Hydrogenated Graphene Nanoribbons for Spintronics

TL;DR

This paper explores how hydrogenation of graphene nanoribbons can induce magnetic properties and influence transport, offering new possibilities for carbon-based spintronic devices.

Contribution

It demonstrates that hydrogenation can induce magnetic moments and tunable interactions in graphene nanoribbons, regardless of edge passivation, and analyzes their transport properties for spintronics.

Findings

Hydrogenation induces localized magnetic moments in graphene nanoribbons.

Magnetic interactions depend on hydrogen atom positions and sublattice.

Hydrogenated nanoribbons show potential for magnetoresistive device applications.

Abstract

We show how hydrogenation of graphene nanoribbons at small concentrations can open new venues towards carbon-based spintronics applications regardless of any especific edge termination or passivation of the nanoribbons. Density functional theory calculations show that an adsorbed H atom induces a spin density on the surrounding $\pi$ orbitals whose symmetry and degree of localization depends on the distance to the edges of the nanoribbon. As expected for graphene-based systems, these induced magnetic moments interact ferromagnetically or antiferromagnetically depending on the relative adsorption graphene sublattice, but the magnitude of the interactions are found to strongly vary with the position of the H atoms relative to the edges. We also calculate, with the help of the Hubbard model, the transport properties of hydrogenated armchair semiconducting graphene nanoribbons in the diluted regime and show how the exchange coupling between H atoms can be exploited in the design of novel magnetoresistive devices.