A New Paradigm to Half-Metallicity in Graphene Nanoribbons

TL;DR

This paper demonstrates a new method to induce half-metallicity in zigzag graphene nanoribbons using bias voltage or strain, enabling spin-resolved electronic properties for advanced device applications.

Contribution

It introduces a novel approach to achieve half-metallicity in graphene nanoribbons by sandwiching them with boron nitride and applying external stimuli, expanding the possibilities for spintronic devices.

Findings

Half-metallicity can be tuned by bias voltage or strain.

Sandwiched nanoribbons exhibit enhanced coupling effects.

Potential for integration into current semiconductor technology.

Abstract

In contrast to the well recognized transverse-electric-field-induced half-metallicity in zigzag graphene nanoribbons, here we demonstrate by first-principles calculations that zigzag graphene nanoribbons sandwiched between hexagonal boron nitride nanoribbons or sheets can be tuned into half-metal simply by a bias voltage or a moderate compressive strain. The half-metallicity is attributed to an enhanced coupling effect of spontaneous polarization and asymmetrical exchange correlation along the ribbon width. The findings should open a viable route for efficient spin-resolved band engineering in graphene based devices that are compatible with the current technology of semiconductor industry.