Graphene-based spintronic components

TL;DR

This paper demonstrates that graphene nanoribbons can generate nearly 100% spin-polarized currents, tunable via voltage and magnetic configurations, enabling the design of various spintronic devices.

Contribution

It introduces a theoretical approach to control spin-polarized currents in graphene nanoribbons for spintronic applications, including device designs.

Findings

Nearly 100% spin polarization achievable in ZGNRs

Spin current controllable by bias voltage and magnetic configuration

Proposed designs for spin diode, transistor, and logic gates

Abstract

A major challenge of spintronics is in generating, controlling and detecting spin-polarized current. Manipulation of spin-polarized current, in particular, is difficult. We demonstrate here, based on calculated transport properties of graphene nanoribbons, that nearly +-100% spin-polarized current can be generated in zigzag graphene nanoribbons (ZGNRs) and tuned by a source-drain voltage in the bipolar spin diode, in addition to magnetic configurations of the electrodes. This unusual transport property is attributed to the intrinsic transmission selection rule of the spin subbands near the Fermi level in ZGNRs. The simultaneous control of spin current by the bias voltage and the magnetic configurations of the electrodes provides an opportunity to implement a whole range of spintronics devices. We propose theoretical designs for a complete set of basic spintronic devices, including bipolar spin diode, transistor and logic gates, based on ZGNRs.