Analysis of Degradation in Graphene-based Spin Valves

TL;DR

This paper investigates how degradation affects the robustness of spin injection signals in graphene-based spin valves, revealing that degradation, not graphene's intrinsic properties, causes loss of signal robustness and can be mitigated.

Contribution

It identifies degradation mechanisms responsible for loss of spin signal robustness in graphene spin valves, highlighting potential ways to prevent degradation and improve device stability.

Findings

Degradation causes loss of spin signal robustness.

Spin polarization remains robust against bias in non-degraded devices.

Preventing degradation can enhance device performance.

Abstract

The degradation mechanisms of multilayer graphene spin valves are investigated. The spin injection signals in graphene spin valves have been reported to be linearly dependent on the drain bias voltage, which indicates that the spin polarization of injected spins in graphene is robust against the bias voltage. We present that the disappearance of this robustness is due to two different degradation mechanisms of the spin valves. Our findings indicate that the disappearance of the robustness is due to degradation rather than an intrinsic characteristic of graphene. Thus, the robustness can be greatly enhanced if degradation can be prevented.