Non-local electron transport and Coulomb effects in three-terminal metallic conductors

TL;DR

This paper explores how Coulomb interactions influence non-local electron transport and shot noise in three-terminal metallic conductors, revealing different behaviors in normal and superconducting structures and identifying conditions for Coulomb blockade and anti-blockade effects.

Contribution

It uncovers the relationship between Coulomb effects and non-local shot noise, and distinguishes the behavior of normal versus superconducting structures at subgap energies.

Findings

Coulomb interaction suppresses local and non-local conductances in normal structures.

Non-local differential conductance can become negative at non-zero bias in superconducting structures.

Crossed Andreev reflection can lead to positive noise cross-correlations and Coulomb anti-blockade.

Abstract

We demonstrate a close relation between Coulomb effects in non-local electron transport and non-local shot noise in three-terminal metallic conductors. Provided the whole structure is normal, cross-correlations in shot noise are negative and Coulomb interaction tends to suppress both local and non-local conductances of the system. The behavior of normal-superconducting-normal structures at subgap energies is entirely different. In the tunneling limit non-local differential conductance of such systems are found to have an S-like shape and can turn negative at non-zero bias. At high transmissions crossed Andreev reflection yields positive noise cross-correlations and Coulomb anti-blockade of non-local electron transport.