Symmetries of quantum transport with Rashba spin-orbit: Graphene spintronics

TL;DR

This paper investigates how spatial symmetries in graphene nanoribbons with Rashba spin-orbit interaction influence spin-polarized currents, highlighting potential for all-electrical spintronic devices without magnetic elements.

Contribution

It reveals the relationship between device symmetries and spin polarization, demonstrating graphene nanoflakes as promising spintronic components in an all-electrical configuration.

Findings

Spin polarization depends on the spatial symmetry of the device.

Graphene nanoflakes can generate significant spin-polarized currents.

All-electrical control of spin currents is feasible in the studied setups.

Abstract

The lack of some spatial symmetries in planar devices with Rashba spin-orbit interaction opens the possibility of producing spin polarized electrical currents in absence of external magnetic field or magnetic impurities. We study how the direction of the spin polarization of the current is related to spatial symmetries of the device. As an example of these relations we study numerically the spin-resolved current in graphene nanoribbons. Different configurations are explored and analyzed to demonstrate that graphene nanoflakes may be used as excellent spintronic devices in an all-electrical setup.