Strong spin-dependent negative differential resistance in composite graphene superlattices

TL;DR

This paper demonstrates a graphene-based spintronic device exhibiting spin-dependent negative differential resistance, functioning as an Esaki spin diode with potential applications in advanced spintronic circuits.

Contribution

It introduces a novel graphene superlattice device with ferromagnetic insulators that produces spin-dependent NDR, enabling new spintronic functionalities.

Findings

The device shows highly polarized current.

Current and polarization depend non-monotonically on bias.

The system acts as an Esaki spin diode.

Abstract

We find clear signatures of spin-dependent negative differential resistance in compound systems comprising a graphene nanoribbon and a set of ferromagnetic insulator strips deposited on top of it. The periodic array of ferromagnetic strips induces a proximity exchange splitting of the electronic states in graphene, resulting in the appearance of a superlattice with a spin-dependent energy spectrum. The electric current through the device can be highly polarized and both the current and its polarization manifest non-monotonic dependence on the bias voltage. The device operates therefore as an Esaki spin diode, which opens possibilities to design new spintronic circuits.