Spin-resolved crossed Andreev reflection in ballistic heterostructures

TL;DR

This paper provides a theoretical analysis of spin-dependent non-local electron transport phenomena, specifically crossed Andreev reflection, in ballistic NSN heterostructures with spin-active interfaces, revealing complex behaviors across various conditions.

Contribution

It introduces a non-perturbative theoretical framework for understanding spin-resolved crossed Andreev reflection in ballistic heterostructures with arbitrary interface properties.

Findings

Crossed Andreev reflection is highly sensitive to electron spins.

Non-local conductance exhibits rich, tunable behaviors.

Results applicable to hybrid structures with various electrode types.

Abstract

We theoretically analyze non-local effects in electron transport across three-terminal ballistic normal-superconducting-normal (NSN) structures with spin-active interfaces. Subgap electrons entering S-electrode from one N-metal may form Cooper pairs with their counterparts penetrating from another N-metal. This phenomenon of crossed Andreev reflection is highly sensitive to electron spins and yields a rich variety of properties of non-local conductance which we describe non-perturbatively at arbitrary interface transmissions, voltages and temperatures. Our results can be applied to hybrid structures with normal, ferromagnetic and half-metallic electrodes and can be directly tested in future experiments.