Spin-dependent electronic lenses based on hybrid graphene nanostructures

TL;DR

This paper investigates spin-dependent electron focusing in graphene nanostructures with ferromagnetic insulators, demonstrating robust spin localization and potential for tunable polarized electron sources.

Contribution

It introduces a novel hybrid graphene device with spin-dependent electron focusing, showing robustness against disorder and enabling polarized current generation.

Findings

Spin-dependent electron localization at different spots based on spin.

Robustness of spin focusing under moderate edge disorder.

Potential to generate tunable polarized electron currents.

Abstract

We study electronic transport in graphene/ferromagnetic insulator hybrid devices. The system comprises an armchair graphene nanoribbon with a lens-shaped EuO ferromagnetic insulator layer deposited on top of it. When the device supports a large number of propagating modes, the proximity exchange interaction of electrons with the magnetic ions of the ferromagnetic insulator results in electrons being spatially localised at different spots depending on their spin. We found the spin-dependent electron focusing is robust under moderate edge disorder. A spin-polarised electric current can be generated by placing a third contact in the proper place. This opens the possibility to use these effects for fabricating tunable sources of polarized electrons.