Robustness of Spin Polarization in Graphene-based Spin Valves

TL;DR

This paper demonstrates that multi-layer graphene spin valves exhibit exceptional room-temperature spin polarization robustness under bias voltages, surpassing other spintronics devices, due to ideal interface formation, and confirms theoretical predictions with experimental evidence.

Contribution

It reveals unprecedented robustness of spin polarization in graphene spin valves and confirms theoretical predictions about signal intensity ratios in molecular spintronics.

Findings

Spin polarization remains constant up to ±2.7 V bias.

Signal intensity in local scheme is double that in non-local scheme.

Robustness is due to suppression of spin scattering at ideal interfaces.

Abstract

Decrease of spin polarization in spintronics devices under an application of bias voltage is one of currently important problems which should be solved. We reveal unprecedented robustness of spin polarization in multi-layer graphene spin valves at room temperature. Surprisingly, the spin polarization of injected spins is constant up to a bias voltage of +2.7 V and -0.6 V in positive and negative bias voltage applications, which is dramatically superior to all spintronics devices. Our finding is induced by suppression of spin scattering due to an ideal interface formation. Furthermore, we firstly report on important accordance between theory and experiment in molecular spintronics by observing the fact that signal intensity in a local scheme is double of that in a non-local scheme as theory predicts, which provides construction of a steadfast physical basis in this field.