Spin transport in proximity induced ferromagnetic graphene

TL;DR

This paper investigates how magnetic gates induce ferromagnetic correlations in graphene, affecting its transport properties, and proposes methods to measure the induced spin splittings using tunneling resonances and magnetoresistance.

Contribution

It demonstrates the potential to induce and measure significant spin splittings in graphene via magnetic insulator gates, advancing spintronic applications.

Findings

Induced spin splittings of ~5 meV are achievable with EuO gates.

Tunneling resonances can directly reveal the spin splittings.

Magnetoresistance in a spin-valve setup can independently measure the spin polarization.

Abstract

Magnetic gates in close proximity to graphene can induce ferromagnetic correlations. We study the effect of such induced magnetization dependent Zeeman splittings on the graphene transport properties. We estimate that induced spin splittings of the order of \Delta ~ 5 meV could be achieved with the use of magnetic insulator gates, e.g. EuO-gates, deposited on top of graphene. We demonstrate that such splittings in proximity induced ferromagnetic graphene could be determined directly from the tunneling resonances in the linear response conductance, as the top gate creates also a tunable barrier in the graphene layer. We show how such splittings could also be determined independently by magnetoresistance measurements in a spin-valve geometry. Because the spin polarization of the current near the Dirac point increases with the length of the barrier, long magnetic gates are desirable for determining \Delta experimentally.