Will Zigzag Graphene Nanoribbon Turn to Half Metal under Electric Field?

TL;DR

This study predicts that applying an external electric field to zigzag graphene nanoribbons can induce half-metallicity, with the critical field depending on ribbon width, offering potential for spintronics applications.

Contribution

The paper demonstrates that electric fields can induce half-metallicity in zigzag graphene nanoribbons and explores how this effect varies with ribbon width and electric field strength.

Findings

Half-metallicity can be achieved with an external electric field.

Critical electric field decreases as ribbon width increases.

Strong electric fields remove spin polarization by transferring edge electrons.

Abstract

At B3LYP level of theory, we predict that the half-metallicity in zigzag edge graphene nanoribbon (ZGNR) can be realized when an external electric field is applied across the ribbon. The critical electric field to induce the half-metallicity decreases with the increase of the ribbon width. Both the spin polarization and half-metallicity are removed when the edge state electrons fully transferred from one side to the other under very strong electric field. The electric field range under which ZGNR remain half-metallic increases with the ribbon width. Our study demonstrates a rich field-induced spin polarization behavior, which may leads to some important applications in spinstronics.