Anisotropic magneto-Coulomb effect versus spin accumulation in a ferromagnetic single-electron device

TL;DR

This paper studies magneto-transport in ferromagnetic single-electron devices with non-magnetic nanoparticles, distinguishing between spin accumulation and anisotropic magneto-Coulomb effects using simulations and Coulomb blockade measurements.

Contribution

It introduces a method to differentiate spin transport from AMC effects in magnetic single-electron devices through analysis of Coulomb blockade I-V curves.

Findings

Both effects can occur in similar samples, requiring careful analysis.

A simple Coulomb blockade measurement can identify the dominant effect.

Simulation comparison helps attribute observed magnetoresistance to specific mechanisms.

Abstract

We investigate the magneto-transport characteristics of nanospintronics single-electron devices. The devices consist of single non-magnetic nano-objects (nanometer size nanoparticles of Al or Cu) connected to Co ferromagnetic leads. The comparison with simulations allows us attribute the observed magnetoresistance to either spin accumulation or anisotropic magneto-Coulomb effect (AMC), two effects with very different origins. The fact that the two effects are observed in similar samples demonstrates that a careful analysis of Coulomb blockade and magnetoresistance behaviors is necessary in order to discriminate them in magnetic single-electron devices. As a tool for further studies, we propose a simple way to determine if spin transport or AMC effect dominates from the Coulomb blockade I-V curves of the spintronics device.