Direct demonstration of decoupling of spin and charge currents in nanostructures

TL;DR

This paper provides the first direct experimental evidence that spin and charge currents can be decoupled in nanostructures, confirming a fundamental principle in spintronics through a novel measurement technique.

Contribution

It introduces a new measurement method that directly demonstrates the decoupling of spin and charge currents in nanostructures, a key principle in spintronics.

Findings

Spin current is isotropic around the injection point.

Spin and charge currents are demonstrated to be decoupled.

The measurement confirms a fundamental spintronics principle.

Abstract

The notion of decoupling of spin and charge currents is one of the basic principles underlying the rapidly expanding feld of Spintronics. However, no direct demonstration of the phenomenon exists. We report a novel measurement, in which a non-equilibrium spin population is created by a point-like injection of current from a ferromagnet across a tunnel barrier into a one dimensional spin channel, and detected differentially by a pair of ferromagnetic electrodes placed symmetrically about the injection point. We demonstrate that the spin current is strictly isotropic about the injection point and, therefore, completely decoupled from the uni-directional charge current.