Shot noise and multiple Andreev reflections in d-wave superconductors

TL;DR

This paper provides a theoretical analysis of shot noise in d-wave superconducting contacts, revealing how multiple Andreev reflections and impurities influence noise characteristics, aiding in understanding high-temperature superconductor behavior.

Contribution

It introduces a comprehensive theoretical model for shot noise in d-wave superconductors, including effects of multiple Andreev reflections, impurities, and magnetic fields, with implications for experimental tests.

Findings

Enhanced noise-current ratio at low voltages due to multiple charge quanta.

Distinct shot noise signatures caused by impurities and magnetic fields.

Survival of noise features across various crystal misorientations.

Abstract

We present a theoretical analysis of the shot noise in d-wave/d-wave contacts with arbitrary transparency, including the contribution of multiple Andreev reflections. The multiple charge quanta transferred in these processes are revealed as a huge enhancement of the noise-current ratio at low voltages, which survives for all crystal misorientations. We also show how different ingredients like non-magnetic impurities or a magnetic field produce very characteristic hallmarks in the shot noise, which can be used as a further test of the d-wave scenario in superconducting cuprates.