Gate-Tunable Spin Transport and Giant Electroresistance in Ferromagnetic Graphene Vertical Heterostructures

TL;DR

This paper explores how gate voltages can control spin transport and electroresistance in ferromagnetic graphene heterostructures, revealing potential for electrically tunable spintronic devices.

Contribution

It introduces a method to electronically control spin polarization and electroresistance in ferromagnetic graphene heterostructures using gate voltages.

Findings

Gate voltage controls spin polarization of tunneling current.

Opposite spin configuration suppresses Dirac fermion tunneling.

Giant electroresistance achieved in the heterostructure.

Abstract

We investigate spin transport through ferromagnetic graphene vertical heterostructures where a sandwiched tunneling layer is either a normal or ferroelectric insulator. We show that the spin-polarization of the tunneling current is electronically controlled via gate voltages. We also demonstrate that the tunneling current of Dirac fermions can be prohibited when the spin configuration of ferromagnetic graphene sheets is opposite. The giant electroresistance can thus be developed by using the proposed heterostructure in this study. The effects of temperature on the spin transport and the giant electroresistance ratio are also investigated. Our findings discover the prospect of manipulating the spin transport properties in vertical heterostructures through an electric fields via gate and bias electrodes.