Theory of huge tunneling magnetoresistance in graphene

TL;DR

This paper presents a theoretical study of giant tunneling magnetoresistance in graphene modulated by ferromagnetic layers, highlighting the effects of magnetization alignment and electric barriers on electron transmission.

Contribution

It introduces a theoretical model explaining how magnetic and electric barriers in graphene can produce large, tunable tunneling magnetoresistance effects.

Findings

Klein tunneling occurs at specific oblique angles in parallel magnetization.

Transmission is blocked in antiparallel configuration by magnetic-electric barriers.

The magnetoresistance ratio can be significantly tuned by electric barriers.

Abstract

We investigate theoretically the spin-independent tunneling magnetoresistance effect in a graphene monolayer modulated by two parallel ferromagnets deposited on a dielectric layer. For the parallel magnetization configuration, Klein tunneling can be observed in the transmission spectrum, but at specific oblique incident angles. For the antiparallel magnetization configuration, the transmission can be blocked by the magnetic-electric barrier provided by the ferromagnets. Such a transmission discrepancy results in a tremendous magnetoresistance ratio and can be tuned by the inclusion of an electric barrier.