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.
@article{arxiv.1304.3572,
title = {A New Paradigm to Half-Metallicity in Graphene Nanoribbons},
author = {Jin Yu and Wanlin Guo},
journal= {arXiv preprint arXiv:1304.3572},
year = {2013}
}