes at zero voltage in clean d-wave junctions due to resonant Andreev reflection.

Impurity scattering affects the resonance and modifies shot noise behavior.

Magnetic fields and subdominant pairing channels influence shot noise characteristics.

Abstract

We present theoretical calculations and predictions for the shot noise in voltage biased junctions of $d_{x^2-y^2}$ superconductors and normal metal counter-electrodes. In the clean limit for the d-wave superconductor the shot noise vanishes at zero voltage because of resonant Andreev reflection by zero-energy surface bound states. We examine the sensitivity of this resonance to impurity scattering. We report theoretical results for the magnetic field dependence of the shot noise, as well the fingerprints of subdominant $s$- and $d_{xy}$ pairing channels.