Coulomb Promotion of Spin-Dependent Tunnelling

TL;DR

This paper investigates how Coulomb interactions can enhance spin-dependent electron tunnelling in a magnetic single-electron transistor, revealing a novel phenomenon where Coulomb correlations promote current flow under certain conditions.

Contribution

It introduces the concept of Coulomb promotion of spin-dependent tunnelling, showing how Coulomb interactions can enhance current rather than suppress it in a magnetic SET.

Findings

Coulomb interactions can promote spin-dependent tunnelling.

Criteria for Coulomb promotion are established.

The phenomenon occurs under specific conditions involving spin-flip dynamics.

Abstract

We study transport of spin-polarized electrons through a magnetic single-electron transistor (SET) in the presence of an external magnetic field. Assuming the SET to have a nanometer size central island with a single electron level we find that the interplay on the island between coherent spin-flip dynamics and Coulomb interactions can make the Coulomb correlations promote rather than suppress the current through the device. We find the criteria for this new phenomenon -- Coulomb promotion of spin-dependent tunnelling -- to occur.